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 
isLoggable(const char * tag,jint level)46 static jboolean isLoggable(const char* tag, jint level) {
47     return __android_log_is_loggable(level, tag, ANDROID_LOG_INFO);
48 }
49 
android_util_Log_isLoggable(JNIEnv * env,jobject clazz,jstring tag,jint level)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 
android_util_Log_isVerboseLogEnabled(const char * tag)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  */
android_util_Log_println_native(JNIEnv * env,jobject clazz,jint bufID,jint priority,jstring tagObj,jstring msgObj)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  */
android_util_Log_logger_entry_max_payload_native(JNIEnv * env ATTRIBUTE_UNUSED,jobject clazz ATTRIBUTE_UNUSED)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 
register_android_util_Log(JNIEnv * env)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