Use BinaryDictionaryUtils to read dictionary header.

Bug: 8187060
Bug:13035567
Change-Id: I90a5e0665c367f5a1bd786f4babf0d03e79e68fa

1 files changed, 25 insertions, 0 deletions

diff --git a/java/src/com/android/inputmethod/latin/utils/BinaryDictionaryUtils.java b/java/src/com/android/inputmethod/latin/utils/BinaryDictionaryUtils.java
index 6872285ad..638830046 100644
--- a/java/src/com/android/inputmethod/latin/utils/BinaryDictionaryUtils.java
+++ b/java/src/com/android/inputmethod/latin/utils/BinaryDictionaryUtils.java
@@ -17,8 +17,13 @@
 package com.android.inputmethod.latin.utils;
 
 import com.android.inputmethod.annotations.UsedForTesting;
+import com.android.inputmethod.latin.BinaryDictionary;
+import com.android.inputmethod.latin.makedict.DictionaryHeader;
+import com.android.inputmethod.latin.makedict.UnsupportedFormatException;
 import com.android.inputmethod.latin.personalization.PersonalizationHelper;
 
+import java.io.File;
+import java.io.IOException;
 import java.util.Locale;
 import java.util.Map;
 
@@ -39,6 +44,26 @@ public final class BinaryDictionaryUtils {
     private static native int editDistanceNative(int[] before, int[] after);
     private static native int setCurrentTimeForTestNative(int currentTime);
 
+    public static DictionaryHeader getHeader(final File dictFile)
+            throws IOException, UnsupportedFormatException {
+        return getHeaderWithOffsetAndLength(dictFile, 0 /* offset */, dictFile.length());
+    }
+
+    public static DictionaryHeader getHeaderWithOffsetAndLength(final File dictFile,
+            final long offset, final long length) throws IOException, UnsupportedFormatException {
+        // dictType is never used for reading the header. Passing an empty string.
+        final BinaryDictionary binaryDictionary = new BinaryDictionary(
+                dictFile.getAbsolutePath(), offset, length,
+                true /* useFullEditDistance */, null /* locale */, "" /* dictType */,
+                false /* isUpdatable */);
+        final DictionaryHeader header = binaryDictionary.getHeader();
+        binaryDictionary.close();
+        if (header == null) {
+            throw new IOException();
+        }
+        return header;
+    }
+
     public static boolean createEmptyDictFile(final String filePath, final long dictVersion,
             final Locale locale, final Map<String, String> attributeMap) {
         final String[] keyArray = new String[attributeMap.size()];