BOOL CADORecordset::AppendChunk(LPCTSTR lpFieldName, LPVOID lpData, UINT nBytes)
{
FieldPtr pField = m_pRecordset->Fields->GetItem(lpFieldName);
return AppendChunk(pField, lpData, nBytes);
}
nsresult
SourceBuffer::Compact()
{
mMutex.AssertCurrentThreadOwns();
MOZ_ASSERT(mConsumerCount == 0, "Should have no consumers here");
MOZ_ASSERT(mWaitingConsumers.Length() == 0, "Shouldn't have waiters");
MOZ_ASSERT(mStatus, "Should be complete here");
// Compact our waiting consumers list, since we're complete and no future
// consumer will ever have to wait.
mWaitingConsumers.Compact();
// If we have no chunks, then there's nothing to compact.
if (mChunks.Length() < 1) {
return NS_OK;
}
// If we have one chunk, then we can compact if it has excess capacity.
if (mChunks.Length() == 1 && mChunks[0].Length() == mChunks[0].Capacity()) {
return NS_OK;
}
// We can compact our buffer. Determine the total length.
size_t length = 0;
for (uint32_t i = 0 ; i < mChunks.Length() ; ++i) {
length += mChunks[i].Length();
}
Maybe<Chunk> newChunk = CreateChunk(length, /* aRoundUp = */ false);
if (MOZ_UNLIKELY(!newChunk || newChunk->AllocationFailed())) {
NS_WARNING("Failed to allocate chunk for SourceBuffer compacting - OOM?");
return NS_OK;
}
// Copy our old chunks into the new chunk.
for (uint32_t i = 0 ; i < mChunks.Length() ; ++i) {
size_t offset = newChunk->Length();
MOZ_ASSERT(offset < newChunk->Capacity());
MOZ_ASSERT(offset + mChunks[i].Length() <= newChunk->Capacity());
memcpy(newChunk->Data() + offset, mChunks[i].Data(), mChunks[i].Length());
newChunk->AddLength(mChunks[i].Length());
}
MOZ_ASSERT(newChunk->Length() == newChunk->Capacity(),
"Compacted chunk has slack space");
// Replace the old chunks with the new, compact chunk.
mChunks.Clear();
if (MOZ_UNLIKELY(NS_FAILED(AppendChunk(Move(newChunk))))) {
return HandleError(NS_ERROR_OUT_OF_MEMORY);
}
mChunks.Compact();
return NS_OK;
}
BOOL CADORecordset::AppendChunk(int nIndex, LPVOID lpData, UINT nBytes)
{
_variant_t vtIndex;
vtIndex.vt = VT_I2;
vtIndex.iVal = nIndex;
FieldPtr pField = m_pRecordset->Fields->GetItem(vtIndex);
return AppendChunk(pField, lpData, nBytes);
}
BOOL CADORecordset::AppendChunk(LPCTSTR lpFieldName, LPVOID lpData, UINT nBytes)
{
FieldPtr pField;
try
{
pField = m_pRecordset->Fields->GetItem(lpFieldName);
}
catch(_com_error &e)
{
dump_com_error(e);
return FALSE;
}
return AppendChunk(pField, lpData, nBytes);
}
nsresult
SourceBuffer::ExpectLength(size_t aExpectedLength)
{
MOZ_ASSERT(aExpectedLength > 0, "Zero expected size?");
MutexAutoLock lock(mMutex);
if (MOZ_UNLIKELY(mStatus)) {
MOZ_ASSERT_UNREACHABLE("ExpectLength after SourceBuffer is complete");
return NS_OK;
}
if (MOZ_UNLIKELY(mChunks.Length() > 0)) {
MOZ_ASSERT_UNREACHABLE("Duplicate or post-Append call to ExpectLength");
return NS_OK;
}
if (MOZ_UNLIKELY(NS_FAILED(AppendChunk(CreateChunk(aExpectedLength))))) {
return HandleError(NS_ERROR_OUT_OF_MEMORY);
}
return NS_OK;
}
nsresult
SourceBuffer::Append(const char* aData, size_t aLength)
{
MOZ_ASSERT(aData, "Should have a buffer");
MOZ_ASSERT(aLength > 0, "Writing a zero-sized chunk");
size_t currentChunkCapacity = 0;
size_t currentChunkLength = 0;
char* currentChunkData = nullptr;
size_t currentChunkRemaining = 0;
size_t forCurrentChunk = 0;
size_t forNextChunk = 0;
size_t nextChunkCapacity = 0;
{
MutexAutoLock lock(mMutex);
if (MOZ_UNLIKELY(mStatus)) {
// This SourceBuffer is already complete; ignore further data.
return NS_ERROR_FAILURE;
}
if (MOZ_UNLIKELY(mChunks.Length() == 0)) {
if (MOZ_UNLIKELY(NS_FAILED(AppendChunk(CreateChunk(aLength))))) {
return HandleError(NS_ERROR_OUT_OF_MEMORY);
}
}
// Copy out the current chunk's information so we can release the lock.
// Note that this wouldn't be safe if multiple producers were allowed!
Chunk& currentChunk = mChunks.LastElement();
currentChunkCapacity = currentChunk.Capacity();
currentChunkLength = currentChunk.Length();
currentChunkData = currentChunk.Data();
// Partition this data between the current chunk and the next chunk.
// (Because we always allocate a chunk big enough to fit everything passed
// to Append, we'll never need more than those two chunks to store
// everything.)
currentChunkRemaining = currentChunkCapacity - currentChunkLength;
forCurrentChunk = min(aLength, currentChunkRemaining);
forNextChunk = aLength - forCurrentChunk;
// If we'll need another chunk, determine what its capacity should be while
// we still hold the lock.
nextChunkCapacity = forNextChunk > 0
? FibonacciCapacityWithMinimum(forNextChunk)
: 0;
}
// Write everything we can fit into the current chunk.
MOZ_ASSERT(currentChunkLength + forCurrentChunk <= currentChunkCapacity);
memcpy(currentChunkData + currentChunkLength, aData, forCurrentChunk);
// If there's something left, create a new chunk and write it there.
Maybe<Chunk> nextChunk;
if (forNextChunk > 0) {
MOZ_ASSERT(nextChunkCapacity >= forNextChunk, "Next chunk too small?");
nextChunk = CreateChunk(nextChunkCapacity);
if (MOZ_LIKELY(nextChunk && !nextChunk->AllocationFailed())) {
memcpy(nextChunk->Data(), aData + forCurrentChunk, forNextChunk);
nextChunk->AddLength(forNextChunk);
}
}
// Update shared data structures.
{
MutexAutoLock lock(mMutex);
// Update the length of the current chunk.
Chunk& currentChunk = mChunks.LastElement();
MOZ_ASSERT(currentChunk.Data() == currentChunkData, "Multiple producers?");
MOZ_ASSERT(currentChunk.Length() == currentChunkLength,
"Multiple producers?");
currentChunk.AddLength(forCurrentChunk);
// If we created a new chunk, add it to the series.
if (forNextChunk > 0) {
if (MOZ_UNLIKELY(!nextChunk)) {
return HandleError(NS_ERROR_OUT_OF_MEMORY);
}
if (MOZ_UNLIKELY(NS_FAILED(AppendChunk(Move(nextChunk))))) {
return HandleError(NS_ERROR_OUT_OF_MEMORY);
}
}
// Resume any waiting readers now that there's new data.
ResumeWaitingConsumers();
}
return NS_OK;
}