void *decode_block_start(off_t block_seek) {
if (fseeko(gInFile, block_seek, SEEK_SET) == -1)
die("Error seeking to block");
// Some memory in which to keep the discovered filters safe
block_wrapper_t *bw = malloc(sizeof(block_wrapper_t));
bw->block = (lzma_block){ .check = gCheck, .filters = bw->filters,
.version = 0 };
int b = fgetc(gInFile);
if (b == EOF || b == 0)
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, 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, &bw->block) != LZMA_OK)
die("Error initializing file index stream");
return bw;
}
bool is_multi_header(const char *name) {
size_t i = strlen(name);
while (i != 0 && name[i - 1] != '/')
--i;
return strncmp(name + i, "._", 2) == 0;
}
bool loadBlock(std::string &error) {
clearFilters();
position = -1;
//LOG_VERBOSE("seeking to offset %i", (int) iter->block.compressed_file_offset);
reader.seek(iter.block.compressed_file_offset);
strm.avail_in = 0; /* make sure we read new data after lseek */
if (!fill_input_buffer(error)) return false;
if (0 == strm.avail_in) {
error.assign("Unexpected end of file while trying to read block header");
return false;
}
block.version = 0;
block.check = iter.stream.flags->check;
block.header_size = lzma_block_header_size_decode(strm.next_in[0]);
if (block.header_size > strm.avail_in) {
error.assign("Unexpected end of file while trying to read block header");
return false;
}
// Decode the Block Header.
lzma_ret ret = lzma_block_header_decode(&block, NULL, strm.next_in);
if (LZMA_OK != ret) {
errnoLzmaToStr("decoding block header failed", ret, error);
return false;
}
ret = lzma_block_compressed_size(&block, iter.block.unpadded_size);
if (LZMA_OK != ret) {
errnoLzmaToStr("decoding block header failed, invalid compressed size", ret, error);
return false;
}
strm.next_in += block.header_size;
strm.avail_in -= block.header_size;
lzma_end(&strm);
ret = lzma_block_decoder(&strm, &block);
if (LZMA_OK != ret) {
errnoLzmaToStr("couldn't initialize block decoder", ret, error);
return false;
}
position = iter.block.uncompressed_file_offset;
return true;
}
static void decode_thread(size_t thnum) {
lzma_stream stream = LZMA_STREAM_INIT;
lzma_filter filters[LZMA_FILTERS_MAX + 1];
lzma_block block = { .filters = filters, .check = gCheck, .version = 0 };
pipeline_item_t *pi;
io_block_t *ib;
while (PIPELINE_STOP != queue_pop(gPipelineSplitQ, (void**)&pi)) {
ib = (io_block_t*)(pi->data);
block.header_size = lzma_block_header_size_decode(*(ib->input));
if (lzma_block_header_decode(&block, NULL, ib->input) != LZMA_OK)
die("Error decoding block header");
if (lzma_block_decoder(&stream, &block) != LZMA_OK)
die("Error initializing block decode");
stream.avail_in = ib->insize - block.header_size;
stream.next_in = ib->input + block.header_size;
stream.avail_out = gBlockOutSize;
stream.next_out = ib->output;
lzma_ret err = LZMA_OK;
while (err != LZMA_STREAM_END) {
if (err != LZMA_OK)
die("Error decoding block");
err = lzma_code(&stream, LZMA_FINISH);
}
ib->outsize = stream.next_out - ib->output;
queue_push(gPipelineMergeQ, PIPELINE_ITEM, pi);
}
lzma_end(&stream);
}
#pragma mark ARCHIVE
static int tar_ok(struct archive *ar, void *ref) {
return ARCHIVE_OK;
}
static bool tar_next_block(void) {
if (gArItem && !gArNextItem && gArWanted) {
io_block_t *ib = (io_block_t*)(gArItem->data);
if (gArWanted->start < ib->uoffset + ib->outsize)
return true; // No need
}
if (gArLastItem)
queue_push(gPipelineStartQ, PIPELINE_ITEM, gArLastItem);
gArLastItem = gArItem;
gArItem = pipeline_merged();
gArNextItem = false;
return gArItem;
}
static void tar_write_last(void) {
if (gArItem) {
io_block_t *ib = (io_block_t*)(gArItem->data);
fwrite(ib->output + gArLastOffset, gArLastSize, 1, gOutFile);
gArLastSize = 0;
}
}
static ssize_t tar_read(struct archive *ar, void *ref, const void **bufp) {
// If we got here, the last bit of archive is ok to write
tar_write_last();
// Write the first wanted file
if (!tar_next_block())
return 0;
off_t off;
size_t size;
io_block_t *ib = (io_block_t*)(gArItem->data);
if (gWantedFiles) {
debug("tar want: %s", gArWanted->name);
off = gArWanted->start - ib->uoffset;
size = gArWanted->size;
if (off < 0) {
size += off;
off = 0;
}
if (off + size > ib->outsize) {
size = ib->outsize - off;
gArNextItem = true; // force the end of this block
} else {
gArWanted = gArWanted->next;
}
} else {
off = 0;
size = ib->outsize;
}
debug("tar off = %llu, size = %zu", (unsigned long long)off, size);
gArLastOffset = off;
gArLastSize = size;
if (bufp)
*bufp = ib->output + off;
return size;
}
static bool read_block(bool force_stream, lzma_check check, off_t uoffset) {
lzma_filter filters[LZMA_FILTERS_MAX + 1];
lzma_block block = { .filters = filters, .check = check, .version = 0 };
if (rbuf_read(1) != RBUF_FULL)
die("Error reading block header size");
if (gRbuf->input[0] == 0)
return false;
block.header_size = lzma_block_header_size_decode(gRbuf->input[0]);
if (block.header_size > LZMA_BLOCK_HEADER_SIZE_MAX)
die("Block header size too large");
if (rbuf_read(block.header_size) != RBUF_FULL)
die("Error reading block header");
if (lzma_block_header_decode(&block, NULL, gRbuf->input) != LZMA_OK)
die("Error decoding block header");
size_t comp = block.compressed_size, outsize = block.uncompressed_size;
bool sized = (comp != LZMA_VLI_UNKNOWN && outsize != LZMA_VLI_UNKNOWN);
if (force_stream || !sized || outsize > MAXSPLITSIZE) {
read_streaming(&block, sized ? BLOCK_SIZED : BLOCK_UNSIZED, uoffset);
} else {
block_capacity(gRbuf, 0, outsize);
gRbuf->outsize = outsize;
gRbuf->check = check;
gRbuf->btype = BLOCK_SIZED;
if (rbuf_read(lzma_block_total_size(&block)) != RBUF_FULL)
die("Error reading block contents");
rbuf_dispatch();
}
return true;
}
static void read_streaming(lzma_block *block, block_type sized, off_t uoffset) {
lzma_stream stream = LZMA_STREAM_INIT;
if (lzma_block_decoder(&stream, block) != LZMA_OK)
die("Error initializing streaming block decode");
rbuf_cycle(&stream, true, block->header_size);
stream.avail_out = 0;
bool first = true;
pipeline_item_t *pi = NULL;
io_block_t *ib = NULL;
lzma_ret err = LZMA_OK;
while (err != LZMA_STREAM_END) {
if (err != LZMA_OK)
die("Error decoding streaming block");
if (stream.avail_out == 0) {
if (ib) {
ib->outsize = ib->outcap;
ib->uoffset = uoffset;
uoffset += ib->outsize;
pipeline_dispatch(pi, gPipelineMergeQ);
first = false;
}
queue_pop(gPipelineStartQ, (void**)&pi);
ib = (io_block_t*)pi->data;
ib->btype = (first ? sized : BLOCK_CONTINUATION);
block_capacity(ib, 0, STREAMSIZE);
stream.next_out = ib->output;
stream.avail_out = ib->outcap;
}
if (stream.avail_in == 0 && !rbuf_cycle(&stream, false, 0))
die("Error reading streaming block");
err = lzma_code(&stream, LZMA_RUN);
}
if (ib && stream.avail_out != ib->outcap) {
ib->outsize = ib->outcap - stream.avail_out;
pipeline_dispatch(pi, gPipelineMergeQ);
}
rbuf_consume(gRbuf->insize - stream.avail_in);
lzma_end(&stream);
}