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      1 /* //device/libs/android_runtime/android_util_Log.cpp
      2 **
      3 ** Copyright 2006, The Android Open Source Project
      4 **
      5 ** Licensed under the Apache License, Version 2.0 (the "License");
      6 ** you may not use this file except in compliance with the License.
      7 ** You may obtain a copy of the License at
      8 **
      9 **     http://www.apache.org/licenses/LICENSE-2.0
     10 **
     11 ** Unless required by applicable law or agreed to in writing, software
     12 ** distributed under the License is distributed on an "AS IS" BASIS,
     13 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     14 ** See the License for the specific language governing permissions and
     15 ** limitations under the License.
     16 */
     17 
     18 #define LOG_NAMESPACE "log.tag."
     19 #define LOG_TAG "Log_println"
     20 
     21 #include <android-base/macros.h>
     22 #include <assert.h>
     23 #include <cutils/properties.h>
     24 #include <log/logger.h>               // For LOGGER_ENTRY_MAX_PAYLOAD.
     25 #include <utils/Log.h>
     26 #include <utils/String8.h>
     27 
     28 #include "jni.h"
     29 #include "JNIHelp.h"
     30 #include "utils/misc.h"
     31 #include "core_jni_helpers.h"
     32 #include "android_util_Log.h"
     33 
     34 namespace android {
     35 
     36 struct levels_t {
     37     jint verbose;
     38     jint debug;
     39     jint info;
     40     jint warn;
     41     jint error;
     42     jint assert;
     43 };
     44 static levels_t levels;
     45 
     46 static jboolean isLoggable(const char* tag, jint level) {
     47     return __android_log_is_loggable(level, tag, ANDROID_LOG_INFO);
     48 }
     49 
     50 static jboolean android_util_Log_isLoggable(JNIEnv* env, jobject clazz, jstring tag, jint level)
     51 {
     52     if (tag == NULL) {
     53         return false;
     54     }
     55 
     56     const char* chars = env->GetStringUTFChars(tag, NULL);
     57     if (!chars) {
     58         return false;
     59     }
     60 
     61     jboolean result = false;
     62     if ((strlen(chars)+sizeof(LOG_NAMESPACE)) > PROPERTY_KEY_MAX) {
     63         char buf2[200];
     64         snprintf(buf2, sizeof(buf2), "Log tag \"%s\" exceeds limit of %zu characters\n",
     65                 chars, PROPERTY_KEY_MAX - sizeof(LOG_NAMESPACE));
     66 
     67         jniThrowException(env, "java/lang/IllegalArgumentException", buf2);
     68     } else {
     69         result = isLoggable(chars, level);
     70     }
     71 
     72     env->ReleaseStringUTFChars(tag, chars);
     73     return result;
     74 }
     75 
     76 bool android_util_Log_isVerboseLogEnabled(const char* tag) {
     77     return isLoggable(tag, levels.verbose);
     78 }
     79 
     80 /*
     81  * In class android.util.Log:
     82  *  public static native int println_native(int buffer, int priority, String tag, String msg)
     83  */
     84 static jint android_util_Log_println_native(JNIEnv* env, jobject clazz,
     85         jint bufID, jint priority, jstring tagObj, jstring msgObj)
     86 {
     87     const char* tag = NULL;
     88     const char* msg = NULL;
     89 
     90     if (msgObj == NULL) {
     91         jniThrowNullPointerException(env, "println needs a message");
     92         return -1;
     93     }
     94 
     95     if (bufID < 0 || bufID >= LOG_ID_MAX) {
     96         jniThrowNullPointerException(env, "bad bufID");
     97         return -1;
     98     }
     99 
    100     if (tagObj != NULL)
    101         tag = env->GetStringUTFChars(tagObj, NULL);
    102     msg = env->GetStringUTFChars(msgObj, NULL);
    103 
    104     int res = __android_log_buf_write(bufID, (android_LogPriority)priority, tag, msg);
    105 
    106     if (tag != NULL)
    107         env->ReleaseStringUTFChars(tagObj, tag);
    108     env->ReleaseStringUTFChars(msgObj, msg);
    109 
    110     return res;
    111 }
    112 
    113 /*
    114  * In class android.util.Log:
    115  *  private static native int logger_entry_max_payload_native()
    116  */
    117 static jint android_util_Log_logger_entry_max_payload_native(JNIEnv* env ATTRIBUTE_UNUSED,
    118                                                              jobject clazz ATTRIBUTE_UNUSED)
    119 {
    120     return static_cast<jint>(LOGGER_ENTRY_MAX_PAYLOAD);
    121 }
    122 
    123 /*
    124  * JNI registration.
    125  */
    126 static const JNINativeMethod gMethods[] = {
    127     /* name, signature, funcPtr */
    128     { "isLoggable",      "(Ljava/lang/String;I)Z", (void*) android_util_Log_isLoggable },
    129     { "println_native",  "(IILjava/lang/String;Ljava/lang/String;)I", (void*) android_util_Log_println_native },
    130     { "logger_entry_max_payload_native",  "()I", (void*) android_util_Log_logger_entry_max_payload_native },
    131 };
    132 
    133 int register_android_util_Log(JNIEnv* env)
    134 {
    135     jclass clazz = FindClassOrDie(env, "android/util/Log");
    136 
    137     levels.verbose = env->GetStaticIntField(clazz, GetStaticFieldIDOrDie(env, clazz, "VERBOSE", "I"));
    138     levels.debug = env->GetStaticIntField(clazz, GetStaticFieldIDOrDie(env, clazz, "DEBUG", "I"));
    139     levels.info = env->GetStaticIntField(clazz, GetStaticFieldIDOrDie(env, clazz, "INFO", "I"));
    140     levels.warn = env->GetStaticIntField(clazz, GetStaticFieldIDOrDie(env, clazz, "WARN", "I"));
    141     levels.error = env->GetStaticIntField(clazz, GetStaticFieldIDOrDie(env, clazz, "ERROR", "I"));
    142     levels.assert = env->GetStaticIntField(clazz, GetStaticFieldIDOrDie(env, clazz, "ASSERT", "I"));
    143 
    144     return RegisterMethodsOrDie(env, "android/util/Log", gMethods, NELEM(gMethods));
    145 }
    146 
    147 }; // namespace android
    148