[go: nahoru, domu]
android_util_EventLog.cpp revision ca50cd2114f2c509ae2d1d06468e61f3cfc0b280 
1/*
2 * Copyright (C) 2007-2014 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17#include <fcntl.h>
18
19#include "JNIHelp.h"
20#include "core_jni_helpers.h"
21#include "jni.h"
22#include "log/logger.h"
23
24#define UNUSED  __attribute__((__unused__))
25
26// The size of the tag number comes out of the payload size.
27#define MAX_EVENT_PAYLOAD (LOGGER_ENTRY_MAX_PAYLOAD - sizeof(int32_t))
28
29namespace android {
30
31static jclass gCollectionClass;
32static jmethodID gCollectionAddID;
33
34static jclass gEventClass;
35static jmethodID gEventInitID;
36
37static jclass gIntegerClass;
38static jfieldID gIntegerValueID;
39
40static jclass gLongClass;
41static jfieldID gLongValueID;
42
43static jclass gStringClass;
44
45/*
46 * In class android.util.EventLog:
47 *  static native int writeEvent(int tag, int value)
48 */
49static jint android_util_EventLog_writeEvent_Integer(JNIEnv* env UNUSED,
50                                                     jobject clazz UNUSED,
51                                                     jint tag, jint value)
52{
53    return android_btWriteLog(tag, EVENT_TYPE_INT, &value, sizeof(value));
54}
55
56/*
57 * In class android.util.EventLog:
58 *  static native int writeEvent(long tag, long value)
59 */
60static jint android_util_EventLog_writeEvent_Long(JNIEnv* env UNUSED,
61                                                  jobject clazz UNUSED,
62                                                  jint tag, jlong value)
63{
64    return android_btWriteLog(tag, EVENT_TYPE_LONG, &value, sizeof(value));
65}
66
67/*
68 * In class android.util.EventLog:
69 *  static native int writeEvent(int tag, String value)
70 */
71static jint android_util_EventLog_writeEvent_String(JNIEnv* env,
72                                                    jobject clazz UNUSED,
73                                                    jint tag, jstring value) {
74    uint8_t buf[MAX_EVENT_PAYLOAD];
75
76    // Don't throw NPE -- I feel like it's sort of mean for a logging function
77    // to be all crashy if you pass in NULL -- but make the NULL value explicit.
78    const char *str = value != NULL ? env->GetStringUTFChars(value, NULL) : "NULL";
79    uint32_t len = strlen(str);
80    size_t max = sizeof(buf) - sizeof(len) - 2;  // Type byte, final newline
81    if (len > max) len = max;
82
83    buf[0] = EVENT_TYPE_STRING;
84    memcpy(&buf[1], &len, sizeof(len));
85    memcpy(&buf[1 + sizeof(len)], str, len);
86    buf[1 + sizeof(len) + len] = '\n';
87
88    if (value != NULL) env->ReleaseStringUTFChars(value, str);
89    return android_bWriteLog(tag, buf, 2 + sizeof(len) + len);
90}
91
92/*
93 * In class android.util.EventLog:
94 *  static native int writeEvent(long tag, Object... value)
95 */
96static jint android_util_EventLog_writeEvent_Array(JNIEnv* env, jobject clazz,
97                                                   jint tag, jobjectArray value) {
98    if (value == NULL) {
99        return android_util_EventLog_writeEvent_String(env, clazz, tag, NULL);
100    }
101
102    uint8_t buf[MAX_EVENT_PAYLOAD];
103    const size_t max = sizeof(buf) - 1;  // leave room for final newline
104    size_t pos = 2;  // Save room for type tag & array count
105
106    jsize copied = 0, num = env->GetArrayLength(value);
107    for (; copied < num && copied < 255; ++copied) {
108        jobject item = env->GetObjectArrayElement(value, copied);
109        if (item == NULL || env->IsInstanceOf(item, gStringClass)) {
110            if (pos + 1 + sizeof(jint) > max) break;
111            const char *str = item != NULL ? env->GetStringUTFChars((jstring) item, NULL) : "NULL";
112            jint len = strlen(str);
113            if (pos + 1 + sizeof(len) + len > max) len = max - pos - 1 - sizeof(len);
114            buf[pos++] = EVENT_TYPE_STRING;
115            memcpy(&buf[pos], &len, sizeof(len));
116            memcpy(&buf[pos + sizeof(len)], str, len);
117            pos += sizeof(len) + len;
118            if (item != NULL) env->ReleaseStringUTFChars((jstring) item, str);
119        } else if (env->IsInstanceOf(item, gIntegerClass)) {
120            jint intVal = env->GetIntField(item, gIntegerValueID);
121            if (pos + 1 + sizeof(intVal) > max) break;
122            buf[pos++] = EVENT_TYPE_INT;
123            memcpy(&buf[pos], &intVal, sizeof(intVal));
124            pos += sizeof(intVal);
125        } else if (env->IsInstanceOf(item, gLongClass)) {
126            jlong longVal = env->GetLongField(item, gLongValueID);
127            if (pos + 1 + sizeof(longVal) > max) break;
128            buf[pos++] = EVENT_TYPE_LONG;
129            memcpy(&buf[pos], &longVal, sizeof(longVal));
130            pos += sizeof(longVal);
131        } else {
132            jniThrowException(env,
133                    "java/lang/IllegalArgumentException",
134                    "Invalid payload item type");
135            return -1;
136        }
137        env->DeleteLocalRef(item);
138    }
139
140    buf[0] = EVENT_TYPE_LIST;
141    buf[1] = copied;
142    buf[pos++] = '\n';
143    return android_bWriteLog(tag, buf, pos);
144}
145
146/*
147 * In class android.util.EventLog:
148 *  static native void readEvents(int[] tags, Collection<Event> output)
149 *
150 *  Reads events from the event log
151 */
152static void android_util_EventLog_readEvents(JNIEnv* env, jobject clazz UNUSED,
153                                             jintArray tags,
154                                             jobject out) {
155
156    if (tags == NULL || out == NULL) {
157        jniThrowNullPointerException(env, NULL);
158        return;
159    }
160
161    struct logger_list *logger_list = android_logger_list_open(
162        LOG_ID_EVENTS, ANDROID_LOG_RDONLY | ANDROID_LOG_NONBLOCK, 0, 0);
163
164    if (!logger_list) {
165        jniThrowIOException(env, errno);
166        return;
167    }
168
169    jsize tagLength = env->GetArrayLength(tags);
170    jint *tagValues = env->GetIntArrayElements(tags, NULL);
171
172    while (1) {
173        log_msg log_msg;
174        int ret = android_logger_list_read(logger_list, &log_msg);
175
176        if (ret == 0) {
177            break;
178        }
179        if (ret < 0) {
180            if (ret == -EINTR) {
181                continue;
182            }
183            if (ret == -EINVAL) {
184                jniThrowException(env, "java/io/IOException", "Event too short");
185            } else if (ret != -EAGAIN) {
186                jniThrowIOException(env, -ret);  // Will throw on return
187            }
188            break;
189        }
190
191        if (log_msg.id() != LOG_ID_EVENTS) {
192            continue;
193        }
194
195        int32_t tag = * (int32_t *) log_msg.msg();
196
197        int found = 0;
198        for (int i = 0; !found && i < tagLength; ++i) {
199            found = (tag == tagValues[i]);
200        }
201
202        if (found) {
203            jsize len = ret;
204            jbyteArray array = env->NewByteArray(len);
205            if (array == NULL) {
206                break;
207            }
208
209            jbyte *bytes = env->GetByteArrayElements(array, NULL);
210            memcpy(bytes, log_msg.buf, len);
211            env->ReleaseByteArrayElements(array, bytes, 0);
212
213            jobject event = env->NewObject(gEventClass, gEventInitID, array);
214            if (event == NULL) {
215                break;
216            }
217
218            env->CallBooleanMethod(out, gCollectionAddID, event);
219            env->DeleteLocalRef(event);
220            env->DeleteLocalRef(array);
221        }
222    }
223
224    android_logger_list_close(logger_list);
225
226    env->ReleaseIntArrayElements(tags, tagValues, 0);
227}
228
229/*
230 * JNI registration.
231 */
232static JNINativeMethod gRegisterMethods[] = {
233    /* name, signature, funcPtr */
234    { "writeEvent", "(II)I", (void*) android_util_EventLog_writeEvent_Integer },
235    { "writeEvent", "(IJ)I", (void*) android_util_EventLog_writeEvent_Long },
236    { "writeEvent",
237      "(ILjava/lang/String;)I",
238      (void*) android_util_EventLog_writeEvent_String
239    },
240    { "writeEvent",
241      "(I[Ljava/lang/Object;)I",
242      (void*) android_util_EventLog_writeEvent_Array
243    },
244    { "readEvents",
245      "([ILjava/util/Collection;)V",
246      (void*) android_util_EventLog_readEvents
247    },
248};
249
250static struct { const char *name; jclass *clazz; } gClasses[] = {
251    { "android/util/EventLog$Event", &gEventClass },
252    { "java/lang/Integer", &gIntegerClass },
253    { "java/lang/Long", &gLongClass },
254    { "java/lang/String", &gStringClass },
255    { "java/util/Collection", &gCollectionClass },
256};
257
258static struct { jclass *c; const char *name, *ft; jfieldID *id; } gFields[] = {
259    { &gIntegerClass, "value", "I", &gIntegerValueID },
260    { &gLongClass, "value", "J", &gLongValueID },
261};
262
263static struct { jclass *c; const char *name, *mt; jmethodID *id; } gMethods[] = {
264    { &gEventClass, "<init>", "([B)V", &gEventInitID },
265    { &gCollectionClass, "add", "(Ljava/lang/Object;)Z", &gCollectionAddID },
266};
267
268int register_android_util_EventLog(JNIEnv* env) {
269    for (int i = 0; i < NELEM(gClasses); ++i) {
270        jclass clazz = FindClassOrDie(env, gClasses[i].name);
271        *gClasses[i].clazz = MakeGlobalRefOrDie(env, clazz);
272    }
273
274    for (int i = 0; i < NELEM(gFields); ++i) {
275        *gFields[i].id = GetFieldIDOrDie(env,
276                *gFields[i].c, gFields[i].name, gFields[i].ft);
277    }
278
279    for (int i = 0; i < NELEM(gMethods); ++i) {
280        *gMethods[i].id = GetMethodIDOrDie(env,
281                *gMethods[i].c, gMethods[i].name, gMethods[i].mt);
282    }
283
284    return RegisterMethodsOrDie(
285            env,
286            "android/util/EventLog",
287            gRegisterMethods, NELEM(gRegisterMethods));
288}
289
290}; // namespace android
291