add bonus data feature to imgdiff/imgpatch/applypatch
The bonus data option lets you give an additional blob of uncompressed
data to be used when constructing a patch for chunk #1 of an image.
The same blob must be available at patch time, and can be passed to
the command-line applypatch tool (this feature is not accessible from
edify scripts).
This will be used to reduce the size of recovery-from-boot patches by
storing parts of the recovery ramdisk (the UI images) on the system
partition.
Change-Id: Iac1959cdf7f5e4582f8d434e83456e483b64c02c
diff --git a/applypatch/imgpatch.c b/applypatch/imgpatch.c
index e3ee80a..3a1df38 100644
--- a/applypatch/imgpatch.c
+++ b/applypatch/imgpatch.c
@@ -37,7 +37,8 @@
*/
int ApplyImagePatch(const unsigned char* old_data, ssize_t old_size,
const Value* patch,
- SinkFn sink, void* token, SHA_CTX* ctx) {
+ SinkFn sink, void* token, SHA_CTX* ctx,
+ const Value* bonus_data) {
ssize_t pos = 12;
char* header = patch->data;
if (patch->size < 12) {
@@ -123,6 +124,12 @@
// Decompress the source data; the chunk header tells us exactly
// how big we expect it to be when decompressed.
+ // Note: expanded_len will include the bonus data size if
+ // the patch was constructed with bonus data. The
+ // deflation will come up 'bonus_size' bytes short; these
+ // must be appended from the bonus_data value.
+ size_t bonus_size = (i == 1 && bonus_data != NULL) ? bonus_data->size : 0;
+
unsigned char* expanded_source = malloc(expanded_len);
if (expanded_source == NULL) {
printf("failed to allocate %d bytes for expanded_source\n",
@@ -153,13 +160,19 @@
printf("source inflation returned %d\n", ret);
return -1;
}
- // We should have filled the output buffer exactly.
- if (strm.avail_out != 0) {
- printf("source inflation short by %d bytes\n", strm.avail_out);
+ // We should have filled the output buffer exactly, except
+ // for the bonus_size.
+ if (strm.avail_out != bonus_size) {
+ printf("source inflation short by %d bytes\n", strm.avail_out-bonus_size);
return -1;
}
inflateEnd(&strm);
+ if (bonus_size) {
+ memcpy(expanded_source + (expanded_len - bonus_size),
+ bonus_data->data, bonus_size);
+ }
+
// Next, apply the bsdiff patch (in memory) to the uncompressed
// data.
unsigned char* uncompressed_target_data;