Add getDictDecoder.

Bug: 9618601
Change-Id: I173100ac704c03f7d5d0d53477e83cab5d1110d4

7 files changed, 58 insertions, 20 deletions

diff --git a/java/src/com/android/inputmethod/latin/BinaryDictionaryGetter.java b/java/src/com/android/inputmethod/latin/BinaryDictionaryGetter.java
index 2b6d983c0..566184244 100644
--- a/java/src/com/android/inputmethod/latin/BinaryDictionaryGetter.java
+++ b/java/src/com/android/inputmethod/latin/BinaryDictionaryGetter.java
@@ -21,9 +21,10 @@ import android.content.SharedPreferences;
 import android.content.res.AssetFileDescriptor;
 import android.util.Log;
 
+import com.android.inputmethod.latin.makedict.DictDecoder;
+import com.android.inputmethod.latin.makedict.FormatSpec;
 import com.android.inputmethod.latin.makedict.FormatSpec.FileHeader;
 import com.android.inputmethod.latin.makedict.UnsupportedFormatException;
-import com.android.inputmethod.latin.makedict.Ver3DictDecoder;
 import com.android.inputmethod.latin.utils.CollectionUtils;
 import com.android.inputmethod.latin.utils.DictionaryInfoUtils;
 import com.android.inputmethod.latin.utils.LocaleUtils;
@@ -228,7 +229,7 @@ final public class BinaryDictionaryGetter {
     private static boolean hackCanUseDictionaryFile(final Locale locale, final File f) {
         try {
             // Read the version of the file
-            final Ver3DictDecoder dictDecoder = new Ver3DictDecoder(f);
+            final DictDecoder dictDecoder = FormatSpec.getDictDecoder(f);
             final FileHeader header = dictDecoder.readHeader();
 
             final String version = header.mDictionaryOptions.mAttributes.get(VERSION_KEY);
diff --git a/java/src/com/android/inputmethod/latin/makedict/BinaryDictIOUtils.java b/java/src/com/android/inputmethod/latin/makedict/BinaryDictIOUtils.java
index 5cb40f30c..2c5e93e5c 100644
--- a/java/src/com/android/inputmethod/latin/makedict/BinaryDictIOUtils.java
+++ b/java/src/com/android/inputmethod/latin/makedict/BinaryDictIOUtils.java
@@ -148,7 +148,7 @@ public final class BinaryDictIOUtils {
      * @throws IOException if the file can't be read.
      * @throws UnsupportedFormatException if the format of the file is not recognized.
      */
-    /* package */ static void readUnigramsAndBigramsBinary(final Ver3DictDecoder dictDecoder,
+    /* package */ static void readUnigramsAndBigramsBinary(final DictDecoder dictDecoder,
             final Map<Integer, String> words, final Map<Integer, Integer> frequencies,
             final Map<Integer, ArrayList<PendingAttribute>> bigrams) throws IOException,
             UnsupportedFormatException {
@@ -169,7 +169,7 @@ public final class BinaryDictIOUtils {
      * @throws UnsupportedFormatException if the format of the file is not recognized.
      */
     @UsedForTesting
-    /* package */ static int getTerminalPosition(final Ver3DictDecoder dictDecoder,
+    /* package */ static int getTerminalPosition(final DictDecoder dictDecoder,
             final String word) throws IOException, UnsupportedFormatException {
         if (word == null) return FormatSpec.NOT_VALID_WORD;
         dictDecoder.setPosition(0);
@@ -519,7 +519,7 @@ public final class BinaryDictIOUtils {
             final File file, final long offset, final long length)
             throws FileNotFoundException, IOException, UnsupportedFormatException {
         final byte[] buffer = new byte[HEADER_READING_BUFFER_SIZE];
-        final Ver3DictDecoder dictDecoder = new Ver3DictDecoder(file,
+        final DictDecoder dictDecoder = FormatSpec.getDictDecoder(file,
                 new DictDecoder.DictionaryBufferFactory() {
                     @Override
                     public DictBuffer getDictionaryBuffer(File file)
diff --git a/java/src/com/android/inputmethod/latin/makedict/DictDecoder.java b/java/src/com/android/inputmethod/latin/makedict/DictDecoder.java
index 5e398bd41..40e852423 100644
--- a/java/src/com/android/inputmethod/latin/makedict/DictDecoder.java
+++ b/java/src/com/android/inputmethod/latin/makedict/DictDecoder.java
@@ -118,6 +118,14 @@ public interface DictDecoder {
     public boolean readForwardLinkAndAdvancePosition();
     public boolean hasNextPtNodeArray();
 
+    /**
+     * Opens the dictionary file and makes DictBuffer.
+     */
+    @UsedForTesting
+    public void openDictBuffer() throws FileNotFoundException, IOException;
+    @UsedForTesting
+    public boolean isOpenedDictBuffer();
+
     // Flags for DictionaryBufferFactory.
     public static final int USE_READONLY_BYTEBUFFER = 0x01000000;
     public static final int USE_BYTEARRAY = 0x02000000;
diff --git a/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java b/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java
index bf35f6a8a..44ae33de1 100644
--- a/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java
+++ b/java/src/com/android/inputmethod/latin/makedict/FormatSpec.java
@@ -18,8 +18,11 @@ package com.android.inputmethod.latin.makedict;
 
 import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.latin.Constants;
+import com.android.inputmethod.latin.makedict.DictDecoder.DictionaryBufferFactory;
 import com.android.inputmethod.latin.makedict.FusionDictionary.DictionaryOptions;
 
+import java.io.File;
+
 /**
  * Dictionary File Format Specification.
  */
@@ -341,6 +344,28 @@ public final class FormatSpec {
         }
     }
 
+    /**
+     * Returns new dictionary decoder.
+     *
+     * @param dictFile the dictionary file.
+     * @param bufferType the flag indicating buffer type which is used by the dictionary decoder.
+     * @return new dictionary decoder if the dictionary file exists, otherwise null.
+     */
+    public static DictDecoder getDictDecoder(final File dictFile, final int bufferType) {
+        if (!dictFile.isFile()) return null;
+        return new Ver3DictDecoder(dictFile, bufferType);
+    }
+
+    public static DictDecoder getDictDecoder(final File dictFile,
+            final DictionaryBufferFactory factory) {
+        if (!dictFile.isFile()) return null;
+        return new Ver3DictDecoder(dictFile, factory);
+    }
+
+    public static DictDecoder getDictDecoder(final File dictFile) {
+        return getDictDecoder(dictFile, DictDecoder.USE_READONLY_BYTEBUFFER);
+    }
+
     private FormatSpec() {
         // This utility class is not publicly instantiable.
     }
diff --git a/java/src/com/android/inputmethod/latin/makedict/Ver3DictDecoder.java b/java/src/com/android/inputmethod/latin/makedict/Ver3DictDecoder.java
index 6dff9b6d2..1a90a4b98 100644
--- a/java/src/com/android/inputmethod/latin/makedict/Ver3DictDecoder.java
+++ b/java/src/com/android/inputmethod/latin/makedict/Ver3DictDecoder.java
@@ -173,11 +173,7 @@ public class Ver3DictDecoder implements DictDecoder {
     private final DictionaryBufferFactory mBufferFactory;
     private DictBuffer mDictBuffer;
 
-    public Ver3DictDecoder(final File file) {
-        this(file, USE_READONLY_BYTEBUFFER);
-    }
-
-    public Ver3DictDecoder(final File file, final int factoryFlag) {
+    /* package */ Ver3DictDecoder(final File file, final int factoryFlag) {
         mDictionaryBinaryFile = file;
         mDictBuffer = null;
 
@@ -192,15 +188,21 @@ public class Ver3DictDecoder implements DictDecoder {
         }
     }
 
-    public Ver3DictDecoder(final File file, final DictionaryBufferFactory factory) {
+    /* package */ Ver3DictDecoder(final File file, final DictionaryBufferFactory factory) {
         mDictionaryBinaryFile = file;
         mBufferFactory = factory;
     }
 
+    @Override
     public void openDictBuffer() throws FileNotFoundException, IOException {
         mDictBuffer = mBufferFactory.getDictionaryBuffer(mDictionaryBinaryFile);
     }
 
+    @Override
+    public boolean isOpenedDictBuffer() {
+        return mDictBuffer != null;
+    }
+
     /* package */ DictBuffer getDictBuffer() {
         return mDictBuffer;
     }
diff --git a/java/src/com/android/inputmethod/latin/personalization/DynamicPredictionDictionaryBase.java b/java/src/com/android/inputmethod/latin/personalization/DynamicPredictionDictionaryBase.java
index 5b1d0647b..9364fb034 100644
--- a/java/src/com/android/inputmethod/latin/personalization/DynamicPredictionDictionaryBase.java
+++ b/java/src/com/android/inputmethod/latin/personalization/DynamicPredictionDictionaryBase.java
@@ -25,14 +25,13 @@ import com.android.inputmethod.latin.Constants;
 import com.android.inputmethod.latin.ExpandableBinaryDictionary;
 import com.android.inputmethod.latin.LatinImeLogger;
 import com.android.inputmethod.latin.makedict.DictDecoder;
-import com.android.inputmethod.latin.makedict.Ver3DictDecoder;
+import com.android.inputmethod.latin.makedict.FormatSpec;
 import com.android.inputmethod.latin.settings.Settings;
 import com.android.inputmethod.latin.utils.CollectionUtils;
 import com.android.inputmethod.latin.utils.UserHistoryDictIOUtils;
 import com.android.inputmethod.latin.utils.UserHistoryDictIOUtils.OnAddWordListener;
 
 import java.io.File;
-import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.util.ArrayList;
 
@@ -173,16 +172,19 @@ public abstract class DynamicPredictionDictionaryBase extends ExpandableBinaryDi
 
         // Load the dictionary from binary file
         final File dictFile = new File(mContext.getFilesDir(), mFileName);
-        final Ver3DictDecoder dictDecoder = new Ver3DictDecoder(dictFile,
+        final DictDecoder dictDecoder = FormatSpec.getDictDecoder(dictFile,
                 DictDecoder.USE_BYTEARRAY);
+        if (dictDecoder == null) {
+            // This is an expected condition: we don't have a user history dictionary for this
+            // language yet. It will be created sometime later.
+            return;
+        }
+
         try {
             dictDecoder.openDictBuffer();
             UserHistoryDictIOUtils.readDictionaryBinary(dictDecoder, listener);
-        } catch (FileNotFoundException e) {
-            // This is an expected condition: we don't have a user history dictionary for this
-            // language yet. It will be created sometime later.
         } catch (IOException e) {
-            Log.e(TAG, "IOException on opening a bytebuffer", e);
+            Log.d(TAG, "IOException on opening a bytebuffer", e);
         } finally {
             if (PROFILE_SAVE_RESTORE) {
                 final long diff = System.currentTimeMillis() - now;
diff --git a/java/src/com/android/inputmethod/latin/utils/UserHistoryDictIOUtils.java b/java/src/com/android/inputmethod/latin/utils/UserHistoryDictIOUtils.java
index 05f3061a8..ea32a74ff 100644
--- a/java/src/com/android/inputmethod/latin/utils/UserHistoryDictIOUtils.java
+++ b/java/src/com/android/inputmethod/latin/utils/UserHistoryDictIOUtils.java
@@ -20,13 +20,13 @@ import android.util.Log;
 
 import com.android.inputmethod.annotations.UsedForTesting;
 import com.android.inputmethod.latin.makedict.BinaryDictIOUtils;
+import com.android.inputmethod.latin.makedict.DictDecoder;
 import com.android.inputmethod.latin.makedict.DictEncoder;
 import com.android.inputmethod.latin.makedict.FormatSpec.FormatOptions;
 import com.android.inputmethod.latin.makedict.FusionDictionary;
 import com.android.inputmethod.latin.makedict.FusionDictionary.PtNodeArray;
 import com.android.inputmethod.latin.makedict.PendingAttribute;
 import com.android.inputmethod.latin.makedict.UnsupportedFormatException;
-import com.android.inputmethod.latin.makedict.Ver3DictDecoder;
 import com.android.inputmethod.latin.personalization.UserHistoryDictionaryBigramList;
 
 import java.io.IOException;
@@ -125,7 +125,7 @@ public final class UserHistoryDictIOUtils {
     /**
      * Reads dictionary from file.
      */
-    public static void readDictionaryBinary(final Ver3DictDecoder dictDecoder,
+    public static void readDictionaryBinary(final DictDecoder dictDecoder,
             final OnAddWordListener dict) {
         final TreeMap<Integer, String> unigrams = CollectionUtils.newTreeMap();
         final TreeMap<Integer, Integer> frequencies = CollectionUtils.newTreeMap();