Add spellcheck and word suggestion to the prediction service

third_party/prediction/suggest/policyimpl/dictionary/utils/mmapped_buffer.cpp

+/*
+ * 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.
+ */
+
+#include "third_party/prediction/suggest/policyimpl/dictionary/utils/mmapped_buffer.h"
+
+#include <cerrno>
+#include <climits>
+#include <cstdio>
+#include <fcntl.h>
+#include <sys/mman.h>
+#include <unistd.h>
+
+#include "third_party/prediction/suggest/policyimpl/dictionary/utils/file_utils.h"
+
+namespace latinime {
+
+/* static */ MmappedBuffer::MmappedBufferPtr MmappedBuffer::openBuffer(
+    const char* const path,
+    const int bufferOffset,
+    const int bufferSize,
+    const bool isUpdatable) {
+  const int mmapFd = open(path, O_RDONLY);
+  if (mmapFd < 0) {
+    AKLOGE("DICT: Can't open the source. path=%s errno=%d", path, errno);
+    return nullptr;
+  }
+  const int pagesize = sysconf(_SC_PAGESIZE);
+  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 nullptr;
+  }
+  uint8_t* const buffer = static_cast<uint8_t*>(mmappedBuffer) + offset;
+  if (!buffer) {
+    AKLOGE("DICT: buffer is null");
+    close(mmapFd);
+    return nullptr;
+  }
+  return MmappedBufferPtr(new MmappedBuffer(buffer, bufferSize, mmappedBuffer,
+                                            alignedSize, mmapFd, isUpdatable));
+}
+
+/* static */ MmappedBuffer::MmappedBufferPtr MmappedBuffer::openBuffer(
+    const char* const path,
+    const bool isUpdatable) {
+  const int fileSize = FileUtils::getFileSize(path);
+  if (fileSize == -1) {
+    return nullptr;
+  } else if (fileSize == 0) {
+    return MmappedBufferPtr(new MmappedBuffer(isUpdatable));
+  } else {
+    return openBuffer(path, 0 /* bufferOffset */, fileSize, isUpdatable);
+  }
+}
+
+/* static */ MmappedBuffer::MmappedBufferPtr MmappedBuffer::openBuffer(
+    const char* const dirPath,
+    const char* const fileName,
+    const bool isUpdatable) {
+  const int filePathBufferSize = PATH_MAX + 1 /* terminator */;
+  char filePath[filePathBufferSize];
+  const int filePathLength =
+      snprintf(filePath, filePathBufferSize, "%s%s", dirPath, fileName);
+  if (filePathLength >= filePathBufferSize) {
+    return nullptr;
+  }
+  return openBuffer(filePath, isUpdatable);
+}
+
+MmappedBuffer::~MmappedBuffer() {
+  if (mAlignedSize == 0) {
+    return;
+  }
+  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);
+  }
+}
+
+}  // namespace latinime