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 #define LOG_TAG "Stream"
18
19 #include "Stream.h"
20
21 #include <string.h>
22
23 #include "JNIHelpers.h"
24 #include "utils/log.h"
25 #include "utils/math.h"
26
27 static struct {
28 jmethodID read;
29 jmethodID reset;
30 } gInputStreamClassInfo;
31
Stream()32 Stream::Stream()
33 : mPeekBuffer(0)
34 , mPeekSize(0)
35 , mPeekOffset(0) {
36 }
37
~Stream()38 Stream::~Stream() {
39 delete mPeekBuffer;
40 }
41
peek(void * buffer,size_t size)42 size_t Stream::peek(void* buffer, size_t size) {
43 size_t peek_remaining = mPeekSize - mPeekOffset;
44 if (size > peek_remaining) {
45 char* old_peek = mPeekBuffer;
46 mPeekBuffer = new char[size];
47 if (old_peek) {
48 memcpy(mPeekBuffer, old_peek + mPeekOffset, peek_remaining);
49 delete old_peek;
50 }
51 size_t read = doRead(mPeekBuffer + mPeekOffset, size - peek_remaining);
52 mPeekOffset = 0;
53 mPeekSize = peek_remaining + read;
54 }
55 size = min(size, mPeekSize - mPeekOffset);
56 memcpy(buffer, mPeekBuffer + mPeekOffset, size);
57 return size;
58 }
59
read(void * buffer,size_t size)60 size_t Stream::read(void* buffer, size_t size) {
61 size_t bytes_read = 0;
62 size_t peek_remaining = mPeekSize - mPeekOffset;
63 if (peek_remaining) {
64 bytes_read = min(size, peek_remaining);
65 memcpy(buffer, mPeekBuffer + mPeekOffset, bytes_read);
66 mPeekOffset += bytes_read;
67 if (mPeekOffset == mPeekSize) {
68 delete mPeekBuffer;
69 mPeekBuffer = 0;
70 mPeekOffset = 0;
71 mPeekSize = 0;
72 }
73 size -= bytes_read;
74 buffer = ((char*) buffer) + bytes_read;
75 }
76 if (size) {
77 bytes_read += doRead(buffer, size);
78 }
79 return bytes_read;
80 }
81
doRead(void * buffer,size_t size)82 size_t MemoryStream::doRead(void* buffer, size_t size) {
83 size = min(size, mRemaining);
84 memcpy(buffer, mBuffer, size);
85 mBuffer += size;
86 mRemaining -= size;
87 return size;
88 }
89
doRead(void * buffer,size_t size)90 size_t FileStream::doRead(void* buffer, size_t size) {
91 return fread(buffer, 1, size, mFd);
92 }
93
doRead(void * dstBuffer,size_t size)94 size_t JavaInputStream::doRead(void* dstBuffer, size_t size) {
95 size_t totalBytesRead = 0;
96
97 do {
98 size_t requested = min(size, mByteArrayLength);
99
100 jint bytesRead = mEnv->CallIntMethod(mInputStream,
101 gInputStreamClassInfo.read, mByteArray, 0, requested);
102 if (mEnv->ExceptionCheck() || bytesRead < 0) {
103 return 0;
104 }
105
106 mEnv->GetByteArrayRegion(mByteArray, 0, bytesRead, (jbyte*)dstBuffer);
107 dstBuffer = (char*)dstBuffer + bytesRead;
108 totalBytesRead += bytesRead;
109 size -= bytesRead;
110 } while (size > 0);
111
112 return totalBytesRead;
113 }
114
JavaStream_OnLoad(JNIEnv * env)115 jint JavaStream_OnLoad(JNIEnv* env) {
116 // Skip the verbose logging on error for these, as they won't be subject
117 // to obfuscators or similar and are thus unlikely to ever fail
118 jclass inputStreamClazz = env->FindClass("java/io/InputStream");
119 if (!inputStreamClazz) {
120 return -1;
121 }
122 gInputStreamClassInfo.read = env->GetMethodID(inputStreamClazz, "read", "([BII)I");
123 gInputStreamClassInfo.reset = env->GetMethodID(inputStreamClazz, "reset", "()V");
124 if (!gInputStreamClassInfo.read || !gInputStreamClassInfo.reset) {
125 return -1;
126 }
127 return 0;
128 }
129