From 37281ac222ee7ceb8cc3253f13c8fa26a88dd566 Mon Sep 17 00:00:00 2001 From: Mark Adler Date: Tue, 15 Nov 2016 20:45:01 -0700 Subject: Add uncompress2() function, which returns the input size used. --- uncompr.c | 47 ++++++++++++++++++++++++++++++----------------- 1 file changed, 30 insertions(+), 17 deletions(-) (limited to 'uncompr.c') diff --git a/uncompr.c b/uncompr.c index f3f883a..2fbfcc0 100644 --- a/uncompr.c +++ b/uncompr.c @@ -1,5 +1,5 @@ /* uncompr.c -- decompress a memory buffer - * Copyright (C) 1995-2003, 2010, 2014 Jean-loup Gailly, Mark Adler + * Copyright (C) 1995-2003, 2010, 2014, 2016 Jean-loup Gailly, Mark Adler * For conditions of distribution and use, see copyright notice in zlib.h */ @@ -9,31 +9,34 @@ #include "zlib.h" /* =========================================================================== - Decompresses the source buffer into the destination buffer. sourceLen is - the byte length of the source buffer. Upon entry, destLen is the total - size of the destination buffer, which must be large enough to hold the - entire uncompressed data. (The size of the uncompressed data must have - been saved previously by the compressor and transmitted to the decompressor - by some mechanism outside the scope of this compression library.) - Upon exit, destLen is the actual size of the compressed buffer. + Decompresses the source buffer into the destination buffer. *sourceLen is + the byte length of the source buffer. Upon entry, *destLen is the total size + of the destination buffer, which must be large enough to hold the entire + uncompressed data. (The size of the uncompressed data must have been saved + previously by the compressor and transmitted to the decompressor by some + mechanism outside the scope of this compression library.) Upon exit, + *destLen is the size of the decompressed data and *sourceLen is the number + of source bytes consumed. Upon return, source + *sourceLen points to the + first unused input byte. - uncompress 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, or Z_DATA_ERROR if the input data was corrupted, including if the - input data is an incomplete zlib stream. + uncompress 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, or + Z_DATA_ERROR if the input data was corrupted, including if the input data is + an incomplete zlib stream. */ -int ZEXPORT uncompress (dest, destLen, source, sourceLen) +int ZEXPORT uncompress2 (dest, destLen, source, sourceLen) Bytef *dest; uLongf *destLen; const Bytef *source; - uLong sourceLen; + uLong *sourceLen; { z_stream stream; int err; const uInt max = (uInt)0 - 1; - uLong left; + uLong len, left; Byte buf[1]; /* for detection of incomplete stream when *destLen == 0 */ + len = *sourceLen; if (*destLen) { left = *destLen; *destLen = 0; @@ -61,12 +64,13 @@ int ZEXPORT uncompress (dest, destLen, source, sourceLen) left -= stream.avail_out; } if (stream.avail_in == 0) { - stream.avail_in = sourceLen > (uLong)max ? max : (uInt)sourceLen; - sourceLen -= stream.avail_in; + stream.avail_in = len > (uLong)max ? max : (uInt)len; + len -= stream.avail_in; } err = inflate(&stream, Z_NO_FLUSH); } while (err == Z_OK); + *sourceLen -= len + stream.avail_in; if (dest != buf) *destLen = stream.total_out; else if (stream.total_out && err == Z_BUF_ERROR) @@ -78,3 +82,12 @@ int ZEXPORT uncompress (dest, destLen, source, sourceLen) err == Z_BUF_ERROR && left + stream.avail_out ? Z_DATA_ERROR : err; } + +int ZEXPORT uncompress (dest, destLen, source, sourceLen) + Bytef *dest; + uLongf *destLen; + const Bytef *source; + uLong sourceLen; +{ + return uncompress2(dest, destLen, source, &sourceLen); +} -- cgit v1.2.1