StorageFileKeyValue* StorageUnwrittenChunkLister::First(ReadBuffer& firstKey)
{
StorageFileKeyValue* kv;
kv = dataPage.First();
while (kv != NULL && ReadBuffer::Cmp(kv->GetKey(), firstKey) < 0)
kv = dataPage.Next(kv);
return kv;
}
// copy key-values from file chunk to a temporary data page, that will be used for listing
void StorageUnwrittenChunkLister::Init(StorageFileChunk* chunk, ReadBuffer& startKey,
unsigned count)
{
StorageFileKeyValue* kv;
int cmpres;
unsigned num;
uint32_t index;
uint64_t pageOffset;
int ret;
num = 0;
index = 0;
if (ReadBuffer::Cmp(startKey, chunk->indexPage->GetFirstKey()) >= 0)
{
ret = chunk->indexPage->Locate(startKey, index, pageOffset);
ASSERT(ret);
}
kv = chunk->dataPages[index]->LocateKeyValue(startKey, cmpres);
if (kv != NULL && cmpres > 0)
kv = NextChunkKeyValue(chunk, index, kv);
while (kv != NULL)
{
dataPage.Append(kv);
if (kv->GetType() == STORAGE_KEYVALUE_TYPE_SET)
{
num++;
if (count != 0 && num == count)
break;
}
kv = NextChunkKeyValue(chunk, index, kv);
}
dataPage.Finalize();
}
// copy key-values from file chunk to a temporary data page, that will be used for listing
void StorageUnwrittenChunkLister::Init(StorageFileChunk& fileChunk, ReadBuffer& firstKey,
ReadBuffer& prefix, unsigned count, bool forwardDirection_)
{
StorageFileKeyValue* kv;
int cmpres;
unsigned num;
uint32_t index;
uint64_t offset;
int ret;
Log_Debug("Listing unwritten chunk");
num = 0;
index = 0;
forwardDirection = forwardDirection_;
if (forwardDirection && ReadBuffer::Cmp(firstKey, fileChunk.indexPage->GetFirstKey()) < 0)
{
index = 0;
offset = fileChunk.indexPage->GetFirstDatapageOffset();
}
else if (!forwardDirection && firstKey.GetLength() > 0 && ReadBuffer::Cmp(firstKey, fileChunk.indexPage->GetFirstKey()) < 0)
{
// firstKey is set and smaller that the first key in this chunk
dataPage.Finalize();
return;
}
else if (!forwardDirection && firstKey.GetLength() > 0 && ReadBuffer::Cmp(firstKey, fileChunk.indexPage->GetLastKey()) > 0)
{
index = fileChunk.numDataPages - 1;
offset = fileChunk.indexPage->GetLastDatapageOffset();
}
else if (!forwardDirection && firstKey.GetLength() == 0)
{
index = fileChunk.numDataPages - 1;
offset = fileChunk.indexPage->GetLastDatapageOffset();
}
else
{
ret = fileChunk.indexPage->Locate(firstKey, index, offset);
ASSERT(ret);
}
kv = fileChunk.dataPages[index]->LocateKeyValue(firstKey, cmpres);
if (kv != NULL)
{
if (forwardDirection && cmpres > 0)
kv = NextChunkKeyValue(fileChunk, index, kv);
else if (!forwardDirection && cmpres < 0)
kv = PrevChunkKeyValue(fileChunk, index, kv);
}
while (kv != NULL)
{
if (prefix.GetLength() > 0 && !kv->GetKey().BeginsWith(prefix))
break;
dataPage.Append(kv);
if (kv->GetType() == STORAGE_KEYVALUE_TYPE_SET)
{
num++;
if (count != 0 && num == count)
break;
}
if (forwardDirection)
kv = NextChunkKeyValue(fileChunk, index, kv);
else
kv = PrevChunkKeyValue(fileChunk, index, kv);
}
dataPage.Finalize();
}
