bool seekBlockFor(int64_t offset, std::string &error) {
bool matchingBlock =
(position >= 0
&& offset >= (int64_t)iter.block.uncompressed_file_offset
&& offset < (int64_t)(iter.block.uncompressed_file_offset + iter.block.uncompressed_size));
if (matchingBlock && position <= offset) {
/* we already are in the needed block, and still before the requested data; just continue from here */
LOG_VERBOSE("continue reading for offset %i (current position: %i)\n", (int) offset, (int) position);
} else {
if (matchingBlock) {
/* already passed the index we wanted, but same block */
LOG_VERBOSE("restarting block: %i (current position: %i)\n", (int) offset, (int) position);
} else {
LOG_VERBOSE("searching for offset: %i (current position: %i)\n", (int) offset, (int) position);
position = -1;
if (lzma_index_iter_locate(&iter, offset)) {
error.assign("couldn't find offset in index");
return false;
}
// LOG_VERBOSE("seeking to new block\n");
}
discard_output();
/* restart decoder */
if (!loadBlock(error)) return false;
}
return true;
}
lzma_vli find_file_index(void **bdatap) {
if (!gIndex)
decode_index();
// find the last block
lzma_index_iter iter;
lzma_index_iter_init(&iter, gIndex);
lzma_vli loc = lzma_index_uncompressed_size(gIndex) - 1;
if (lzma_index_iter_locate(&iter, loc))
die("Can't locate file index block");
void *bdata = decode_block_start(iter.block.compressed_file_offset);
gFileIndexBuf = malloc(gFIBSize);
gStream.avail_out = gFIBSize;
gStream.avail_in = 0;
// Check if this is really an index
read_file_index_data();
lzma_vli ret = iter.block.compressed_file_offset;
if (xle64dec(gFileIndexBuf + gFIBPos) != PIXZ_INDEX_MAGIC)
ret = 0;
gFIBPos += sizeof(uint64_t);
if (bdatap && ret) {
*bdatap = bdata;
} else {
// Just looking, don't keep things around
if (bdatap)
*bdatap = NULL;
free(bdata);
free(gFileIndexBuf);
gLastFile = gFileIndex = NULL;
lzma_end(&gStream);
}
return ret;
}
static file_ptr
lzma_pread (struct bfd *nbfd, void *stream, void *buf, file_ptr nbytes,
file_ptr offset)
{
struct lzma_stream *lstream = stream;
bfd_size_type chunk_size;
lzma_index_iter iter;
gdb_byte *compressed, *uncompressed;
file_ptr block_offset;
lzma_filter filters[LZMA_FILTERS_MAX + 1];
lzma_block block;
size_t compressed_pos, uncompressed_pos;
file_ptr res;
res = 0;
while (nbytes > 0)
{
if (lstream->data == NULL
|| lstream->data_start > offset || offset >= lstream->data_end)
{
asection *section = lstream->section;
lzma_index_iter_init (&iter, lstream->index);
if (lzma_index_iter_locate (&iter, offset))
break;
compressed = xmalloc (iter.block.total_size);
block_offset = section->filepos + iter.block.compressed_file_offset;
if (bfd_seek (section->owner, block_offset, SEEK_SET) != 0
|| bfd_bread (compressed, iter.block.total_size, section->owner)
!= iter.block.total_size)
{
xfree (compressed);
break;
}
uncompressed = xmalloc (iter.block.uncompressed_size);
memset (&block, 0, sizeof (block));
block.filters = filters;
block.header_size = lzma_block_header_size_decode (compressed[0]);
if (lzma_block_header_decode (&block, &gdb_lzma_allocator, compressed)
!= LZMA_OK)
{
xfree (compressed);
xfree (uncompressed);
break;
}
compressed_pos = block.header_size;
uncompressed_pos = 0;
if (lzma_block_buffer_decode (&block, &gdb_lzma_allocator,
compressed, &compressed_pos,
iter.block.total_size,
uncompressed, &uncompressed_pos,
iter.block.uncompressed_size)
!= LZMA_OK)
{
xfree (compressed);
xfree (uncompressed);
break;
}
xfree (compressed);
xfree (lstream->data);
lstream->data = uncompressed;
lstream->data_start = iter.block.uncompressed_file_offset;
lstream->data_end = (iter.block.uncompressed_file_offset
+ iter.block.uncompressed_size);
}
chunk_size = min (nbytes, lstream->data_end - offset);
memcpy (buf, lstream->data + offset - lstream->data_start, chunk_size);
buf = (gdb_byte *) buf + chunk_size;
offset += chunk_size;
nbytes -= chunk_size;
res += chunk_size;
}
return res;
}
static void
test_locate(void)
{
lzma_index *i = lzma_index_init(NULL);
expect(i != NULL);
lzma_index_iter r;
lzma_index_iter_init(&r, i);
// Cannot locate anything from an empty Index.
expect(lzma_index_iter_locate(&r, 0));
expect(lzma_index_iter_locate(&r, 555));
// One empty Record: nothing is found since there's no uncompressed
// data.
expect(lzma_index_append(i, NULL, 16, 0) == LZMA_OK);
expect(lzma_index_iter_locate(&r, 0));
// Non-empty Record and we can find something.
expect(lzma_index_append(i, NULL, 32, 5) == LZMA_OK);
expect(!lzma_index_iter_locate(&r, 0));
expect(r.block.total_size == 32);
expect(r.block.uncompressed_size == 5);
expect(r.block.compressed_file_offset
== LZMA_STREAM_HEADER_SIZE + 16);
expect(r.block.uncompressed_file_offset == 0);
// Still cannot find anything past the end.
expect(lzma_index_iter_locate(&r, 5));
// Add the third Record.
expect(lzma_index_append(i, NULL, 40, 11) == LZMA_OK);
expect(!lzma_index_iter_locate(&r, 0));
expect(r.block.total_size == 32);
expect(r.block.uncompressed_size == 5);
expect(r.block.compressed_file_offset
== LZMA_STREAM_HEADER_SIZE + 16);
expect(r.block.uncompressed_file_offset == 0);
expect(!lzma_index_iter_next(&r, LZMA_INDEX_ITER_BLOCK));
expect(r.block.total_size == 40);
expect(r.block.uncompressed_size == 11);
expect(r.block.compressed_file_offset
== LZMA_STREAM_HEADER_SIZE + 16 + 32);
expect(r.block.uncompressed_file_offset == 5);
expect(!lzma_index_iter_locate(&r, 2));
expect(r.block.total_size == 32);
expect(r.block.uncompressed_size == 5);
expect(r.block.compressed_file_offset
== LZMA_STREAM_HEADER_SIZE + 16);
expect(r.block.uncompressed_file_offset == 0);
expect(!lzma_index_iter_locate(&r, 5));
expect(r.block.total_size == 40);
expect(r.block.uncompressed_size == 11);
expect(r.block.compressed_file_offset
== LZMA_STREAM_HEADER_SIZE + 16 + 32);
expect(r.block.uncompressed_file_offset == 5);
expect(!lzma_index_iter_locate(&r, 5 + 11 - 1));
expect(r.block.total_size == 40);
expect(r.block.uncompressed_size == 11);
expect(r.block.compressed_file_offset
== LZMA_STREAM_HEADER_SIZE + 16 + 32);
expect(r.block.uncompressed_file_offset == 5);
expect(lzma_index_iter_locate(&r, 5 + 11));
expect(lzma_index_iter_locate(&r, 5 + 15));
// Large Index
lzma_index_end(i, NULL);
i = lzma_index_init(NULL);
expect(i != NULL);
lzma_index_iter_init(&r, i);
for (size_t n = 4; n <= 4 * 5555; n += 4)
expect(lzma_index_append(i, NULL, n + 8, n) == LZMA_OK);
expect(lzma_index_block_count(i) == 5555);
// First Record
expect(!lzma_index_iter_locate(&r, 0));
expect(r.block.total_size == 4 + 8);
expect(r.block.uncompressed_size == 4);
expect(r.block.compressed_file_offset == LZMA_STREAM_HEADER_SIZE);
expect(r.block.uncompressed_file_offset == 0);
expect(!lzma_index_iter_locate(&r, 3));
expect(r.block.total_size == 4 + 8);
expect(r.block.uncompressed_size == 4);
expect(r.block.compressed_file_offset == LZMA_STREAM_HEADER_SIZE);
expect(r.block.uncompressed_file_offset == 0);
// Second Record
expect(!lzma_index_iter_locate(&r, 4));
expect(r.block.total_size == 2 * 4 + 8);
expect(r.block.uncompressed_size == 2 * 4);
expect(r.block.compressed_file_offset
== LZMA_STREAM_HEADER_SIZE + 4 + 8);
expect(r.block.uncompressed_file_offset == 4);
// Last Record
expect(!lzma_index_iter_locate(
&r, lzma_index_uncompressed_size(i) - 1));
expect(r.block.total_size == 4 * 5555 + 8);
expect(r.block.uncompressed_size == 4 * 5555);
expect(r.block.compressed_file_offset == lzma_index_total_size(i)
+ LZMA_STREAM_HEADER_SIZE - 4 * 5555 - 8);
expect(r.block.uncompressed_file_offset
== lzma_index_uncompressed_size(i) - 4 * 5555);
// Allocation chunk boundaries. See INDEX_GROUP_SIZE in
// liblzma/common/index.c.
const size_t group_multiple = 256 * 4;
const size_t radius = 8;
const size_t start = group_multiple - radius;
lzma_vli ubase = 0;
lzma_vli tbase = 0;
size_t n;
for (n = 1; n < start; ++n) {
ubase += n * 4;
tbase += n * 4 + 8;
}
while (n < start + 2 * radius) {
expect(!lzma_index_iter_locate(&r, ubase + n * 4));
expect(r.block.compressed_file_offset == tbase + n * 4 + 8
+ LZMA_STREAM_HEADER_SIZE);
expect(r.block.uncompressed_file_offset == ubase + n * 4);
tbase += n * 4 + 8;
ubase += n * 4;
++n;
expect(r.block.total_size == n * 4 + 8);
expect(r.block.uncompressed_size == n * 4);
}
// Do it also backwards.
while (n > start) {
expect(!lzma_index_iter_locate(&r, ubase + (n - 1) * 4));
expect(r.block.total_size == n * 4 + 8);
expect(r.block.uncompressed_size == n * 4);
--n;
tbase -= n * 4 + 8;
ubase -= n * 4;
expect(r.block.compressed_file_offset == tbase + n * 4 + 8
+ LZMA_STREAM_HEADER_SIZE);
expect(r.block.uncompressed_file_offset == ubase + n * 4);
}
// Test locating in concatenated Index.
lzma_index_end(i, NULL);
i = lzma_index_init(NULL);
expect(i != NULL);
lzma_index_iter_init(&r, i);
for (n = 0; n < group_multiple; ++n)
expect(lzma_index_append(i, NULL, 8, 0) == LZMA_OK);
expect(lzma_index_append(i, NULL, 16, 1) == LZMA_OK);
expect(!lzma_index_iter_locate(&r, 0));
expect(r.block.total_size == 16);
expect(r.block.uncompressed_size == 1);
expect(r.block.compressed_file_offset
== LZMA_STREAM_HEADER_SIZE + group_multiple * 8);
expect(r.block.uncompressed_file_offset == 0);
lzma_index_end(i, NULL);
}
