Merge "libsnapshot: Remove the IByteSink API." (d71f1c72) · Commits · e / os / android_system_core

fs_mgr/libsnapshot/include/libsnapshot/cow_reader.h

+0 −34

Original line number	Diff line number	Diff line
		@@ -29,35 +29,6 @@ namespace snapshot {

		class ICowOpIter;

		// A ByteSink object handles requests for a buffer of a specific size. It
		// always owns the underlying buffer. It's designed to minimize potential
		// copying as we parse or decompress the COW.
		class IByteSink {
		public:
		virtual ~IByteSink() {}

		// Called when the reader has data. The size of the request is given. The
		// sink must return a valid pointer (or null on failure), and return the
		// maximum number of bytes that can be written to the returned buffer.
		//
		// The returned buffer is owned by IByteSink, but must remain valid until
		// the read operation has completed (or the entire buffer has been
		// covered by calls to ReturnData).
		//
		// After calling GetBuffer(), all previous buffers returned are no longer
		// valid.
		//
		// GetBuffer() is intended to be sequential. A returned size of N indicates
		// that the output stream will advance by N bytes, and the ReturnData call
		// indicates that those bytes have been fulfilled. Therefore, it is
		// possible to have ReturnBuffer do nothing, if the implementation doesn't
		// care about incremental writes.
		virtual void* GetBuffer(size_t requested, size_t* actual) = 0;

		// Called when a section returned by \|GetBuffer\| has been filled with data.
		virtual bool ReturnData(void* buffer, size_t length) = 0;
		};

		// Interface for reading from a snapuserd COW.
		class ICowReader {
		public:
		@@ -83,10 +54,6 @@ class ICowReader {
		// Return an iterator for retrieving CowOperation entries in merge order
		virtual std::unique_ptr<ICowOpIter> GetMergeOpIter(bool ignore_progress) = 0;

		// Get decoded bytes from the data section, handling any decompression.
		// All retrieved data is passed to the sink.
		virtual bool ReadData(const CowOperation& op, IByteSink* sink) = 0;

		// Get decoded bytes from the data section, handling any decompression.
		//
		// If ignore_bytes is non-zero, it specifies the initial number of bytes
		@@ -153,7 +120,6 @@ class CowReader final : public ICowReader {
		std::unique_ptr<ICowOpIter> GetRevMergeOpIter(bool ignore_progress = false) override;
		std::unique_ptr<ICowOpIter> GetMergeOpIter(bool ignore_progress = false) override;

		bool ReadData(const CowOperation& op, IByteSink* sink) override;
		ssize_t ReadData(const CowOperation& op, void* buffer, size_t buffer_size,
		size_t ignore_bytes = 0) override;

fs_mgr/libsnapshot/libsnapshot_cow/cow_decompress.cpp

+0 −210

Original line number	Diff line number	Diff line
		@@ -64,69 +64,17 @@ std::unique_ptr<IDecompressor> IDecompressor::FromString(std::string_view compre
		}
		}

		class NoDecompressor final : public IDecompressor {
		public:
		bool Decompress(size_t) override;
		ssize_t Decompress(void*, size_t, size_t, size_t) override {
		LOG(ERROR) << "Not supported";
		return -1;
		}
		};

		bool NoDecompressor::Decompress(size_t) {
		size_t stream_remaining = stream_->Size();
		while (stream_remaining) {
		size_t buffer_size = stream_remaining;
		uint8_t* buffer = reinterpret_cast<uint8_t*>(sink_->GetBuffer(buffer_size, &buffer_size));
		if (!buffer) {
		LOG(ERROR) << "Could not acquire buffer from sink";
		return false;
		}

		// Read until we can fill the buffer.
		uint8_t* buffer_pos = buffer;
		size_t bytes_to_read = std::min(buffer_size, stream_remaining);
		while (bytes_to_read) {
		ssize_t read = stream_->Read(buffer_pos, bytes_to_read);
		if (read < 0) {
		return false;
		}
		if (!read) {
		LOG(ERROR) << "Stream ended prematurely";
		return false;
		}
		if (!sink_->ReturnData(buffer_pos, read)) {
		LOG(ERROR) << "Could not return buffer to sink";
		return false;
		}
		buffer_pos += read;
		bytes_to_read -= read;
		stream_remaining -= read;
		}
		}
		return true;
		}

		std::unique_ptr<IDecompressor> IDecompressor::Uncompressed() {
		return std::unique_ptr<IDecompressor>(new NoDecompressor());
		}

		// Read chunks of the COW and incrementally stream them to the decoder.
		class StreamDecompressor : public IDecompressor {
		public:
		bool Decompress(size_t output_bytes) override;
		ssize_t Decompress(void* buffer, size_t buffer_size, size_t decompressed_size,
		size_t ignore_bytes) override;

		virtual bool Init() = 0;
		virtual bool DecompressInput(const uint8_t* data, size_t length) = 0;
		virtual bool PartialDecompress(const uint8_t* data, size_t length) = 0;
		bool OutputFull() const { return !ignore_bytes_ && !output_buffer_remaining_; }

		protected:
		bool GetFreshBuffer();

		size_t output_bytes_;
		size_t stream_remaining_;
		uint8_t* output_buffer_ = nullptr;
		size_t output_buffer_remaining_ = 0;
		@@ -136,43 +84,6 @@ class StreamDecompressor : public IDecompressor {

		static constexpr size_t kChunkSize = 4096;

		bool StreamDecompressor::Decompress(size_t output_bytes) {
		if (!Init()) {
		return false;
		}

		stream_remaining_ = stream_->Size();
		output_bytes_ = output_bytes;

		uint8_t chunk[kChunkSize];
		while (stream_remaining_) {
		size_t max_read = std::min(stream_remaining_, sizeof(chunk));
		ssize_t read = stream_->Read(chunk, max_read);
		if (read < 0) {
		return false;
		}
		if (!read) {
		LOG(ERROR) << "Stream ended prematurely";
		return false;
		}
		if (!DecompressInput(chunk, read)) {
		return false;
		}

		stream_remaining_ -= read;

		if (stream_remaining_ && decompressor_ended_) {
		LOG(ERROR) << "Decompressor terminated early";
		return false;
		}
		}
		if (!decompressor_ended_) {
		LOG(ERROR) << "Decompressor expected more bytes";
		return false;
		}
		return true;
		}

		ssize_t StreamDecompressor::Decompress(void* buffer, size_t buffer_size, size_t,
		size_t ignore_bytes) {
		if (!Init()) {
		@@ -220,23 +131,11 @@ ssize_t StreamDecompressor::Decompress(void* buffer, size_t buffer_size, size_t,
		return buffer_size - output_buffer_remaining_;
		}

		bool StreamDecompressor::GetFreshBuffer() {
		size_t request_size = std::min(output_bytes_, kChunkSize);
		output_buffer_ =
		reinterpret_cast<uint8_t*>(sink_->GetBuffer(request_size, &output_buffer_remaining_));
		if (!output_buffer_) {
		LOG(ERROR) << "Could not acquire buffer from sink";
		return false;
		}
		return true;
		}

		class GzDecompressor final : public StreamDecompressor {
		public:
		~GzDecompressor();

		bool Init() override;
		bool DecompressInput(const uint8_t* data, size_t length) override;
		bool PartialDecompress(const uint8_t* data, size_t length) override;

		private:
		@@ -255,50 +154,6 @@ GzDecompressor::~GzDecompressor() {
		inflateEnd(&z_);
		}

		bool GzDecompressor::DecompressInput(const uint8_t* data, size_t length) {
		z_.next_in = reinterpret_cast<Bytef>(const_cast<uint8_t>(data));
		z_.avail_in = length;

		while (z_.avail_in) {
		// If no more output buffer, grab a new buffer.
		if (z_.avail_out == 0) {
		if (!GetFreshBuffer()) {
		return false;
		}
		z_.next_out = reinterpret_cast<Bytef*>(output_buffer_);
		z_.avail_out = output_buffer_remaining_;
		}

		// Remember the position of the output buffer so we can call ReturnData.
		auto avail_out = z_.avail_out;

		// Decompress.
		int rv = inflate(&z_, Z_NO_FLUSH);
		if (rv != Z_OK && rv != Z_STREAM_END) {
		LOG(ERROR) << "inflate returned error code " << rv;
		return false;
		}

		size_t returned = avail_out - z_.avail_out;
		if (!sink_->ReturnData(output_buffer_, returned)) {
		LOG(ERROR) << "Could not return buffer to sink";
		return false;
		}
		output_buffer_ += returned;
		output_buffer_remaining_ -= returned;

		if (rv == Z_STREAM_END) {
		if (z_.avail_in) {
		LOG(ERROR) << "Gz stream ended prematurely";
		return false;
		}
		decompressor_ended_ = true;
		return true;
		}
		}
		return true;
		}

		bool GzDecompressor::PartialDecompress(const uint8_t* data, size_t length) {
		z_.next_in = reinterpret_cast<Bytef>(const_cast<uint8_t>(data));
		z_.avail_in = length;
		@@ -362,7 +217,6 @@ class BrotliDecompressor final : public StreamDecompressor {
		~BrotliDecompressor();

		bool Init() override;
		bool DecompressInput(const uint8_t* data, size_t length) override;
		bool PartialDecompress(const uint8_t* data, size_t length) override;

		private:
		@@ -380,31 +234,6 @@ BrotliDecompressor::~BrotliDecompressor() {
		}
		}

		bool BrotliDecompressor::DecompressInput(const uint8_t* data, size_t length) {
		size_t available_in = length;
		const uint8_t* next_in = data;

		bool needs_more_output = false;
		while (available_in \|\| needs_more_output) {
		if (!output_buffer_remaining_ && !GetFreshBuffer()) {
		return false;
		}

		auto output_buffer = output_buffer_;
		auto r = BrotliDecoderDecompressStream(decoder_, &available_in, &next_in,
		&output_buffer_remaining_, &output_buffer_, nullptr);
		if (r == BROTLI_DECODER_RESULT_ERROR) {
		LOG(ERROR) << "brotli decode failed";
		return false;
		}
		if (!sink_->ReturnData(output_buffer, output_buffer_ - output_buffer)) {
		return false;
		}
		needs_more_output = (r == BROTLI_DECODER_RESULT_NEEDS_MORE_OUTPUT);
		}
		return true;
		}

		bool BrotliDecompressor::PartialDecompress(const uint8_t* data, size_t length) {
		size_t available_in = length;
		const uint8_t* next_in = data;
		@@ -451,45 +280,6 @@ class Lz4Decompressor final : public IDecompressor {
		public:
		~Lz4Decompressor() override = default;

		bool Decompress(const size_t output_size) override {
		size_t actual_buffer_size = 0;
		auto&& output_buffer = sink_->GetBuffer(output_size, &actual_buffer_size);
		if (actual_buffer_size != output_size) {
		LOG(ERROR) << "Failed to allocate buffer of size " << output_size << " only got "
		<< actual_buffer_size << " bytes";
		return false;
		}
		// If input size is same as output size, then input is uncompressed.
		if (stream_->Size() == output_size) {
		ssize_t bytes_read = stream_->ReadFully(output_buffer, output_size);
		if (bytes_read != output_size) {
		LOG(ERROR) << "Failed to read all input at once. Expected: " << output_size
		<< " actual: " << bytes_read;
		return false;
		}
		sink_->ReturnData(output_buffer, output_size);
		return true;
		}
		std::string input_buffer;
		input_buffer.resize(stream_->Size());
		ssize_t bytes_read = stream_->ReadFully(input_buffer.data(), input_buffer.size());
		if (bytes_read != input_buffer.size()) {
		LOG(ERROR) << "Failed to read all input at once. Expected: " << input_buffer.size()
		<< " actual: " << bytes_read;
		return false;
		}
		const int bytes_decompressed =
		LZ4_decompress_safe(input_buffer.data(), static_cast<char*>(output_buffer),
		input_buffer.size(), output_size);
		if (bytes_decompressed != output_size) {
		LOG(ERROR) << "Failed to decompress LZ4 block, expected output size: " << output_size
		<< ", actual: " << bytes_decompressed;
		return false;
		}
		sink_->ReturnData(output_buffer, output_size);
		return true;
		}

		ssize_t Decompress(void* buffer, size_t buffer_size, size_t decompressed_size,
		size_t ignore_bytes) override {
		std::string input_buffer(stream_->Size(), '\0');

fs_mgr/libsnapshot/libsnapshot_cow/cow_decompress.h

+0 −5

Original line number	Diff line number	Diff line
		@@ -50,9 +50,6 @@ class IDecompressor {

		static std::unique_ptr<IDecompressor> FromString(std::string_view compressor);

		// \|output_bytes\| is the expected total number of bytes to sink.
		virtual bool Decompress(size_t output_bytes) = 0;

		// Decompress at most \|buffer_size\| bytes, ignoring the first \|ignore_bytes\|
		// of the decoded stream. \|buffer_size\| must be at least one byte.
		// \|decompressed_size\| is the expected total size if the entire stream were
		@@ -64,11 +61,9 @@ class IDecompressor {
		size_t ignore_bytes = 0) = 0;

		void set_stream(IByteStream* stream) { stream_ = stream; }
		void set_sink(IByteSink* sink) { sink_ = sink; }

		protected:
		IByteStream* stream_ = nullptr;
		IByteSink* sink_ = nullptr;
		};

		} // namespace snapshot

fs_mgr/libsnapshot/libsnapshot_cow/cow_reader.cpp

+0 −32

Original line number	Diff line number	Diff line
		@@ -770,38 +770,6 @@ class CowDataStream final : public IByteStream {
		size_t remaining_;
		};

		bool CowReader::ReadData(const CowOperation& op, IByteSink* sink) {
		std::unique_ptr<IDecompressor> decompressor;
		switch (op.compression) {
		case kCowCompressNone:
		decompressor = IDecompressor::Uncompressed();
		break;
		case kCowCompressGz:
		decompressor = IDecompressor::Gz();
		break;
		case kCowCompressBrotli:
		decompressor = IDecompressor::Brotli();
		break;
		case kCowCompressLz4:
		decompressor = IDecompressor::Lz4();
		break;
		default:
		LOG(ERROR) << "Unknown compression type: " << op.compression;
		return false;
		}

		uint64_t offset;
		if (op.type == kCowXorOp) {
		offset = data_loc_->at(op.new_block);
		} else {
		offset = op.source;
		}
		CowDataStream stream(this, offset, op.data_length);
		decompressor->set_stream(&stream);
		decompressor->set_sink(sink);
		return decompressor->Decompress(header_.block_size);
		}

		ssize_t CowReader::ReadData(const CowOperation& op, void* buffer, size_t buffer_size,
		size_t ignore_bytes) {
		std::unique_ptr<IDecompressor> decompressor;

fs_mgr/libsnapshot/snapuserd/include/snapuserd/snapuserd_buffer.h

+5 −6

Original line number	Diff line number	Diff line
		@@ -25,16 +25,15 @@
		namespace android {
		namespace snapshot {

		class BufferSink : public IByteSink {
		class BufferSink final {
		public:
		void Initialize(size_t size);
		void* GetBufPtr() { return buffer_.get(); }
		void Clear() { memset(GetBufPtr(), 0, buffer_size_); }
		void* GetPayloadBuffer(size_t size);
		void* GetBuffer(size_t requested, size_t* actual) override;
		void* GetBuffer(size_t requested, size_t* actual);
		void UpdateBufferOffset(size_t size) { buffer_offset_ += size; }
		struct dm_user_header* GetHeaderPtr();
		bool ReturnData(void*, size_t) override { return true; }
		void ResetBufferOffset() { buffer_offset_ = 0; }
		void* GetPayloadBufPtr();

		@@ -44,12 +43,12 @@ class BufferSink : public IByteSink {
		size_t buffer_size_;
		};

		class XorSink : public IByteSink {
		class XorSink final {
		public:
		void Initialize(BufferSink* sink, size_t size);
		void Reset();
		void* GetBuffer(size_t requested, size_t* actual) override;
		bool ReturnData(void* buffer, size_t len) override;
		void* GetBuffer(size_t requested, size_t* actual);
		bool ReturnData(void* buffer, size_t len);

		private:
		BufferSink* bufsink_;