1 files changed, 213 insertions, 0 deletions
diff --git a/java/src/com/android/inputmethod/latin/makedict/Ver3DictDecoder.java b/java/src/com/android/inputmethod/latin/makedict/Ver3DictDecoder.java
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index 000000000..7c18c8caa
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+++ b/java/src/com/android/inputmethod/latin/makedict/Ver3DictDecoder.java
@@ -0,0 +1,213 @@
+/*
+ * 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.
+ */
+
+package com.android.inputmethod.latin.makedict;
+
+import com.android.inputmethod.annotations.UsedForTesting;
+import com.android.inputmethod.latin.makedict.BinaryDictDecoderUtils.CharEncoding;
+import com.android.inputmethod.latin.makedict.BinaryDictDecoderUtils.DictBuffer;
+import com.android.inputmethod.latin.makedict.FormatSpec.FileHeader;
+import com.android.inputmethod.latin.makedict.FormatSpec.FormatOptions;
+import com.android.inputmethod.latin.utils.ByteArrayDictBuffer;
+import com.android.inputmethod.latin.utils.JniUtils;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileNotFoundException;
+import java.io.IOException;
+import java.io.RandomAccessFile;
+import java.nio.ByteBuffer;
+import java.nio.channels.FileChannel;
+import java.util.HashMap;
+
+// TODO: Make an interface "DictDecoder".
+@UsedForTesting
+public class Ver3DictDecoder {
+
+    static {
+        JniUtils.loadNativeLibrary();
+    }
+
+    // TODO: implement something sensical instead of just a phony method
+    private static native int doNothing();
+
+    public interface DictionaryBufferFactory {
+        public DictBuffer getDictionaryBuffer(final File file)
+                throws FileNotFoundException, IOException;
+    }
+
+    /**
+     * Creates DictionaryBuffer using a ByteBuffer
+     *
+     * This class uses less memory than DictionaryBufferFromByteArrayFactory,
+     * but doesn't perform as fast.
+     * When operating on a big dictionary, this class is preferred.
+     */
+    public static final class DictionaryBufferFromReadOnlyByteBufferFactory
+            implements DictionaryBufferFactory {
+        @Override
+        public DictBuffer getDictionaryBuffer(final File file)
+                throws FileNotFoundException, IOException {
+            FileInputStream inStream = null;
+            ByteBuffer buffer = null;
+            try {
+                inStream = new FileInputStream(file);
+                buffer = inStream.getChannel().map(FileChannel.MapMode.READ_ONLY,
+                        0, file.length());
+            } finally {
+                if (inStream != null) {
+                    inStream.close();
+                }
+            }
+            if (buffer != null) {
+                return new BinaryDictDecoderUtils.ByteBufferDictBuffer(buffer);
+            }
+            return null;
+        }
+    }
+
+    /**
+     * Creates DictionaryBuffer using a byte array
+     *
+     * This class performs faster than other classes, but consumes more memory.
+     * When operating on a small dictionary, this class is preferred.
+     */
+    public static final class DictionaryBufferFromByteArrayFactory
+            implements DictionaryBufferFactory {
+        @Override
+        public DictBuffer getDictionaryBuffer(final File file)
+                throws FileNotFoundException, IOException {
+            FileInputStream inStream = null;
+            try {
+                inStream = new FileInputStream(file);
+                final byte[] array = new byte[(int) file.length()];
+                inStream.read(array);
+                return new ByteArrayDictBuffer(array);
+            } finally {
+                if (inStream != null) {
+                    inStream.close();
+                }
+            }
+        }
+    }
+
+    /**
+     * Creates DictionaryBuffer using a writable ByteBuffer and a RandomAccessFile.
+     *
+     * This class doesn't perform as fast as other classes,
+     * but this class is the only option available for destructive operations (insert or delete)
+     * on a dictionary.
+     */
+    @UsedForTesting
+    public static final class DictionaryBufferFromWritableByteBufferFactory
+            implements DictionaryBufferFactory {
+        @Override
+        public DictBuffer getDictionaryBuffer(final File file)
+                throws FileNotFoundException, IOException {
+            RandomAccessFile raFile = null;
+            ByteBuffer buffer = null;
+            try {
+                raFile = new RandomAccessFile(file, "rw");
+                buffer = raFile.getChannel().map(FileChannel.MapMode.READ_WRITE, 0, file.length());
+            } finally {
+                if (raFile != null) {
+                    raFile.close();
+                }
+            }
+            if (buffer != null) {
+                return new BinaryDictDecoderUtils.ByteBufferDictBuffer(buffer);
+            }
+            return null;
+        }
+    }
+
+    private final static class HeaderReader {
+        protected static int readVersion(final DictBuffer dictBuffer)
+                throws IOException, UnsupportedFormatException {
+            return BinaryDictDecoderUtils.checkFormatVersion(dictBuffer);
+        }
+
+        protected static int readOptionFlags(final DictBuffer dictBuffer) {
+            return dictBuffer.readUnsignedShort();
+        }
+
+        protected static int readHeaderSize(final DictBuffer dictBuffer) {
+            return dictBuffer.readInt();
+        }
+
+        protected static HashMap<String, String> readAttributes(final DictBuffer dictBuffer,
+                final int headerSize) {
+            final HashMap<String, String> attributes = new HashMap<String, String>();
+            while (dictBuffer.position() < headerSize) {
+                // We can avoid an infinite loop here since dictBuffer.position() is always
+                // increased by calling CharEncoding.readString.
+                final String key = CharEncoding.readString(dictBuffer);
+                final String value = CharEncoding.readString(dictBuffer);
+                attributes.put(key, value);
+            }
+            dictBuffer.position(headerSize);
+            return attributes;
+        }
+    }
+
+    private final File mDictionaryBinaryFile;
+    private DictBuffer mDictBuffer;
+
+    public Ver3DictDecoder(final File file) {
+        mDictionaryBinaryFile = file;
+        mDictBuffer = null;
+    }
+
+    public void openDictBuffer(final DictionaryBufferFactory factory)
+            throws FileNotFoundException, IOException {
+        mDictBuffer = factory.getDictionaryBuffer(mDictionaryBinaryFile);
+    }
+
+    public DictBuffer getDictBuffer() {
+        return mDictBuffer;
+    }
+
+    @UsedForTesting
+    public DictBuffer openAndGetDictBuffer(
+            final DictionaryBufferFactory factory)
+                    throws FileNotFoundException, IOException {
+        openDictBuffer(factory);
+        return getDictBuffer();
+    }
+
+    // TODO : Define public functions of decoders
+    public FileHeader readHeader() throws IOException, UnsupportedFormatException {
+        final int version = HeaderReader.readVersion(mDictBuffer);
+        final int optionsFlags = HeaderReader.readOptionFlags(mDictBuffer);
+
+        final int headerSize = HeaderReader.readHeaderSize(mDictBuffer);
+
+        if (headerSize < 0) {
+            throw new UnsupportedFormatException("header size can't be negative.");
+        }
+
+        final HashMap<String, String> attributes = HeaderReader.readAttributes(mDictBuffer,
+                headerSize);
+
+        final FileHeader header = new FileHeader(headerSize,
+                new FusionDictionary.DictionaryOptions(attributes,
+                        0 != (optionsFlags & FormatSpec.GERMAN_UMLAUT_PROCESSING_FLAG),
+                        0 != (optionsFlags & FormatSpec.FRENCH_LIGATURE_PROCESSING_FLAG)),
+                new FormatOptions(version,
+                        0 != (optionsFlags & FormatSpec.SUPPORTS_DYNAMIC_UPDATE)));
+        return header;
+    }
+}