void BufferManager::writeFile(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;
}
for (int i = 0; i < blockNum; i++)
writeFileBlock(fileName, i);
}
/*
* write file data to disk
*/
bool Directory::writeFile(int iNodeNumber, string &data) {
// get the number of nodes the file currently has allocated (must be at least 1)
int currentNumberOfBlocks = iNodeList->getNumberOfBlocks(iNodeNumber);
// calculate number of Blocks needed
int numberOfBlocksNeeded = (data.length() + getDataInBlock() - 1) / getDataInBlock();
if (numberOfBlocksNeeded > currentNumberOfBlocks + iNodeList->getNumberOfFreeINodes()) {
cout << "Not enough space on disk for file" << endl;
return false;
}
// point to the first block number
int currentDiskBlockNumber = 0;
int dataPointer = 0;
FileHeaderData fileHeaderData;
for (int i=0;i<numberOfBlocksNeeded;i++) {
// get currentDiskBlockNumber, add to iNode if necessary
if (i == currentNumberOfBlocks) {
currentDiskBlockNumber = freeBlockList->getBlock();
iNodeList->addBlockToINode(iNodeNumber, currentDiskBlockNumber);
currentNumberOfBlocks ++;
} else {
currentDiskBlockNumber = iNodeList->getBlockNumber(iNodeNumber,i);
}
// current block header
dataPointer = i * getDataInBlock();
fileHeaderData.lengthOfBlock = min((unsigned int)data.length() - dataPointer, getDataInBlock());
// write the file block header
writeFileBlockHeader(currentDiskBlockNumber, fileHeaderData);
// write the file block
writeFileBlock(currentDiskBlockNumber, data, dataPointer, dataPointer+fileHeaderData.lengthOfBlock);
}
// remove any un-needed blocks from the iNode
for (int i=currentNumberOfBlocks;i>numberOfBlocksNeeded;i--) {
iNodeList->removeBlockFromINode(iNodeNumber);
}
// set the iNodeSize
iNodeList->setINodeSize(iNodeNumber,data.length());
return true;
}