android_util_Log.cpp revision 4b57553e693c9705e8363d3e0e9d881261b3e6fa 
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
34namespace android {
35
36struct levels_t {
37    jint verbose;
38    jint debug;
39    jint info;
40    jint warn;
41    jint error;
42    jint assert;
43};
44static levels_t levels;
45
46static 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
60static 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        return false;
68    }
69
70    int logLevel = toLevel(buf);
71    return logLevel >= 0 && level >= logLevel;
72}
73
74static 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
100bool 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 */
108static 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 */
140static 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
146int 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