int BufferManager::insertBlock(const std::string &fileName, const std::string& content)
{
int n = fileName.find(".index", 0);
std::string indexName = fileName.substr(0, n);
Index* indexPtr = Cat.getIndexPtr(indexName);
std::list<Block*>::iterator it;
if (indexPtr->emptyBlockOffset.empty() == 1)
{
it = addBlockInFile(fileName);
(*it)->blockOffset = indexPtr->blockNum;
(*it)->fileName = fileName;
(*it)->isDirty = 1;
indexPtr->blockNum++;
(*it)->changeContent(0, content);
}
else
{
int blockOffset = indexPtr->emptyBlockOffset.back();
indexPtr->emptyBlockOffset.pop_back();
it = readFileBlock(fileName, blockOffset);
(*it)->changeContent(0, content);
}
return (*it)->blockOffset;
}
std::string BufferManager::getBlock(const std::string& fileName, int blockOffset,int start,int end)
{
int n = fileName.find(".index", 0);
Index *indexPtr = Cat.getIndexPtr(fileName.substr(0, n));
std::list<Block*>::iterator it = readFileBlock(fileName, blockOffset);
std::string record = "";
for (int i = start; i < end; i++)
record += (*it)->content[i];
return record;
}
void BufferManager::readFile(const std::string& fileName)
{
int blockNum; int n;
if ((n = fileName.find(".table", 0)) != std::string::npos)
{
Table* tablePtr = Cat.getTablePtr(fileName.substr(0,n));
blockNum = tablePtr->blockNum;
}
if ((n = fileName.find(".index", 0)) != std::string::npos)
{
Index* indexPtr = Cat.getIndexPtr(fileName.substr(0, n));
blockNum = indexPtr->blockNum;
}
std::list<Block*>::iterator it;
for (int i = 0; i < blockNum; i++)
it = readFileBlock(fileName, i);
}
