Add spellcheck and word suggestion to the prediction service

third_party/android_prediction/suggest/policyimpl/dictionary/header/header_read_write_utils.cpp

Index: third_party/android_prediction/suggest/policyimpl/dictionary/header/header_read_write_utils.cpp
diff --git a/third_party/android_prediction/suggest/policyimpl/dictionary/header/header_read_write_utils.cpp b/third_party/android_prediction/suggest/policyimpl/dictionary/header/header_read_write_utils.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..c2420361b9bc702f06e75d4dfc6aef61852f07be
--- /dev/null
+++ b/third_party/android_prediction/suggest/policyimpl/dictionary/header/header_read_write_utils.cpp
@@ -0,0 +1,231 @@
+/*
+ * Copyright (C) 2013, 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/header/header_read_write_utils.h"
+
+#include <cctype>
+#include <cstdio>
+#include <vector>
+
+#include "third_party/android_prediction/defines.h"
+#include "third_party/android_prediction/suggest/policyimpl/dictionary/utils/buffer_with_extendable_buffer.h"
+#include "third_party/android_prediction/suggest/policyimpl/dictionary/utils/byte_array_utils.h"
+
+namespace latinime {
+
+// Number of base-10 digits in the largest integer + 1 to leave room for a zero terminator.
+// As such, this is the maximum number of characters will be needed to represent an int as a
+// string, including the terminator; this is used as the size of a string buffer large enough to
+// hold any value that is intended to fit in an integer, e.g. in the code that reads the header
+// of the binary dictionary where a {key,value} string pair scheme is used.
+const int HeaderReadWriteUtils::LARGEST_INT_DIGIT_COUNT = 11;
+
+const int HeaderReadWriteUtils::MAX_ATTRIBUTE_KEY_LENGTH = 256;
+const int HeaderReadWriteUtils::MAX_ATTRIBUTE_VALUE_LENGTH = 256;
+
+const int HeaderReadWriteUtils::HEADER_MAGIC_NUMBER_SIZE = 4;
+const int HeaderReadWriteUtils::HEADER_DICTIONARY_VERSION_SIZE = 2;
+const int HeaderReadWriteUtils::HEADER_FLAG_SIZE = 2;
+const int HeaderReadWriteUtils::HEADER_SIZE_FIELD_SIZE = 4;
+
+const HeaderReadWriteUtils::DictionaryFlags HeaderReadWriteUtils::NO_FLAGS = 0;
+
+typedef DictionaryHeaderStructurePolicy::AttributeMap AttributeMap;
+
+/* static */ int HeaderReadWriteUtils::getHeaderSize(const uint8_t *const dictBuf) {
+    // See the format of the header in the comment in
+    // BinaryDictionaryFormatUtils::detectFormatVersion()
+    return ByteArrayUtils::readUint32(dictBuf, HEADER_MAGIC_NUMBER_SIZE
+            + HEADER_DICTIONARY_VERSION_SIZE + HEADER_FLAG_SIZE);
+}
+
+/* static */ HeaderReadWriteUtils::DictionaryFlags
+        HeaderReadWriteUtils::getFlags(const uint8_t *const dictBuf) {
+    return ByteArrayUtils::readUint16(dictBuf,
+            HEADER_MAGIC_NUMBER_SIZE + HEADER_DICTIONARY_VERSION_SIZE);
+}
+
+/* static */ HeaderReadWriteUtils::DictionaryFlags
+        HeaderReadWriteUtils::createAndGetDictionaryFlagsUsingAttributeMap(
+                const AttributeMap *const attributeMap) {
+    return NO_FLAGS;
+}
+
+/* static */ void HeaderReadWriteUtils::fetchAllHeaderAttributes(const uint8_t *const dictBuf,
+        AttributeMap *const headerAttributes) {
+    const int headerSize = getHeaderSize(dictBuf);
+    int pos = getHeaderOptionsPosition();
+    if (pos == NOT_A_DICT_POS) {
+        // The header doesn't have header options.
+        return;
+    }
+    int keyBuffer[MAX_ATTRIBUTE_KEY_LENGTH];
+    int valueBuffer[MAX_ATTRIBUTE_VALUE_LENGTH];
+    while (pos < headerSize) {
+        const int keyLength = ByteArrayUtils::readStringAndAdvancePosition(dictBuf,
+                MAX_ATTRIBUTE_KEY_LENGTH, keyBuffer, &pos);
+        std::vector<int> key;
+        key.insert(key.end(), keyBuffer, keyBuffer + keyLength);
+        const int valueLength = ByteArrayUtils::readStringAndAdvancePosition(dictBuf,
+                MAX_ATTRIBUTE_VALUE_LENGTH, valueBuffer, &pos);
+        std::vector<int> value;
+        value.insert(value.end(), valueBuffer, valueBuffer + valueLength);
+        headerAttributes->insert(AttributeMap::value_type(key, value));
+    }
+}
+
+/* static */ bool HeaderReadWriteUtils::writeDictionaryVersion(
+        BufferWithExtendableBuffer *const buffer, const FormatUtils::FORMAT_VERSION version,
+        int *const writingPos) {
+    if (!buffer->writeUintAndAdvancePosition(FormatUtils::MAGIC_NUMBER, HEADER_MAGIC_NUMBER_SIZE,
+            writingPos)) {
+        return false;
+    }
+    switch (version) {
+        case FormatUtils::VERSION_2:
+            // Version 2 dictionary writing is not supported.
+            return false;
+        case FormatUtils::VERSION_4_ONLY_FOR_TESTING:
+        case FormatUtils::VERSION_4:
+        case FormatUtils::VERSION_4_DEV:
+            return buffer->writeUintAndAdvancePosition(version /* data */,
+                    HEADER_DICTIONARY_VERSION_SIZE, writingPos);
+        default:
+            return false;
+    }
+}
+
+/* static */ bool HeaderReadWriteUtils::writeDictionaryFlags(
+        BufferWithExtendableBuffer *const buffer, const DictionaryFlags flags,
+        int *const writingPos) {
+    return buffer->writeUintAndAdvancePosition(flags, HEADER_FLAG_SIZE, writingPos);
+}
+
+/* static */ bool HeaderReadWriteUtils::writeDictionaryHeaderSize(
+        BufferWithExtendableBuffer *const buffer, const int size, int *const writingPos) {
+    return buffer->writeUintAndAdvancePosition(size, HEADER_SIZE_FIELD_SIZE, writingPos);
+}
+
+/* static */ bool HeaderReadWriteUtils::writeHeaderAttributes(
+        BufferWithExtendableBuffer *const buffer, const AttributeMap *const headerAttributes,
+        int *const writingPos) {
+    for (AttributeMap::const_iterator it = headerAttributes->begin();
+            it != headerAttributes->end(); ++it) {
+        if (it->first.empty() || it->second.empty()) {
+            continue;
+        }
+        // Write a key.
+        if (!buffer->writeCodePointsAndAdvancePosition(&(it->first.at(0)), it->first.size(),
+                true /* writesTerminator */, writingPos)) {
+            return false;
+        }
+        // Write a value.
+        if (!buffer->writeCodePointsAndAdvancePosition(&(it->second.at(0)), it->second.size(),
+                true /* writesTerminator */, writingPos)) {
+            return false;
+        }
+    }
+    return true;
+}
+
+/* static */ void HeaderReadWriteUtils::setCodePointVectorAttribute(
+        AttributeMap *const headerAttributes, const char *const key, const std::vector<int> value) {
+    AttributeMap::key_type keyVector;
+    insertCharactersIntoVector(key, &keyVector);
+    (*headerAttributes)[keyVector] = value;
+}
+
+/* static */ void HeaderReadWriteUtils::setBoolAttribute(AttributeMap *const headerAttributes,
+        const char *const key, const bool value) {
+    setIntAttribute(headerAttributes, key, value ? 1 : 0);
+}
+
+/* static */ void HeaderReadWriteUtils::setIntAttribute(AttributeMap *const headerAttributes,
+        const char *const key, const int value) {
+    AttributeMap::key_type keyVector;
+    insertCharactersIntoVector(key, &keyVector);
+    setIntAttributeInner(headerAttributes, &keyVector, value);
+}
+
+/* static */ void HeaderReadWriteUtils::setIntAttributeInner(AttributeMap *const headerAttributes,
+        const AttributeMap::key_type *const key, const int value) {
+    AttributeMap::mapped_type valueVector;
+    char charBuf[LARGEST_INT_DIGIT_COUNT];
+    snprintf(charBuf, sizeof(charBuf), "%d", value);
+    insertCharactersIntoVector(charBuf, &valueVector);
+    (*headerAttributes)[*key] = valueVector;
+}
+
+/* static */ const std::vector<int> HeaderReadWriteUtils::readCodePointVectorAttributeValue(
+        const AttributeMap *const headerAttributes, const char *const key) {
+    AttributeMap::key_type keyVector;
+    insertCharactersIntoVector(key, &keyVector);
+    AttributeMap::const_iterator it = headerAttributes->find(keyVector);
+    if (it == headerAttributes->end()) {
+        return std::vector<int>();
+    } else {
+        return it->second;
+    }
+}
+
+/* static */ bool HeaderReadWriteUtils::readBoolAttributeValue(
+        const AttributeMap *const headerAttributes, const char *const key,
+        const bool defaultValue) {
+    const int intDefaultValue = defaultValue ? 1 : 0;
+    const int intValue = readIntAttributeValue(headerAttributes, key, intDefaultValue);
+    return intValue != 0;
+}
+
+/* static */ int HeaderReadWriteUtils::readIntAttributeValue(
+        const AttributeMap *const headerAttributes, const char *const key,
+        const int defaultValue) {
+    AttributeMap::key_type keyVector;
+    insertCharactersIntoVector(key, &keyVector);
+    return readIntAttributeValueInner(headerAttributes, &keyVector, defaultValue);
+}
+
+/* static */ int HeaderReadWriteUtils::readIntAttributeValueInner(
+        const AttributeMap *const headerAttributes, const AttributeMap::key_type *const key,
+        const int defaultValue) {
+    AttributeMap::const_iterator it = headerAttributes->find(*key);
+    if (it != headerAttributes->end()) {
+        int value = 0;
+        bool isNegative = false;
+        for (size_t i = 0; i < it->second.size(); ++i) {
+            if (i == 0 && it->second.at(i) == '-') {
+                isNegative = true;
+            } else {
+                if (!isdigit(it->second.at(i))) {
+                    // If not a number.
+                    return defaultValue;
+                }
+                value *= 10;
+                value += it->second.at(i) - '0';
+            }
+        }
+        return isNegative ? -value : value;
+    }
+    return defaultValue;
+}
+
+/* static */ void HeaderReadWriteUtils::insertCharactersIntoVector(const char *const characters,
+        std::vector<int> *const vector) {
+    for (int i = 0; characters[i]; ++i) {
+        vector->push_back(characters[i]);
+    }
+}
+
+} // namespace latinime