/*
* Copyright (C) 2017 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.
*/
// Simple JNI wrapper for the SmartSelection library.
#include "textclassifier_jni.h"
#include <jni.h>
#include <vector>
#include "lang_id/lang-id.h"
#include "smartselect/text-classification-model.h"
using libtextclassifier::TextClassificationModel;
using libtextclassifier::ModelOptions;
using libtextclassifier::nlp_core::lang_id::LangId;
namespace {
bool JStringToUtf8String(JNIEnv* env, const jstring& jstr,
std::string* result) {
if (jstr == nullptr) {
*result = std::string();
return false;
}
jclass string_class = env->FindClass("java/lang/String");
jmethodID get_bytes_id =
env->GetMethodID(string_class, "getBytes", "(Ljava/lang/String;)[B");
jstring encoding = env->NewStringUTF("UTF-8");
jbyteArray array = reinterpret_cast<jbyteArray>(
env->CallObjectMethod(jstr, get_bytes_id, encoding));
jbyte* const array_bytes = env->GetByteArrayElements(array, JNI_FALSE);
int length = env->GetArrayLength(array);
*result = std::string(reinterpret_cast<char*>(array_bytes), length);
// Release the array.
env->ReleaseByteArrayElements(array, array_bytes, JNI_ABORT);
env->DeleteLocalRef(array);
env->DeleteLocalRef(string_class);
env->DeleteLocalRef(encoding);
return true;
}
std::string ToStlString(JNIEnv* env, const jstring& str) {
std::string result;
JStringToUtf8String(env, str, &result);
return result;
}
jobjectArray ScoredStringsToJObjectArray(
JNIEnv* env, const std::string& result_class_name,
const std::vector<std::pair<std::string, float>>& classification_result) {
jclass result_class = env->FindClass(result_class_name.c_str());
jmethodID result_class_constructor =
env->GetMethodID(result_class, "<init>", "(Ljava/lang/String;F)V");
jobjectArray results =
env->NewObjectArray(classification_result.size(), result_class, nullptr);
for (int i = 0; i < classification_result.size(); i++) {
jstring row_string =
env->NewStringUTF(classification_result[i].first.c_str());
jobject result =
env->NewObject(result_class, result_class_constructor, row_string,
static_cast<jfloat>(classification_result[i].second));
env->SetObjectArrayElement(results, i, result);
env->DeleteLocalRef(result);
}
env->DeleteLocalRef(result_class);
return results;
}
} // namespace
namespace libtextclassifier {
using libtextclassifier::CodepointSpan;
namespace {
CodepointSpan ConvertIndicesBMPUTF8(const std::string& utf8_str,
CodepointSpan orig_indices,
bool from_utf8) {
const libtextclassifier::UnicodeText unicode_str =
libtextclassifier::UTF8ToUnicodeText(utf8_str, /*do_copy=*/false);
int unicode_index = 0;
int bmp_index = 0;
const int* source_index;
const int* target_index;
if (from_utf8) {
source_index = &unicode_index;
target_index = &bmp_index;
} else {
source_index = &bmp_index;
target_index = &unicode_index;
}
CodepointSpan result{-1, -1};
std::function<void()> assign_indices_fn = [&result, &orig_indices,
&source_index, &target_index]() {
if (orig_indices.first == *source_index) {
result.first = *target_index;
}
if (orig_indices.second == *source_index) {
result.second = *target_index;
}
};
for (auto it = unicode_str.begin(); it != unicode_str.end();
++it, ++unicode_index, ++bmp_index) {
assign_indices_fn();
// There is 1 extra character in the input for each UTF8 character > 0xFFFF.
if (*it > 0xFFFF) {
++bmp_index;
}
}
assign_indices_fn();
return result;
}
} // namespace
CodepointSpan ConvertIndicesBMPToUTF8(const std::string& utf8_str,
CodepointSpan orig_indices) {
return ConvertIndicesBMPUTF8(utf8_str, orig_indices, /*from_utf8=*/false);
}
CodepointSpan ConvertIndicesUTF8ToBMP(const std::string& utf8_str,
CodepointSpan orig_indices) {
return ConvertIndicesBMPUTF8(utf8_str, orig_indices, /*from_utf8=*/true);
}
} // namespace libtextclassifier
using libtextclassifier::ConvertIndicesUTF8ToBMP;
using libtextclassifier::ConvertIndicesBMPToUTF8;
using libtextclassifier::CodepointSpan;
JNIEXPORT jlong JNICALL
Java_android_view_textclassifier_SmartSelection_nativeNew(JNIEnv* env,
jobject thiz,
jint fd) {
TextClassificationModel* model = new TextClassificationModel(fd);
return reinterpret_cast<jlong>(model);
}
JNIEXPORT jintArray JNICALL
Java_android_view_textclassifier_SmartSelection_nativeSuggest(
JNIEnv* env, jobject thiz, jlong ptr, jstring context, jint selection_begin,
jint selection_end) {
TextClassificationModel* model =
reinterpret_cast<TextClassificationModel*>(ptr);
const std::string context_utf8 = ToStlString(env, context);
CodepointSpan input_indices =
ConvertIndicesBMPToUTF8(context_utf8, {selection_begin, selection_end});
CodepointSpan selection =
model->SuggestSelection(context_utf8, input_indices);
selection = ConvertIndicesUTF8ToBMP(context_utf8, selection);
jintArray result = env->NewIntArray(2);
env->SetIntArrayRegion(result, 0, 1, &(std::get<0>(selection)));
env->SetIntArrayRegion(result, 1, 1, &(std::get<1>(selection)));
return result;
}
JNIEXPORT jobjectArray JNICALL
Java_android_view_textclassifier_SmartSelection_nativeClassifyText(
JNIEnv* env, jobject thiz, jlong ptr, jstring context, jint selection_begin,
jint selection_end, jint input_flags) {
TextClassificationModel* ff_model =
reinterpret_cast<TextClassificationModel*>(ptr);
const std::vector<std::pair<std::string, float>> classification_result =
ff_model->ClassifyText(ToStlString(env, context),
{selection_begin, selection_end}, input_flags);
return ScoredStringsToJObjectArray(
env, "android/view/textclassifier/SmartSelection$ClassificationResult",
classification_result);
}
JNIEXPORT void JNICALL
Java_android_view_textclassifier_SmartSelection_nativeClose(JNIEnv* env,
jobject thiz,
jlong ptr) {
TextClassificationModel* model =
reinterpret_cast<TextClassificationModel*>(ptr);
delete model;
}
JNIEXPORT jlong JNICALL Java_android_view_textclassifier_LangId_nativeNew(
JNIEnv* env, jobject thiz, jint fd) {
return reinterpret_cast<jlong>(new LangId(fd));
}
JNIEXPORT jstring JNICALL
Java_android_view_textclassifier_SmartSelection_nativeGetLanguage(JNIEnv* env,
jobject clazz,
jint fd) {
ModelOptions model_options;
if (ReadSelectionModelOptions(fd, &model_options)) {
return env->NewStringUTF(model_options.language().c_str());
} else {
return env->NewStringUTF("UNK");
}
}
JNIEXPORT jint JNICALL
Java_android_view_textclassifier_SmartSelection_nativeGetVersion(JNIEnv* env,
jobject clazz,
jint fd) {
ModelOptions model_options;
if (ReadSelectionModelOptions(fd, &model_options)) {
return model_options.version();
} else {
return -1;
}
}
JNIEXPORT jobjectArray JNICALL
Java_android_view_textclassifier_LangId_nativeFindLanguages(JNIEnv* env,
jobject thiz,
jlong ptr,
jstring text) {
LangId* lang_id = reinterpret_cast<LangId*>(ptr);
const std::vector<std::pair<std::string, float>> scored_languages =
lang_id->FindLanguages(ToStlString(env, text));
return ScoredStringsToJObjectArray(
env, "android/view/textclassifier/LangId$ClassificationResult",
scored_languages);
}
JNIEXPORT void JNICALL Java_android_view_textclassifier_LangId_nativeClose(
JNIEnv* env, jobject thiz, jlong ptr) {
LangId* lang_id = reinterpret_cast<LangId*>(ptr);
delete lang_id;
}
JNIEXPORT int JNICALL Java_android_view_textclassifier_LangId_nativeGetVersion(
JNIEnv* env, jobject clazz, jint fd) {
std::unique_ptr<LangId> lang_id(new LangId(fd));
return lang_id->version();
}