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authorDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2021-01-16 00:23:20 +0100
committerDavid Oberhollenzer <david.oberhollenzer@sigma-star.at>2021-01-19 06:01:51 +0100
commit8026849fda277f54a2a3e4fa5cf5d183cbc84bef (patch)
treef000e36ec9caab771888ad03338094a92e2e958b /lib/sqfs/block_processor/common.c
parentc1a5ea0d4dceeb9354ff792fc510caa854223463 (diff)
libsqfs: Implement exact matching of fragments
Signed-off-by: David Oberhollenzer <david.oberhollenzer@sigma-star.at>
Diffstat (limited to 'lib/sqfs/block_processor/common.c')
-rw-r--r--lib/sqfs/block_processor/common.c86
1 files changed, 80 insertions, 6 deletions
diff --git a/lib/sqfs/block_processor/common.c b/lib/sqfs/block_processor/common.c
index 97cb790..d6c0889 100644
--- a/lib/sqfs/block_processor/common.c
+++ b/lib/sqfs/block_processor/common.c
@@ -176,8 +176,11 @@ static int process_completed_fragment(sqfs_block_processor_t *proc,
search.hash = frag->checksum;
search.size = frag->size;
+ proc->frag_cmp_current = frag;
entry = hash_table_search_pre_hashed(proc->frag_ht,
search.hash, &search);
+ proc->frag_cmp_current = NULL;
+
if (entry != NULL) {
if (frag->inode != NULL) {
chunk = entry->data;
@@ -238,8 +241,11 @@ static int process_completed_fragment(sqfs_block_processor_t *proc,
chunk->size = frag->size;
chunk->hash = frag->checksum;
+ proc->frag_cmp_current = frag;
entry = hash_table_insert_pre_hashed(proc->frag_ht, chunk->hash,
chunk, chunk);
+ proc->frag_cmp_current = NULL;
+
if (entry == NULL) {
free(chunk);
goto fail_outblk;
@@ -268,12 +274,69 @@ static uint32_t chunk_info_hash(void *user, const void *key)
return chunk->hash;
}
-static bool chunk_info_equals(void *user, const void *a, const void *b)
+static bool chunk_info_equals(void *user, const void *k, const void *c)
{
- const chunk_info_t *a_ = a, *b_ = b;
- (void)user;
- return a_->size == b_->size &&
- a_->hash == b_->hash;
+ const chunk_info_t *key = k, *cmp = c;
+ sqfs_block_processor_t *proc = user;
+ sqfs_fragment_t frag;
+ unsigned char *temp;
+ size_t size;
+ int ret;
+
+ if (key->size != cmp->size || key->hash != cmp->hash)
+ return false;
+
+ if (proc->file == NULL || proc->uncmp == NULL)
+ return true;
+
+ ret = proc->compare_frag_in_flight(proc, proc->frag_cmp_current,
+ cmp->index, cmp->offset);
+ if (ret == 0)
+ return true;
+
+ if (proc->buffered_index != cmp->index ||
+ proc->buffered_blk_size == 0) {
+ if (sqfs_frag_table_lookup(proc->frag_tbl, cmp->index, &frag))
+ return false;
+
+ proc->buffered_index = 0xFFFFFFFF;
+ size = SQFS_ON_DISK_BLOCK_SIZE(frag.size);
+
+ if (SQFS_IS_BLOCK_COMPRESSED(frag.size)) {
+ temp = proc->frag_buffer + proc->max_block_size;
+
+ ret = proc->file->read_at(proc->file, frag.start_offset,
+ temp, size);
+ if (ret != 0)
+ return false;
+
+ ret = proc->uncmp->do_block(proc->uncmp, temp, size,
+ proc->frag_buffer,
+ proc->max_block_size);
+ if (ret <= 0)
+ return false;
+
+ size = ret;
+ } else {
+ ret = proc->file->read_at(proc->file, frag.start_offset,
+ proc->frag_buffer, size);
+ if (ret != 0)
+ return false;
+ }
+
+ proc->buffered_index = cmp->index;
+ proc->buffered_blk_size = size;
+ }
+
+ if (cmp->offset >= proc->buffered_blk_size)
+ return false;
+
+ if (cmp->size > (proc->buffered_blk_size - cmp->offset))
+ return false;
+
+ return memcmp(proc->frag_buffer + cmp->offset,
+ proc->frag_cmp_current->data,
+ cmp->size) == 0;
}
static void ht_delete_function(struct hash_entry *entry)
@@ -289,6 +352,7 @@ void block_processor_cleanup(sqfs_block_processor_t *base)
release_old_block(base, base->frag_block);
free(base->blk_current);
+ free(base->frag_buffer);
while (base->free_list != NULL) {
it = base->free_list;
@@ -311,12 +375,22 @@ int block_processor_init(sqfs_block_processor_t *base,
base->wr = desc->wr;
base->file = desc->file;
base->uncmp = desc->uncmp;
+ base->buffered_index = 0xFFFFFFFF;
base->stats.size = sizeof(base->stats);
+ if (desc->file != NULL && desc->uncmp != NULL && desc->tbl != NULL) {
+ base->frag_buffer = malloc(2 * desc->max_block_size);
+ if (base->frag_buffer == NULL)
+ return SQFS_ERROR_ALLOC;
+ }
+
base->frag_ht = hash_table_create(chunk_info_hash, chunk_info_equals);
- if (base->frag_ht == NULL)
+ if (base->frag_ht == NULL) {
+ free(base->frag_buffer);
return SQFS_ERROR_ALLOC;
+ }
+ base->frag_ht->user = base;
return 0;
}