1 files changed, 123 insertions, 0 deletions
diff --git a/native/jni/src/dictionary/property/ngram_context.cpp b/native/jni/src/dictionary/property/ngram_context.cpp
new file mode 100644
index 000000000..7b9c3eff6
--- /dev/null
+++ b/native/jni/src/dictionary/property/ngram_context.cpp
@@ -0,0 +1,123 @@
+/*
+ * Copyright (C) 2014 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 "dictionary/property/ngram_context.h"
+
+#include "dictionary/interface/dictionary_structure_with_buffer_policy.h"
+#include "utils/char_utils.h"
+
+namespace latinime {
+
+NgramContext::NgramContext() : mPrevWordCount(0) {}
+
+NgramContext::NgramContext(const NgramContext &ngramContext)
+        : mPrevWordCount(ngramContext.mPrevWordCount) {
+    for (size_t i = 0; i < mPrevWordCount; ++i) {
+        mPrevWordCodePointCount[i] = ngramContext.mPrevWordCodePointCount[i];
+        memmove(mPrevWordCodePoints[i], ngramContext.mPrevWordCodePoints[i],
+                sizeof(mPrevWordCodePoints[i][0]) * mPrevWordCodePointCount[i]);
+        mIsBeginningOfSentence[i] = ngramContext.mIsBeginningOfSentence[i];
+    }
+}
+
+NgramContext::NgramContext(const int prevWordCodePoints[][MAX_WORD_LENGTH],
+        const int *const prevWordCodePointCount, const bool *const isBeginningOfSentence,
+        const size_t prevWordCount)
+        : mPrevWordCount(std::min(NELEMS(mPrevWordCodePoints), prevWordCount)) {
+    clear();
+    for (size_t i = 0; i < mPrevWordCount; ++i) {
+        if (prevWordCodePointCount[i] < 0 || prevWordCodePointCount[i] > MAX_WORD_LENGTH) {
+            continue;
+        }
+        memmove(mPrevWordCodePoints[i], prevWordCodePoints[i],
+                sizeof(mPrevWordCodePoints[i][0]) * prevWordCodePointCount[i]);
+        mPrevWordCodePointCount[i] = prevWordCodePointCount[i];
+        mIsBeginningOfSentence[i] = isBeginningOfSentence[i];
+    }
+}
+
+NgramContext::NgramContext(const int *const prevWordCodePoints, const int prevWordCodePointCount,
+        const bool isBeginningOfSentence) : mPrevWordCount(1) {
+    clear();
+    if (prevWordCodePointCount > MAX_WORD_LENGTH || !prevWordCodePoints) {
+        return;
+    }
+    memmove(mPrevWordCodePoints[0], prevWordCodePoints,
+            sizeof(mPrevWordCodePoints[0][0]) * prevWordCodePointCount);
+    mPrevWordCodePointCount[0] = prevWordCodePointCount;
+    mIsBeginningOfSentence[0] = isBeginningOfSentence;
+}
+
+bool NgramContext::isValid() const {
+    if (mPrevWordCodePointCount[0] > 0) {
+        return true;
+    }
+    if (mIsBeginningOfSentence[0]) {
+        return true;
+    }
+    return false;
+}
+
+const CodePointArrayView NgramContext::getNthPrevWordCodePoints(const size_t n) const {
+    if (n <= 0 || n > mPrevWordCount) {
+        return CodePointArrayView();
+    }
+    return CodePointArrayView(mPrevWordCodePoints[n - 1], mPrevWordCodePointCount[n - 1]);
+}
+
+bool NgramContext::isNthPrevWordBeginningOfSentence(const size_t n) const {
+    if (n <= 0 || n > mPrevWordCount) {
+        return false;
+    }
+    return mIsBeginningOfSentence[n - 1];
+}
+
+/* static */ int NgramContext::getWordId(
+        const DictionaryStructureWithBufferPolicy *const dictStructurePolicy,
+        const int *const wordCodePoints, const int wordCodePointCount,
+        const bool isBeginningOfSentence, const bool tryLowerCaseSearch) {
+    if (!dictStructurePolicy || !wordCodePoints || wordCodePointCount > MAX_WORD_LENGTH) {
+        return NOT_A_WORD_ID;
+    }
+    int codePoints[MAX_WORD_LENGTH];
+    int codePointCount = wordCodePointCount;
+    memmove(codePoints, wordCodePoints, sizeof(int) * codePointCount);
+    if (isBeginningOfSentence) {
+        codePointCount = CharUtils::attachBeginningOfSentenceMarker(codePoints, codePointCount,
+                MAX_WORD_LENGTH);
+        if (codePointCount <= 0) {
+            return NOT_A_WORD_ID;
+        }
+    }
+    const CodePointArrayView codePointArrayView(codePoints, codePointCount);
+    const int wordId = dictStructurePolicy->getWordId(codePointArrayView,
+            false /* forceLowerCaseSearch */);
+    if (wordId != NOT_A_WORD_ID || !tryLowerCaseSearch) {
+        // Return the id when when the word was found or doesn't try lower case search.
+        return wordId;
+    }
+    // Check bigrams for lower-cased previous word if original was not found. Useful for
+    // auto-capitalized words like "The [current_word]".
+    return dictStructurePolicy->getWordId(codePointArrayView, true /* forceLowerCaseSearch */);
+}
+
+void NgramContext::clear() {
+    for (size_t i = 0; i < NELEMS(mPrevWordCodePoints); ++i) {
+        mPrevWordCodePointCount[i] = 0;
+        mIsBeginningOfSentence[i] = false;
+    }
+}
+} // namespace latinime