long HFSGetFileBlock(CICell ih, char *filePath, u_int64_t *firstBlock)
{
char entry[512];
long result, flags;
u_int32_t dirID;
void *extents;
HFSCatalogFile *hfsFile = (void *)entry;
HFSPlusCatalogFile *hfsPlusFile = (void *)entry;
if (HFSInitPartition(ih) == -1)
{
return -1;
}
dirID = kHFSRootFolderID;
// Skip a lead '/'. Start in the system folder if there are two.
if (filePath[0] == '/')
{
if (filePath[1] == '/')
{
if (gIsHFSPlus)
{
dirID = SWAP_BE32(((long *) gHFSPlus->finderInfo)[5]);
}
else
{
dirID = SWAP_BE32(gHFSMDB->drFndrInfo[5]);
}
if (dirID == 0)
{
return -1;
}
filePath++;
}
filePath++;
}
result = ResolvePathToCatalogEntry(filePath, &flags, entry, dirID, 0);
if ((result == -1) || ((flags & kFileTypeMask) != kFileTypeFlat))
{
printf("HFS: Resolve path %s failed\n", filePath);
return -1;
}
if (gIsHFSPlus) {
extents = &hfsPlusFile->dataFork.extents;
} else {
extents = &hfsFile->dataExtents;
}
#if DEBUG
printf("extent start 0x%x\n", GetExtentStart(extents, 0));
printf("block size 0x%x\n", gBlockSize);
printf("Allocation offset 0x%x\n", (unsigned long)gAllocationOffset);
#endif
*firstBlock = ((u_int64_t) GetExtentStart(extents, 0) * (u_int64_t) gBlockSize + gAllocationOffset) / 512ULL;
return 0;
}
static long ReadExtent(char * extent, long extentSize,
long extentFile, long offset, long size,
void * buffer, long cache)
{
long lastOffset, blockNumber, countedBlocks = 0;
long nextExtent = 0, sizeRead = 0, readSize;
long nextExtentBlock, currentExtentBlock = 0;
long long readOffset;
long extentDensity, sizeofExtent, currentExtentSize;
char *currentExtent, *extentBuffer = 0, *bufferPos = buffer;
if (offset >= extentSize) return 0;
if (gIsHFSPlus) {
extentDensity = kHFSPlusExtentDensity;
sizeofExtent = sizeof(HFSPlusExtentDescriptor);
} else {
extentDensity = kHFSExtentDensity;
sizeofExtent = sizeof(HFSExtentDescriptor);
}
lastOffset = offset + size;
while (offset < lastOffset) {
blockNumber = offset / gBlockSize;
// Find the extent for the offset.
for (; ; nextExtent++) {
if (nextExtent < extentDensity) {
if ((countedBlocks+GetExtentSize(extent, nextExtent)-1)<blockNumber) {
countedBlocks += GetExtentSize(extent, nextExtent);
continue;
}
currentExtent = extent + nextExtent * sizeofExtent;
break;
}
if (extentBuffer == 0) {
extentBuffer = malloc(sizeofExtent * extentDensity);
if (extentBuffer == 0) return -1;
}
nextExtentBlock = nextExtent / extentDensity;
if (currentExtentBlock != nextExtentBlock) {
ReadExtentsEntry(extentFile, countedBlocks, extentBuffer);
currentExtentBlock = nextExtentBlock;
}
currentExtentSize = GetExtentSize(extentBuffer, nextExtent % extentDensity);
if ((countedBlocks + currentExtentSize - 1) >= blockNumber) {
currentExtent = extentBuffer + sizeofExtent * (nextExtent % extentDensity);
break;
}
countedBlocks += currentExtentSize;
}
readOffset = ((blockNumber - countedBlocks) * gBlockSize) +
(offset % gBlockSize);
readSize = GetExtentSize(currentExtent, 0) * gBlockSize - readOffset;
if (readSize > (size - sizeRead)) readSize = size - sizeRead;
readOffset += (long long)GetExtentStart(currentExtent, 0) * gBlockSize;
CacheRead(gCurrentIH, bufferPos, gAllocationOffset + readOffset,
readSize, cache);
sizeRead += readSize;
offset += readSize;
bufferPos += readSize;
}
if (extentBuffer) free(extentBuffer);
return sizeRead;
}
