Remove shouldBlockAutoCorrectionBySafetyNet

Bug: 13756409

[Category diff]
+1      27
-1       0
+2       0
-2       0
+3       0
-3       1
+4      11
-4       0
+5      51
-5       0
+6       0
-6      38
+7       0
-7      50

[Weighted category diff]
+1      28
-1       0
+2       0
-2       0
+3       0
-3       1
+4      11
-4       0
+5      51
-5       0
+6       0
-6      39
+7       0
-7      50

show diff for ./en_user_log_phones_2011_08.csv
+1       4
+4       5
+5       7
-6       9
-7       7

The increase of false positives comes from the spaceless
typing test cases that are synthetic data.

Change-Id: I4ea77aa56ebfaa5518c71107169e1d2332de6327

java/src/com/android/inputmethod/latin/suggestions/SuggestionStripLayoutHelper.java

@@ -321,18 +321,6 @@ final class SuggestionStripLayoutHelper {
         } else {
             color = mColorSuggested;
         }
-        if (DebugFlags.DEBUG_ENABLED && suggestedWords.size() > 1) {
-            // If we auto-correct, then the autocorrection is in slot 0 and the typed word
-            // is in slot 1.
-            if (indexInSuggestedWords == SuggestedWords.INDEX_OF_AUTO_CORRECTION
-                    && suggestedWords.mWillAutoCorrect
-                    && AutoCorrectionUtils.shouldBlockAutoCorrectionBySafetyNet(
-                            suggestedWords.getLabel(SuggestedWords.INDEX_OF_AUTO_CORRECTION),
-                            suggestedWords.getLabel(SuggestedWords.INDEX_OF_TYPED_WORD))) {
-                return 0xFFFF0000;
-            }
-        }
-
         if (suggestedWords.mIsObsoleteSuggestions && !isTypedWord) {
             return applyAlpha(color, mAlphaObsoleted);
         }

java/src/com/android/inputmethod/latin/utils/AutoCorrectionUtils.java

@@ -52,41 +52,9 @@ public final class AutoCorrectionUtils {
                 if (DBG) {
                     Log.d(TAG, "Auto corrected by S-threshold.");
                 }
-                return !shouldBlockAutoCorrectionBySafetyNet(consideredWord, suggestion.mWord);
+                return true;
             }
         }
         return false;
     }
-
-    // TODO: Resolve the inconsistencies between the native auto correction algorithms and
-    // this safety net
-    public static boolean shouldBlockAutoCorrectionBySafetyNet(final String typedWord,
-            final String suggestion) {
-        // Safety net for auto correction.
-        // Actually if we hit this safety net, it's a bug.
-        // If user selected aggressive auto correction mode, there is no need to use the safety
-        // net.
-        // If the length of typed word is less than MINIMUM_SAFETY_NET_CHAR_LENGTH,
-        // we should not use net because relatively edit distance can be big.
-        final int typedWordLength = typedWord.length();
-        if (typedWordLength < MINIMUM_SAFETY_NET_CHAR_LENGTH) {
-            return false;
-        }
-        final int maxEditDistanceOfNativeDictionary = (typedWordLength / 2) + 1;
-        final int distance = BinaryDictionaryUtils.editDistance(typedWord, suggestion);
-        if (DBG) {
-            Log.d(TAG, "Autocorrected edit distance = " + distance
-                    + ", " + maxEditDistanceOfNativeDictionary);
-        }
-        if (distance > maxEditDistanceOfNativeDictionary) {
-            if (DBG) {
-                Log.e(TAG, "Safety net: before = " + typedWord + ", after = " + suggestion);
-                Log.e(TAG, "(Error) The edit distance of this correction exceeds limit. "
-                        + "Turning off auto-correction.");
-            }
-            return true;
-        } else {
-            return false;
-        }
-    }
 }

java/src/com/android/inputmethod/latin/utils/BinaryDictionaryUtils.java

@@ -43,7 +43,6 @@ public final class BinaryDictionaryUtils {
     private static native boolean createEmptyDictFileNative(String filePath, long dictVersion,
             String locale, String[] attributeKeyStringArray, String[] attributeValueStringArray);
     private static native float calcNormalizedScoreNative(int[] before, int[] after, int score);
-    private static native int editDistanceNative(int[] before, int[] after);
     private static native int setCurrentTimeForTestNative(int currentTime);
 
     public static DictionaryHeader getHeader(final File dictFile)
@@ -112,14 +111,6 @@ public final class BinaryDictionaryUtils {
                 StringUtils.toCodePointArray(after), score);
     }
 
-    public static int editDistance(final String before, final String after) {
-        if (before == null || after == null) {
-            throw new IllegalArgumentException();
-        }
-        return editDistanceNative(StringUtils.toCodePointArray(before),
-                StringUtils.toCodePointArray(after));
-    }
-
     /**
      * Control the current time to be used in the native code. If currentTime >= 0, this method sets
      * the current time and gets into test mode.

native/jni/com_android_inputmethod_latin_BinaryDictionaryUtils.cpp

@@ -68,18 +68,6 @@ static jfloat latinime_BinaryDictionaryUtils_calcNormalizedScore(JNIEnv *env, jc
             afterCodePoints, afterLength, score);
 }
 
-static jint latinime_BinaryDictionaryUtils_editDistance(JNIEnv *env, jclass clazz, jintArray before,
-        jintArray after) {
-    jsize beforeLength = env->GetArrayLength(before);
-    jsize afterLength = env->GetArrayLength(after);
-    int beforeCodePoints[beforeLength];
-    int afterCodePoints[afterLength];
-    env->GetIntArrayRegion(before, 0, beforeLength, beforeCodePoints);
-    env->GetIntArrayRegion(after, 0, afterLength, afterCodePoints);
-    return AutocorrectionThresholdUtils::editDistance(beforeCodePoints, beforeLength,
-            afterCodePoints, afterLength);
-}
-
 static int latinime_BinaryDictionaryUtils_setCurrentTimeForTest(JNIEnv *env, jclass clazz,
         jint currentTime) {
     if (currentTime >= 0) {
@@ -103,11 +91,6 @@ static const JNINativeMethod sMethods[] = {
         const_cast<char *>("([I[II)F"),
         reinterpret_cast<void *>(latinime_BinaryDictionaryUtils_calcNormalizedScore)
     },
-    {
-        const_cast<char *>("editDistanceNative"),
-        const_cast<char *>("([I[I)I"),
-        reinterpret_cast<void *>(latinime_BinaryDictionaryUtils_editDistance)
-    },
     {
         const_cast<char *>("setCurrentTimeForTestNative"),
         const_cast<char *>("(I)I"),

tests/src/com/android/inputmethod/latin/utils/EditDistanceTests.java

@@ -1,99 +0,0 @@
-/*
- * Copyright (C) 2010 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.utils;
-
-import android.test.AndroidTestCase;
-import android.test.suitebuilder.annotation.SmallTest;
-
-@SmallTest
-public class EditDistanceTests extends AndroidTestCase {
-    /*
-     * dist(kitten, sitting) == 3
-     *
-     * kitten-
-     * .|||.|
-     * sitting
-     */
-    public void testExample1() {
-        final int dist = BinaryDictionaryUtils.editDistance("kitten", "sitting");
-        assertEquals("edit distance between 'kitten' and 'sitting' is 3",
-                3, dist);
-    }
-
-    /*
-     * dist(Sunday, Saturday) == 3
-     *
-     * Saturday
-     * |  |.|||
-     * S--unday
-     */
-    public void testExample2() {
-        final int dist = BinaryDictionaryUtils.editDistance("Saturday", "Sunday");
-        assertEquals("edit distance between 'Saturday' and 'Sunday' is 3",
-                3, dist);
-    }
-
-    public void testBothEmpty() {
-        final int dist = BinaryDictionaryUtils.editDistance("", "");
-        assertEquals("when both string are empty, no edits are needed",
-                0, dist);
-    }
-
-    public void testFirstArgIsEmpty() {
-        final int dist = BinaryDictionaryUtils.editDistance("", "aaaa");
-        assertEquals("when only one string of the arguments is empty,"
-                 + " the edit distance is the length of the other.",
-                 4, dist);
-    }
-
-    public void testSecoondArgIsEmpty() {
-        final int dist = BinaryDictionaryUtils.editDistance("aaaa", "");
-        assertEquals("when only one string of the arguments is empty,"
-                 + " the edit distance is the length of the other.",
-                 4, dist);
-    }
-
-    public void testSameStrings() {
-        final String arg1 = "The quick brown fox jumps over the lazy dog.";
-        final String arg2 = "The quick brown fox jumps over the lazy dog.";
-        final int dist = BinaryDictionaryUtils.editDistance(arg1, arg2);
-        assertEquals("when same strings are passed, distance equals 0.",
-                0, dist);
-    }
-
-    public void testSameReference() {
-        final String arg = "The quick brown fox jumps over the lazy dog.";
-        final int dist = BinaryDictionaryUtils.editDistance(arg, arg);
-        assertEquals("when same string references are passed, the distance equals 0.",
-                0, dist);
-    }
-
-    public void testNullArg() {
-        try {
-            BinaryDictionaryUtils.editDistance(null, "aaa");
-            fail("IllegalArgumentException should be thrown.");
-        } catch (Exception e) {
-            assertTrue(e instanceof IllegalArgumentException);
-        }
-        try {
-            BinaryDictionaryUtils.editDistance("aaa", null);
-            fail("IllegalArgumentException should be thrown.");
-        } catch (Exception e) {
-            assertTrue(e instanceof IllegalArgumentException);
-        }
-    }
-}