base init

src/game/fifo_allocator.h

@@ -0,0 +1,82 @@
+#ifndef _FIFO_ALLOCATOR_H_
+#define _FIFO_ALLOCATOR_H_
+
+#include <deque>
+
+#ifdef __GNUC__
+#include <tr1/unordered_map>
+#define TR1_NS std::tr1
+#else
+#include <unordered_map>
+#define TR1_NS std
+#endif
+
+// Allocator implementation detail with simple FIFO grow-only pool.
+// It relies on default CRT malloc/free.
+class FifoAllocator {
+public:
+	FifoAllocator() {}
+	~FifoAllocator() {}
+
+	void SetUp() {}
+	void TearDown() {
+		CleanUp(); // deallocate pooled blocks
+	}
+
+	void* Alloc(size_t size) {
+		void* p = NULL;
+		PoolType& pool = pool_map_[size];
+		if (pool.size() < kWatermark) {
+			p = ::malloc(size);
+		} else {
+			p = pool.front();
+			pool.pop_front();
+		}
+		if (p != NULL) {
+			alloc_map_[p] = size;
+		}
+		return p;
+	}
+	void Free(void* p) {
+		if (p == NULL) {
+			return;
+		}
+		AllocMapType::iterator it = alloc_map_.find(p);
+		if (it == alloc_map_.end()) {
+			return;
+		}
+		size_t size = it->second;
+		alloc_map_.erase(it);
+		PoolMapType::iterator it2 = pool_map_.find(size);
+		if (it2 == pool_map_.end()) {
+			return;
+		}
+		PoolType& pool = it2->second;
+		pool.push_back(p);
+	}
+
+private:
+	void CleanUp() {
+		PoolMapType::iterator it = pool_map_.begin(), end = pool_map_.end();
+		for ( ; it != end; ++it) {
+			PoolType& pool = it->second;
+			PoolType::iterator it2 = pool.begin(), end2 = pool.end();
+			for ( ; it2 != end2; ++it2) {
+				::free(*it2);
+			}
+			pool.clear();
+		}
+		pool_map_.clear();
+	}
+
+	typedef std::deque<void*> PoolType;
+	typedef std::unordered_map<size_t, PoolType> PoolMapType;
+	typedef std::unordered_map<void*, size_t> AllocMapType;
+
+	static const size_t kWatermark = 4; // FIFO enforcement level
+
+	PoolMapType pool_map_;
+	AllocMapType alloc_map_;
+};
+
+#endif // _FIFO_ALLOCATOR_H_