android_media_MediaDataSource.cpp revision fbc164ba3c2105265b031503bdfebdbcd7256fbe 
1/*
2 * Copyright 2015, 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//#define LOG_NDEBUG 0
18#define LOG_TAG "JMediaDataSource-JNI"
19#include <utils/Log.h>
20
21#include "android_media_MediaDataSource.h"
22
23#include "android_runtime/AndroidRuntime.h"
24#include "android_runtime/Log.h"
25#include "jni.h"
26#include "JNIHelp.h"
27
28#include <binder/MemoryDealer.h>
29#include <media/stagefright/foundation/ADebug.h>
30#include <nativehelper/ScopedLocalRef.h>
31
32namespace android {
33
34JMediaDataSource::JMediaDataSource(JNIEnv* env, jobject source)
35    : mJavaObjStatus(OK), mSizeIsCached(false), mCachedSize(0), mMemory(NULL) {
36    mMediaDataSourceObj = env->NewGlobalRef(source);
37    CHECK(mMediaDataSourceObj != NULL);
38
39    ScopedLocalRef<jclass> mediaDataSourceClass(env, env->GetObjectClass(mMediaDataSourceObj));
40    CHECK(mediaDataSourceClass.get() != NULL);
41
42    mReadMethod = env->GetMethodID(mediaDataSourceClass.get(), "readAt", "(J[BII)I");
43    CHECK(mReadMethod != NULL);
44    mGetSizeMethod = env->GetMethodID(mediaDataSourceClass.get(), "getSize", "()J");
45    CHECK(mGetSizeMethod != NULL);
46    mCloseMethod = env->GetMethodID(mediaDataSourceClass.get(), "close", "()V");
47    CHECK(mCloseMethod != NULL);
48
49    ScopedLocalRef<jbyteArray> tmp(env, env->NewByteArray(kBufferSize));
50    mByteArrayObj = (jbyteArray)env->NewGlobalRef(tmp.get());
51    CHECK(mByteArrayObj != NULL);
52
53    sp<MemoryDealer> memoryDealer = new MemoryDealer(kBufferSize, "JMediaDataSource");
54    mMemory = memoryDealer->allocate(kBufferSize);
55    if (mMemory == NULL) {
56        ALOGE("Failed to allocate memory!");
57    }
58}
59
60JMediaDataSource::~JMediaDataSource() {
61    JNIEnv* env = AndroidRuntime::getJNIEnv();
62    env->DeleteGlobalRef(mMediaDataSourceObj);
63    env->DeleteGlobalRef(mByteArrayObj);
64}
65
66sp<IMemory> JMediaDataSource::getIMemory() {
67    Mutex::Autolock lock(mLock);
68    return mMemory;
69}
70
71ssize_t JMediaDataSource::readAt(off64_t offset, size_t size) {
72    Mutex::Autolock lock(mLock);
73
74    if (mJavaObjStatus != OK || mMemory == NULL) {
75        return -1;
76    }
77    if (size > kBufferSize) {
78        size = kBufferSize;
79    }
80
81    JNIEnv* env = AndroidRuntime::getJNIEnv();
82    jint numread = env->CallIntMethod(mMediaDataSourceObj, mReadMethod,
83            (jlong)offset, mByteArrayObj, (jint)0, (jint)size);
84    if (env->ExceptionCheck()) {
85        ALOGW("An exception occurred in readAt()");
86        LOGW_EX(env);
87        env->ExceptionClear();
88        mJavaObjStatus = UNKNOWN_ERROR;
89        return -1;
90    }
91    if (numread < 0) {
92        if (numread != -1) {
93            ALOGW("An error occurred in readAt()");
94            mJavaObjStatus = UNKNOWN_ERROR;
95            return -1;
96        } else {
97            // numread == -1 indicates EOF
98            return 0;
99        }
100    }
101    if ((size_t)numread > size) {
102        ALOGE("readAt read too many bytes.");
103        mJavaObjStatus = UNKNOWN_ERROR;
104        return -1;
105    }
106
107    ALOGV("readAt %lld / %zu => %d.", (long long)offset, size, numread);
108    env->GetByteArrayRegion(mByteArrayObj, 0, numread, (jbyte*)mMemory->pointer());
109    return numread;
110}
111
112status_t JMediaDataSource::getSize(off64_t* size) {
113    Mutex::Autolock lock(mLock);
114
115    if (mJavaObjStatus != OK) {
116        return UNKNOWN_ERROR;
117    }
118    if (mSizeIsCached) {
119        return mCachedSize;
120    }
121
122    JNIEnv* env = AndroidRuntime::getJNIEnv();
123    *size = env->CallLongMethod(mMediaDataSourceObj, mGetSizeMethod);
124    if (env->ExceptionCheck()) {
125        ALOGW("An exception occurred in getSize()");
126        LOGW_EX(env);
127        env->ExceptionClear();
128        // After returning an error, size shouldn't be used by callers.
129        *size = UNKNOWN_ERROR;
130        mJavaObjStatus = UNKNOWN_ERROR;
131        return UNKNOWN_ERROR;
132    }
133
134    // The minimum size should be -1, which indicates unknown size.
135    if (*size < 0) {
136        *size = -1;
137    }
138
139    mCachedSize = *size;
140    mSizeIsCached = true;
141    return OK;
142}
143
144void JMediaDataSource::close() {
145    Mutex::Autolock lock(mLock);
146
147    JNIEnv* env = AndroidRuntime::getJNIEnv();
148    env->CallVoidMethod(mMediaDataSourceObj, mCloseMethod);
149    // The closed state is effectively the same as an error state.
150    mJavaObjStatus = UNKNOWN_ERROR;
151}
152
153uint32_t JMediaDataSource::getFlags() {
154    return 0;
155}
156
157}  // namespace android
158