Improve contrib/blast to return unused bytes. Fix the test code
to report the count of unused bytes at the end correctly. Add the
ability to provide initial input to blast().
diff --git a/contrib/blast/blast.c b/contrib/blast/blast.c
index 69ef0fe..52b59da 100644
--- a/contrib/blast/blast.c
+++ b/contrib/blast/blast.c
@@ -1,7 +1,7 @@
/* blast.c
- * Copyright (C) 2003, 2012 Mark Adler
+ * Copyright (C) 2003, 2012, 2013 Mark Adler
* For conditions of distribution and use, see copyright notice in blast.h
- * version 1.2, 24 Oct 2012
+ * version 1.3, 24 Aug 2013
*
* blast.c decompresses data compressed by the PKWare Compression Library.
* This function provides functionality similar to the explode() function of
@@ -24,8 +24,12 @@
* 1.1 16 Feb 2003 - Fixed distance check for > 4 GB uncompressed data
* 1.2 24 Oct 2012 - Add note about using binary mode in stdio
* - Fix comparisons of differently signed integers
+ * 1.3 24 Aug 2013 - Return unused input from blast()
+ * - Fix test code to correctly report unused input
+ * - Enable the provision of initial input to blast()
*/
+#include <stddef.h> /* for NULL */
#include <setjmp.h> /* for setjmp(), longjmp(), and jmp_buf */
#include "blast.h" /* prototype for blast() */
@@ -376,7 +380,8 @@
}
/* See comments in blast.h */
-int blast(blast_in infun, void *inhow, blast_out outfun, void *outhow)
+int blast(blast_in infun, void *inhow, blast_out outfun, void *outhow,
+ unsigned *left, unsigned char **in)
{
struct state s; /* input/output state */
int err; /* return value */
@@ -384,7 +389,12 @@
/* initialize input state */
s.infun = infun;
s.inhow = inhow;
- s.left = 0;
+ if (left != NULL && *left) {
+ s.left = *left;
+ s.in = *in;
+ }
+ else
+ s.left = 0;
s.bitbuf = 0;
s.bitcnt = 0;
@@ -400,6 +410,12 @@
else
err = decomp(&s); /* decompress */
+ /* return unused input */
+ if (left != NULL)
+ *left = s.left;
+ if (in != NULL)
+ *in = s.left ? s.in : NULL;
+
/* write any leftover output and update the error code if needed */
if (err != 1 && s.next && s.outfun(s.outhow, s.out, s.next) && err == 0)
err = 1;
@@ -429,16 +445,20 @@
/* Decompress a PKWare Compression Library stream from stdin to stdout */
int main(void)
{
- int ret, n;
+ int ret;
+ unsigned left;
/* decompress to stdout */
- ret = blast(inf, stdin, outf, stdout);
- if (ret != 0) fprintf(stderr, "blast error: %d\n", ret);
+ left = 0;
+ ret = blast(inf, stdin, outf, stdout, &left, NULL);
+ if (ret != 0)
+ fprintf(stderr, "blast error: %d\n", ret);
- /* see if there are any leftover bytes */
- n = 0;
- while (getchar() != EOF) n++;
- if (n) fprintf(stderr, "blast warning: %d unused bytes of input\n", n);
+ /* count any leftover bytes */
+ while (getchar() != EOF)
+ left++;
+ if (left)
+ fprintf(stderr, "blast warning: %u unused bytes of input\n", left);
/* return blast() error code */
return ret;
diff --git a/contrib/blast/blast.h b/contrib/blast/blast.h
index 658cfd3..6cf65ed 100644
--- a/contrib/blast/blast.h
+++ b/contrib/blast/blast.h
@@ -1,6 +1,6 @@
/* blast.h -- interface for blast.c
- Copyright (C) 2003, 2012 Mark Adler
- version 1.2, 24 Oct 2012
+ Copyright (C) 2003, 2012, 2013 Mark Adler
+ version 1.3, 24 Aug 2013
This software is provided 'as-is', without any express or implied
warranty. In no event will the author be held liable for any damages
@@ -42,7 +42,8 @@
*/
-int blast(blast_in infun, void *inhow, blast_out outfun, void *outhow);
+int blast(blast_in infun, void *inhow, blast_out outfun, void *outhow,
+ unsigned *left, unsigned char **in);
/* Decompress input to output using the provided infun() and outfun() calls.
* On success, the return value of blast() is zero. If there is an error in
* the source data, i.e. it is not in the proper format, then a negative value
@@ -55,12 +56,19 @@
* an input error. (blast() only asks for input if it needs it.) inhow is for
* use by the application to pass an input descriptor to infun(), if desired.
*
+ * If left and in are not NULL and *left is not zero when blast() is called,
+ * then the *left bytes are *in are consumed for input before infun() is used.
+ *
* The output function is invoked: err = outfun(how, buf, len), where the bytes
* to be written are buf[0..len-1]. If err is not zero, then blast() returns
* with an output error. outfun() is always called with len <= 4096. outhow
* is for use by the application to pass an output descriptor to outfun(), if
* desired.
*
+ * If there is any unused input, *left is set to the number of bytes that were
+ * read and *in points to them. Otherwise *left is set to zero and *in is set
+ * to NULL. If left or in are NULL, then they are not set.
+ *
* The return codes are:
*
* 2: ran out of input before completing decompression
