Add HidlMemoryCache and mapMemory(memory_block)

The HidlMemoryCache is a singleton class which provides cache for
sp<IMemory>. It works as an abstraction layer on top of the
IMapper. It supports, but is not limited to, the Ashmem type
HidlMemory.

Bug: 69640640
Test: hidl_test/internal master/sailfish
Change-Id: I69cca18dbdda532eaae409ee9372b3080f7d58dd
diff --git a/libhidlcache/mapping.cpp b/libhidlcache/mapping.cpp
new file mode 100644
index 0000000..2a23e6f
--- /dev/null
+++ b/libhidlcache/mapping.cpp
@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2016 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.
+ */
+#define LOG_TAG "libhidlmemory"
+
+#include <map>
+#include <mutex>
+#include <string>
+
+#include <hidlmemory/mapping.h>
+
+#include <android-base/logging.h>
+#include <hidl/HidlSupport.h>
+#include "HidlMemoryCache.h"
+
+using android::hardware::HidlMemoryCache;
+using android::hidl::memory::block::V1_0::MemoryBlock;
+using android::hidl::memory::token::V1_0::IMemoryToken;
+using android::hidl::memory::V1_0::IMemory;
+
+namespace android {
+namespace hardware {
+
+sp<IMemory> mapMemory(const ::android::hidl::memory::block::V1_0::MemoryBlock& block) {
+    sp<HidlMemoryCache> c = HidlMemoryCache::getInstance();
+    return c->map(block);
+}
+
+sp<RefBase> lockMemoryCache(const sp<::android::hidl::memory::token::V1_0::IMemoryToken> key) {
+    sp<HidlMemoryCache> c = HidlMemoryCache::getInstance();
+    return c->lockGuard(key);
+}
+
+}  // namespace hardware
+}  // namespace android