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pull/2/head
Dave Vasilevsky 15 years ago
parent 841c7bdd39
commit 9fb824505b
2 changed files with 121 additions and 26 deletions
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145
read.c
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@ -24,10 +24,15 @@ struct file_index_t {
};
typedef struct file_index_t file_index_t;
typedef struct {
lzma_block block;
lzma_filter filters[LZMA_FILTERS_MAX + 1];
} block_wrapper_t;
#pragma mark GLOBALS
FILE *gInFile = NULL, *gOutFile = NULL;
FILE *gInFile = NULL;
lzma_stream gStream = LZMA_STREAM_INIT;
lzma_check gCheck = LZMA_CHECK_NONE;
@ -47,6 +52,7 @@ size_t gMoved = 0;
void die(const char *fmt, ...);
void decode_index(void);
void *decode_block_start(off_t block_seek);
void dump_file_index(void);
void free_file_index(void);
@ -56,7 +62,8 @@ char *read_file_index_name(void);
void read_file_index_make_space(void);
void read_file_index_data(void);
void read_buf(void);
void extract_file(const char *target);
void extract_block(off_t block_seek, off_t skip, off_t size);
#pragma mark FUNCTION DEFINITIONS
@ -66,14 +73,15 @@ int main(int argc, char **argv) {
die("Need two arguments");
if (!(gInFile = fopen(argv[1], "r")))
die("Can't open input file");
if (!(gOutFile = fopen(argv[2], "w")))
die("Can't open output file");
char *target = argv[2];
decode_index();
read_file_index();
lzma_index_end(gIndex, NULL);
dump_file_index();
extract_file(target);
free_file_index();
lzma_index_end(gIndex, NULL);
return 0;
}
@ -121,30 +129,38 @@ void decode_index(void) {
}
}
void read_file_index(void) {
// find the last block
lzma_vli loc = lzma_index_uncompressed_size(gIndex) - 1;
lzma_index_record rec;
if (lzma_index_locate(gIndex, &rec, loc))
die("Can't locate file index block");
if (fseeko(gInFile, rec.stream_offset, SEEK_SET) == -1)
die("Error seeking to file index");
void *decode_block_start(off_t block_seek) {
if (fseeko(gInFile, block_seek, SEEK_SET) == -1)
die("Error seeking to block");
block_wrapper_t *bw = malloc(sizeof(block_wrapper_t));
bw->block = (lzma_block){ .check = gCheck, .filters = bw->filters };
lzma_filter filters[LZMA_FILTERS_MAX + 1];
lzma_block block = { .check = gCheck, .filters = filters };
int b = fgetc(gInFile);
if (b == EOF || b == 0)
die("Error reading file index block size");
block.header_size = lzma_block_header_size_decode(b);
uint8_t hdrbuf[block.header_size];
die("Error reading block size");
bw->block.header_size = lzma_block_header_size_decode(b);
uint8_t hdrbuf[bw->block.header_size];
hdrbuf[0] = (uint8_t)b;
if (fread(hdrbuf + 1, block.header_size - 1, 1, gInFile) != 1)
die("Error reading file index block header");
if (lzma_block_header_decode(&block, NULL, hdrbuf) != LZMA_OK)
if (fread(hdrbuf + 1, bw->block.header_size - 1, 1, gInFile) != 1)
die("Error reading block header");
if (lzma_block_header_decode(&bw->block, NULL, hdrbuf) != LZMA_OK)
die("Error decoding file index block header");
if (lzma_block_decoder(&gStream, &block) != LZMA_OK)
if (lzma_block_decoder(&gStream, &bw->block) != LZMA_OK)
die("Error initializing file index stream");
return bw;
}
void read_file_index(void) {
// find the last block
lzma_vli loc = lzma_index_uncompressed_size(gIndex) - 1;
lzma_index_record rec;
if (lzma_index_locate(gIndex, &rec, loc))
die("Can't locate file index block");
void *bdata = decode_block_start(rec.stream_offset);
gFileIndexBuf = malloc(gFIBSize);
gStream.avail_out = gFIBSize;
gStream.avail_in = 0;
@ -167,6 +183,7 @@ void read_file_index(void) {
}
free(gFileIndexBuf);
lzma_end(&gStream);
free(bdata);
}
char *read_file_index_name(void) {
@ -216,7 +233,7 @@ void read_file_index_data(void) {
gStream.next_in = gFIBInputBuf;
}
gFIBErr = lzma_code(&gStream, feof(gInFile) ? LZMA_FINISH : LZMA_RUN);
gFIBErr = lzma_code(&gStream, LZMA_RUN);
if (gFIBErr != LZMA_OK && gFIBErr != LZMA_STREAM_END)
die("Error decoding file index data");
}
@ -224,7 +241,7 @@ void read_file_index_data(void) {
void dump_file_index(void) {
for (file_index_t *f = gFileIndex; f != NULL; f = f->next) {
printf("%s\n", f->name ? f->name : "");
printf("%10llx %s\n", f->offset, f->name ? f->name : "");
}
}
@ -237,3 +254,81 @@ void free_file_index(void) {
}
gFileIndex = gLastFile = NULL;
}
void extract_file(const char *target) {
// find it in the index
file_index_t *f;
for (f = gFileIndex; f != NULL; f = f->next) {
if (f->name && strcmp(f->name, target) == 0)
break;
}
if (!f)
die("Can't find target file");
off_t fstart = f->offset, fsize = f->next->offset - fstart;
// extract the data
lzma_index_record rec;
lzma_index_rewind(gIndex);
while (fsize && !lzma_index_read(gIndex, &rec)) {
off_t bstart = rec.uncompressed_offset,
bsize = rec.uncompressed_size;
if (fstart > bstart + bsize)
continue;
off_t dstart = fstart > bstart ? fstart - bstart : 0;
bsize -= dstart;
off_t dsize = fsize > bsize ? bsize : fsize;
fsize -= dsize;
extract_block(rec.stream_offset, dstart, dsize);
}
if (fsize)
die("Block with file contents missing");
}
void extract_block(off_t block_seek, off_t skip, off_t size) {
void *bdata = decode_block_start(block_seek);
uint8_t ibuf[CHUNKSIZE], obuf[CHUNKSIZE];
gStream.avail_in = 0;
lzma_ret err = LZMA_OK;
while (size && err != LZMA_STREAM_END) {
gStream.next_out = obuf;
gStream.avail_out = CHUNKSIZE;
if (gStream.avail_in == 0) {
gStream.avail_in = fread(ibuf, 1, CHUNKSIZE, gInFile);
if (ferror(gInFile))
die("Error reading block data");
gStream.next_in = ibuf;
}
err = lzma_code(&gStream, LZMA_RUN);
if (err != LZMA_OK && err != LZMA_STREAM_END)
die("Error decoding block");
// do we want to write?
uint8_t *start = obuf;
size_t out = gStream.next_out - obuf;
if (out <= skip) {
skip -= out;
continue;
}
// what do we want to write?
start += skip;
out -= skip;
skip = 0;
if (out > size)
out = size;
if (fwrite(start, out, 1, stdout) != 1)
die("Error writing output");
size -= out;
}
if (size)
die("Block data missing");
lzma_end(&gStream);
free(bdata);
}

2
write.c
Unescape Escape View File

@ -274,7 +274,7 @@ void add_file(off_t offset, const char *name) {
void dump_file_index(void) {
for (file_index_t *f = gFileIndex; f != NULL; f = f->next) {
printf("%s\n", f->name ? f->name : "");
printf("%10llx %s\n", f->offset, f->name ? f->name : "");
}
}

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