libdmg-hfsplus/hfs/extents.c

120 строки
3.1 KiB
C

#include <stdlib.h>
#include <string.h>
#include <hfs/hfsplus.h>
static inline void flipExtentDescriptor(HFSPlusExtentDescriptor* extentDescriptor) {
FLIPENDIAN(extentDescriptor->startBlock);
FLIPENDIAN(extentDescriptor->blockCount);
}
void flipExtentRecord(HFSPlusExtentRecord* extentRecord) {
HFSPlusExtentDescriptor *extentDescriptor;
extentDescriptor = (HFSPlusExtentDescriptor*)extentRecord;
flipExtentDescriptor(&extentDescriptor[0]);
flipExtentDescriptor(&extentDescriptor[1]);
flipExtentDescriptor(&extentDescriptor[2]);
flipExtentDescriptor(&extentDescriptor[3]);
flipExtentDescriptor(&extentDescriptor[4]);
flipExtentDescriptor(&extentDescriptor[5]);
flipExtentDescriptor(&extentDescriptor[6]);
flipExtentDescriptor(&extentDescriptor[7]);
}
static int extentCompare(BTKey* vLeft, BTKey* vRight) {
HFSPlusExtentKey* left;
HFSPlusExtentKey* right;
left = (HFSPlusExtentKey*) vLeft;
right =(HFSPlusExtentKey*) vRight;
if(left->forkType < right->forkType) {
return -1;
} else if(left->forkType > right->forkType) {
return 1;
} else {
if(left->fileID < right->fileID) {
return -1;
} else if(left->fileID > right->fileID) {
return 1;
} else {
if(left->startBlock < right->startBlock) {
return -1;
} else if(left->startBlock > right->startBlock) {
return 1;
} else {
/* do a safety check on key length. Otherwise, bad things may happen later on when we try to add or remove with this key */
if(left->keyLength == right->keyLength) {
return 0;
} else if(left->keyLength < right->keyLength) {
return -1;
} else {
return 1;
}
return 0;
}
}
}
}
static BTKey* extentKeyRead(off_t offset, io_func* io) {
HFSPlusExtentKey* key;
key = (HFSPlusExtentKey*) malloc(sizeof(HFSPlusExtentKey));
if(!READ(io, offset, sizeof(HFSPlusExtentKey), key))
return NULL;
FLIPENDIAN(key->keyLength);
FLIPENDIAN(key->forkType);
FLIPENDIAN(key->fileID);
FLIPENDIAN(key->startBlock);
return (BTKey*)key;
}
static int extentKeyWrite(off_t offset, BTKey* toWrite, io_func* io) {
HFSPlusExtentKey* key;
key = (HFSPlusExtentKey*) malloc(sizeof(HFSPlusExtentKey));
memcpy(key, toWrite, sizeof(HFSPlusExtentKey));
FLIPENDIAN(key->keyLength);
FLIPENDIAN(key->forkType);
FLIPENDIAN(key->fileID);
FLIPENDIAN(key->startBlock);
if(!WRITE(io, offset, sizeof(HFSPlusExtentKey), key))
return FALSE;
free(key);
return TRUE;
}
static void extentKeyPrint(BTKey* toPrint) {
HFSPlusExtentKey* key;
key = (HFSPlusExtentKey*)toPrint;
printf("extent%d:%d:%d", key->forkType, key->fileID, key->startBlock);
}
static BTKey* extentDataRead(off_t offset, io_func* io) {
HFSPlusExtentRecord* record;
record = (HFSPlusExtentRecord*) malloc(sizeof(HFSPlusExtentRecord));
if(!READ(io, offset, sizeof(HFSPlusExtentRecord), record))
return NULL;
flipExtentRecord(record);
return (BTKey*)record;
}
BTree* openExtentsTree(io_func* file) {
return openBTree(file, &extentCompare, &extentKeyRead, &extentKeyWrite, &extentKeyPrint, &extentDataRead);
}