AU: Really delta compress the kernel if an old kernel is provided.
Before this change, we always sent the full kernel (bzipped). Now,
if an old kernel is provided, we select the cheapest way to send
the kernel. If a full kernel update is really needed, the user
has the option of not providing an old kernel.
BUG=7705
TEST=unit tests, emerged on the device
Change-Id: I8dbfbfdf690fcbb50d5e6b5db52d994e448d5d25
Review URL: http://codereview.chromium.org/3767002
diff --git a/delta_diff_generator.cc b/delta_diff_generator.cc
index f024481..3dcd2cb 100644
--- a/delta_diff_generator.cc
+++ b/delta_diff_generator.cc
@@ -54,6 +54,13 @@
const uint64_t kVersionNumber = 1;
const uint64_t kFullUpdateChunkSize = 128 * 1024; // bytes
+static const char* kInstallOperationTypes[] = {
+ "REPLACE",
+ "REPLACE_BZ",
+ "MOVE",
+ "BSDIFF"
+};
+
// Stores all Extents for a file into 'out'. Returns true on success.
bool GatherExtents(const string& path,
google::protobuf::RepeatedPtrField<Extent>* out) {
@@ -163,7 +170,8 @@
TEST_AND_RETURN_FALSE(DeltaDiffGenerator::ReadFileToDiff(old_root + path,
new_root + path,
&data,
- &operation));
+ &operation,
+ true));
// Write the data
if (operation.type() != DeltaArchiveManifest_InstallOperation_Type_MOVE) {
@@ -395,51 +403,40 @@
}
}
-// Delta compresses a kernel partition new_kernel_part with knowledge of
-// the old kernel partition old_kernel_part.
+// Delta compresses a kernel partition |new_kernel_part| with knowledge of the
+// old kernel partition |old_kernel_part|. If |old_kernel_part| is an empty
+// string, generates a full update of the partition.
bool DeltaCompressKernelPartition(
const string& old_kernel_part,
const string& new_kernel_part,
vector<DeltaArchiveManifest_InstallOperation>* ops,
int blobs_fd,
off_t* blobs_length) {
- // For now, just bsdiff the kernel partition as a whole.
- // TODO(adlr): Use knowledge of how the kernel partition is laid out
- // to more efficiently compress it.
-
LOG(INFO) << "Delta compressing kernel partition...";
+ LOG_IF(INFO, old_kernel_part.empty()) << "Generating full kernel update...";
// Add a new install operation
ops->resize(1);
DeltaArchiveManifest_InstallOperation* op = &(*ops)[0];
- op->set_type(DeltaArchiveManifest_InstallOperation_Type_REPLACE_BZ);
- op->set_data_offset(*blobs_length);
- // Do the actual compression
vector<char> data;
- TEST_AND_RETURN_FALSE(utils::ReadFile(new_kernel_part, &data));
- TEST_AND_RETURN_FALSE(!data.empty());
+ TEST_AND_RETURN_FALSE(DeltaDiffGenerator::ReadFileToDiff(old_kernel_part,
+ new_kernel_part,
+ &data,
+ op,
+ false));
- vector<char> data_bz;
- TEST_AND_RETURN_FALSE(BzipCompress(data, &data_bz));
- CHECK(!data_bz.empty());
+ // Write the data
+ if (op->type() != DeltaArchiveManifest_InstallOperation_Type_MOVE) {
+ op->set_data_offset(*blobs_length);
+ op->set_data_length(data.size());
+ }
- TEST_AND_RETURN_FALSE(utils::WriteAll(blobs_fd, &data_bz[0], data_bz.size()));
- *blobs_length += data_bz.size();
+ TEST_AND_RETURN_FALSE(utils::WriteAll(blobs_fd, &data[0], data.size()));
+ *blobs_length += data.size();
- off_t new_part_size = utils::FileSize(new_kernel_part);
- TEST_AND_RETURN_FALSE(new_part_size >= 0);
-
- op->set_data_length(data_bz.size());
-
- op->set_dst_length(new_part_size);
-
- // There's a single dest extent
- Extent* dst_extent = op->add_dst_extents();
- dst_extent->set_start_block(0);
- dst_extent->set_num_blocks((new_part_size + kBlockSize - 1) / kBlockSize);
-
- LOG(INFO) << "Done compressing kernel partition.";
+ LOG(INFO) << "Done delta compressing kernel partition: "
+ << kInstallOperationTypes[op->type()];
return true;
}
@@ -456,13 +453,6 @@
off_t size;
};
-static const char* kInstallOperationTypes[] = {
- "REPLACE",
- "REPLACE_BZ",
- "MOVE",
- "BSDIFF"
-};
-
void ReportPayloadUsage(const Graph& graph,
const DeltaArchiveManifest& manifest,
const int64_t manifest_metadata_size) {
@@ -517,7 +507,8 @@
const string& old_filename,
const string& new_filename,
vector<char>* out_data,
- DeltaArchiveManifest_InstallOperation* out_op) {
+ DeltaArchiveManifest_InstallOperation* out_op,
+ bool gather_extents) {
// Read new data in
vector<char> new_data;
TEST_AND_RETURN_FALSE(utils::ReadFile(new_filename, &new_data));
@@ -544,10 +535,13 @@
// Do we have an original file to consider?
struct stat old_stbuf;
- if (0 != stat(old_filename.c_str(), &old_stbuf)) {
+ bool no_original = old_filename.empty();
+ if (!no_original && 0 != stat(old_filename.c_str(), &old_stbuf)) {
// If stat-ing the old file fails, it should be because it doesn't exist.
TEST_AND_RETURN_FALSE(errno == ENOTDIR || errno == ENOENT);
- } else {
+ no_original = true;
+ }
+ if (!no_original) {
// Read old data
vector<char> old_data;
TEST_AND_RETURN_FALSE(utils::ReadFile(old_filename, &old_data));
@@ -576,13 +570,26 @@
if (operation.type() == DeltaArchiveManifest_InstallOperation_Type_MOVE ||
operation.type() == DeltaArchiveManifest_InstallOperation_Type_BSDIFF) {
- TEST_AND_RETURN_FALSE(
- GatherExtents(old_filename, operation.mutable_src_extents()));
+ if (gather_extents) {
+ TEST_AND_RETURN_FALSE(
+ GatherExtents(old_filename, operation.mutable_src_extents()));
+ } else {
+ Extent* src_extent = operation.add_src_extents();
+ src_extent->set_start_block(0);
+ src_extent->set_num_blocks(
+ (old_stbuf.st_size + kBlockSize - 1) / kBlockSize);
+ }
operation.set_src_length(old_stbuf.st_size);
}
- TEST_AND_RETURN_FALSE(
- GatherExtents(new_filename, operation.mutable_dst_extents()));
+ if (gather_extents) {
+ TEST_AND_RETURN_FALSE(
+ GatherExtents(new_filename, operation.mutable_dst_extents()));
+ } else {
+ Extent* dst_extent = operation.add_dst_extents();
+ dst_extent->set_start_block(0);
+ dst_extent->set_num_blocks((new_data.size() + kBlockSize - 1) / kBlockSize);
+ }
operation.set_dst_length(new_data.size());
out_data->swap(data);
@@ -1273,8 +1280,6 @@
TEST_AND_RETURN_FALSE(old_image_block_size == new_image_block_size);
LOG_IF(WARNING, old_image_block_count != new_image_block_count)
<< "Old and new images have different block counts.";
- // Sanity check kernel partition arg
- TEST_AND_RETURN_FALSE(utils::FileSize(old_kernel_part) >= 0);
}
// Sanity check kernel partition arg
TEST_AND_RETURN_FALSE(utils::FileSize(new_kernel_part) >= 0);