Reland "EGL: Refactor multifile blobcache"

This reverts commit 437354181694798af24038dd65455eeab06a329e.

Previous CL was reverted due to boot time regressions.

Main change from previous CL is removal of thread.join() if
the thread was not initialized.  This was happening at boot
because a number of processes try to use the cache without
providing a location for the cache.  In that case, both old
and new cache will not initialize.

Test: Boot (quickly)
Test: pubg_mobile_launch ANGLE trace
Test: /data/nativetest64/EGL_test/EGL_test
Test: /data/nativetest64/libEGL_test/libEGL_test
Bug: b/266725576

Change-Id: Ib9add1c8342278a46c2e629c919719f973f8c612
diff --git a/opengl/libs/EGL/MultifileBlobCache.h b/opengl/libs/EGL/MultifileBlobCache.h
new file mode 100644
index 0000000..c0cc9dc
--- /dev/null
+++ b/opengl/libs/EGL/MultifileBlobCache.h
@@ -0,0 +1,167 @@
+/*
+ ** Copyright 2022, 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.
+ */
+
+#ifndef ANDROID_MULTIFILE_BLOB_CACHE_H
+#define ANDROID_MULTIFILE_BLOB_CACHE_H
+
+#include <EGL/egl.h>
+#include <EGL/eglext.h>
+
+#include <future>
+#include <map>
+#include <queue>
+#include <string>
+#include <thread>
+#include <unordered_map>
+#include <unordered_set>
+
+namespace android {
+
+struct MultifileHeader {
+    EGLsizeiANDROID keySize;
+    EGLsizeiANDROID valueSize;
+};
+
+struct MultifileEntryStats {
+    EGLsizeiANDROID valueSize;
+    size_t fileSize;
+    time_t accessTime;
+};
+
+struct MultifileHotCache {
+    int entryFd;
+    uint8_t* entryBuffer;
+    size_t entrySize;
+};
+
+enum class TaskCommand {
+    Invalid = 0,
+    WriteToDisk,
+    Exit,
+};
+
+class DeferredTask {
+public:
+    DeferredTask(TaskCommand command)
+          : mCommand(command), mEntryHash(0), mBuffer(nullptr), mBufferSize(0) {}
+
+    TaskCommand getTaskCommand() { return mCommand; }
+
+    void initWriteToDisk(uint32_t entryHash, std::string fullPath, uint8_t* buffer,
+                         size_t bufferSize) {
+        mCommand = TaskCommand::WriteToDisk;
+        mEntryHash = entryHash;
+        mFullPath = std::move(fullPath);
+        mBuffer = buffer;
+        mBufferSize = bufferSize;
+    }
+
+    uint32_t getEntryHash() { return mEntryHash; }
+    std::string& getFullPath() { return mFullPath; }
+    uint8_t* getBuffer() { return mBuffer; }
+    size_t getBufferSize() { return mBufferSize; };
+
+private:
+    TaskCommand mCommand;
+
+    // Parameters for WriteToDisk
+    uint32_t mEntryHash;
+    std::string mFullPath;
+    uint8_t* mBuffer;
+    size_t mBufferSize;
+};
+
+class MultifileBlobCache {
+public:
+    MultifileBlobCache(size_t maxTotalSize, size_t maxHotCacheSize, const std::string& baseDir);
+    ~MultifileBlobCache();
+
+    void set(const void* key, EGLsizeiANDROID keySize, const void* value,
+             EGLsizeiANDROID valueSize);
+    EGLsizeiANDROID get(const void* key, EGLsizeiANDROID keySize, void* value,
+                        EGLsizeiANDROID valueSize);
+
+    void finish();
+
+    size_t getTotalSize() const { return mTotalCacheSize; }
+
+private:
+    void trackEntry(uint32_t entryHash, EGLsizeiANDROID valueSize, size_t fileSize,
+                    time_t accessTime);
+    bool contains(uint32_t entryHash) const;
+    bool removeEntry(uint32_t entryHash);
+    MultifileEntryStats getEntryStats(uint32_t entryHash);
+
+    size_t getFileSize(uint32_t entryHash);
+    size_t getValueSize(uint32_t entryHash);
+
+    void increaseTotalCacheSize(size_t fileSize);
+    void decreaseTotalCacheSize(size_t fileSize);
+
+    bool addToHotCache(uint32_t entryHash, int fd, uint8_t* entryBufer, size_t entrySize);
+    bool removeFromHotCache(uint32_t entryHash);
+
+    void trimCache(size_t cacheByteLimit);
+    bool applyLRU(size_t cacheLimit);
+
+    bool mInitialized;
+    std::string mMultifileDirName;
+
+    std::unordered_set<uint32_t> mEntries;
+    std::unordered_map<uint32_t, MultifileEntryStats> mEntryStats;
+    std::unordered_map<uint32_t, MultifileHotCache> mHotCache;
+
+    size_t mMaxKeySize;
+    size_t mMaxValueSize;
+    size_t mMaxTotalSize;
+    size_t mTotalCacheSize;
+    size_t mHotCacheLimit;
+    size_t mHotCacheEntryLimit;
+    size_t mHotCacheSize;
+
+    // Below are the components used for deferred writes
+
+    // Track whether we have pending writes for an entry
+    std::multimap<uint32_t, uint8_t*> mDeferredWrites;
+
+    // Functions to work through tasks in the queue
+    void processTasks();
+    void processTasksImpl(bool* exitThread);
+    void processTask(DeferredTask& task);
+
+    // Used by main thread to create work for the worker thread
+    void queueTask(DeferredTask&& task);
+
+    // Used by main thread to wait for worker thread to complete all outstanding work.
+    void waitForWorkComplete();
+
+    std::thread mTaskThread;
+    std::queue<DeferredTask> mTasks;
+    std::mutex mWorkerMutex;
+
+    // This condition will block the worker thread until a task is queued
+    std::condition_variable mWorkAvailableCondition;
+
+    // This condition will block the main thread while the worker thread still has tasks
+    std::condition_variable mWorkerIdleCondition;
+
+    // This bool will track whether all tasks have been completed
+    bool mWorkerThreadIdle;
+};
+
+}; // namespace android
+
+#endif // ANDROID_MULTIFILE_BLOB_CACHE_H