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 <log/log.h>               // For LOGGER_ENTRY_MAX_PAYLOAD.
24 #include <utils/Log.h>
25 #include <utils/String8.h>
26 
27 #include "jni.h"
28 #include <nativehelper/JNIHelp.h>
29 #include "utils/misc.h"
30 #include "core_jni_helpers.h"
31 #include "android_util_Log.h"
32 
33 namespace android {
34 
35 struct levels_t {
36     jint verbose;
37     jint debug;
38     jint info;
39     jint warn;
40     jint error;
41     jint assert;
42 };
43 static levels_t levels;
44 
isLoggable(const char * tag,jint level)45 static jboolean isLoggable(const char* tag, jint level) {
46     return __android_log_is_loggable(level, tag, ANDROID_LOG_INFO);
47 }
48 
android_util_Log_isLoggable(JNIEnv * env,jobject clazz,jstring tag,jint level)49 static jboolean android_util_Log_isLoggable(JNIEnv* env, jobject clazz, jstring tag, jint level)
50 {
51     if (tag == NULL) {
52         return false;
53     }
54 
55     const char* chars = env->GetStringUTFChars(tag, NULL);
56     if (!chars) {
57         return false;
58     }
59 
60     jboolean result = isLoggable(chars, level);
61 
62     env->ReleaseStringUTFChars(tag, chars);
63     return result;
64 }
65 
android_util_Log_isVerboseLogEnabled(const char * tag)66 bool android_util_Log_isVerboseLogEnabled(const char* tag) {
67     return isLoggable(tag, levels.verbose);
68 }
69 
70 /*
71  * In class android.util.Log:
72  *  public static native int println_native(int buffer, int priority, String tag, String msg)
73  */
android_util_Log_println_native(JNIEnv * env,jobject clazz,jint bufID,jint priority,jstring tagObj,jstring msgObj)74 static jint android_util_Log_println_native(JNIEnv* env, jobject clazz,
75         jint bufID, jint priority, jstring tagObj, jstring msgObj)
76 {
77     const char* tag = NULL;
78     const char* msg = NULL;
79 
80     if (msgObj == NULL) {
81         jniThrowNullPointerException(env, "println needs a message");
82         return -1;
83     }
84 
85     if (bufID < 0 || bufID >= LOG_ID_MAX) {
86         jniThrowNullPointerException(env, "bad bufID");
87         return -1;
88     }
89 
90     if (tagObj != NULL)
91         tag = env->GetStringUTFChars(tagObj, NULL);
92     msg = env->GetStringUTFChars(msgObj, NULL);
93 
94     int res = __android_log_buf_write(bufID, (android_LogPriority)priority, tag, msg);
95 
96     if (tag != NULL)
97         env->ReleaseStringUTFChars(tagObj, tag);
98     env->ReleaseStringUTFChars(msgObj, msg);
99 
100     return res;
101 }
102 
103 /*
104  * In class android.util.Log:
105  *  private static native int logger_entry_max_payload_native()
106  */
android_util_Log_logger_entry_max_payload_native(JNIEnv * env ATTRIBUTE_UNUSED,jobject clazz ATTRIBUTE_UNUSED)107 static jint android_util_Log_logger_entry_max_payload_native(JNIEnv* env ATTRIBUTE_UNUSED,
108                                                              jobject clazz ATTRIBUTE_UNUSED)
109 {
110     return static_cast<jint>(LOGGER_ENTRY_MAX_PAYLOAD);
111 }
112 
113 /*
114  * JNI registration.
115  */
116 static const JNINativeMethod gMethods[] = {
117     /* name, signature, funcPtr */
118     { "isLoggable",      "(Ljava/lang/String;I)Z", (void*) android_util_Log_isLoggable },
119     { "println_native",  "(IILjava/lang/String;Ljava/lang/String;)I", (void*) android_util_Log_println_native },
120     { "logger_entry_max_payload_native",  "()I", (void*) android_util_Log_logger_entry_max_payload_native },
121 };
122 
register_android_util_Log(JNIEnv * env)123 int register_android_util_Log(JNIEnv* env)
124 {
125     jclass clazz = FindClassOrDie(env, "android/util/Log");
126 
127     levels.verbose = env->GetStaticIntField(clazz, GetStaticFieldIDOrDie(env, clazz, "VERBOSE", "I"));
128     levels.debug = env->GetStaticIntField(clazz, GetStaticFieldIDOrDie(env, clazz, "DEBUG", "I"));
129     levels.info = env->GetStaticIntField(clazz, GetStaticFieldIDOrDie(env, clazz, "INFO", "I"));
130     levels.warn = env->GetStaticIntField(clazz, GetStaticFieldIDOrDie(env, clazz, "WARN", "I"));
131     levels.error = env->GetStaticIntField(clazz, GetStaticFieldIDOrDie(env, clazz, "ERROR", "I"));
132     levels.assert = env->GetStaticIntField(clazz, GetStaticFieldIDOrDie(env, clazz, "ASSERT", "I"));
133 
134     return RegisterMethodsOrDie(env, "android/util/Log", gMethods, NELEM(gMethods));
135 }
136 
137 }; // namespace android
138