logd: add a SerializedLogBuffer suitable for compression
Initial commit for a SerializedLogBuffer. The intention here is for
the serialized data to be compressed (currently using zlib) to allow
for substantially longer logs in the same memory footprint.
Test: unit tests
Change-Id: I2528e4e1ff1cf3bc91130173a107f371f04d911a
diff --git a/logd/CompressionEngine.h b/logd/CompressionEngine.h
new file mode 100644
index 0000000..d760cea
--- /dev/null
+++ b/logd/CompressionEngine.h
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2020 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#pragma once
+
+#include <span>
+#include <vector>
+
+class CompressionEngine {
+ public:
+ static CompressionEngine& GetInstance();
+
+ virtual ~CompressionEngine(){};
+
+ virtual bool Compress(std::span<uint8_t> in, std::vector<uint8_t>& out) = 0;
+ // Decompress the contents of `in` into `out`. `out_size` must be set to the decompressed size
+ // of the contents.
+ virtual bool Decompress(const std::vector<uint8_t>& in, std::vector<uint8_t>& out,
+ size_t out_size) = 0;
+};
+
+class ZlibCompressionEngine : public CompressionEngine {
+ public:
+ bool Compress(std::span<uint8_t> in, std::vector<uint8_t>& out) override;
+ bool Decompress(const std::vector<uint8_t>& in, std::vector<uint8_t>& out,
+ size_t out_size) override;
+};
+
+class ZstdCompressionEngine : public CompressionEngine {
+ public:
+ bool Compress(std::span<uint8_t> in, std::vector<uint8_t>& out) override;
+ bool Decompress(const std::vector<uint8_t>& in, std::vector<uint8_t>& out,
+ size_t out_size) override;
+};
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