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
24namespace 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