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| author | Mathieu Chartier <mathieuc@google.com> | 2016-02-25 13:52:10 -0800 |
|---|---|---|
| committer | Mathieu Chartier <mathieuc@google.com> | 2016-02-25 14:55:55 -0800 |
| commit | a6e81ed4c185b7362cd5199ebe5507d00883a9b0 (patch) | |
| tree | 851f18eeb8b6401793051d5f52dfad1f7e69f965 /compiler/image_writer.cc | |
| parent | eea36cb923b078b86c7b5033ce75fe1b8ea4e522 (diff) | |
| download | android_art-a6e81ed4c185b7362cd5199ebe5507d00883a9b0.tar.gz android_art-a6e81ed4c185b7362cd5199ebe5507d00883a9b0.tar.bz2 android_art-a6e81ed4c185b7362cd5199ebe5507d00883a9b0.zip | |
Add lz4hc image compression format
Smaller than lz4 and decompresses at the same speed. Compression is
a bit slower.
Example saves on old FB APK:
Uncompressed: 44748800 bytes
LZ4: 12443648 bytes
LZ4HC: 11055104 bytes
Generating the image slows down by ~1s per 20MB of image due to
slower compression. Decompression is about the same speed but there
should be a slight speedup since less data needs to be read from
flash.
Added test.
Bug: 22858531
Change-Id: Ib2704305b9bec5b0ba3b1e871f59f4eedff330b7
Diffstat (limited to 'compiler/image_writer.cc')
| -rw-r--r-- | compiler/image_writer.cc | 23 |
1 files changed, 20 insertions, 3 deletions
diff --git a/compiler/image_writer.cc b/compiler/image_writer.cc index 5eff8f37ec..871435b85f 100644 --- a/compiler/image_writer.cc +++ b/compiler/image_writer.cc @@ -18,6 +18,7 @@ #include <sys/stat.h> #include <lz4.h> +#include <lz4hc.h> #include <memory> #include <numeric> @@ -224,18 +225,28 @@ bool ImageWriter::Write(int image_fd, char* image_data = reinterpret_cast<char*>(image_info.image_->Begin()) + sizeof(ImageHeader); size_t data_size; const char* image_data_to_write; + const uint64_t compress_start_time = NanoTime(); CHECK_EQ(image_header->storage_mode_, image_storage_mode_); switch (image_storage_mode_) { case ImageHeader::kStorageModeLZ4: { - size_t compressed_max_size = LZ4_compressBound(image_data_size); + const size_t compressed_max_size = LZ4_compressBound(image_data_size); compressed_data.reset(new char[compressed_max_size]); data_size = LZ4_compress( reinterpret_cast<char*>(image_info.image_->Begin()) + sizeof(ImageHeader), &compressed_data[0], image_data_size); - image_data_to_write = &compressed_data[0]; - VLOG(compiler) << "Compressed from " << image_data_size << " to " << data_size; + + break; + } + case ImageHeader::kStorageModeLZ4HC: { + // Bound is same as non HC. + const size_t compressed_max_size = LZ4_compressBound(image_data_size); + compressed_data.reset(new char[compressed_max_size]); + data_size = LZ4_compressHC( + reinterpret_cast<char*>(image_info.image_->Begin()) + sizeof(ImageHeader), + &compressed_data[0], + image_data_size); break; } case ImageHeader::kStorageModeUncompressed: { @@ -249,6 +260,12 @@ bool ImageWriter::Write(int image_fd, } } + if (compressed_data != nullptr) { + image_data_to_write = &compressed_data[0]; + VLOG(compiler) << "Compressed from " << image_data_size << " to " << data_size << " in " + << PrettyDuration(NanoTime() - compress_start_time); + } + // Write header first, as uncompressed. image_header->data_size_ = data_size; if (!image_file->WriteFully(image_info.image_->Begin(), sizeof(ImageHeader))) { |