Function FIO_analyzeFrames

freebsd/contrib/zstd/programs/fileio.c:2813–2901

}

static InfoError
FIO_analyzeFrames(fileInfo_t* info, FILE* const srcFile)
{
    /* begin analyzing frame */
    for ( ; ; ) {
        BYTE headerBuffer[ZSTD_FRAMEHEADERSIZE_MAX];
        size_t const numBytesRead = fread(headerBuffer, 1, sizeof(headerBuffer), srcFile);
        if (numBytesRead < ZSTD_FRAMEHEADERSIZE_MIN(ZSTD_f_zstd1)) {
            if ( feof(srcFile)
              && (numBytesRead == 0)
              && (info->compressedSize > 0)
              && (info->compressedSize != UTIL_FILESIZE_UNKNOWN) ) {
                unsigned long long file_position = (unsigned long long) LONG_TELL(srcFile);
                unsigned long long file_size = (unsigned long long) info->compressedSize;
                ERROR_IF(file_position != file_size, info_truncated_input,
                  "Error: seeked to position %llu, which is beyond file size of %llu\n",
                  file_position,
                  file_size);
                break;  /* correct end of file => success */
            }
            ERROR_IF(feof(srcFile), info_not_zstd, "Error: reached end of file with incomplete frame");
            ERROR_IF(1, info_frame_error, "Error: did not reach end of file but ran out of frames");
        }
        {   U32 const magicNumber = MEM_readLE32(headerBuffer);
            /* Zstandard frame */
            if (magicNumber == ZSTD_MAGICNUMBER) {
                ZSTD_frameHeader header;
                U64 const frameContentSize = ZSTD_getFrameContentSize(headerBuffer, numBytesRead);
                if ( frameContentSize == ZSTD_CONTENTSIZE_ERROR
                  || frameContentSize == ZSTD_CONTENTSIZE_UNKNOWN ) {
                    info->decompUnavailable = 1;
                } else {
                    info->decompressedSize += frameContentSize;
                }
                ERROR_IF(ZSTD_getFrameHeader(&header, headerBuffer, numBytesRead) != 0,
                        info_frame_error, "Error: could not decode frame header");
                info->windowSize = header.windowSize;
                /* move to the end of the frame header */
                {   size_t const headerSize = ZSTD_frameHeaderSize(headerBuffer, numBytesRead);
                    ERROR_IF(ZSTD_isError(headerSize), info_frame_error, "Error: could not determine frame header size");
                    ERROR_IF(fseek(srcFile, ((long)headerSize)-((long)numBytesRead), SEEK_CUR) != 0,
                            info_frame_error, "Error: could not move to end of frame header");
                }

                /* skip all blocks in the frame */
                {   int lastBlock = 0;
                    do {
                        BYTE blockHeaderBuffer[3];
                        ERROR_IF(fread(blockHeaderBuffer, 1, 3, srcFile) != 3,
                                info_frame_error, "Error while reading block header");
                        {   U32 const blockHeader = MEM_readLE24(blockHeaderBuffer);
                            U32 const blockTypeID = (blockHeader >> 1) & 3;
                            U32 const isRLE = (blockTypeID == 1);
                            U32 const isWrongBlock = (blockTypeID == 3);
                            long const blockSize = isRLE ? 1 : (long)(blockHeader >> 3);
                            ERROR_IF(isWrongBlock, info_frame_error, "Error: unsupported block type");
                            lastBlock = blockHeader & 1;
                            ERROR_IF(fseek(srcFile, blockSize, SEEK_CUR) != 0,