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added in logic for parsing through blocks/frames

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This commit is contained in:
Paul Cruz
2017-06-12 15:22:48 -07:00
parent 786b7cac27
commit 9cb602ee25
1 changed files with 85 additions and 16 deletions
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programs/fileio.c
+79 -10
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@@ -870,6 +870,8 @@ typedef struct {
int usesCheck; int usesCheck;
} fileInfo_t; } fileInfo_t;
/* /*
* Reads information from file, stores in *info * Reads information from file, stores in *info
* if successful, returns 0, otherwise returns 1 * if successful, returns 0, otherwise returns 1
@@ -880,26 +882,93 @@ int getFileInfo(fileInfo_t* info, const char* inFileName){
return 1; return 1;
} }
info->compressedSize = UTIL_getFileSize(inFileName); info->compressedSize = UTIL_getFileSize(inFileName);
BYTE* frameHeaderBuffer = malloc(ZSTD_frameHeaderSize_max);
fread(frameHeaderBuffer, ZSTD_frameHeaderSize_max, 1, srcFile);
info->decompressedSize = 0; info->decompressedSize = 0;
info->numActualFrames = 0; info->numActualFrames = 0;
info-> numSkippableFrames = 0; info-> numSkippableFrames = 0;
/* begin analyzing frame */ /* begin analyzing frame */
while(1){
info->decompressedSize += ZSTD_getFrameContentSize((void*)frameHeaderBuffer, ZSTD_FRAMEHEADERSIZE_MAX); BYTE magicNumberBuffer[4];
U32 magicNumber = frameHeaderBuffer[0] + (frameHeaderBuffer[1] << 8) + (frameHeaderBuffer[2] << 16) + (frameHeaderBuffer[3] << 24); int numBytesRead = fread(magicNumberBuffer, 1, 4, srcFile);
if(numBytesRead != 4) break;
U32 magicNumber = MEM_readLE32(magicNumberBuffer);
if(magicNumber==ZSTD_MAGICNUMBER){ if(magicNumber==ZSTD_MAGICNUMBER){
DISPLAY("Hello\n");
int frameContentSizeBytes=0;
info->numActualFrames++; info->numActualFrames++;
BYTE frameHeaderDescriptor;
fread(&frameHeaderDescriptor, 1, 1, srcFile);
/* calculate actual frame header size */
int frameContentSizeFlag = frameHeaderDescriptor >> 6;
int singleSegmentFlag = (frameHeaderDescriptor & (1 << 5)) >> 5;
int contentChecksumFlag = (frameHeaderDescriptor & (1 << 2)) >> 2;
int dictionaryIDFlag = frameHeaderDescriptor & 3;
if(frameContentSizeFlag!=0){
frameContentSizeBytes = 1 << frameContentSizeFlag;
}
else if(singleSegmentFlag){
frameContentSizeBytes = 1;
}
int windowDescriptorBytes = singleSegmentFlag ? 0 : 1;
int dictionaryIDBytes = dictionaryIDFlag ? 1 << (dictionaryIDFlag - 1): 0;
int totalFrameHeaderBytes = 4 + 1 + windowDescriptorBytes + frameContentSizeBytes + dictionaryIDBytes;
/* reset to beginning of from and read entire header */
fseek(srcFile, -5, SEEK_CUR);
BYTE* frameHeader = malloc(totalFrameHeaderBytes);
fread(frameHeader, totalFrameHeaderBytes, 1, srcFile);
/* get decompressed file size */
info->decompressedSize = ZSTD_getFrameContentSize(frameHeader, totalFrameHeaderBytes);
/* check if checksum is used */
if(contentChecksumFlag){
info->usesCheck = 1;
}
/* skip the rest of the blocks in the frame */
int lastBlock = 0;
do{
BYTE blockHeaderBuffer[3];
fread(blockHeaderBuffer, 3, 1, srcFile);
U32 blockHeader = MEM_readLE24(blockHeaderBuffer);
lastBlock = blockHeader & 1;
int blockSize = (blockHeader - (blockHeader & 7)) >> 3;
fseek(srcFile, blockSize, SEEK_CUR);
}while(lastBlock != 1);
if(contentChecksumFlag){
fseek(srcFile, 4, SEEK_CUR);
}
} }
else if(magicNumber==ZSTD_MAGIC_SKIPPABLE_START){ else if(magicNumber==ZSTD_MAGIC_SKIPPABLE_START){
info->numSkippableFrames++; info->numSkippableFrames++;
BYTE frameSizeBuffer[4];
fread(frameSizeBuffer, 4, 1, srcFile);
long frameSize = MEM_readLE32(frameSizeBuffer);
fseek(srcFile, frameSize, SEEK_CUR);
} }
const int checksumBitMask = 4;
if(frameHeaderBuffer[1] & checksumBitMask){
DISPLAY("Uses checksum\n"); // int isSkippableFrame = 0;
info->usesCheck = 1; // /* analyze the first 18 bytes (magic number + frame header) of the frame */
// BYTE* frameHeaderBuffer = malloc(ZSTD_frameHeaderSize_max);
// fread(frameHeaderBuffer, ZSTD_frameHeaderSize_max, 1, srcFile);
// info->decompressedSize += ZSTD_getFrameContentSize((void*)frameHeaderBuffer, ZSTD_FRAMEHEADERSIZE_MAX);
// U32 magicNumber = frameHeaderBuffer[0] + (frameHeaderBuffer[1] << 8) + (frameHeaderBuffer[2] << 16) + (frameHeaderBuffer[3] << 24);
// if(magicNumber==ZSTD_MAGICNUMBER){
// info->numActualFrames++;
// }
// else if(magicNumber==ZSTD_MAGIC_SKIPPABLE_START){
// info->numSkippableFrames++;
// isSkippableFrame = 1;
// }
// const int checksumBitMask = 4;
// if(frameHeaderBuffer[1] & checksumBitMask){
// DISPLAY("Uses checksum\n");
// info->usesCheck = 1;
// }
} }
return 0; return 0;
} }