AU: Optimize BzipExtentWriter's memory use.
This patch introduces the following two changes:
- Reduces the output buffer size from 1MiB to 16KiB.
- Avoids copying of the input data when there's no leftover data. This
covers the current DeltaPerformer usage of the writer.
BUG=chromium:234578
TEST=unit tests; tested full update on device
Change-Id: I44f74b4fd8b05b082fde84d5ac06d9b1c1177b81
Reviewed-on: https://gerrit.chromium.org/gerrit/49047
Tested-by: Darin Petkov <[email protected]>
Reviewed-by: Chris Sosa <[email protected]>
Commit-Queue: Darin Petkov <[email protected]>
diff --git a/bzip_extent_writer_unittest.cc b/bzip_extent_writer_unittest.cc
index d724bc4..38ba117 100644
--- a/bzip_extent_writer_unittest.cc
+++ b/bzip_extent_writer_unittest.cc
@@ -53,8 +53,8 @@
extents.push_back(extent);
// 'echo test | bzip2 | hexdump' yields:
- const char test_uncompressed[] = "test\n";
- unsigned char test[] = {
+ static const char test_uncompressed[] = "test\n";
+ static const unsigned char test[] = {
0x42, 0x5a, 0x68, 0x39, 0x31, 0x41, 0x59, 0x26, 0x53, 0x59, 0xcc, 0xc3,
0x71, 0xd4, 0x00, 0x00, 0x02, 0x41, 0x80, 0x00, 0x10, 0x02, 0x00, 0x0c,
0x00, 0x20, 0x00, 0x21, 0x9a, 0x68, 0x33, 0x4d, 0x19, 0x97, 0x8b, 0xb9,
@@ -101,12 +101,16 @@
BzipExtentWriter bzip_writer(&direct_writer);
EXPECT_TRUE(bzip_writer.Init(fd(), extents, kBlockSize));
+ vector<char> original_compressed_data = compressed_data;
for (vector<char>::size_type i = 0; i < compressed_data.size();
i += kChunkSize) {
size_t this_chunk_size = min(kChunkSize, compressed_data.size() - i);
EXPECT_TRUE(bzip_writer.Write(&compressed_data[i], this_chunk_size));
}
EXPECT_TRUE(bzip_writer.End());
+
+ // Check that the const input has not been clobbered.
+ ExpectVectorsEq(original_compressed_data, compressed_data);
vector<char> output(kDecompressedLength + 1);
ssize_t bytes_read = pread(fd(), &output[0], output.size(), 0);
