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| <title>zlib - Chicken - SWIG example</title> |
| </head> |
| <body> |
| <center><h1>zlib - Chicken - SWIG</h1></center> |
| |
| <h2>Table of Contents</h2> |
| <a href="#build">Building the example</a><br> |
| <a href="#zlibh">zlib.h</a><br> |
| <a href="#devel">How the zlib wrapper was developed</a><br> |
| |
| <center><h2><a name="build">Building the example</a></h2></center> |
| |
| zlib must be installed for this example to work.<br> |
| |
| Just type <code>make</code> to build this example.<br> |
| |
| If zlib is not installed in /usr/lib and /usr/include, then do |
| something similar to the following: |
| |
| <blockquote> |
| <pre>make SWIGOPT="-I/usr/local/include" LIBS="-L/usr/local/lib -lz"</pre> |
| </blockquote> |
| |
| <center><h2><a name="zlibh">zlib.h</a></h2></center> |
| <blockquote> |
| <pre> |
| <font color="blue">001:</font> /* zlib.h -- interface of the 'zlib' general purpose compression library |
| <font color="blue">002:</font> version 1.1.4, March 11th, 2002 |
| <font color="blue">003:</font> |
| <font color="blue">004:</font> Copyright (C) 1995-2002 Jean-loup Gailly and Mark Adler |
| <font color="blue">005:</font> |
| <font color="blue">006:</font> This software is provided 'as-is', without any express or implied |
| <font color="blue">007:</font> warranty. In no event will the authors be held liable for any damages |
| <font color="blue">008:</font> arising from the use of this software. |
| <font color="blue">009:</font> |
| <font color="blue">010:</font> Permission is granted to anyone to use this software for any purpose, |
| <font color="blue">011:</font> including commercial applications, and to alter it and redistribute it |
| <font color="blue">012:</font> freely, subject to the following restrictions: |
| <font color="blue">013:</font> |
| <font color="blue">014:</font> 1. The origin of this software must not be misrepresented; you must not |
| <font color="blue">015:</font> claim that you wrote the original software. If you use this software |
| <font color="blue">016:</font> in a product, an acknowledgment in the product documentation would be |
| <font color="blue">017:</font> appreciated but is not required. |
| <font color="blue">018:</font> 2. Altered source versions must be plainly marked as such, and must not be |
| <font color="blue">019:</font> misrepresented as being the original software. |
| <font color="blue">020:</font> 3. This notice may not be removed or altered from any source distribution. |
| <font color="blue">021:</font> |
| <font color="blue">022:</font> Jean-loup Gailly Mark Adler |
| <font color="blue">023:</font> jloup@gzip.org madler@alumni.caltech.edu |
| <font color="blue">024:</font> |
| <font color="blue">025:</font> |
| <font color="blue">026:</font> The data format used by the zlib library is described by RFCs (Request for |
| <font color="blue">027:</font> Comments) 1950 to 1952 in the files ftp://ds.internic.net/rfc/rfc1950.txt |
| <font color="blue">028:</font> (zlib format), rfc1951.txt (deflate format) and rfc1952.txt (gzip format). |
| <font color="blue">029:</font> */ |
| <font color="blue">030:</font> |
| <font color="blue">031:</font> #ifndef _ZLIB_H |
| <font color="blue">032:</font> #define _ZLIB_H |
| <font color="blue">033:</font> |
| <font color="blue">034:</font> #include "zconf.h" |
| <font color="blue">035:</font> |
| <font color="blue">036:</font> #ifdef __cplusplus |
| <font color="blue">037:</font> extern "C" { |
| <font color="blue">038:</font> #endif |
| <font color="blue">039:</font> |
| <font color="blue">040:</font> #define ZLIB_VERSION "1.1.4" |
| <font color="blue">041:</font> |
| <font color="blue">042:</font> /* |
| <font color="blue">043:</font> The 'zlib' compression library provides in-memory compression and |
| <font color="blue">044:</font> decompression functions, including integrity checks of the uncompressed |
| <font color="blue">045:</font> data. This version of the library supports only one compression method |
| <font color="blue">046:</font> (deflation) but other algorithms will be added later and will have the same |
| <font color="blue">047:</font> stream interface. |
| <font color="blue">048:</font> |
| <font color="blue">049:</font> Compression can be done in a single step if the buffers are large |
| <font color="blue">050:</font> enough (for example if an input file is mmap'ed), or can be done by |
| <font color="blue">051:</font> repeated calls of the compression function. In the latter case, the |
| <font color="blue">052:</font> application must provide more input and/or consume the output |
| <font color="blue">053:</font> (providing more output space) before each call. |
| <font color="blue">054:</font> |
| <font color="blue">055:</font> The library also supports reading and writing files in gzip (.gz) format |
| <font color="blue">056:</font> with an interface similar to that of stdio. |
| <font color="blue">057:</font> |
| <font color="blue">058:</font> The library does not install any signal handler. The decoder checks |
| <font color="blue">059:</font> the consistency of the compressed data, so the library should never |
| <font color="blue">060:</font> crash even in case of corrupted input. |
| <font color="blue">061:</font> */ |
| <font color="blue">062:</font> |
| <font color="blue"><a name="l63">063:</a></font> typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size)); |
| <font color="blue">064:</font> typedef void (*free_func) OF((voidpf opaque, voidpf address)); |
| <font color="blue">065:</font> |
| <font color="blue">066:</font> struct internal_state; |
| <font color="blue">067:</font> |
| <font color="blue">068:</font> typedef struct z_stream_s { |
| <font color="blue">069:</font> Bytef *next_in; /* next input byte */ |
| <font color="blue">070:</font> uInt avail_in; /* number of bytes available at next_in */ |
| <font color="blue">071:</font> uLong total_in; /* total nb of input bytes read so far */ |
| <font color="blue">072:</font> |
| <font color="blue">073:</font> Bytef *next_out; /* next output byte should be put there */ |
| <font color="blue">074:</font> uInt avail_out; /* remaining free space at next_out */ |
| <font color="blue">075:</font> uLong total_out; /* total nb of bytes output so far */ |
| <font color="blue">076:</font> |
| <font color="blue">077:</font> char *msg; /* last error message, NULL if no error */ |
| <font color="blue"><a name="l78">078:</a></font> struct internal_state FAR *state; /* not visible by applications */ |
| <font color="blue">079:</font> |
| <font color="blue"><a name="l80">080:</a></font> alloc_func zalloc; /* used to allocate the internal state */ |
| <font color="blue">081:</font> free_func zfree; /* used to free the internal state */ |
| <font color="blue">082:</font> voidpf opaque; /* private data object passed to zalloc and zfree */ |
| <font color="blue">083:</font> |
| <font color="blue">084:</font> int data_type; /* best guess about the data type: ascii or binary */ |
| <font color="blue">085:</font> uLong adler; /* adler32 value of the uncompressed data */ |
| <font color="blue">086:</font> uLong reserved; /* reserved for future use */ |
| <font color="blue">087:</font> } z_stream; |
| <font color="blue">088:</font> |
| <font color="blue">089:</font> typedef z_stream FAR *z_streamp; |
| <font color="blue">090:</font> |
| <font color="blue">091:</font> /* |
| <font color="blue">092:</font> The application must update next_in and avail_in when avail_in has |
| <font color="blue">093:</font> dropped to zero. It must update next_out and avail_out when avail_out |
| <font color="blue">094:</font> has dropped to zero. The application must initialize zalloc, zfree and |
| <font color="blue">095:</font> opaque before calling the init function. All other fields are set by the |
| <font color="blue">096:</font> compression library and must not be updated by the application. |
| <font color="blue">097:</font> |
| <font color="blue">098:</font> The opaque value provided by the application will be passed as the first |
| <font color="blue">099:</font> parameter for calls of zalloc and zfree. This can be useful for custom |
| <font color="blue">100:</font> memory management. The compression library attaches no meaning to the |
| <font color="blue">101:</font> opaque value. |
| <font color="blue">102:</font> |
| <font color="blue">103:</font> zalloc must return Z_NULL if there is not enough memory for the object. |
| <font color="blue">104:</font> If zlib is used in a multi-threaded application, zalloc and zfree must be |
| <font color="blue">105:</font> thread safe. |
| <font color="blue">106:</font> |
| <font color="blue">107:</font> On 16-bit systems, the functions zalloc and zfree must be able to allocate |
| <font color="blue">108:</font> exactly 65536 bytes, but will not be required to allocate more than this |
| <font color="blue">109:</font> if the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, |
| <font color="blue">110:</font> pointers returned by zalloc for objects of exactly 65536 bytes *must* |
| <font color="blue">111:</font> have their offset normalized to zero. The default allocation function |
| <font color="blue">112:</font> provided by this library ensures this (see zutil.c). To reduce memory |
| <font color="blue">113:</font> requirements and avoid any allocation of 64K objects, at the expense of |
| <font color="blue">114:</font> compression ratio, compile the library with -DMAX_WBITS=14 (see zconf.h). |
| <font color="blue">115:</font> |
| <font color="blue">116:</font> The fields total_in and total_out can be used for statistics or |
| <font color="blue">117:</font> progress reports. After compression, total_in holds the total size of |
| <font color="blue">118:</font> the uncompressed data and may be saved for use in the decompressor |
| <font color="blue">119:</font> (particularly if the decompressor wants to decompress everything in |
| <font color="blue">120:</font> a single step). |
| <font color="blue">121:</font> */ |
| <font color="blue">122:</font> |
| <font color="blue">123:</font> /* constants */ |
| <font color="blue">124:</font> |
| <font color="blue">125:</font> #define Z_NO_FLUSH 0 |
| <font color="blue">126:</font> #define Z_PARTIAL_FLUSH 1 /* will be removed, use Z_SYNC_FLUSH instead */ |
| <font color="blue">127:</font> #define Z_SYNC_FLUSH 2 |
| <font color="blue">128:</font> #define Z_FULL_FLUSH 3 |
| <font color="blue">129:</font> #define Z_FINISH 4 |
| <font color="blue">130:</font> /* Allowed flush values; see deflate() below for details */ |
| <font color="blue">131:</font> |
| <font color="blue">132:</font> #define Z_OK 0 |
| <font color="blue">133:</font> #define Z_STREAM_END 1 |
| <font color="blue">134:</font> #define Z_NEED_DICT 2 |
| <font color="blue">135:</font> #define Z_ERRNO (-1) |
| <font color="blue">136:</font> #define Z_STREAM_ERROR (-2) |
| <font color="blue">137:</font> #define Z_DATA_ERROR (-3) |
| <font color="blue">138:</font> #define Z_MEM_ERROR (-4) |
| <font color="blue">139:</font> #define Z_BUF_ERROR (-5) |
| <font color="blue">140:</font> #define Z_VERSION_ERROR (-6) |
| <font color="blue">141:</font> /* Return codes for the compression/decompression functions. Negative |
| <font color="blue">142:</font> * values are errors, positive values are used for special but normal events. |
| <font color="blue">143:</font> */ |
| <font color="blue">144:</font> |
| <font color="blue">145:</font> #define Z_NO_COMPRESSION 0 |
| <font color="blue">146:</font> #define Z_BEST_SPEED 1 |
| <font color="blue">147:</font> #define Z_BEST_COMPRESSION 9 |
| <font color="blue">148:</font> #define Z_DEFAULT_COMPRESSION (-1) |
| <font color="blue">149:</font> /* compression levels */ |
| <font color="blue">150:</font> |
| <font color="blue">151:</font> #define Z_FILTERED 1 |
| <font color="blue">152:</font> #define Z_HUFFMAN_ONLY 2 |
| <font color="blue">153:</font> #define Z_DEFAULT_STRATEGY 0 |
| <font color="blue">154:</font> /* compression strategy; see deflateInit2() below for details */ |
| <font color="blue">155:</font> |
| <font color="blue">156:</font> #define Z_BINARY 0 |
| <font color="blue">157:</font> #define Z_ASCII 1 |
| <font color="blue">158:</font> #define Z_UNKNOWN 2 |
| <font color="blue">159:</font> /* Possible values of the data_type field */ |
| <font color="blue">160:</font> |
| <font color="blue">161:</font> #define Z_DEFLATED 8 |
| <font color="blue">162:</font> /* The deflate compression method (the only one supported in this version) */ |
| <font color="blue">163:</font> |
| <font color="blue">164:</font> #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */ |
| <font color="blue">165:</font> |
| <font color="blue">166:</font> #define zlib_version zlibVersion() |
| <font color="blue">167:</font> /* for compatibility with versions < 1.0.2 */ |
| <font color="blue">168:</font> |
| <font color="blue">169:</font> /* basic functions */ |
| <font color="blue">170:</font> |
| <font color="blue">171:</font> ZEXTERN const char * ZEXPORT zlibVersion OF((void)); |
| <font color="blue">172:</font> /* The application can compare zlibVersion and ZLIB_VERSION for consistency. |
| <font color="blue">173:</font> If the first character differs, the library code actually used is |
| <font color="blue">174:</font> not compatible with the zlib.h header file used by the application. |
| <font color="blue">175:</font> This check is automatically made by deflateInit and inflateInit. |
| <font color="blue">176:</font> */ |
| <font color="blue">177:</font> |
| <font color="blue">178:</font> /* |
| <font color="blue">179:</font> ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level)); |
| <font color="blue">180:</font> |
| <font color="blue">181:</font> Initializes the internal stream state for compression. The fields |
| <font color="blue">182:</font> zalloc, zfree and opaque must be initialized before by the caller. |
| <font color="blue">183:</font> If zalloc and zfree are set to Z_NULL, deflateInit updates them to |
| <font color="blue">184:</font> use default allocation functions. |
| <font color="blue">185:</font> |
| <font color="blue">186:</font> The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: |
| <font color="blue">187:</font> 1 gives best speed, 9 gives best compression, 0 gives no compression at |
| <font color="blue">188:</font> all (the input data is simply copied a block at a time). |
| <font color="blue">189:</font> Z_DEFAULT_COMPRESSION requests a default compromise between speed and |
| <font color="blue">190:</font> compression (currently equivalent to level 6). |
| <font color="blue">191:</font> |
| <font color="blue">192:</font> deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not |
| <font color="blue">193:</font> enough memory, Z_STREAM_ERROR if level is not a valid compression level, |
| <font color="blue">194:</font> Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible |
| <font color="blue">195:</font> with the version assumed by the caller (ZLIB_VERSION). |
| <font color="blue">196:</font> msg is set to null if there is no error message. deflateInit does not |
| <font color="blue">197:</font> perform any compression: this will be done by deflate(). |
| <font color="blue">198:</font> */ |
| <font color="blue">199:</font> |
| <font color="blue">200:</font> |
| <font color="blue">201:</font> ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush)); |
| <font color="blue">202:</font> /* |
| <font color="blue">203:</font> deflate compresses as much data as possible, and stops when the input |
| <font color="blue">204:</font> buffer becomes empty or the output buffer becomes full. It may introduce some |
| <font color="blue">205:</font> output latency (reading input without producing any output) except when |
| <font color="blue">206:</font> forced to flush. |
| <font color="blue">207:</font> |
| <font color="blue">208:</font> The detailed semantics are as follows. deflate performs one or both of the |
| <font color="blue">209:</font> following actions: |
| <font color="blue">210:</font> |
| <font color="blue">211:</font> - Compress more input starting at next_in and update next_in and avail_in |
| <font color="blue">212:</font> accordingly. If not all input can be processed (because there is not |
| <font color="blue">213:</font> enough room in the output buffer), next_in and avail_in are updated and |
| <font color="blue">214:</font> processing will resume at this point for the next call of deflate(). |
| <font color="blue">215:</font> |
| <font color="blue">216:</font> - Provide more output starting at next_out and update next_out and avail_out |
| <font color="blue">217:</font> accordingly. This action is forced if the parameter flush is non zero. |
| <font color="blue">218:</font> Forcing flush frequently degrades the compression ratio, so this parameter |
| <font color="blue">219:</font> should be set only when necessary (in interactive applications). |
| <font color="blue">220:</font> Some output may be provided even if flush is not set. |
| <font color="blue">221:</font> |
| <font color="blue">222:</font> Before the call of deflate(), the application should ensure that at least |
| <font color="blue">223:</font> one of the actions is possible, by providing more input and/or consuming |
| <font color="blue">224:</font> more output, and updating avail_in or avail_out accordingly; avail_out |
| <font color="blue">225:</font> should never be zero before the call. The application can consume the |
| <font color="blue">226:</font> compressed output when it wants, for example when the output buffer is full |
| <font color="blue">227:</font> (avail_out == 0), or after each call of deflate(). If deflate returns Z_OK |
| <font color="blue">228:</font> and with zero avail_out, it must be called again after making room in the |
| <font color="blue">229:</font> output buffer because there might be more output pending. |
| <font color="blue">230:</font> |
| <font color="blue">231:</font> If the parameter flush is set to Z_SYNC_FLUSH, all pending output is |
| <font color="blue">232:</font> flushed to the output buffer and the output is aligned on a byte boundary, so |
| <font color="blue">233:</font> that the decompressor can get all input data available so far. (In particular |
| <font color="blue">234:</font> avail_in is zero after the call if enough output space has been provided |
| <font color="blue">235:</font> before the call.) Flushing may degrade compression for some compression |
| <font color="blue">236:</font> algorithms and so it should be used only when necessary. |
| <font color="blue">237:</font> |
| <font color="blue">238:</font> If flush is set to Z_FULL_FLUSH, all output is flushed as with |
| <font color="blue">239:</font> Z_SYNC_FLUSH, and the compression state is reset so that decompression can |
| <font color="blue">240:</font> restart from this point if previous compressed data has been damaged or if |
| <font color="blue">241:</font> random access is desired. Using Z_FULL_FLUSH too often can seriously degrade |
| <font color="blue">242:</font> the compression. |
| <font color="blue">243:</font> |
| <font color="blue">244:</font> If deflate returns with avail_out == 0, this function must be called again |
| <font color="blue">245:</font> with the same value of the flush parameter and more output space (updated |
| <font color="blue">246:</font> avail_out), until the flush is complete (deflate returns with non-zero |
| <font color="blue">247:</font> avail_out). |
| <font color="blue">248:</font> |
| <font color="blue">249:</font> If the parameter flush is set to Z_FINISH, pending input is processed, |
| <font color="blue">250:</font> pending output is flushed and deflate returns with Z_STREAM_END if there |
| <font color="blue">251:</font> was enough output space; if deflate returns with Z_OK, this function must be |
| <font color="blue">252:</font> called again with Z_FINISH and more output space (updated avail_out) but no |
| <font color="blue">253:</font> more input data, until it returns with Z_STREAM_END or an error. After |
| <font color="blue">254:</font> deflate has returned Z_STREAM_END, the only possible operations on the |
| <font color="blue">255:</font> stream are deflateReset or deflateEnd. |
| <font color="blue">256:</font> |
| <font color="blue">257:</font> Z_FINISH can be used immediately after deflateInit if all the compression |
| <font color="blue">258:</font> is to be done in a single step. In this case, avail_out must be at least |
| <font color="blue">259:</font> 0.1% larger than avail_in plus 12 bytes. If deflate does not return |
| <font color="blue">260:</font> Z_STREAM_END, then it must be called again as described above. |
| <font color="blue">261:</font> |
| <font color="blue">262:</font> deflate() sets strm->adler to the adler32 checksum of all input read |
| <font color="blue">263:</font> so far (that is, total_in bytes). |
| <font color="blue">264:</font> |
| <font color="blue">265:</font> deflate() may update data_type if it can make a good guess about |
| <font color="blue">266:</font> the input data type (Z_ASCII or Z_BINARY). In doubt, the data is considered |
| <font color="blue">267:</font> binary. This field is only for information purposes and does not affect |
| <font color="blue">268:</font> the compression algorithm in any manner. |
| <font color="blue">269:</font> |
| <font color="blue">270:</font> deflate() returns Z_OK if some progress has been made (more input |
| <font color="blue">271:</font> processed or more output produced), Z_STREAM_END if all input has been |
| <font color="blue">272:</font> consumed and all output has been produced (only when flush is set to |
| <font color="blue">273:</font> Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example |
| <font color="blue">274:</font> if next_in or next_out was NULL), Z_BUF_ERROR if no progress is possible |
| <font color="blue">275:</font> (for example avail_in or avail_out was zero). |
| <font color="blue">276:</font> */ |
| <font color="blue">277:</font> |
| <font color="blue">278:</font> |
| <font color="blue">279:</font> ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm)); |
| <font color="blue">280:</font> /* |
| <font color="blue">281:</font> All dynamically allocated data structures for this stream are freed. |
| <font color="blue">282:</font> This function discards any unprocessed input and does not flush any |
| <font color="blue">283:</font> pending output. |
| <font color="blue">284:</font> |
| <font color="blue">285:</font> deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the |
| <font color="blue">286:</font> stream state was inconsistent, Z_DATA_ERROR if the stream was freed |
| <font color="blue">287:</font> prematurely (some input or output was discarded). In the error case, |
| <font color="blue">288:</font> msg may be set but then points to a static string (which must not be |
| <font color="blue">289:</font> deallocated). |
| <font color="blue">290:</font> */ |
| <font color="blue">291:</font> |
| <font color="blue">292:</font> |
| <font color="blue">293:</font> /* |
| <font color="blue">294:</font> ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm)); |
| <font color="blue">295:</font> |
| <font color="blue">296:</font> Initializes the internal stream state for decompression. The fields |
| <font color="blue">297:</font> next_in, avail_in, zalloc, zfree and opaque must be initialized before by |
| <font color="blue">298:</font> the caller. If next_in is not Z_NULL and avail_in is large enough (the exact |
| <font color="blue">299:</font> value depends on the compression method), inflateInit determines the |
| <font color="blue">300:</font> compression method from the zlib header and allocates all data structures |
| <font color="blue">301:</font> accordingly; otherwise the allocation will be deferred to the first call of |
| <font color="blue">302:</font> inflate. If zalloc and zfree are set to Z_NULL, inflateInit updates them to |
| <font color="blue">303:</font> use default allocation functions. |
| <font color="blue">304:</font> |
| <font color="blue">305:</font> inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough |
| <font color="blue">306:</font> memory, Z_VERSION_ERROR if the zlib library version is incompatible with the |
| <font color="blue">307:</font> version assumed by the caller. msg is set to null if there is no error |
| <font color="blue">308:</font> message. inflateInit does not perform any decompression apart from reading |
| <font color="blue">309:</font> the zlib header if present: this will be done by inflate(). (So next_in and |
| <font color="blue">310:</font> avail_in may be modified, but next_out and avail_out are unchanged.) |
| <font color="blue">311:</font> */ |
| <font color="blue">312:</font> |
| <font color="blue">313:</font> |
| <font color="blue">314:</font> ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush)); |
| <font color="blue">315:</font> /* |
| <font color="blue">316:</font> inflate decompresses as much data as possible, and stops when the input |
| <font color="blue">317:</font> buffer becomes empty or the output buffer becomes full. It may some |
| <font color="blue">318:</font> introduce some output latency (reading input without producing any output) |
| <font color="blue">319:</font> except when forced to flush. |
| <font color="blue">320:</font> |
| <font color="blue">321:</font> The detailed semantics are as follows. inflate performs one or both of the |
| <font color="blue">322:</font> following actions: |
| <font color="blue">323:</font> |
| <font color="blue">324:</font> - Decompress more input starting at next_in and update next_in and avail_in |
| <font color="blue">325:</font> accordingly. If not all input can be processed (because there is not |
| <font color="blue">326:</font> enough room in the output buffer), next_in is updated and processing |
| <font color="blue">327:</font> will resume at this point for the next call of inflate(). |
| <font color="blue">328:</font> |
| <font color="blue">329:</font> - Provide more output starting at next_out and update next_out and avail_out |
| <font color="blue">330:</font> accordingly. inflate() provides as much output as possible, until there |
| <font color="blue">331:</font> is no more input data or no more space in the output buffer (see below |
| <font color="blue">332:</font> about the flush parameter). |
| <font color="blue">333:</font> |
| <font color="blue">334:</font> Before the call of inflate(), the application should ensure that at least |
| <font color="blue">335:</font> one of the actions is possible, by providing more input and/or consuming |
| <font color="blue">336:</font> more output, and updating the next_* and avail_* values accordingly. |
| <font color="blue">337:</font> The application can consume the uncompressed output when it wants, for |
| <font color="blue">338:</font> example when the output buffer is full (avail_out == 0), or after each |
| <font color="blue">339:</font> call of inflate(). If inflate returns Z_OK and with zero avail_out, it |
| <font color="blue">340:</font> must be called again after making room in the output buffer because there |
| <font color="blue">341:</font> might be more output pending. |
| <font color="blue">342:</font> |
| <font color="blue">343:</font> If the parameter flush is set to Z_SYNC_FLUSH, inflate flushes as much |
| <font color="blue">344:</font> output as possible to the output buffer. The flushing behavior of inflate is |
| <font color="blue">345:</font> not specified for values of the flush parameter other than Z_SYNC_FLUSH |
| <font color="blue">346:</font> and Z_FINISH, but the current implementation actually flushes as much output |
| <font color="blue">347:</font> as possible anyway. |
| <font color="blue">348:</font> |
| <font color="blue">349:</font> inflate() should normally be called until it returns Z_STREAM_END or an |
| <font color="blue">350:</font> error. However if all decompression is to be performed in a single step |
| <font color="blue">351:</font> (a single call of inflate), the parameter flush should be set to |
| <font color="blue">352:</font> Z_FINISH. In this case all pending input is processed and all pending |
| <font color="blue">353:</font> output is flushed; avail_out must be large enough to hold all the |
| <font color="blue">354:</font> uncompressed data. (The size of the uncompressed data may have been saved |
| <font color="blue">355:</font> by the compressor for this purpose.) The next operation on this stream must |
| <font color="blue">356:</font> be inflateEnd to deallocate the decompression state. The use of Z_FINISH |
| <font color="blue">357:</font> is never required, but can be used to inform inflate that a faster routine |
| <font color="blue">358:</font> may be used for the single inflate() call. |
| <font color="blue">359:</font> |
| <font color="blue">360:</font> If a preset dictionary is needed at this point (see inflateSetDictionary |
| <font color="blue">361:</font> below), inflate sets strm-adler to the adler32 checksum of the |
| <font color="blue">362:</font> dictionary chosen by the compressor and returns Z_NEED_DICT; otherwise |
| <font color="blue">363:</font> it sets strm->adler to the adler32 checksum of all output produced |
| <font color="blue">364:</font> so far (that is, total_out bytes) and returns Z_OK, Z_STREAM_END or |
| <font color="blue">365:</font> an error code as described below. At the end of the stream, inflate() |
| <font color="blue">366:</font> checks that its computed adler32 checksum is equal to that saved by the |
| <font color="blue">367:</font> compressor and returns Z_STREAM_END only if the checksum is correct. |
| <font color="blue">368:</font> |
| <font color="blue">369:</font> inflate() returns Z_OK if some progress has been made (more input processed |
| <font color="blue">370:</font> or more output produced), Z_STREAM_END if the end of the compressed data has |
| <font color="blue">371:</font> been reached and all uncompressed output has been produced, Z_NEED_DICT if a |
| <font color="blue">372:</font> preset dictionary is needed at this point, Z_DATA_ERROR if the input data was |
| <font color="blue">373:</font> corrupted (input stream not conforming to the zlib format or incorrect |
| <font color="blue">374:</font> adler32 checksum), Z_STREAM_ERROR if the stream structure was inconsistent |
| <font color="blue">375:</font> (for example if next_in or next_out was NULL), Z_MEM_ERROR if there was not |
| <font color="blue">376:</font> enough memory, Z_BUF_ERROR if no progress is possible or if there was not |
| <font color="blue">377:</font> enough room in the output buffer when Z_FINISH is used. In the Z_DATA_ERROR |
| <font color="blue">378:</font> case, the application may then call inflateSync to look for a good |
| <font color="blue">379:</font> compression block. |
| <font color="blue">380:</font> */ |
| <font color="blue">381:</font> |
| <font color="blue">382:</font> |
| <font color="blue">383:</font> ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm)); |
| <font color="blue">384:</font> /* |
| <font color="blue">385:</font> All dynamically allocated data structures for this stream are freed. |
| <font color="blue">386:</font> This function discards any unprocessed input and does not flush any |
| <font color="blue">387:</font> pending output. |
| <font color="blue">388:</font> |
| <font color="blue">389:</font> inflateEnd returns Z_OK if success, Z_STREAM_ERROR if the stream state |
| <font color="blue">390:</font> was inconsistent. In the error case, msg may be set but then points to a |
| <font color="blue">391:</font> static string (which must not be deallocated). |
| <font color="blue">392:</font> */ |
| <font color="blue">393:</font> |
| <font color="blue">394:</font> /* Advanced functions */ |
| <font color="blue">395:</font> |
| <font color="blue">396:</font> /* |
| <font color="blue">397:</font> The following functions are needed only in some special applications. |
| <font color="blue">398:</font> */ |
| <font color="blue">399:</font> |
| <font color="blue">400:</font> /* |
| <font color="blue">401:</font> ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm, |
| <font color="blue">402:</font> int level, |
| <font color="blue">403:</font> int method, |
| <font color="blue">404:</font> int windowBits, |
| <font color="blue">405:</font> int memLevel, |
| <font color="blue">406:</font> int strategy)); |
| <font color="blue">407:</font> |
| <font color="blue">408:</font> This is another version of deflateInit with more compression options. The |
| <font color="blue">409:</font> fields next_in, zalloc, zfree and opaque must be initialized before by |
| <font color="blue">410:</font> the caller. |
| <font color="blue">411:</font> |
| <font color="blue">412:</font> The method parameter is the compression method. It must be Z_DEFLATED in |
| <font color="blue">413:</font> this version of the library. |
| <font color="blue">414:</font> |
| <font color="blue">415:</font> The windowBits parameter is the base two logarithm of the window size |
| <font color="blue">416:</font> (the size of the history buffer). It should be in the range 8..15 for this |
| <font color="blue">417:</font> version of the library. Larger values of this parameter result in better |
| <font color="blue">418:</font> compression at the expense of memory usage. The default value is 15 if |
| <font color="blue">419:</font> deflateInit is used instead. |
| <font color="blue">420:</font> |
| <font color="blue">421:</font> The memLevel parameter specifies how much memory should be allocated |
| <font color="blue">422:</font> for the internal compression state. memLevel=1 uses minimum memory but |
| <font color="blue">423:</font> is slow and reduces compression ratio; memLevel=9 uses maximum memory |
| <font color="blue">424:</font> for optimal speed. The default value is 8. See zconf.h for total memory |
| <font color="blue">425:</font> usage as a function of windowBits and memLevel. |
| <font color="blue">426:</font> |
| <font color="blue">427:</font> The strategy parameter is used to tune the compression algorithm. Use the |
| <font color="blue">428:</font> value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a |
| <font color="blue">429:</font> filter (or predictor), or Z_HUFFMAN_ONLY to force Huffman encoding only (no |
| <font color="blue">430:</font> string match). Filtered data consists mostly of small values with a |
| <font color="blue">431:</font> somewhat random distribution. In this case, the compression algorithm is |
| <font color="blue">432:</font> tuned to compress them better. The effect of Z_FILTERED is to force more |
| <font color="blue">433:</font> Huffman coding and less string matching; it is somewhat intermediate |
| <font color="blue">434:</font> between Z_DEFAULT and Z_HUFFMAN_ONLY. The strategy parameter only affects |
| <font color="blue">435:</font> the compression ratio but not the correctness of the compressed output even |
| <font color="blue">436:</font> if it is not set appropriately. |
| <font color="blue">437:</font> |
| <font color="blue">438:</font> deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough |
| <font color="blue">439:</font> memory, Z_STREAM_ERROR if a parameter is invalid (such as an invalid |
| <font color="blue">440:</font> method). msg is set to null if there is no error message. deflateInit2 does |
| <font color="blue">441:</font> not perform any compression: this will be done by deflate(). |
| <font color="blue">442:</font> */ |
| <font color="blue">443:</font> |
| <font color="blue">444:</font> ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm, |
| <font color="blue">445:</font> const Bytef *dictionary, |
| <font color="blue">446:</font> uInt dictLength)); |
| <font color="blue">447:</font> /* |
| <font color="blue">448:</font> Initializes the compression dictionary from the given byte sequence |
| <font color="blue">449:</font> without producing any compressed output. This function must be called |
| <font color="blue">450:</font> immediately after deflateInit, deflateInit2 or deflateReset, before any |
| <font color="blue">451:</font> call of deflate. The compressor and decompressor must use exactly the same |
| <font color="blue">452:</font> dictionary (see inflateSetDictionary). |
| <font color="blue">453:</font> |
| <font color="blue">454:</font> The dictionary should consist of strings (byte sequences) that are likely |
| <font color="blue">455:</font> to be encountered later in the data to be compressed, with the most commonly |
| <font color="blue">456:</font> used strings preferably put towards the end of the dictionary. Using a |
| <font color="blue">457:</font> dictionary is most useful when the data to be compressed is short and can be |
| <font color="blue">458:</font> predicted with good accuracy; the data can then be compressed better than |
| <font color="blue">459:</font> with the default empty dictionary. |
| <font color="blue">460:</font> |
| <font color="blue">461:</font> Depending on the size of the compression data structures selected by |
| <font color="blue">462:</font> deflateInit or deflateInit2, a part of the dictionary may in effect be |
| <font color="blue">463:</font> discarded, for example if the dictionary is larger than the window size in |
| <font color="blue">464:</font> deflate or deflate2. Thus the strings most likely to be useful should be |
| <font color="blue">465:</font> put at the end of the dictionary, not at the front. |
| <font color="blue">466:</font> |
| <font color="blue">467:</font> Upon return of this function, strm->adler is set to the Adler32 value |
| <font color="blue">468:</font> of the dictionary; the decompressor may later use this value to determine |
| <font color="blue">469:</font> which dictionary has been used by the compressor. (The Adler32 value |
| <font color="blue">470:</font> applies to the whole dictionary even if only a subset of the dictionary is |
| <font color="blue">471:</font> actually used by the compressor.) |
| <font color="blue">472:</font> |
| <font color="blue">473:</font> deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a |
| <font color="blue">474:</font> parameter is invalid (such as NULL dictionary) or the stream state is |
| <font color="blue">475:</font> inconsistent (for example if deflate has already been called for this stream |
| <font color="blue">476:</font> or if the compression method is bsort). deflateSetDictionary does not |
| <font color="blue">477:</font> perform any compression: this will be done by deflate(). |
| <font color="blue">478:</font> */ |
| <font color="blue">479:</font> |
| <font color="blue">480:</font> ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest, |
| <font color="blue">481:</font> z_streamp source)); |
| <font color="blue">482:</font> /* |
| <font color="blue">483:</font> Sets the destination stream as a complete copy of the source stream. |
| <font color="blue">484:</font> |
| <font color="blue">485:</font> This function can be useful when several compression strategies will be |
| <font color="blue">486:</font> tried, for example when there are several ways of pre-processing the input |
| <font color="blue">487:</font> data with a filter. The streams that will be discarded should then be freed |
| <font color="blue">488:</font> by calling deflateEnd. Note that deflateCopy duplicates the internal |
| <font color="blue">489:</font> compression state which can be quite large, so this strategy is slow and |
| <font color="blue">490:</font> can consume lots of memory. |
| <font color="blue">491:</font> |
| <font color="blue">492:</font> deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not |
| <font color="blue">493:</font> enough memory, Z_STREAM_ERROR if the source stream state was inconsistent |
| <font color="blue">494:</font> (such as zalloc being NULL). msg is left unchanged in both source and |
| <font color="blue">495:</font> destination. |
| <font color="blue">496:</font> */ |
| <font color="blue">497:</font> |
| <font color="blue">498:</font> ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm)); |
| <font color="blue">499:</font> /* |
| <font color="blue">500:</font> This function is equivalent to deflateEnd followed by deflateInit, |
| <font color="blue">501:</font> but does not free and reallocate all the internal compression state. |
| <font color="blue">502:</font> The stream will keep the same compression level and any other attributes |
| <font color="blue">503:</font> that may have been set by deflateInit2. |
| <font color="blue">504:</font> |
| <font color="blue">505:</font> deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source |
| <font color="blue">506:</font> stream state was inconsistent (such as zalloc or state being NULL). |
| <font color="blue">507:</font> */ |
| <font color="blue">508:</font> |
| <font color="blue">509:</font> ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm, |
| <font color="blue">510:</font> int level, |
| <font color="blue">511:</font> int strategy)); |
| <font color="blue">512:</font> /* |
| <font color="blue">513:</font> Dynamically update the compression level and compression strategy. The |
| <font color="blue">514:</font> interpretation of level and strategy is as in deflateInit2. This can be |
| <font color="blue">515:</font> used to switch between compression and straight copy of the input data, or |
| <font color="blue">516:</font> to switch to a different kind of input data requiring a different |
| <font color="blue">517:</font> strategy. If the compression level is changed, the input available so far |
| <font color="blue">518:</font> is compressed with the old level (and may be flushed); the new level will |
| <font color="blue">519:</font> take effect only at the next call of deflate(). |
| <font color="blue">520:</font> |
| <font color="blue">521:</font> Before the call of deflateParams, the stream state must be set as for |
| <font color="blue">522:</font> a call of deflate(), since the currently available input may have to |
| <font color="blue">523:</font> be compressed and flushed. In particular, strm->avail_out must be non-zero. |
| <font color="blue">524:</font> |
| <font color="blue">525:</font> deflateParams returns Z_OK if success, Z_STREAM_ERROR if the source |
| <font color="blue">526:</font> stream state was inconsistent or if a parameter was invalid, Z_BUF_ERROR |
| <font color="blue">527:</font> if strm->avail_out was zero. |
| <font color="blue">528:</font> */ |
| <font color="blue">529:</font> |
| <font color="blue">530:</font> /* |
| <font color="blue">531:</font> ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm, |
| <font color="blue">532:</font> int windowBits)); |
| <font color="blue">533:</font> |
| <font color="blue">534:</font> This is another version of inflateInit with an extra parameter. The |
| <font color="blue">535:</font> fields next_in, avail_in, zalloc, zfree and opaque must be initialized |
| <font color="blue">536:</font> before by the caller. |
| <font color="blue">537:</font> |
| <font color="blue">538:</font> The windowBits parameter is the base two logarithm of the maximum window |
| <font color="blue">539:</font> size (the size of the history buffer). It should be in the range 8..15 for |
| <font color="blue">540:</font> this version of the library. The default value is 15 if inflateInit is used |
| <font color="blue">541:</font> instead. If a compressed stream with a larger window size is given as |
| <font color="blue">542:</font> input, inflate() will return with the error code Z_DATA_ERROR instead of |
| <font color="blue">543:</font> trying to allocate a larger window. |
| <font color="blue">544:</font> |
| <font color="blue">545:</font> inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough |
| <font color="blue">546:</font> memory, Z_STREAM_ERROR if a parameter is invalid (such as a negative |
| <font color="blue">547:</font> memLevel). msg is set to null if there is no error message. inflateInit2 |
| <font color="blue">548:</font> does not perform any decompression apart from reading the zlib header if |
| <font color="blue">549:</font> present: this will be done by inflate(). (So next_in and avail_in may be |
| <font color="blue">550:</font> modified, but next_out and avail_out are unchanged.) |
| <font color="blue">551:</font> */ |
| <font color="blue">552:</font> |
| <font color="blue">553:</font> ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm, |
| <font color="blue">554:</font> const Bytef *dictionary, |
| <font color="blue">555:</font> uInt dictLength)); |
| <font color="blue">556:</font> /* |
| <font color="blue">557:</font> Initializes the decompression dictionary from the given uncompressed byte |
| <font color="blue">558:</font> sequence. This function must be called immediately after a call of inflate |
| <font color="blue">559:</font> if this call returned Z_NEED_DICT. The dictionary chosen by the compressor |
| <font color="blue">560:</font> can be determined from the Adler32 value returned by this call of |
| <font color="blue">561:</font> inflate. The compressor and decompressor must use exactly the same |
| <font color="blue">562:</font> dictionary (see deflateSetDictionary). |
| <font color="blue">563:</font> |
| <font color="blue">564:</font> inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a |
| <font color="blue">565:</font> parameter is invalid (such as NULL dictionary) or the stream state is |
| <font color="blue">566:</font> inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the |
| <font color="blue">567:</font> expected one (incorrect Adler32 value). inflateSetDictionary does not |
| <font color="blue">568:</font> perform any decompression: this will be done by subsequent calls of |
| <font color="blue">569:</font> inflate(). |
| <font color="blue">570:</font> */ |
| <font color="blue">571:</font> |
| <font color="blue">572:</font> ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm)); |
| <font color="blue">573:</font> /* |
| <font color="blue">574:</font> Skips invalid compressed data until a full flush point (see above the |
| <font color="blue">575:</font> description of deflate with Z_FULL_FLUSH) can be found, or until all |
| <font color="blue">576:</font> available input is skipped. No output is provided. |
| <font color="blue">577:</font> |
| <font color="blue">578:</font> inflateSync returns Z_OK if a full flush point has been found, Z_BUF_ERROR |
| <font color="blue">579:</font> if no more input was provided, Z_DATA_ERROR if no flush point has been found, |
| <font color="blue">580:</font> or Z_STREAM_ERROR if the stream structure was inconsistent. In the success |
| <font color="blue">581:</font> case, the application may save the current current value of total_in which |
| <font color="blue">582:</font> indicates where valid compressed data was found. In the error case, the |
| <font color="blue">583:</font> application may repeatedly call inflateSync, providing more input each time, |
| <font color="blue">584:</font> until success or end of the input data. |
| <font color="blue">585:</font> */ |
| <font color="blue">586:</font> |
| <font color="blue">587:</font> ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm)); |
| <font color="blue">588:</font> /* |
| <font color="blue">589:</font> This function is equivalent to inflateEnd followed by inflateInit, |
| <font color="blue">590:</font> but does not free and reallocate all the internal decompression state. |
| <font color="blue">591:</font> The stream will keep attributes that may have been set by inflateInit2. |
| <font color="blue">592:</font> |
| <font color="blue">593:</font> inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source |
| <font color="blue">594:</font> stream state was inconsistent (such as zalloc or state being NULL). |
| <font color="blue">595:</font> */ |
| <font color="blue">596:</font> |
| <font color="blue">597:</font> |
| <font color="blue">598:</font> /* utility functions */ |
| <font color="blue">599:</font> |
| <font color="blue">600:</font> /* |
| <font color="blue">601:</font> The following utility functions are implemented on top of the |
| <font color="blue">602:</font> basic stream-oriented functions. To simplify the interface, some |
| <font color="blue">603:</font> default options are assumed (compression level and memory usage, |
| <font color="blue">604:</font> standard memory allocation functions). The source code of these |
| <font color="blue">605:</font> utility functions can easily be modified if you need special options. |
| <font color="blue">606:</font> */ |
| <font color="blue">607:</font> |
| <font color="blue">608:</font> ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen, |
| <font color="blue">609:</font> const Bytef *source, uLong sourceLen)); |
| <font color="blue">610:</font> /* |
| <font color="blue">611:</font> Compresses the source buffer into the destination buffer. sourceLen is |
| <font color="blue">612:</font> the byte length of the source buffer. Upon entry, destLen is the total |
| <font color="blue">613:</font> size of the destination buffer, which must be at least 0.1% larger than |
| <font color="blue">614:</font> sourceLen plus 12 bytes. Upon exit, destLen is the actual size of the |
| <font color="blue">615:</font> compressed buffer. |
| <font color="blue">616:</font> This function can be used to compress a whole file at once if the |
| <font color="blue">617:</font> input file is mmap'ed. |
| <font color="blue">618:</font> compress returns Z_OK if success, Z_MEM_ERROR if there was not |
| <font color="blue">619:</font> enough memory, Z_BUF_ERROR if there was not enough room in the output |
| <font color="blue">620:</font> buffer. |
| <font color="blue">621:</font> */ |
| <font color="blue">622:</font> |
| <font color="blue">623:</font> ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen, |
| <font color="blue">624:</font> const Bytef *source, uLong sourceLen, |
| <font color="blue">625:</font> int level)); |
| <font color="blue">626:</font> /* |
| <font color="blue">627:</font> Compresses the source buffer into the destination buffer. The level |
| <font color="blue">628:</font> parameter has the same meaning as in deflateInit. sourceLen is the byte |
| <font color="blue">629:</font> length of the source buffer. Upon entry, destLen is the total size of the |
| <font color="blue">630:</font> destination buffer, which must be at least 0.1% larger than sourceLen plus |
| <font color="blue">631:</font> 12 bytes. Upon exit, destLen is the actual size of the compressed buffer. |
| <font color="blue">632:</font> |
| <font color="blue">633:</font> compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough |
| <font color="blue">634:</font> memory, Z_BUF_ERROR if there was not enough room in the output buffer, |
| <font color="blue">635:</font> Z_STREAM_ERROR if the level parameter is invalid. |
| <font color="blue">636:</font> */ |
| <font color="blue">637:</font> |
| <font color="blue">638:</font> ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen, |
| <font color="blue">639:</font> const Bytef *source, uLong sourceLen)); |
| <font color="blue">640:</font> /* |
| <font color="blue">641:</font> Decompresses the source buffer into the destination buffer. sourceLen is |
| <font color="blue">642:</font> the byte length of the source buffer. Upon entry, destLen is the total |
| <font color="blue">643:</font> size of the destination buffer, which must be large enough to hold the |
| <font color="blue">644:</font> entire uncompressed data. (The size of the uncompressed data must have |
| <font color="blue">645:</font> been saved previously by the compressor and transmitted to the decompressor |
| <font color="blue">646:</font> by some mechanism outside the scope of this compression library.) |
| <font color="blue">647:</font> Upon exit, destLen is the actual size of the compressed buffer. |
| <font color="blue">648:</font> This function can be used to decompress a whole file at once if the |
| <font color="blue">649:</font> input file is mmap'ed. |
| <font color="blue">650:</font> |
| <font color="blue">651:</font> uncompress returns Z_OK if success, Z_MEM_ERROR if there was not |
| <font color="blue">652:</font> enough memory, Z_BUF_ERROR if there was not enough room in the output |
| <font color="blue">653:</font> buffer, or Z_DATA_ERROR if the input data was corrupted. |
| <font color="blue">654:</font> */ |
| <font color="blue">655:</font> |
| <font color="blue">656:</font> |
| <font color="blue">657:</font> typedef voidp gzFile; |
| <font color="blue">658:</font> |
| <font color="blue">659:</font> ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode)); |
| <font color="blue">660:</font> /* |
| <font color="blue">661:</font> Opens a gzip (.gz) file for reading or writing. The mode parameter |
| <font color="blue">662:</font> is as in fopen ("rb" or "wb") but can also include a compression level |
| <font color="blue">663:</font> ("wb9") or a strategy: 'f' for filtered data as in "wb6f", 'h' for |
| <font color="blue">664:</font> Huffman only compression as in "wb1h". (See the description |
| <font color="blue">665:</font> of deflateInit2 for more information about the strategy parameter.) |
| <font color="blue">666:</font> |
| <font color="blue">667:</font> gzopen can be used to read a file which is not in gzip format; in this |
| <font color="blue">668:</font> case gzread will directly read from the file without decompression. |
| <font color="blue">669:</font> |
| <font color="blue">670:</font> gzopen returns NULL if the file could not be opened or if there was |
| <font color="blue">671:</font> insufficient memory to allocate the (de)compression state; errno |
| <font color="blue">672:</font> can be checked to distinguish the two cases (if errno is zero, the |
| <font color="blue">673:</font> zlib error is Z_MEM_ERROR). */ |
| <font color="blue">674:</font> |
| <font color="blue">675:</font> ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode)); |
| <font color="blue">676:</font> /* |
| <font color="blue">677:</font> gzdopen() associates a gzFile with the file descriptor fd. File |
| <font color="blue">678:</font> descriptors are obtained from calls like open, dup, creat, pipe or |
| <font color="blue">679:</font> fileno (in the file has been previously opened with fopen). |
| <font color="blue">680:</font> The mode parameter is as in gzopen. |
| <font color="blue">681:</font> The next call of gzclose on the returned gzFile will also close the |
| <font color="blue">682:</font> file descriptor fd, just like fclose(fdopen(fd), mode) closes the file |
| <font color="blue">683:</font> descriptor fd. If you want to keep fd open, use gzdopen(dup(fd), mode). |
| <font color="blue">684:</font> gzdopen returns NULL if there was insufficient memory to allocate |
| <font color="blue">685:</font> the (de)compression state. |
| <font color="blue">686:</font> */ |
| <font color="blue">687:</font> |
| <font color="blue">688:</font> ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy)); |
| <font color="blue">689:</font> /* |
| <font color="blue">690:</font> Dynamically update the compression level or strategy. See the description |
| <font color="blue">691:</font> of deflateInit2 for the meaning of these parameters. |
| <font color="blue">692:</font> gzsetparams returns Z_OK if success, or Z_STREAM_ERROR if the file was not |
| <font color="blue">693:</font> opened for writing. |
| <font color="blue">694:</font> */ |
| <font color="blue">695:</font> |
| <font color="blue">696:</font> ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len)); |
| <font color="blue">697:</font> /* |
| <font color="blue">698:</font> Reads the given number of uncompressed bytes from the compressed file. |
| <font color="blue">699:</font> If the input file was not in gzip format, gzread copies the given number |
| <font color="blue">700:</font> of bytes into the buffer. |
| <font color="blue">701:</font> gzread returns the number of uncompressed bytes actually read (0 for |
| <font color="blue">702:</font> end of file, -1 for error). */ |
| <font color="blue">703:</font> |
| <font color="blue">704:</font> ZEXTERN int ZEXPORT gzwrite OF((gzFile file, |
| <font color="blue">705:</font> const voidp buf, unsigned len)); |
| <font color="blue">706:</font> /* |
| <font color="blue">707:</font> Writes the given number of uncompressed bytes into the compressed file. |
| <font color="blue">708:</font> gzwrite returns the number of uncompressed bytes actually written |
| <font color="blue">709:</font> (0 in case of error). |
| <font color="blue">710:</font> */ |
| <font color="blue">711:</font> |
| <font color="blue">712:</font> ZEXTERN int ZEXPORTVA gzprintf OF((gzFile file, const char *format, ...)); |
| <font color="blue">713:</font> /* |
| <font color="blue">714:</font> Converts, formats, and writes the args to the compressed file under |
| <font color="blue">715:</font> control of the format string, as in fprintf. gzprintf returns the number of |
| <font color="blue">716:</font> uncompressed bytes actually written (0 in case of error). |
| <font color="blue">717:</font> */ |
| <font color="blue">718:</font> |
| <font color="blue">719:</font> ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s)); |
| <font color="blue">720:</font> /* |
| <font color="blue">721:</font> Writes the given null-terminated string to the compressed file, excluding |
| <font color="blue">722:</font> the terminating null character. |
| <font color="blue">723:</font> gzputs returns the number of characters written, or -1 in case of error. |
| <font color="blue">724:</font> */ |
| <font color="blue">725:</font> |
| <font color="blue">726:</font> ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len)); |
| <font color="blue">727:</font> /* |
| <font color="blue">728:</font> Reads bytes from the compressed file until len-1 characters are read, or |
| <font color="blue">729:</font> a newline character is read and transferred to buf, or an end-of-file |
| <font color="blue">730:</font> condition is encountered. The string is then terminated with a null |
| <font color="blue">731:</font> character. |
| <font color="blue">732:</font> gzgets returns buf, or Z_NULL in case of error. |
| <font color="blue">733:</font> */ |
| <font color="blue">734:</font> |
| <font color="blue">735:</font> ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c)); |
| <font color="blue">736:</font> /* |
| <font color="blue">737:</font> Writes c, converted to an unsigned char, into the compressed file. |
| <font color="blue">738:</font> gzputc returns the value that was written, or -1 in case of error. |
| <font color="blue">739:</font> */ |
| <font color="blue">740:</font> |
| <font color="blue">741:</font> ZEXTERN int ZEXPORT gzgetc OF((gzFile file)); |
| <font color="blue">742:</font> /* |
| <font color="blue">743:</font> Reads one byte from the compressed file. gzgetc returns this byte |
| <font color="blue">744:</font> or -1 in case of end of file or error. |
| <font color="blue">745:</font> */ |
| <font color="blue">746:</font> |
| <font color="blue">747:</font> ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush)); |
| <font color="blue">748:</font> /* |
| <font color="blue">749:</font> Flushes all pending output into the compressed file. The parameter |
| <font color="blue">750:</font> flush is as in the deflate() function. The return value is the zlib |
| <font color="blue">751:</font> error number (see function gzerror below). gzflush returns Z_OK if |
| <font color="blue">752:</font> the flush parameter is Z_FINISH and all output could be flushed. |
| <font color="blue">753:</font> gzflush should be called only when strictly necessary because it can |
| <font color="blue">754:</font> degrade compression. |
| <font color="blue">755:</font> */ |
| <font color="blue">756:</font> |
| <font color="blue">757:</font> ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file, |
| <font color="blue">758:</font> z_off_t offset, int whence)); |
| <font color="blue">759:</font> /* |
| <font color="blue">760:</font> Sets the starting position for the next gzread or gzwrite on the |
| <font color="blue">761:</font> given compressed file. The offset represents a number of bytes in the |
| <font color="blue">762:</font> uncompressed data stream. The whence parameter is defined as in lseek(2); |
| <font color="blue">763:</font> the value SEEK_END is not supported. |
| <font color="blue">764:</font> If the file is opened for reading, this function is emulated but can be |
| <font color="blue">765:</font> extremely slow. If the file is opened for writing, only forward seeks are |
| <font color="blue">766:</font> supported; gzseek then compresses a sequence of zeroes up to the new |
| <font color="blue">767:</font> starting position. |
| <font color="blue">768:</font> |
| <font color="blue">769:</font> gzseek returns the resulting offset location as measured in bytes from |
| <font color="blue">770:</font> the beginning of the uncompressed stream, or -1 in case of error, in |
| <font color="blue">771:</font> particular if the file is opened for writing and the new starting position |
| <font color="blue">772:</font> would be before the current position. |
| <font color="blue">773:</font> */ |
| <font color="blue">774:</font> |
| <font color="blue">775:</font> ZEXTERN int ZEXPORT gzrewind OF((gzFile file)); |
| <font color="blue">776:</font> /* |
| <font color="blue">777:</font> Rewinds the given file. This function is supported only for reading. |
| <font color="blue">778:</font> |
| <font color="blue">779:</font> gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET) |
| <font color="blue">780:</font> */ |
| <font color="blue">781:</font> |
| <font color="blue">782:</font> ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file)); |
| <font color="blue">783:</font> /* |
| <font color="blue">784:</font> Returns the starting position for the next gzread or gzwrite on the |
| <font color="blue">785:</font> given compressed file. This position represents a number of bytes in the |
| <font color="blue">786:</font> uncompressed data stream. |
| <font color="blue">787:</font> |
| <font color="blue">788:</font> gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR) |
| <font color="blue">789:</font> */ |
| <font color="blue">790:</font> |
| <font color="blue">791:</font> ZEXTERN int ZEXPORT gzeof OF((gzFile file)); |
| <font color="blue">792:</font> /* |
| <font color="blue">793:</font> Returns 1 when EOF has previously been detected reading the given |
| <font color="blue">794:</font> input stream, otherwise zero. |
| <font color="blue">795:</font> */ |
| <font color="blue">796:</font> |
| <font color="blue">797:</font> ZEXTERN int ZEXPORT gzclose OF((gzFile file)); |
| <font color="blue">798:</font> /* |
| <font color="blue">799:</font> Flushes all pending output if necessary, closes the compressed file |
| <font color="blue">800:</font> and deallocates all the (de)compression state. The return value is the zlib |
| <font color="blue">801:</font> error number (see function gzerror below). |
| <font color="blue">802:</font> */ |
| <font color="blue">803:</font> |
| <font color="blue">804:</font> ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum)); |
| <font color="blue">805:</font> /* |
| <font color="blue">806:</font> Returns the error message for the last error which occurred on the |
| <font color="blue">807:</font> given compressed file. errnum is set to zlib error number. If an |
| <font color="blue">808:</font> error occurred in the file system and not in the compression library, |
| <font color="blue">809:</font> errnum is set to Z_ERRNO and the application may consult errno |
| <font color="blue">810:</font> to get the exact error code. |
| <font color="blue">811:</font> */ |
| <font color="blue">812:</font> |
| <font color="blue">813:</font> /* checksum functions */ |
| <font color="blue">814:</font> |
| <font color="blue">815:</font> /* |
| <font color="blue">816:</font> These functions are not related to compression but are exported |
| <font color="blue">817:</font> anyway because they might be useful in applications using the |
| <font color="blue">818:</font> compression library. |
| <font color="blue">819:</font> */ |
| <font color="blue">820:</font> |
| <font color="blue">821:</font> ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len)); |
| <font color="blue">822:</font> |
| <font color="blue">823:</font> /* |
| <font color="blue">824:</font> Update a running Adler-32 checksum with the bytes buf[0..len-1] and |
| <font color="blue">825:</font> return the updated checksum. If buf is NULL, this function returns |
| <font color="blue">826:</font> the required initial value for the checksum. |
| <font color="blue">827:</font> An Adler-32 checksum is almost as reliable as a CRC32 but can be computed |
| <font color="blue">828:</font> much faster. Usage example: |
| <font color="blue">829:</font> |
| <font color="blue">830:</font> uLong adler = adler32(0L, Z_NULL, 0); |
| <font color="blue">831:</font> |
| <font color="blue">832:</font> while (read_buffer(buffer, length) != EOF) { |
| <font color="blue">833:</font> adler = adler32(adler, buffer, length); |
| <font color="blue">834:</font> } |
| <font color="blue">835:</font> if (adler != original_adler) error(); |
| <font color="blue">836:</font> */ |
| <font color="blue">837:</font> |
| <font color="blue">838:</font> ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len)); |
| <font color="blue">839:</font> /* |
| <font color="blue">840:</font> Update a running crc with the bytes buf[0..len-1] and return the updated |
| <font color="blue">841:</font> crc. If buf is NULL, this function returns the required initial value |
| <font color="blue">842:</font> for the crc. Pre- and post-conditioning (one's complement) is performed |
| <font color="blue">843:</font> within this function so it shouldn't be done by the application. |
| <font color="blue">844:</font> Usage example: |
| <font color="blue">845:</font> |
| <font color="blue">846:</font> uLong crc = crc32(0L, Z_NULL, 0); |
| <font color="blue">847:</font> |
| <font color="blue">848:</font> while (read_buffer(buffer, length) != EOF) { |
| <font color="blue">849:</font> crc = crc32(crc, buffer, length); |
| <font color="blue">850:</font> } |
| <font color="blue">851:</font> if (crc != original_crc) error(); |
| <font color="blue">852:</font> */ |
| <font color="blue">853:</font> |
| <font color="blue">854:</font> |
| <font color="blue">855:</font> /* various hacks, don't look :) */ |
| <font color="blue">856:</font> |
| <font color="blue">857:</font> /* deflateInit and inflateInit are macros to allow checking the zlib version |
| <font color="blue">858:</font> * and the compiler's view of z_stream: |
| <font color="blue">859:</font> */ |
| <font color="blue">860:</font> ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level, |
| <font color="blue">861:</font> const char *version, int stream_size)); |
| <font color="blue">862:</font> ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm, |
| <font color="blue">863:</font> const char *version, int stream_size)); |
| <font color="blue">864:</font> ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method, |
| <font color="blue">865:</font> int windowBits, int memLevel, |
| <font color="blue">866:</font> int strategy, const char *version, |
| <font color="blue">867:</font> int stream_size)); |
| <font color="blue">868:</font> ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits, |
| <font color="blue">869:</font> const char *version, int stream_size)); |
| <font color="blue"><a name="initmacros">870:</a></font> #define deflateInit(strm, level) \ |
| <font color="blue">871:</font> deflateInit_((strm), (level), ZLIB_VERSION, sizeof(z_stream)) |
| <font color="blue">872:</font> #define inflateInit(strm) \ |
| <font color="blue">873:</font> inflateInit_((strm), ZLIB_VERSION, sizeof(z_stream)) |
| <font color="blue">874:</font> #define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ |
| <font color="blue">875:</font> deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ |
| <font color="blue">876:</font> (strategy), ZLIB_VERSION, sizeof(z_stream)) |
| <font color="blue">877:</font> #define inflateInit2(strm, windowBits) \ |
| <font color="blue">878:</font> inflateInit2_((strm), (windowBits), ZLIB_VERSION, sizeof(z_stream)) |
| <font color="blue">879:</font> |
| <font color="blue">880:</font> |
| <font color="blue">881:</font> #if !defined(_Z_UTIL_H) && !defined(NO_DUMMY_DECL) |
| <font color="blue">882:</font> struct internal_state {int dummy;}; /* hack for buggy compilers */ |
| <font color="blue">883:</font> #endif |
| <font color="blue">884:</font> |
| <font color="blue">885:</font> ZEXTERN const char * ZEXPORT zError OF((int err)); |
| <font color="blue">886:</font> ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp z)); |
| <font color="blue">887:</font> ZEXTERN const uLongf * ZEXPORT get_crc_table OF((void)); |
| <font color="blue">888:</font> |
| <font color="blue">889:</font> #ifdef __cplusplus |
| <font color="blue">890:</font> } |
| <font color="blue">891:</font> #endif |
| <font color="blue">892:</font> |
| <font color="blue">893:</font> #endif /* _ZLIB_H */ |
| </pre> |
| </blockquote> |
| |
| <center><h2><a name="devel">How the zlib wrapper was developed</a></h2></center> |
| |
| <h3>Attempt #1</h3> |
| <blockquote> |
| <pre> |
| /* File : example.i */ |
| %module example |
| %{ |
| /* Put headers and other declarations here */ |
| #include "zlib.h" |
| %} |
| |
| %include typemaps.i |
| |
| %include "zlib.h" |
| </pre> |
| </blockquote> |
| |
| The result is: |
| |
| <blockquote> |
| <pre> |
| % swig -chicken -I/usr/include example.i |
| <a href="#l63">/usr/include/zlib.h:63</a>: Syntax error in input. |
| <a href="#l78">/usr/include/zlib.h:78</a>: Syntax error in input. |
| <a href="#l80">/usr/include/zlib.h:80</a>: Syntax error in input. |
| </pre> |
| </blockquote> |
| |
| The first problem we see is that the macro <code>OF(...)</code> is |
| not defined. |
| |
| <h3>Attempt #2</h3> |
| |
| We make sure to include <tt>zconf.h</tt> so that SWIG can see the |
| definition of <code>OF(...)</code>. We try again. |
| |
| <blockquote> |
| <pre> |
| /* File : example.i */ |
| %module example |
| %{ |
| /* Put headers and other declarations here */ |
| #include "zlib.h" |
| %} |
| |
| %include typemaps.i |
| |
| <font color="red">%include "zconf.h"</font> |
| %include "zlib.h" |
| </pre> |
| </blockquote> |
| |
| The result is: |
| |
| <blockquote> |
| <pre> |
| % swig -chicken -I/usr/include example.i |
| </pre> |
| </blockquote> |
| |
| This seems to work! But we should take a peek inside the generated |
| <tt>example_wrap.c</tt> to see what the names of the Scheme |
| procedures will be. |
| |
| <blockquote> |
| <pre> |
| % grep C_intern example_wrap.c |
| C_word err = C_intern2 (&a, errorhook); |
| sym = C_intern (&a, 21, "example:max-mem-level"); |
| sym = C_intern (&a, 17, "example:max-wbits"); |
| sym = C_intern (&a, 16, "example:seek-set"); |
| sym = C_intern (&a, 16, "example:seek-cur"); |
| sym = C_intern (&a, 16, "example:seek-end"); |
| sym = C_intern (&a, 20, "example:zlib-version"); |
| sym = C_intern (&a, 28, "example:z-stream-next-in-set"); |
| sym = C_intern (&a, 28, "example:z-stream-next-in-get"); |
| sym = C_intern (&a, 29, "example:z-stream-avail-in-set"); |
| sym = C_intern (&a, 29, "example:z-stream-avail-in-get"); |
| sym = C_intern (&a, 29, "example:z-stream-total-in-set"); |
| sym = C_intern (&a, 29, "example:z-stream-total-in-get"); |
| sym = C_intern (&a, 29, "example:z-stream-next-out-set"); |
| sym = C_intern (&a, 29, "example:z-stream-next-out-get"); |
| sym = C_intern (&a, 30, "example:z-stream-avail-out-set"); |
| sym = C_intern (&a, 30, "example:z-stream-avail-out-get"); |
| sym = C_intern (&a, 30, "example:z-stream-total-out-set"); |
| sym = C_intern (&a, 30, "example:z-stream-total-out-get"); |
| sym = C_intern (&a, 24, "example:z-stream-msg-set"); |
| sym = C_intern (&a, 24, "example:z-stream-msg-get"); |
| sym = C_intern (&a, 26, "example:z-stream-state-set"); |
| sym = C_intern (&a, 26, "example:z-stream-state-get"); |
| sym = C_intern (&a, 27, "example:z-stream-zalloc-set"); |
| sym = C_intern (&a, 27, "example:z-stream-zalloc-get"); |
| sym = C_intern (&a, 26, "example:z-stream-zfree-set"); |
| sym = C_intern (&a, 26, "example:z-stream-zfree-get"); |
| sym = C_intern (&a, 27, "example:z-stream-opaque-set"); |
| sym = C_intern (&a, 27, "example:z-stream-opaque-get"); |
| sym = C_intern (&a, 30, "example:z-stream-data-type-set"); |
| sym = C_intern (&a, 30, "example:z-stream-data-type-get"); |
| sym = C_intern (&a, 26, "example:z-stream-adler-set"); |
| sym = C_intern (&a, 26, "example:z-stream-adler-get"); |
| sym = C_intern (&a, 29, "example:z-stream-reserved-set"); |
| sym = C_intern (&a, 29, "example:z-stream-reserved-get"); |
| sym = C_intern (&a, 20, "example:new-z-stream"); |
| sym = C_intern (&a, 23, "example:delete-z-stream"); |
| sym = C_intern (&a, 18, "example:z-no-flush"); |
| sym = C_intern (&a, 23, "example:z-partial-flush"); |
| sym = C_intern (&a, 20, "example:z-sync-flush"); |
| sym = C_intern (&a, 20, "example:z-full-flush"); |
| sym = C_intern (&a, 16, "example:z-finish"); |
| sym = C_intern (&a, 12, "example:z-ok"); |
| sym = C_intern (&a, 20, "example:z-stream-end"); |
| sym = C_intern (&a, 19, "example:z-need-dict"); |
| sym = C_intern (&a, 15, "example:z-errno"); |
| sym = C_intern (&a, 22, "example:z-stream-error"); |
| sym = C_intern (&a, 20, "example:z-data-error"); |
| sym = C_intern (&a, 19, "example:z-mem-error"); |
| sym = C_intern (&a, 19, "example:z-buf-error"); |
| sym = C_intern (&a, 23, "example:z-version-error"); |
| sym = C_intern (&a, 24, "example:z-no-compression"); |
| sym = C_intern (&a, 20, "example:z-best-speed"); |
| sym = C_intern (&a, 26, "example:z-best-compression"); |
| sym = C_intern (&a, 29, "example:z-default-compression"); |
| sym = C_intern (&a, 18, "example:z-filtered"); |
| sym = C_intern (&a, 22, "example:z-huffman-only"); |
| sym = C_intern (&a, 26, "example:z-default-strategy"); |
| sym = C_intern (&a, 16, "example:z-binary"); |
| sym = C_intern (&a, 15, "example:z-ascii"); |
| sym = C_intern (&a, 17, "example:z-unknown"); |
| sym = C_intern (&a, 18, "example:z-deflated"); |
| sym = C_intern (&a, 14, "example:z-null"); |
| sym = C_intern (&a, 19, "example:zlibversion"); |
| sym = C_intern (&a, 15, "example:deflate"); |
| sym = C_intern (&a, 18, "example:deflateend"); |
| sym = C_intern (&a, 15, "example:inflate"); |
| sym = C_intern (&a, 18, "example:inflateend"); |
| sym = C_intern (&a, 28, "example:deflatesetdictionary"); |
| sym = C_intern (&a, 19, "example:deflatecopy"); |
| sym = C_intern (&a, 20, "example:deflatereset"); |
| sym = C_intern (&a, 21, "example:deflateparams"); |
| sym = C_intern (&a, 28, "example:inflatesetdictionary"); |
| sym = C_intern (&a, 19, "example:inflatesync"); |
| sym = C_intern (&a, 20, "example:inflatereset"); |
| sym = C_intern (&a, 16, "example:compress"); |
| sym = C_intern (&a, 17, "example:compress2"); |
| sym = C_intern (&a, 18, "example:uncompress"); |
| sym = C_intern (&a, 14, "example:gzopen"); |
| sym = C_intern (&a, 15, "example:gzdopen"); |
| sym = C_intern (&a, 19, "example:gzsetparams"); |
| sym = C_intern (&a, 14, "example:gzread"); |
| sym = C_intern (&a, 15, "example:gzwrite"); |
| sym = C_intern (&a, 16, "example:gzprintf"); |
| sym = C_intern (&a, 14, "example:gzputs"); |
| sym = C_intern (&a, 14, "example:gzgets"); |
| sym = C_intern (&a, 14, "example:gzputc"); |
| sym = C_intern (&a, 14, "example:gzgetc"); |
| sym = C_intern (&a, 15, "example:gzflush"); |
| sym = C_intern (&a, 14, "example:gzseek"); |
| sym = C_intern (&a, 16, "example:gzrewind"); |
| sym = C_intern (&a, 14, "example:gztell"); |
| sym = C_intern (&a, 13, "example:gzeof"); |
| sym = C_intern (&a, 15, "example:gzclose"); |
| sym = C_intern (&a, 15, "example:gzerror"); |
| sym = C_intern (&a, 15, "example:adler32"); |
| sym = C_intern (&a, 13, "example:crc32"); |
| sym = C_intern (&a, 20, "example:deflateinit-"); |
| sym = C_intern (&a, 20, "example:inflateinit-"); |
| sym = C_intern (&a, 21, "example:deflateinit2-"); |
| sym = C_intern (&a, 21, "example:inflateinit2-"); |
| sym = C_intern (&a, 32, "example:internal-state-dummy-set"); |
| sym = C_intern (&a, 32, "example:internal-state-dummy-get"); |
| sym = C_intern (&a, 26, "example:new-internal-state"); |
| sym = C_intern (&a, 29, "example:delete-internal-state"); |
| sym = C_intern (&a, 14, "example:zerror"); |
| sym = C_intern (&a, 24, "example:inflatesyncpoint"); |
| sym = C_intern (&a, 21, "example:get-crc-table"); |
| </pre> |
| </blockquote> |
| |
| In fact, we want the Scheme procedure names to begin with |
| <code>zlib</code> instead of <code>example</code>. For |
| <code>example:zlib-version</code>, we want |
| <code>zlib-version</code>. And we want dashes when the case |
| switches to/from upper/lowercase; ex. the function |
| <code>deflateEnd()</code> should be the Scheme procedure |
| <code>zlib-deflate-end</code>. |
| |
| <h3>Attempt #3</h3> |
| |
| We make sure to add <tt>-prefix zlib -mixed</tt> to the |
| <tt>swig</tt> command line, and we rename |
| <code>ZLIB_VERSION</code> to <code>VERSION</code>. We try again. |
| |
| <blockquote> |
| <pre> |
| /* File : example.i */ |
| %module example |
| %{ |
| /* Put headers and other declarations here */ |
| #include "zlib.h" |
| %} |
| |
| %include typemaps.i |
| |
| <font color="red">%rename(VERSION) ZLIB_VERSION;</font> |
| |
| %include "zconf.h" |
| %include "zlib.h" |
| </pre> |
| </blockquote> |
| |
| The result is: |
| |
| <blockquote> |
| <pre> |
| % swig -chicken <font color="red">-prefix zlib -mixed</font> -I/usr/include example.i |
| % grep C_intern example_wrap.c |
| C_word err = C_intern2 (&a, errorhook); |
| sym = C_intern (&a, 18, "zlib:max-mem-level"); |
| sym = C_intern (&a, 14, "zlib:max-wbits"); |
| sym = C_intern (&a, 13, "zlib:seek-set"); |
| sym = C_intern (&a, 13, "zlib:seek-cur"); |
| sym = C_intern (&a, 13, "zlib:seek-end"); |
| sym = C_intern (&a, 12, "zlib:version"); |
| sym = C_intern (&a, 25, "zlib:z-stream-next-in-set"); |
| sym = C_intern (&a, 25, "zlib:z-stream-next-in-get"); |
| sym = C_intern (&a, 26, "zlib:z-stream-avail-in-set"); |
| sym = C_intern (&a, 26, "zlib:z-stream-avail-in-get"); |
| sym = C_intern (&a, 26, "zlib:z-stream-total-in-set"); |
| sym = C_intern (&a, 26, "zlib:z-stream-total-in-get"); |
| sym = C_intern (&a, 26, "zlib:z-stream-next-out-set"); |
| sym = C_intern (&a, 26, "zlib:z-stream-next-out-get"); |
| sym = C_intern (&a, 27, "zlib:z-stream-avail-out-set"); |
| sym = C_intern (&a, 27, "zlib:z-stream-avail-out-get"); |
| sym = C_intern (&a, 27, "zlib:z-stream-total-out-set"); |
| sym = C_intern (&a, 27, "zlib:z-stream-total-out-get"); |
| sym = C_intern (&a, 21, "zlib:z-stream-msg-set"); |
| sym = C_intern (&a, 21, "zlib:z-stream-msg-get"); |
| sym = C_intern (&a, 23, "zlib:z-stream-state-set"); |
| sym = C_intern (&a, 23, "zlib:z-stream-state-get"); |
| sym = C_intern (&a, 24, "zlib:z-stream-zalloc-set"); |
| sym = C_intern (&a, 24, "zlib:z-stream-zalloc-get"); |
| sym = C_intern (&a, 23, "zlib:z-stream-zfree-set"); |
| sym = C_intern (&a, 23, "zlib:z-stream-zfree-get"); |
| sym = C_intern (&a, 24, "zlib:z-stream-opaque-set"); |
| sym = C_intern (&a, 24, "zlib:z-stream-opaque-get"); |
| sym = C_intern (&a, 27, "zlib:z-stream-data-type-set"); |
| sym = C_intern (&a, 27, "zlib:z-stream-data-type-get"); |
| sym = C_intern (&a, 23, "zlib:z-stream-adler-set"); |
| sym = C_intern (&a, 23, "zlib:z-stream-adler-get"); |
| sym = C_intern (&a, 26, "zlib:z-stream-reserved-set"); |
| sym = C_intern (&a, 26, "zlib:z-stream-reserved-get"); |
| sym = C_intern (&a, 17, "zlib:new-z-stream"); |
| sym = C_intern (&a, 20, "zlib:delete-z-stream"); |
| sym = C_intern (&a, 15, "zlib:z-no-flush"); |
| sym = C_intern (&a, 20, "zlib:z-partial-flush"); |
| sym = C_intern (&a, 17, "zlib:z-sync-flush"); |
| sym = C_intern (&a, 17, "zlib:z-full-flush"); |
| sym = C_intern (&a, 13, "zlib:z-finish"); |
| sym = C_intern (&a, 9, "zlib:z-ok"); |
| sym = C_intern (&a, 17, "zlib:z-stream-end"); |
| sym = C_intern (&a, 16, "zlib:z-need-dict"); |
| sym = C_intern (&a, 12, "zlib:z-errno"); |
| sym = C_intern (&a, 19, "zlib:z-stream-error"); |
| sym = C_intern (&a, 17, "zlib:z-data-error"); |
| sym = C_intern (&a, 16, "zlib:z-mem-error"); |
| sym = C_intern (&a, 16, "zlib:z-buf-error"); |
| sym = C_intern (&a, 20, "zlib:z-version-error"); |
| sym = C_intern (&a, 21, "zlib:z-no-compression"); |
| sym = C_intern (&a, 17, "zlib:z-best-speed"); |
| sym = C_intern (&a, 23, "zlib:z-best-compression"); |
| sym = C_intern (&a, 26, "zlib:z-default-compression"); |
| sym = C_intern (&a, 15, "zlib:z-filtered"); |
| sym = C_intern (&a, 19, "zlib:z-huffman-only"); |
| sym = C_intern (&a, 23, "zlib:z-default-strategy"); |
| sym = C_intern (&a, 13, "zlib:z-binary"); |
| sym = C_intern (&a, 12, "zlib:z-ascii"); |
| sym = C_intern (&a, 14, "zlib:z-unknown"); |
| sym = C_intern (&a, 15, "zlib:z-deflated"); |
| sym = C_intern (&a, 11, "zlib:z-null"); |
| sym = C_intern (&a, 17, "zlib:zlib-version"); |
| sym = C_intern (&a, 12, "zlib:deflate"); |
| sym = C_intern (&a, 16, "zlib:deflate-end"); |
| sym = C_intern (&a, 12, "zlib:inflate"); |
| sym = C_intern (&a, 16, "zlib:inflate-end"); |
| sym = C_intern (&a, 27, "zlib:deflate-set-dictionary"); |
| sym = C_intern (&a, 17, "zlib:deflate-copy"); |
| sym = C_intern (&a, 18, "zlib:deflate-reset"); |
| sym = C_intern (&a, 19, "zlib:deflate-params"); |
| sym = C_intern (&a, 27, "zlib:inflate-set-dictionary"); |
| sym = C_intern (&a, 17, "zlib:inflate-sync"); |
| sym = C_intern (&a, 18, "zlib:inflate-reset"); |
| sym = C_intern (&a, 13, "zlib:compress"); |
| sym = C_intern (&a, 14, "zlib:compress2"); |
| sym = C_intern (&a, 15, "zlib:uncompress"); |
| sym = C_intern (&a, 11, "zlib:gzopen"); |
| sym = C_intern (&a, 12, "zlib:gzdopen"); |
| sym = C_intern (&a, 16, "zlib:gzsetparams"); |
| sym = C_intern (&a, 11, "zlib:gzread"); |
| sym = C_intern (&a, 12, "zlib:gzwrite"); |
| sym = C_intern (&a, 13, "zlib:gzprintf"); |
| sym = C_intern (&a, 11, "zlib:gzputs"); |
| sym = C_intern (&a, 11, "zlib:gzgets"); |
| sym = C_intern (&a, 11, "zlib:gzputc"); |
| sym = C_intern (&a, 11, "zlib:gzgetc"); |
| sym = C_intern (&a, 12, "zlib:gzflush"); |
| sym = C_intern (&a, 11, "zlib:gzseek"); |
| sym = C_intern (&a, 13, "zlib:gzrewind"); |
| sym = C_intern (&a, 11, "zlib:gztell"); |
| sym = C_intern (&a, 10, "zlib:gzeof"); |
| sym = C_intern (&a, 12, "zlib:gzclose"); |
| sym = C_intern (&a, 12, "zlib:gzerror"); |
| sym = C_intern (&a, 12, "zlib:adler32"); |
| sym = C_intern (&a, 10, "zlib:crc32"); |
| sym = C_intern (&a, 18, "zlib:deflate-init-"); |
| sym = C_intern (&a, 18, "zlib:inflate-init-"); |
| sym = C_intern (&a, 19, "zlib:deflate-init2-"); |
| sym = C_intern (&a, 19, "zlib:inflate-init2-"); |
| sym = C_intern (&a, 29, "zlib:internal-state-dummy-set"); |
| sym = C_intern (&a, 29, "zlib:internal-state-dummy-get"); |
| sym = C_intern (&a, 23, "zlib:new-internal-state"); |
| sym = C_intern (&a, 26, "zlib:delete-internal-state"); |
| sym = C_intern (&a, 12, "zlib:ze-rror"); |
| sym = C_intern (&a, 23, "zlib:inflate-sync-point"); |
| sym = C_intern (&a, 18, "zlib:get-crc-table"); |
| </pre> |
| </blockquote> |
| |
| Much better. The only problem is the identifier |
| <code>zlib:ze-rror</code>, and we are missing |
| <code>zlib:deflate-init</code> and <code>zlib:inflate-init</code> |
| because they are defined as macros (see <a |
| href="#initmacros">macro definitions</a>). |
| |
| <h3>Attempt #4</h3> |
| |
| We make sure to rename <code>zError</code> to |
| <code>z_error</code>, and we inline some helper functions for the |
| <code>zlib:...-init</code> macros. We try again. |
| |
| <blockquote> |
| <pre> |
| /* File : example.i */ |
| %module example |
| %{ |
| /* Put headers and other declarations here */ |
| #include "zlib.h" |
| %} |
| |
| %include typemaps.i |
| |
| %rename(VERSION) ZLIB_VERSION; |
| <font color="red">%rename(z_error) zError;</font> |
| |
| %include "zconf.h" |
| %include "zlib.h" |
| |
| <font color="red">%inline %{ |
| /* %inline blocks are seen by SWIG and are inserted into the header |
| portion of example_wrap.c, so that they are also seen by the C |
| compiler. */ |
| int deflate_init(z_streamp strm, int level) { |
| return deflateInit(strm,level); /* call macro */ |
| } |
| int inflate_init(z_streamp strm) { |
| return inflateInit(strm); /* call macro */ |
| } |
| %} |
| </font> |
| |
| </pre> |
| </blockquote> |
| |
| The result is: |
| |
| <blockquote> |
| <pre> |
| % swig -chicken -prefix zlib -mixed -I/usr/include example.i |
| % grep C_intern example_wrap.c |
| C_word err = C_intern2 (&a, errorhook); |
| sym = C_intern (&a, 18, "zlib:max-mem-level"); |
| sym = C_intern (&a, 14, "zlib:max-wbits"); |
| sym = C_intern (&a, 13, "zlib:seek-set"); |
| sym = C_intern (&a, 13, "zlib:seek-cur"); |
| sym = C_intern (&a, 13, "zlib:seek-end"); |
| sym = C_intern (&a, 12, "zlib:version"); |
| sym = C_intern (&a, 25, "zlib:z-stream-next-in-set"); |
| sym = C_intern (&a, 25, "zlib:z-stream-next-in-get"); |
| sym = C_intern (&a, 26, "zlib:z-stream-avail-in-set"); |
| sym = C_intern (&a, 26, "zlib:z-stream-avail-in-get"); |
| sym = C_intern (&a, 26, "zlib:z-stream-total-in-set"); |
| sym = C_intern (&a, 26, "zlib:z-stream-total-in-get"); |
| sym = C_intern (&a, 26, "zlib:z-stream-next-out-set"); |
| sym = C_intern (&a, 26, "zlib:z-stream-next-out-get"); |
| sym = C_intern (&a, 27, "zlib:z-stream-avail-out-set"); |
| sym = C_intern (&a, 27, "zlib:z-stream-avail-out-get"); |
| sym = C_intern (&a, 27, "zlib:z-stream-total-out-set"); |
| sym = C_intern (&a, 27, "zlib:z-stream-total-out-get"); |
| sym = C_intern (&a, 21, "zlib:z-stream-msg-set"); |
| sym = C_intern (&a, 21, "zlib:z-stream-msg-get"); |
| sym = C_intern (&a, 23, "zlib:z-stream-state-set"); |
| sym = C_intern (&a, 23, "zlib:z-stream-state-get"); |
| sym = C_intern (&a, 24, "zlib:z-stream-zalloc-set"); |
| sym = C_intern (&a, 24, "zlib:z-stream-zalloc-get"); |
| sym = C_intern (&a, 23, "zlib:z-stream-zfree-set"); |
| sym = C_intern (&a, 23, "zlib:z-stream-zfree-get"); |
| sym = C_intern (&a, 24, "zlib:z-stream-opaque-set"); |
| sym = C_intern (&a, 24, "zlib:z-stream-opaque-get"); |
| sym = C_intern (&a, 27, "zlib:z-stream-data-type-set"); |
| sym = C_intern (&a, 27, "zlib:z-stream-data-type-get"); |
| sym = C_intern (&a, 23, "zlib:z-stream-adler-set"); |
| sym = C_intern (&a, 23, "zlib:z-stream-adler-get"); |
| sym = C_intern (&a, 26, "zlib:z-stream-reserved-set"); |
| sym = C_intern (&a, 26, "zlib:z-stream-reserved-get"); |
| sym = C_intern (&a, 17, "zlib:new-z-stream"); |
| sym = C_intern (&a, 20, "zlib:delete-z-stream"); |
| sym = C_intern (&a, 15, "zlib:z-no-flush"); |
| sym = C_intern (&a, 20, "zlib:z-partial-flush"); |
| sym = C_intern (&a, 17, "zlib:z-sync-flush"); |
| sym = C_intern (&a, 17, "zlib:z-full-flush"); |
| sym = C_intern (&a, 13, "zlib:z-finish"); |
| sym = C_intern (&a, 9, "zlib:z-ok"); |
| sym = C_intern (&a, 17, "zlib:z-stream-end"); |
| sym = C_intern (&a, 16, "zlib:z-need-dict"); |
| sym = C_intern (&a, 12, "zlib:z-errno"); |
| sym = C_intern (&a, 19, "zlib:z-stream-error"); |
| sym = C_intern (&a, 17, "zlib:z-data-error"); |
| sym = C_intern (&a, 16, "zlib:z-mem-error"); |
| sym = C_intern (&a, 16, "zlib:z-buf-error"); |
| sym = C_intern (&a, 20, "zlib:z-version-error"); |
| sym = C_intern (&a, 21, "zlib:z-no-compression"); |
| sym = C_intern (&a, 17, "zlib:z-best-speed"); |
| sym = C_intern (&a, 23, "zlib:z-best-compression"); |
| sym = C_intern (&a, 26, "zlib:z-default-compression"); |
| sym = C_intern (&a, 15, "zlib:z-filtered"); |
| sym = C_intern (&a, 19, "zlib:z-huffman-only"); |
| sym = C_intern (&a, 23, "zlib:z-default-strategy"); |
| sym = C_intern (&a, 13, "zlib:z-binary"); |
| sym = C_intern (&a, 12, "zlib:z-ascii"); |
| sym = C_intern (&a, 14, "zlib:z-unknown"); |
| sym = C_intern (&a, 15, "zlib:z-deflated"); |
| sym = C_intern (&a, 11, "zlib:z-null"); |
| sym = C_intern (&a, 17, "zlib:zlib-version"); |
| sym = C_intern (&a, 12, "zlib:deflate"); |
| sym = C_intern (&a, 16, "zlib:deflate-end"); |
| sym = C_intern (&a, 12, "zlib:inflate"); |
| sym = C_intern (&a, 16, "zlib:inflate-end"); |
| sym = C_intern (&a, 27, "zlib:deflate-set-dictionary"); |
| sym = C_intern (&a, 17, "zlib:deflate-copy"); |
| sym = C_intern (&a, 18, "zlib:deflate-reset"); |
| sym = C_intern (&a, 19, "zlib:deflate-params"); |
| sym = C_intern (&a, 27, "zlib:inflate-set-dictionary"); |
| sym = C_intern (&a, 17, "zlib:inflate-sync"); |
| sym = C_intern (&a, 18, "zlib:inflate-reset"); |
| sym = C_intern (&a, 13, "zlib:compress"); |
| sym = C_intern (&a, 14, "zlib:compress2"); |
| sym = C_intern (&a, 15, "zlib:uncompress"); |
| sym = C_intern (&a, 11, "zlib:gzopen"); |
| sym = C_intern (&a, 12, "zlib:gzdopen"); |
| sym = C_intern (&a, 16, "zlib:gzsetparams"); |
| sym = C_intern (&a, 11, "zlib:gzread"); |
| sym = C_intern (&a, 12, "zlib:gzwrite"); |
| sym = C_intern (&a, 13, "zlib:gzprintf"); |
| sym = C_intern (&a, 11, "zlib:gzputs"); |
| sym = C_intern (&a, 11, "zlib:gzgets"); |
| sym = C_intern (&a, 11, "zlib:gzputc"); |
| sym = C_intern (&a, 11, "zlib:gzgetc"); |
| sym = C_intern (&a, 12, "zlib:gzflush"); |
| sym = C_intern (&a, 11, "zlib:gzseek"); |
| sym = C_intern (&a, 13, "zlib:gzrewind"); |
| sym = C_intern (&a, 11, "zlib:gztell"); |
| sym = C_intern (&a, 10, "zlib:gzeof"); |
| sym = C_intern (&a, 12, "zlib:gzclose"); |
| sym = C_intern (&a, 12, "zlib:gzerror"); |
| sym = C_intern (&a, 12, "zlib:adler32"); |
| sym = C_intern (&a, 10, "zlib:crc32"); |
| sym = C_intern (&a, 18, "zlib:deflate-init-"); |
| sym = C_intern (&a, 18, "zlib:inflate-init-"); |
| sym = C_intern (&a, 19, "zlib:deflate-init2-"); |
| sym = C_intern (&a, 19, "zlib:inflate-init2-"); |
| sym = C_intern (&a, 29, "zlib:internal-state-dummy-set"); |
| sym = C_intern (&a, 29, "zlib:internal-state-dummy-get"); |
| sym = C_intern (&a, 23, "zlib:new-internal-state"); |
| sym = C_intern (&a, 26, "zlib:delete-internal-state"); |
| sym = C_intern (&a, 12, "zlib:z-error"); |
| sym = C_intern (&a, 23, "zlib:inflate-sync-point"); |
| sym = C_intern (&a, 18, "zlib:get-crc-table"); |
| sym = C_intern (&a, 17, "zlib:deflate-init"); |
| sym = C_intern (&a, 17, "zlib:inflate-init"); |
| </pre> |
| </blockquote> |
| |
| Perfect! Now let's integrate this zlib extension into a |
| CHICKEN interpreter. To save some time, in this |
| Examples/chicken/zlib directory: |
| <ol> |
| <li>Backup the original <tt>example.i</tt>.</li> |
| <li>Copy and paste the <tt>example.i</tt> text from above and |
| put it into the file called <tt>example.i</tt></li> |
| <li>Run 'make' as per <a href="#build">Building the |
| example</a>.</li> |
| <li>Run the resultant executable <tt>zlib</tt>.</li> |
| </ol> |
| |
| The interpreter interaction is as follows: |
| |
| <blockquote> |
| <pre> |
| % ./zlib |
| zlib |
| |
| A SWIG example for the CHICKEN compiler |
| Author: Jonah Beckford, February 2003 |
| |
| Scheme Procedures: |
| |
| zlib:max-mem-level |
| zlib:max-wbits |
| zlib:seek-set |
| zlib:seek-cur |
| zlib:seek-end |
| zlib:version |
| zlib:z-stream-next-in-set |
| zlib:z-stream-next-in-get |
| zlib:z-stream-avail-in-set |
| ... |
| zlib:get-crc-table |
| zlib:deflate-init |
| zlib:inflate-init |
| ; This is the CHICKEN interpreter - Version 0, Build 1095 - windows-cygwin-x86 |
| ; (c)2000-2003 Felix L. Winkelmann |
| >>> (define s (zlib:new-z-stream)) |
| >>> s |
| #<tagged pointer #<c++ "z_stream *">(#<pointer 6d9290>)> |
| >>> (zlib:z-stream-next-in-get s) |
| #f |
| >>> (zlib:z-stream-next-in-set s "some dummy stream data") |
| Error: Type error. Expected _p_Bytef: "bad argument type" |
| >>> (exit) |
| </pre> |
| </blockquote> |
| |
| Apparently we cannot use Scheme strings as <code>Bytef *</code>. The SWIG |
| manual shows many ways how to handle strings and byte arrays, but |
| to be simplistic, let's just make the <code>Bytef *</code> look |
| like a <code>char *</code>, which is automatically handled as a |
| string by SWIG CHICKEN. |
| |
| <h3>Attempt #5</h3> |
| |
| We make sure to add an %apply construct so that <code>Bytef |
| *</code> is handled the same as <code>char *</code> to SWIG. We |
| try again. |
| |
| <blockquote> |
| <pre> |
| /* File : example.i */ |
| %module example |
| %{ |
| /* Put headers and other declarations here */ |
| #include "zlib.h" |
| %} |
| |
| %include typemaps.i |
| |
| %rename(VERSION) ZLIB_VERSION; |
| %rename(z_error) zError; |
| <font color="red">%apply char * { Bytef * };</font> |
| |
| %include "zconf.h" |
| %include "zlib.h" |
| |
| %inline %{ |
| /* %inline blocks are seen by SWIG and are inserted into the header |
| portion of example_wrap.c, so that they are also seen by the C |
| compiler. */ |
| int deflate_init(z_streamp strm, int level) { |
| return deflateInit(strm,level); /* call macro */ |
| } |
| int inflate_init(z_streamp strm) { |
| return inflateInit(strm); /* call macro */ |
| } |
| %} |
| </pre> |
| </blockquote> |
| |
| Build the example once more.<br> |
| |
| The interpreter interaction is as follows: |
| |
| <blockquote> |
| <pre> |
| % ./zlib |
| zlib |
| |
| A SWIG example for the CHICKEN compiler |
| Author: Jonah Beckford, February 2003 |
| |
| Scheme Procedures: |
| |
| zlib:max-mem-level |
| zlib:max-wbits |
| zlib:seek-set |
| zlib:seek-cur |
| zlib:seek-end |
| zlib:version |
| zlib:z-stream-next-in-set |
| zlib:z-stream-next-in-get |
| zlib:z-stream-avail-in-set |
| ... |
| zlib:get-crc-table |
| zlib:deflate-init |
| zlib:inflate-init |
| ; This is the CHICKEN interpreter - Version 0, Build 1095 - windows-cygwin-x86 |
| ; (c)2000-2003 Felix L. Winkelmann |
| >>> (define s (zlib:new-z-stream)) |
| <em>Init zstream</em> |
| >>> (zlib:z-stream-zalloc-set s #f) |
| >>> (zlib:z-stream-zfree-set s #f) |
| >>> (zlib:z-stream-opaque-set s #f) |
| >>> (zlib:deflate-init s (zlib:z-default-compression)) |
| 0 |
| <em>Deflate something small so we don't need to loop/stream data</em> |
| >>> (define in "some dummy data") |
| >>> (define out (make-string 1000)) |
| >>> (zlib:z-stream-next-in-set s in) |
| >>> (zlib:z-stream-avail-in-set s (string-length in)) |
| >>> (zlib:z-stream-next-out-set s out) |
| >>> (zlib:z-stream-avail-out-set s (string-length out)) |
| >>> (zlib:deflate s (zlib:z-finish)) |
| 1 <em>;; (zlib:z-stream-end) == 1, which is good</em> |
| >>> (zlib:z-stream-total-out-get s) |
| 23. |
| >>> out |
| " " |
| </pre> |
| </blockquote> |
| |
| We see the problem ... the compression is occurring as it should, |
| but we cannot see any of the compressed output. This is because |
| when SWIG CHICKEN passes a Scheme string to a C function, it |
| duplicates the string before calling the C function. We want to |
| save the memory address that |
| <code>zlib:z-stream-next-out-set</code> is using, so we can |
| display this later. While we are at it, we can foresee that |
| <code>compress</code>, <code>compress2</code> and |
| <code>uncompress</code> will all need some finessing to work with |
| mutating strings. |
| |
| <h3>Attempt #6</h3> |
| |
| When we have to finesse strings, we must use typemaps. As well, |
| we define some functions to save and restore the |
| <code>next_out</code> element. We try again. |
| |
| <blockquote> |
| <pre> |
| /* File : example.i */ |
| %module example |
| %{ |
| /* Put headers and other declarations here */ |
| #include "zlib.h" |
| %} |
| |
| %include typemaps.i |
| |
| %rename(VERSION) ZLIB_VERSION; |
| %rename(z_error) zError; |
| %apply char * { Bytef * }; |
| <font color="red"> |
| /* Allow the sourceLen to be automatically filled in from the length |
| of the 'source' string */ |
| %typemap(in) (const Bytef *source, uLong sourceLen) |
| %{ if (!C_swig_is_string ($input)) { |
| swig_barf (SWIG_BARF1_BAD_ARGUMENT_TYPE, "Argument $input is not a string"); |
| } |
| $2 = (uLong) C_header_size ($input); |
| $1 = C_c_string ($input); |
| %} |
| |
| /* Allocate space the size of which is determined by the Scheme |
| integer argument, and make a temporary integer so we can set |
| destLen. */ |
| %typemap(in) (Bytef *dest, uLongf *destLen) (uLong len) |
| %{ if (!C_swig_is_fixnum ($input)) { |
| swig_barf (SWIG_BARF1_BAD_ARGUMENT_TYPE, "Argument $input is not a integer"); |
| } |
| len = (uLong) C_unfix ($input); |
| $2 = &len; |
| $1 = (char *) malloc (*$2); |
| %} |
| |
| /* Return the mutated string as a new object. */ |
| %typemap(argout) (Bytef *dest, uLongf *destLen) |
| (C_word *scmstr) |
| %{ scmstr = C_alloc (C_SIZEOF_STRING (*$2)); |
| SWIG_APPEND_VALUE(C_string (&scmstr, *$2, $1)); |
| free ($1); |
| %} |
| </font> |
| %include "zconf.h" |
| %include "zlib.h" |
| <font color="red"> |
| /* Ignore destLen as an input argument, and make a temporary integer so |
| we can set destLen. */ |
| %typemap(in, numinputs=0) uLongf *destLen (uLong len) |
| "$1 = &len;"; |
| |
| /* Return a sized string as a new object. */ |
| %typemap(argout) |
| (void *outstr, uLongf *destLen) (C_word *scmstr) |
| %{ scmstr = C_alloc (C_SIZEOF_STRING (*$2)); |
| SWIG_APPEND_VALUE(C_string (&scmstr, *$2, $1)); |
| %} |
| </font> |
| %inline %{ |
| /* %inline blocks are seen by SWIG and are inserted into the header |
| portion of example_wrap.c, so that they are also seen by the C |
| compiler. */ |
| int deflate_init(z_streamp strm, int level) { |
| return deflateInit(strm,level); /* call macro */ |
| } |
| int inflate_init(z_streamp strm) { |
| return inflateInit(strm); /* call macro */ |
| } |
| <font color="red">void* z_stream_save_next_out(z_streamp strm) { |
| return (void*) strm->next_out; |
| } |
| void z_stream_get_next_chunk(z_streamp strm, void *outstr, uLongf *destLen) { |
| *destLen = strm->next_out - (Bytef*)outstr; |
| }</font> |
| %} |
| </pre> |
| </blockquote> |
| |
| And that's it. Try building the entire example from the |
| Makefile. Run <tt>./zlib test-zlib.scm</tt> to test it out. |
| |
| </body> |
| </html> |
