From 799c87c0d8fc5af306f8c7a160dfd3d75746c2ce Mon Sep 17 00:00:00 2001 From: Mark Adler Date: Sat, 24 Aug 2013 01:53:31 -0700 Subject: [PATCH] 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(). --- contrib/blast/blast.c | 42 +++++++++++++++++++++++++++++++----------- contrib/blast/blast.h | 14 +++++++++++--- 2 files changed, 42 insertions(+), 14 deletions(-) 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 /* for NULL */ #include /* for setjmp(), longjmp(), and jmp_buf */ #include "blast.h" /* prototype for blast() */ @@ -376,7 +380,8 @@ local int decomp(struct state *s) } /* 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 @@ int blast(blast_in infun, void *inhow, blast_out outfun, void *outhow) /* 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 @@ int blast(blast_in infun, void *inhow, blast_out outfun, void *outhow) 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 @@ local int outf(void *how, unsigned char *buf, unsigned len) /* 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 @@ typedef int (*blast_out)(void *how, unsigned char *buf, unsigned len); */ -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 @@ int blast(blast_in infun, void *inhow, blast_out outfun, void *outhow); * 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