Home | History | Annotate | Download | only in utility 
      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 
     23 FixedBlockWriter::FixedBlockWriter(FixedBlockProcessor &fixedBlockProcessor)
     24         : FixedBlockAdapter(fixedBlockProcessor) {}
     25 
     26 
     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 + mPosition, buffer, bytesToStore);
     34     mPosition += bytesToStore;
     35     return bytesToStore;
     36 }
     37 
     38 int32_t FixedBlockWriter::processVariableBlock(uint8_t *buffer, int32_t numBytes) {
     39     int32_t result = 0;
     40     int32_t bytesLeft = numBytes;
     41 
     42     // If we already have data in storage then add to it.
     43     if (mPosition > 0) {
     44         int32_t bytesWritten = writeToStorage(buffer, bytesLeft);
     45         buffer += bytesWritten;
     46         bytesLeft -= bytesWritten;
     47         // If storage full then flush it out
     48         if (mPosition == mSize) {
     49             result = mFixedBlockProcessor.onProcessFixedBlock(mStorage, mSize);
     50             mPosition = 0;
     51         }
     52     }
     53 
     54     // Write through if enough for a complete block.
     55     while(bytesLeft > mSize && result == 0) {
     56         result = mFixedBlockProcessor.onProcessFixedBlock(buffer, mSize);
     57         buffer += mSize;
     58         bytesLeft -= mSize;
     59     }
     60 
     61     // Save any remaining partial block for next time.
     62     if (bytesLeft > 0) {
     63         writeToStorage(buffer, bytesLeft);
     64     }
     65 
     66     return result;
     67 }
     68