Merge "Refactoring checkAndPrepareWriting." into lmp-dev

main
Keisuke Kuroyanagi 2014-07-24 21:39:09 +00:00 committed by Android (Google) Code Review
commit f78eb27c7e
1 changed files with 30 additions and 20 deletions

View File

@ -107,27 +107,37 @@ bool BufferWithExtendableBuffer::extendBuffer() {
}
bool BufferWithExtendableBuffer::checkAndPrepareWriting(const int pos, const int size) {
if (isInAdditionalBuffer(pos)) {
const int tailPosition = getTailPosition();
if (pos == tailPosition) {
// Append data to the tail.
if (pos + size > static_cast<int>(mAdditionalBuffer.size()) + mOriginalBufferSize) {
// Need to extend buffer.
if (!extendBuffer()) {
return false;
}
}
mUsedAdditionalBufferSize += size;
} else if (pos + size > tailPosition) {
// The access will beyond the tail of used region.
return false;
}
} else {
if (pos < 0 || mOriginalBufferSize < pos + size) {
// Invalid position or violate the boundary.
return false;
}
if (pos < 0 || size < 0) {
// Invalid position or size.
return false;
}
const size_t totalRequiredSize = static_cast<size_t>(pos + size);
if (!isInAdditionalBuffer(pos)) {
// Here don't need to care about the additional buffer.
if (static_cast<size_t>(mOriginalBufferSize) < totalRequiredSize) {
// Violate the boundary.
return false;
}
// The buffer has sufficient capacity.
return true;
}
// Hereafter, pos is in the additional buffer.
const size_t tailPosition = static_cast<size_t>(getTailPosition());
if (totalRequiredSize <= tailPosition) {
// The buffer has sufficient capacity.
return true;
}
if (static_cast<size_t>(pos) != tailPosition) {
// The additional buffer must be extended from the tail position.
return false;
}
const size_t extendSize = totalRequiredSize -
std::min(mAdditionalBuffer.size() + mOriginalBufferSize, totalRequiredSize);
if (extendSize > 0 && !extendBuffer()) {
// Failed to extend the buffer.
return false;
}
mUsedAdditionalBufferSize += size;
return true;
}