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      1 /*
      2  * Copyright (C) 2013, The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *     http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include "log_utils.h"
     18 
     19 #include <cstdio>
     20 #include <stdarg.h>
     21 
     22 #include "defines.h"
     23 
     24 namespace latinime {
     25     /* static */ void LogUtils::logToJava(JNIEnv *const env, const char *const format, ...) {
     26         static const char *TAG = "LatinIME:LogUtils";
     27         const jclass androidUtilLogClass = env->FindClass("android/util/Log");
     28         if (!androidUtilLogClass) {
     29             // If we can't find the class, we are probably in off-device testing, and
     30             // it's expected. Regardless, logging is not essential to functionality, so
     31             // we should just return. However, FindClass has thrown an exception behind
     32             // our back and there is no way to prevent it from doing that, so we clear
     33             // the exception before we return.
     34             env->ExceptionClear();
     35             return;
     36         }
     37         const jmethodID logDotIMethodId = env->GetStaticMethodID(androidUtilLogClass, "i",
     38                 "(Ljava/lang/String;Ljava/lang/String;)I");
     39         if (!logDotIMethodId) {
     40             env->ExceptionClear();
     41             if (androidUtilLogClass) env->DeleteLocalRef(androidUtilLogClass);
     42             return;
     43         }
     44         const jstring javaTag = env->NewStringUTF(TAG);
     45 
     46         static const int DEFAULT_LINE_SIZE = 128;
     47         char fixedSizeCString[DEFAULT_LINE_SIZE];
     48         va_list argList;
     49         va_start(argList, format);
     50         // Get the necessary size. Add 1 for the 0 terminator.
     51         const int size = vsnprintf(fixedSizeCString, DEFAULT_LINE_SIZE, format, argList) + 1;
     52         va_end(argList);
     53 
     54         jstring javaString;
     55         if (size <= DEFAULT_LINE_SIZE) {
     56             // The buffer was large enough.
     57             javaString = env->NewStringUTF(fixedSizeCString);
     58         } else {
     59             // The buffer was not large enough.
     60             va_start(argList, format);
     61             char variableSizeCString[size];
     62             vsnprintf(variableSizeCString, size, format, argList);
     63             va_end(argList);
     64             javaString = env->NewStringUTF(variableSizeCString);
     65         }
     66 
     67         env->CallStaticIntMethod(androidUtilLogClass, logDotIMethodId, javaTag, javaString);
     68         if (javaString) env->DeleteLocalRef(javaString);
     69         if (javaTag) env->DeleteLocalRef(javaTag);
     70         if (androidUtilLogClass) env->DeleteLocalRef(androidUtilLogClass);
     71     }
     72 }
     73