1 files changed, 102 insertions, 0 deletions
diff --git a/native/jni/src/suggest/policyimpl/dictionary/utils/mmapped_buffer.h b/native/jni/src/suggest/policyimpl/dictionary/utils/mmapped_buffer.h
new file mode 100644
index 000000000..6febd7832
--- /dev/null
+++ b/native/jni/src/suggest/policyimpl/dictionary/utils/mmapped_buffer.h
@@ -0,0 +1,102 @@
+/*
+ * Copyright (C) 2013, 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 LATINIME_MMAPPED_BUFFER_H
+#define LATINIME_MMAPPED_BUFFER_H
+
+#include <cerrno>
+#include <fcntl.h>
+#include <stdint.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+#include "defines.h"
+
+namespace latinime {
+
+class MmappedBuffer {
+ public:
+    static MmappedBuffer* openBuffer(const char *const path, const int pathLength,
+            const int bufferOffset, const int bufferSize, const bool isUpdatable) {
+        const int openMode = isUpdatable ? O_RDWR : O_RDONLY;
+        const int mmapFd = open(path, openMode);
+        if (mmapFd < 0) {
+            AKLOGE("DICT: Can't open the source. path=%s errno=%d", path, errno);
+            return 0;
+        }
+        const int pagesize = getpagesize();
+        const int offset = bufferOffset % pagesize;
+        int alignedOffset = bufferOffset - offset;
+        int alignedSize = bufferSize + offset;
+        const int protMode = isUpdatable ? PROT_READ | PROT_WRITE : PROT_READ;
+        void *const mmappedBuffer = mmap(0, alignedSize, protMode, MAP_PRIVATE, mmapFd,
+                alignedOffset);
+        if (mmappedBuffer == MAP_FAILED) {
+            AKLOGE("DICT: Can't mmap dictionary. errno=%d", errno);
+            close(mmapFd);
+            return 0;
+        }
+        uint8_t *const buffer = static_cast<uint8_t *>(mmappedBuffer) + offset;
+        if (!buffer) {
+            AKLOGE("DICT: buffer is null");
+            close(mmapFd);
+            return 0;
+        }
+        return new MmappedBuffer(buffer, bufferSize, mmappedBuffer, alignedSize, mmapFd,
+                isUpdatable);
+    }
+
+    ~MmappedBuffer() {
+        int ret = munmap(mMmappedBuffer, mAlignedSize);
+        if (ret != 0) {
+            AKLOGE("DICT: Failure in munmap. ret=%d errno=%d", ret, errno);
+        }
+        ret = close(mMmapFd);
+        if (ret != 0) {
+            AKLOGE("DICT: Failure in close. ret=%d errno=%d", ret, errno);
+        }
+    }
+
+    AK_FORCE_INLINE uint8_t *getBuffer() const {
+        return mBuffer;
+    }
+
+    AK_FORCE_INLINE int getBufferSize() const {
+        return mBufferSize;
+    }
+
+    AK_FORCE_INLINE bool isUpdatable() const {
+        return mIsUpdatable;
+    }
+
+ private:
+    AK_FORCE_INLINE MmappedBuffer(uint8_t *const buffer, const int bufferSize,
+            void *const mmappedBuffer, const int alignedSize, const int mmapFd,
+            const bool isUpdatable)
+            : mBuffer(buffer), mBufferSize(bufferSize), mMmappedBuffer(mmappedBuffer),
+              mAlignedSize(alignedSize), mMmapFd(mmapFd), mIsUpdatable(isUpdatable) {}
+
+    DISALLOW_IMPLICIT_CONSTRUCTORS(MmappedBuffer);
+
+    uint8_t *const mBuffer;
+    const int mBufferSize;
+    void *const mMmappedBuffer;
+    const int mAlignedSize;
+    const int mMmapFd;
+    const bool mIsUpdatable;
+};
+}
+#endif /* LATINIME_MMAPPED_BUFFER_H */