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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 <assert.h>
     22 #include <cutils/properties.h>
     23 #include <utils/Log.h>
     24 #include <utils/String8.h>
     25 
     26 #include "jni.h"
     27 #include "JNIHelp.h"
     28 #include "utils/misc.h"
     29 #include "android_runtime/AndroidRuntime.h"
     30 #include "android_util_Log.h"
     31 
     32 #define MIN(a,b) ((a<b)?a:b)
     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 int toLevel(const char* value)
     47 {
     48     switch (value[0]) {
     49         case 'V': return levels.verbose;
     50         case 'D': return levels.debug;
     51         case 'I': return levels.info;
     52         case 'W': return levels.warn;
     53         case 'E': return levels.error;
     54         case 'A': return levels.assert;
     55         case 'S': return -1; // SUPPRESS
     56     }
     57     return levels.info;
     58 }
     59 
     60 static jboolean isLoggable(const char* tag, jint level) {
     61     String8 key;
     62     key.append(LOG_NAMESPACE);
     63     key.append(tag);
     64 
     65     char buf[PROPERTY_VALUE_MAX];
     66     if (property_get(key.string(), buf, "") <= 0) {
     67         buf[0] = '\0';
     68     }
     69 
     70     int logLevel = toLevel(buf);
     71     return logLevel >= 0 && level >= logLevel;
     72 }
     73 
     74 static jboolean android_util_Log_isLoggable(JNIEnv* env, jobject clazz, jstring tag, jint level)
     75 {
     76     if (tag == NULL) {
     77         return false;
     78     }
     79 
     80     const char* chars = env->GetStringUTFChars(tag, NULL);
     81     if (!chars) {
     82         return false;
     83     }
     84 
     85     jboolean result = false;
     86     if ((strlen(chars)+sizeof(LOG_NAMESPACE)) > PROPERTY_KEY_MAX) {
     87         char buf2[200];
     88         snprintf(buf2, sizeof(buf2), "Log tag \"%s\" exceeds limit of %d characters\n",
     89                 chars, PROPERTY_KEY_MAX - sizeof(LOG_NAMESPACE));
     90 
     91         jniThrowException(env, "java/lang/IllegalArgumentException", buf2);
     92     } else {
     93         result = isLoggable(chars, level);
     94     }
     95 
     96     env->ReleaseStringUTFChars(tag, chars);
     97     return result;
     98 }
     99 
    100 bool android_util_Log_isVerboseLogEnabled(const char* tag) {
    101     return isLoggable(tag, levels.verbose);
    102 }
    103 
    104 /*
    105  * In class android.util.Log:
    106  *  public static native int println_native(int buffer, int priority, String tag, String msg)
    107  */
    108 static jint android_util_Log_println_native(JNIEnv* env, jobject clazz,
    109         jint bufID, jint priority, jstring tagObj, jstring msgObj)
    110 {
    111     const char* tag = NULL;
    112     const char* msg = NULL;
    113 
    114     if (msgObj == NULL) {
    115         jniThrowNullPointerException(env, "println needs a message");
    116         return -1;
    117     }
    118 
    119     if (bufID < 0 || bufID >= LOG_ID_MAX) {
    120         jniThrowNullPointerException(env, "bad bufID");
    121         return -1;
    122     }
    123 
    124     if (tagObj != NULL)
    125         tag = env->GetStringUTFChars(tagObj, NULL);
    126     msg = env->GetStringUTFChars(msgObj, NULL);
    127 
    128     int res = __android_log_buf_write(bufID, (android_LogPriority)priority, tag, msg);
    129 
    130     if (tag != NULL)
    131         env->ReleaseStringUTFChars(tagObj, tag);
    132     env->ReleaseStringUTFChars(msgObj, msg);
    133 
    134     return res;
    135 }
    136 
    137 /*
    138  * JNI registration.
    139  */
    140 static JNINativeMethod gMethods[] = {
    141     /* name, signature, funcPtr */
    142     { "isLoggable",      "(Ljava/lang/String;I)Z", (void*) android_util_Log_isLoggable },
    143     { "println_native",  "(IILjava/lang/String;Ljava/lang/String;)I", (void*) android_util_Log_println_native },
    144 };
    145 
    146 int register_android_util_Log(JNIEnv* env)
    147 {
    148     jclass clazz = env->FindClass("android/util/Log");
    149 
    150     if (clazz == NULL) {
    151         ALOGE("Can't find android/util/Log");
    152         return -1;
    153     }
    154 
    155     levels.verbose = env->GetStaticIntField(clazz, env->GetStaticFieldID(clazz, "VERBOSE", "I"));
    156     levels.debug = env->GetStaticIntField(clazz, env->GetStaticFieldID(clazz, "DEBUG", "I"));
    157     levels.info = env->GetStaticIntField(clazz, env->GetStaticFieldID(clazz, "INFO", "I"));
    158     levels.warn = env->GetStaticIntField(clazz, env->GetStaticFieldID(clazz, "WARN", "I"));
    159     levels.error = env->GetStaticIntField(clazz, env->GetStaticFieldID(clazz, "ERROR", "I"));
    160     levels.assert = env->GetStaticIntField(clazz, env->GetStaticFieldID(clazz, "ASSERT", "I"));
    161 
    162     return AndroidRuntime::registerNativeMethods(env, "android/util/Log", gMethods, NELEM(gMethods));
    163 }
    164 
    165 }; // namespace android
    166