| /* compress.c -- compress a memory buffer |
| * Copyright (C) 1995-2005, 2014, 2016 Jean-loup Gailly, Mark Adler |
| * For conditions of distribution and use, see copyright notice in zlib.h |
| */ |
| |
| #include "zbuild.h" |
| #include "zutil.h" |
| |
| /* =========================================================================== |
| * Architecture-specific hooks. |
| */ |
| #ifdef S390_DFLTCC_DEFLATE |
| # include "arch/s390/dfltcc_common.h" |
| #else |
| /* Returns the upper bound on compressed data length based on uncompressed data length, assuming default settings. |
| * Zero means that arch-specific deflation code behaves identically to the regular zlib-ng algorithms. */ |
| # define DEFLATE_BOUND_COMPLEN(source_len) 0 |
| #endif |
| |
| /* =========================================================================== |
| Compresses the source buffer into the destination buffer. The level |
| parameter has the same meaning as in deflateInit. sourceLen is the byte |
| length of the source buffer. Upon entry, destLen is the total size of the |
| destination buffer, which must be at least 0.1% larger than sourceLen plus |
| 12 bytes. Upon exit, destLen is the actual size of the compressed buffer. |
| |
| compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough |
| memory, Z_BUF_ERROR if there was not enough room in the output buffer, |
| Z_STREAM_ERROR if the level parameter is invalid. |
| */ |
| int Z_EXPORT PREFIX(compress2)(unsigned char *dest, z_uintmax_t *destLen, const unsigned char *source, |
| z_uintmax_t sourceLen, int level) { |
| PREFIX3(stream) stream; |
| int err; |
| const unsigned int max = (unsigned int)-1; |
| z_size_t left; |
| |
| left = *destLen; |
| *destLen = 0; |
| |
| stream.zalloc = NULL; |
| stream.zfree = NULL; |
| stream.opaque = NULL; |
| |
| err = PREFIX(deflateInit)(&stream, level); |
| if (err != Z_OK) |
| return err; |
| |
| stream.next_out = dest; |
| stream.avail_out = 0; |
| stream.next_in = (z_const unsigned char *)source; |
| stream.avail_in = 0; |
| |
| do { |
| if (stream.avail_out == 0) { |
| stream.avail_out = left > (unsigned long)max ? max : (unsigned int)left; |
| left -= stream.avail_out; |
| } |
| if (stream.avail_in == 0) { |
| stream.avail_in = sourceLen > (unsigned long)max ? max : (unsigned int)sourceLen; |
| sourceLen -= stream.avail_in; |
| } |
| err = PREFIX(deflate)(&stream, sourceLen ? Z_NO_FLUSH : Z_FINISH); |
| } while (err == Z_OK); |
| |
| *destLen = stream.total_out; |
| PREFIX(deflateEnd)(&stream); |
| return err == Z_STREAM_END ? Z_OK : err; |
| } |
| |
| /* =========================================================================== |
| */ |
| int Z_EXPORT PREFIX(compress)(unsigned char *dest, z_uintmax_t *destLen, const unsigned char *source, z_uintmax_t sourceLen) { |
| return PREFIX(compress2)(dest, destLen, source, sourceLen, Z_DEFAULT_COMPRESSION); |
| } |
| |
| /* =========================================================================== |
| If the default memLevel or windowBits for deflateInit() is changed, then |
| this function needs to be updated. |
| */ |
| z_uintmax_t Z_EXPORT PREFIX(compressBound)(z_uintmax_t sourceLen) { |
| z_uintmax_t complen = DEFLATE_BOUND_COMPLEN(sourceLen); |
| |
| if (complen > 0) |
| /* Architecture-specific code provided an upper bound. */ |
| return complen + ZLIB_WRAPLEN; |
| |
| #ifndef NO_QUICK_STRATEGY |
| return sourceLen /* The source size itself */ |
| + (sourceLen == 0 ? 1 : 0) /* Always at least one byte for any input */ |
| + (sourceLen < 9 ? 1 : 0) /* One extra byte for lengths less than 9 */ |
| + DEFLATE_QUICK_OVERHEAD(sourceLen) /* Source encoding overhead, padded to next full byte */ |
| + DEFLATE_BLOCK_OVERHEAD /* Deflate block overhead bytes */ |
| + ZLIB_WRAPLEN; /* zlib wrapper */ |
| #else |
| return sourceLen + (sourceLen >> 4) + 7 + ZLIB_WRAPLEN; |
| #endif |
| } |