Add spellcheck and word suggestion to the prediction service

third_party/android_prediction/suggest/policyimpl/dictionary/structure/v4/ver4_pt_node_array_reader.cpp

Index: third_party/android_prediction/suggest/policyimpl/dictionary/structure/v4/ver4_pt_node_array_reader.cpp
diff --git a/third_party/android_prediction/suggest/policyimpl/dictionary/structure/v4/ver4_pt_node_array_reader.cpp b/third_party/android_prediction/suggest/policyimpl/dictionary/structure/v4/ver4_pt_node_array_reader.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..23066361875e9a115dbc9984cdbaba853441e771
--- /dev/null
+++ b/third_party/android_prediction/suggest/policyimpl/dictionary/structure/v4/ver4_pt_node_array_reader.cpp
@@ -0,0 +1,79 @@
+/*
+ * 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 "third_party/android_prediction/suggest/policyimpl/dictionary/structure/v4/ver4_pt_node_array_reader.h"
+
+#include "third_party/android_prediction/suggest/policyimpl/dictionary/structure/pt_common/dynamic_pt_reading_utils.h"
+#include "third_party/android_prediction/suggest/policyimpl/dictionary/structure/pt_common/patricia_trie_reading_utils.h"
+#include "third_party/android_prediction/suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.h"
+
+namespace latinime {
+
+bool Ver4PtNodeArrayReader::readPtNodeArrayInfoAndReturnIfValid(const int ptNodeArrayPos,
+        int *const outPtNodeCount, int *const outFirstPtNodePos) const {
+    if (ptNodeArrayPos < 0 || ptNodeArrayPos >= mBuffer->getTailPosition()) {
+        // Reading invalid position because of a bug or a broken dictionary.
+        AKLOGE("Reading PtNode array info from invalid dictionary position: %d, dict size: %d",
+                ptNodeArrayPos, mBuffer->getTailPosition());
+        ASSERT(false);
+        return false;
+    }
+    const bool usesAdditionalBuffer = mBuffer->isInAdditionalBuffer(ptNodeArrayPos);
+    const uint8_t *const dictBuf = mBuffer->getBuffer(usesAdditionalBuffer);
+    int readingPos = ptNodeArrayPos;
+    if (usesAdditionalBuffer) {
+        readingPos -= mBuffer->getOriginalBufferSize();
+    }
+    const int ptNodeCountInArray = PatriciaTrieReadingUtils::getPtNodeArraySizeAndAdvancePosition(
+            dictBuf, &readingPos);
+    if (usesAdditionalBuffer) {
+        readingPos += mBuffer->getOriginalBufferSize();
+    }
+    if (ptNodeCountInArray < 0) {
+        AKLOGE("Invalid PtNode count in an array: %d.", ptNodeCountInArray);
+        return false;
+    }
+    *outPtNodeCount = ptNodeCountInArray;
+    *outFirstPtNodePos = readingPos;
+    return true;
+}
+
+bool Ver4PtNodeArrayReader::readForwardLinkAndReturnIfValid(const int forwordLinkPos,
+        int *const outNextPtNodeArrayPos) const {
+    if (forwordLinkPos < 0 || forwordLinkPos >= mBuffer->getTailPosition()) {
+        // Reading invalid position because of bug or broken dictionary.
+        AKLOGE("Reading forward link from invalid dictionary position: %d, dict size: %d",
+                forwordLinkPos, mBuffer->getTailPosition());
+        ASSERT(false);
+        return false;
+    }
+    const bool usesAdditionalBuffer = mBuffer->isInAdditionalBuffer(forwordLinkPos);
+    const uint8_t *const dictBuf = mBuffer->getBuffer(usesAdditionalBuffer);
+    int readingPos = forwordLinkPos;
+    if (usesAdditionalBuffer) {
+        readingPos -= mBuffer->getOriginalBufferSize();
+    }
+    const int nextPtNodeArrayOffset =
+            DynamicPtReadingUtils::getForwardLinkPosition(dictBuf, readingPos);
+    if (DynamicPtReadingUtils::isValidForwardLinkPosition(nextPtNodeArrayOffset)) {
+        *outNextPtNodeArrayPos = forwordLinkPos + nextPtNodeArrayOffset;
+    } else {
+        *outNextPtNodeArrayPos = NOT_A_DICT_POS;
+    }
+    return true;
+}
+
+} // namespace latinime