1 /*
2 * Copyright (C) 2017 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 <stdint.h>
18 #include <memory.h>
19
20 #include "FixedBlockAdapter.h"
21 #include "FixedBlockWriter.h"
22
FixedBlockWriter(FixedBlockProcessor & fixedBlockProcessor)23 FixedBlockWriter::FixedBlockWriter(FixedBlockProcessor &fixedBlockProcessor)
24 : FixedBlockAdapter(fixedBlockProcessor) {}
25
26
writeToStorage(uint8_t * buffer,int32_t numBytes)27 int32_t FixedBlockWriter::writeToStorage(uint8_t *buffer, int32_t numBytes) {
28 int32_t bytesToStore = numBytes;
29 int32_t roomAvailable = mSize - mPosition;
30 if (bytesToStore > roomAvailable) {
31 bytesToStore = roomAvailable;
32 }
33 memcpy(mStorage.get() + mPosition, buffer, bytesToStore);
34 mPosition += bytesToStore;
35 return bytesToStore;
36 }
37
write(uint8_t * buffer,int32_t numBytes)38 int32_t FixedBlockWriter::write(uint8_t *buffer, int32_t numBytes) {
39 int32_t bytesLeft = numBytes;
40
41 // If we already have data in storage then add to it.
42 if (mPosition > 0) {
43 int32_t bytesWritten = writeToStorage(buffer, bytesLeft);
44 buffer += bytesWritten;
45 bytesLeft -= bytesWritten;
46 // If storage full then flush it out
47 if (mPosition == mSize) {
48 bytesWritten = mFixedBlockProcessor.onProcessFixedBlock(mStorage.get(), mSize);
49 if (bytesWritten < 0) return bytesWritten;
50 mPosition = 0;
51 if (bytesWritten < mSize) {
52 // Only some of the data was written! This should not happen.
53 return -1;
54 }
55 }
56 }
57
58 // Write through if enough for a complete block.
59 while(bytesLeft > mSize) {
60 int32_t bytesWritten = mFixedBlockProcessor.onProcessFixedBlock(buffer, mSize);
61 if (bytesWritten < 0) return bytesWritten;
62 buffer += bytesWritten;
63 bytesLeft -= bytesWritten;
64 }
65
66 // Save any remaining partial blocks for next time.
67 if (bytesLeft > 0) {
68 int32_t bytesWritten = writeToStorage(buffer, bytesLeft);
69 bytesLeft -= bytesWritten;
70 }
71
72 return numBytes - bytesLeft;
73 }
74