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Diffstat (limited to 'Source/FreeImage/ZLibInterface.cpp')
| -rw-r--r-- | Source/FreeImage/ZLibInterface.cpp | 229 |
1 files changed, 229 insertions, 0 deletions
diff --git a/Source/FreeImage/ZLibInterface.cpp b/Source/FreeImage/ZLibInterface.cpp new file mode 100644 index 0000000..5a147df --- /dev/null +++ b/Source/FreeImage/ZLibInterface.cpp @@ -0,0 +1,229 @@ +// ========================================================== +// ZLib library interface +// +// Design and implementation by +// - Floris van den Berg (flvdberg@wxs.nl) +// +// This file is part of FreeImage 3 +// +// COVERED CODE IS PROVIDED UNDER THIS LICENSE ON AN "AS IS" BASIS, WITHOUT WARRANTY +// OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, WITHOUT LIMITATION, WARRANTIES +// THAT THE COVERED CODE IS FREE OF DEFECTS, MERCHANTABLE, FIT FOR A PARTICULAR PURPOSE +// OR NON-INFRINGING. THE ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE COVERED +// CODE IS WITH YOU. SHOULD ANY COVERED CODE PROVE DEFECTIVE IN ANY RESPECT, YOU (NOT +// THE INITIAL DEVELOPER OR ANY OTHER CONTRIBUTOR) ASSUME THE COST OF ANY NECESSARY +// SERVICING, REPAIR OR CORRECTION. THIS DISCLAIMER OF WARRANTY CONSTITUTES AN ESSENTIAL +// PART OF THIS LICENSE. NO USE OF ANY COVERED CODE IS AUTHORIZED HEREUNDER EXCEPT UNDER +// THIS DISCLAIMER. +// +// Use at your own risk! +// ========================================================== + +#include <zlib.h> +#include "FreeImage.h" +#include "Utilities.h" +#ifdef __APPLE__ +#include "zutil.h" +#elif defined(WIN32) || defined(_WIN32) +#include <zutil.h> /* must be the last header because of error C3163 in VS2008 (_vsnprintf defined in stdio.h) */ +#else +#include "../../../zlib-1.2.3/zutil.h" +#endif + +/** +Compresses a source buffer into a target buffer, using the ZLib library. +Upon entry, target_size is the total size of the destination buffer, +which must be at least 0.1% larger than source_size plus 12 bytes. + +@param target Destination buffer +@param target_size Size of the destination buffer, in bytes +@param source Source buffer +@param source_size Size of the source buffer, in bytes +@return Returns the actual size of the compressed buffer, returns 0 if an error occured +@see FreeImage_ZLibUncompress +*/ +DWORD DLL_CALLCONV +FreeImage_ZLibCompress(BYTE *target, DWORD target_size, BYTE *source, DWORD source_size) { + uLongf dest_len = (uLongf)target_size; + + int zerr = compress(target, &dest_len, source, source_size); + switch(zerr) { + case Z_MEM_ERROR: // not enough memory + case Z_BUF_ERROR: // not enough room in the output buffer + FreeImage_OutputMessageProc(FIF_UNKNOWN, "Zlib error : %s", zError(zerr)); + return 0; + case Z_OK: + return dest_len; + } + + return 0; +} + +/** +Decompresses a source buffer into a target buffer, using the ZLib library. +Upon entry, target_size 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. + +@param target Destination buffer +@param target_size Size of the destination buffer, in bytes +@param source Source buffer +@param source_size Size of the source buffer, in bytes +@return Returns the actual size of the uncompressed buffer, returns 0 if an error occured +@see FreeImage_ZLibCompress +*/ +DWORD DLL_CALLCONV +FreeImage_ZLibUncompress(BYTE *target, DWORD target_size, BYTE *source, DWORD source_size) { + uLongf dest_len = (uLongf)target_size; + + int zerr = uncompress(target, &dest_len, source, source_size); + switch(zerr) { + case Z_MEM_ERROR: // not enough memory + case Z_BUF_ERROR: // not enough room in the output buffer + case Z_DATA_ERROR: // input data was corrupted + FreeImage_OutputMessageProc(FIF_UNKNOWN, "Zlib error : %s", zError(zerr)); + return 0; + case Z_OK: + return dest_len; + } + + return 0; +} + +/** +Compresses a source buffer into a target buffer, using the ZLib library. +On success, the target buffer contains a GZIP compatible layout. +Upon entry, target_size is the total size of the destination buffer, +which must be at least 0.1% larger than source_size plus 24 bytes. + +@param target Destination buffer +@param target_size Size of the destination buffer, in bytes +@param source Source buffer +@param source_size Size of the source buffer, in bytes +@return Returns the actual size of the compressed buffer, returns 0 if an error occured +@see FreeImage_ZLibCompress +*/ +DWORD DLL_CALLCONV +FreeImage_ZLibGZip(BYTE *target, DWORD target_size, BYTE *source, DWORD source_size) { + uLongf dest_len = (uLongf)target_size - 12; + DWORD crc = crc32(0L, NULL, 0); + + // set up header (stolen from zlib/gzio.c) + sprintf((char *)target, "%c%c%c%c%c%c%c%c", 0x1f, 0x8b, + Z_DEFLATED, 0 /*flags*/, 0,0,0,0 /*time*/); + int zerr = compress2(target + 8, &dest_len, source, source_size, Z_BEST_COMPRESSION); + switch(zerr) { + case Z_MEM_ERROR: // not enough memory + case Z_BUF_ERROR: // not enough room in the output buffer + FreeImage_OutputMessageProc(FIF_UNKNOWN, "Zlib error : %s", zError(zerr)); + return 0; + case Z_OK: { + // patch header, setup crc and length (stolen from mod_trace_output) + BYTE *p = target + 8; *p++ = 2; *p = OS_CODE; // xflags, os_code + crc = crc32(crc, source, source_size); + memcpy(target + 4 + dest_len, &crc, 4); + memcpy(target + 8 + dest_len, &source_size, 4); + return dest_len + 12; + } + } + return 0; +} + +/** +Decompresses a gzipped source buffer into a target buffer, using the ZLib library. +Upon entry, target_size 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. + +@param target Destination buffer +@param target_size Size of the destination buffer, in bytes +@param source Source buffer +@param source_size Size of the source buffer, in bytes +@return Returns the actual size of the uncompressed buffer, returns 0 if an error occured +@see FreeImage_ZLibGZip +*/ + +static int get_byte(z_stream *stream) { + if (stream->avail_in <= 0) return EOF; + stream->avail_in--; + return *(stream->next_in)++; +} + +static int checkheader(z_stream *stream) { + int flags, c; + DWORD len; + + if (get_byte(stream) != 0x1f || get_byte(stream) != 0x8b) + return Z_DATA_ERROR; + if (get_byte(stream) != Z_DEFLATED || ((flags = get_byte(stream)) & 0xE0) != 0) + return Z_DATA_ERROR; + for (len = 0; len < 6; len++) (void)get_byte(stream); + + if ((flags & 0x04) != 0) { /* skip the extra field */ + len = (DWORD)get_byte(stream); + len += ((DWORD)get_byte(stream)) << 8; + /* len is garbage if EOF but the loop below will quit anyway */ + while (len-- != 0 && get_byte(stream) != EOF) ; + } + if ((flags & 0x08) != 0) { /* skip the original file name */ + while ((c = get_byte(stream)) != 0 && c != EOF) ; + } + if ((flags & 0x10) != 0) { /* skip the .gz file comment */ + while ((c = get_byte(stream)) != 0 && c != EOF) ; + } + if ((flags & 0x02) != 0) { /* skip the header crc */ + for (len = 0; len < 2; len++) (void)get_byte(stream); + } + return Z_OK; +} + +DWORD DLL_CALLCONV +FreeImage_ZLibGUnzip(BYTE *target, DWORD target_size, BYTE *source, DWORD source_size) { + DWORD src_len = source_size; + DWORD dest_len = target_size; + int zerr = Z_DATA_ERROR; + + if (src_len > 0) { + z_stream stream; + memset(&stream, 0, sizeof (stream)); + if ((zerr = inflateInit2(&stream, -MAX_WBITS)) == Z_OK) { + stream.next_in = source; + stream.avail_in = source_size; + + stream.next_out = target; + stream.avail_out = target_size; + + if ((zerr = checkheader(&stream)) == Z_OK) { + zerr = inflate (&stream, Z_NO_FLUSH); + dest_len = target_size - stream.avail_out; + + if (zerr == Z_OK || zerr == Z_STREAM_END) + inflateEnd(&stream); + } + } + } + if (zerr != Z_OK && zerr != Z_STREAM_END) { + FreeImage_OutputMessageProc(FIF_UNKNOWN, "Zlib error : %s", zError(zerr)); + return 0; + } + return dest_len; +} + +/** +Update a running crc from source and return the updated crc, using the ZLib library. +If source is NULL, this function returns the required initial value for the crc. + +@param crc Running crc value +@param source Source buffer +@param source_size Size of the source buffer, in bytes +@return Returns the new crc value +*/ +DWORD DLL_CALLCONV +FreeImage_ZLibCRC32(DWORD crc, BYTE *source, DWORD source_size) { + + return crc32(crc, source, source_size); +} |