diff options
Diffstat (limited to 'dom/script/ScriptCompression.cpp')
| -rw-r--r-- | dom/script/ScriptCompression.cpp | 174 |
1 files changed, 174 insertions, 0 deletions
diff --git a/dom/script/ScriptCompression.cpp b/dom/script/ScriptCompression.cpp new file mode 100644 index 0000000000..7aa8f08de2 --- /dev/null +++ b/dom/script/ScriptCompression.cpp @@ -0,0 +1,174 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "zlib.h" +#include "ScriptLoadRequest.h" +#include "ScriptLoader.h" +#include "mozilla/PerfStats.h" +#include "mozilla/ProfilerMarkers.h" +#include "mozilla/Vector.h" +#include "mozilla/ScopeExit.h" +#include "mozilla/Preferences.h" +#include "mozilla/StaticPrefs_browser.h" + +using namespace mozilla; + +namespace JS::loader { + +#undef LOG +#define LOG(args) \ + MOZ_LOG(mozilla::dom::ScriptLoader::gScriptLoaderLog, \ + mozilla::LogLevel::Debug, args) + +/* + * ScriptBytecodeDataLayout + * + * ScriptBytecodeDataLayout provides accessors to maintain the correct data + * layout of the ScriptLoadRequest's script bytecode buffer. + */ +class ScriptBytecodeDataLayout { + public: + explicit ScriptBytecodeDataLayout(mozilla::Vector<uint8_t>& aBytecode, + size_t aBytecodeOffset) + : mBytecode(aBytecode), mBytecodeOffset(aBytecodeOffset) {} + + uint8_t* prelude() const { return mBytecode.begin(); } + size_t preludeLength() const { return mBytecodeOffset; } + + uint8_t* bytecode() const { return prelude() + mBytecodeOffset; } + size_t bytecodeLength() const { return mBytecode.length() - preludeLength(); } + + mozilla::Vector<uint8_t>& mBytecode; + size_t mBytecodeOffset; +}; + +/* + * ScriptBytecodeCompressedDataLayout + * + * ScriptBytecodeCompressedDataLayout provides accessors to maintain the correct + * data layout of a compressed script bytecode buffer. + */ +class ScriptBytecodeCompressedDataLayout { + public: + using UncompressedLengthType = uint32_t; + + explicit ScriptBytecodeCompressedDataLayout( + mozilla::Vector<uint8_t>& aBytecode, size_t aBytecodeOffset) + : mBytecode(aBytecode), mBytecodeOffset(aBytecodeOffset) {} + + uint8_t* prelude() const { return mBytecode.begin(); } + size_t preludeLength() const { return mBytecodeOffset; } + + uint8_t* uncompressedLength() const { return prelude() + mBytecodeOffset; } + size_t uncompressedLengthLength() const { + return sizeof(UncompressedLengthType); + } + + uint8_t* bytecode() const { + return uncompressedLength() + uncompressedLengthLength(); + } + size_t bytecodeLength() const { + return mBytecode.length() - uncompressedLengthLength() - preludeLength(); + } + + mozilla::Vector<uint8_t>& mBytecode; + size_t mBytecodeOffset; +}; + +bool ScriptBytecodeCompress(Vector<uint8_t>& aBytecodeBuf, + size_t aBytecodeOffset, + Vector<uint8_t>& aCompressedBytecodeBufOut) { + // TODO probably need to move this to a helper thread + + AUTO_PROFILER_MARKER_TEXT("ScriptBytecodeCompress", JS, {}, ""_ns); + PerfStats::AutoMetricRecording<PerfStats::Metric::JSBC_Compression> + autoRecording; + + ScriptBytecodeDataLayout uncompressedLayout(aBytecodeBuf, aBytecodeOffset); + ScriptBytecodeCompressedDataLayout compressedLayout( + aCompressedBytecodeBufOut, uncompressedLayout.preludeLength()); + ScriptBytecodeCompressedDataLayout::UncompressedLengthType + uncompressedLength = uncompressedLayout.bytecodeLength(); + z_stream zstream{.next_in = uncompressedLayout.bytecode(), + .avail_in = uncompressedLength}; + auto compressedLength = deflateBound(&zstream, uncompressedLength); + if (!aCompressedBytecodeBufOut.resizeUninitialized( + compressedLength + compressedLayout.preludeLength() + + compressedLayout.uncompressedLengthLength())) { + return false; + } + memcpy(compressedLayout.prelude(), uncompressedLayout.prelude(), + uncompressedLayout.preludeLength()); + memcpy(compressedLayout.uncompressedLength(), &uncompressedLength, + sizeof(uncompressedLength)); + zstream.next_out = compressedLayout.bytecode(); + zstream.avail_out = compressedLength; + + const uint32_t compressionLevel = + StaticPrefs::browser_cache_jsbc_compression_level(); + if (deflateInit(&zstream, compressionLevel) != Z_OK) { + LOG( + ("ScriptLoadRequest: Unable to initialize bytecode cache " + "compression.")); + return false; + } + auto autoDestroy = MakeScopeExit([&]() { deflateEnd(&zstream); }); + + int ret = deflate(&zstream, Z_FINISH); + if (ret == Z_MEM_ERROR) { + return false; + } + MOZ_RELEASE_ASSERT(ret == Z_STREAM_END); + + aCompressedBytecodeBufOut.shrinkTo(zstream.next_out - + aCompressedBytecodeBufOut.begin()); + return true; +} + +bool ScriptBytecodeDecompress(Vector<uint8_t>& aCompressedBytecodeBuf, + size_t aBytecodeOffset, + Vector<uint8_t>& aBytecodeBufOut) { + AUTO_PROFILER_MARKER_TEXT("ScriptBytecodeDecompress", JS, {}, ""_ns); + PerfStats::AutoMetricRecording<PerfStats::Metric::JSBC_Decompression> + autoRecording; + + ScriptBytecodeDataLayout uncompressedLayout(aBytecodeBufOut, aBytecodeOffset); + ScriptBytecodeCompressedDataLayout compressedLayout( + aCompressedBytecodeBuf, uncompressedLayout.preludeLength()); + ScriptBytecodeCompressedDataLayout::UncompressedLengthType uncompressedLength; + memcpy(&uncompressedLength, compressedLayout.uncompressedLength(), + compressedLayout.uncompressedLengthLength()); + if (!aBytecodeBufOut.resizeUninitialized(uncompressedLayout.preludeLength() + + uncompressedLength)) { + return false; + } + memcpy(uncompressedLayout.prelude(), compressedLayout.prelude(), + compressedLayout.preludeLength()); + + z_stream zstream{nullptr}; + zstream.next_in = compressedLayout.bytecode(); + zstream.avail_in = static_cast<uint32_t>(compressedLayout.bytecodeLength()); + zstream.next_out = uncompressedLayout.bytecode(); + zstream.avail_out = uncompressedLength; + if (inflateInit(&zstream) != Z_OK) { + LOG(("ScriptLoadRequest: inflateInit FAILED (%s)", zstream.msg)); + return false; + } + auto autoDestroy = MakeScopeExit([&]() { inflateEnd(&zstream); }); + + int ret = inflate(&zstream, Z_NO_FLUSH); + bool ok = (ret == Z_OK || ret == Z_STREAM_END) && zstream.avail_in == 0; + if (!ok) { + LOG(("ScriptLoadReques: inflate FAILED (%s)", zstream.msg)); + return false; + } + + return true; +} + +#undef LOG + +} // namespace JS::loader |