1 /*
2  * Copyright (C) 2013 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 "inputstream_wrapper.h"
18 #include "error_codes.h"
19 
20 jmethodID InputStreamWrapper::sReadID = NULL;
21 jmethodID InputStreamWrapper::sSkipID = NULL;
22 
read(int32_t length,int32_t offset)23 int32_t InputStreamWrapper::read(int32_t length, int32_t offset) {
24     if (offset < 0 || length < 0 || (offset + length) > getBufferSize()) {
25         return J_ERROR_BAD_ARGS;
26     }
27     int32_t bytesRead = 0;
28     mEnv->ReleaseByteArrayElements(mByteArray, mBytes, JNI_COMMIT);
29     mBytes = NULL;
30     if (mEnv->ExceptionCheck()) {
31         return J_EXCEPTION;
32     }
33     bytesRead = static_cast<int32_t>(mEnv->CallIntMethod(mStream, sReadID,
34             mByteArray, offset, length));
35     if (mEnv->ExceptionCheck()) {
36         return J_EXCEPTION;
37     }
38     mBytes = mEnv->GetByteArrayElements(mByteArray, NULL);
39     if (mBytes == NULL || mEnv->ExceptionCheck()) {
40         return J_EXCEPTION;
41     }
42     if (bytesRead == END_OF_STREAM) {
43         return J_DONE;
44     }
45     return bytesRead;
46 }
47 
skip(int64_t count)48 int64_t InputStreamWrapper::skip(int64_t count) {
49     int64_t bytesSkipped = 0;
50     bytesSkipped = static_cast<int64_t>(mEnv->CallLongMethod(mStream, sSkipID,
51             static_cast<jlong>(count)));
52     if (mEnv->ExceptionCheck() || bytesSkipped < 0) {
53         return J_EXCEPTION;
54     }
55     return bytesSkipped;
56 }
57 
58 // Acts like a read call that returns the End Of Image marker for a JPEG file.
forceReadEOI()59 int32_t InputStreamWrapper::forceReadEOI() {
60     mBytes[0] = (jbyte) 0xFF;
61     mBytes[1] = (jbyte) 0xD9;
62     return 2;
63 }
64 
setReadSkipMethodIDs(jmethodID readID,jmethodID skipID)65 void InputStreamWrapper::setReadSkipMethodIDs(jmethodID readID,
66         jmethodID skipID) {
67     sReadID = readID;
68     sSkipID = skipID;
69 }
70