/*
* bufTable for pages belonging to the file. For each page encountered:
* (a) if the page is dirty, call file->writePage() to flush the page to disk
* and then set the dirty bit for the page to false,
* (b) remove the page from the hashtable (whether the page is clean or dirty)
* (c) invoke the Clear() method of BufDesc for the page frame.
*
* Throws PagePinnedException if some page of the file is pinned.
* Throws BadBufferException if an invalid page belonging to the file is encountered.
* params: File* file
*/
void BufMgr::flushFile(const File* file)
{
// Scan for pages belonging to the file
for (FrameId i = 0; i < numBufs; i++)
{
// Invalid page
if(bufDescTable[i].file == file && bufDescTable[i].valid == false) {
throw BadBufferException(i, bufDescTable[i].dirty, false, bufDescTable[i].refbit);
}
// found a page belonging to the file
if (bufDescTable[i].file == file && bufDescTable[i].valid == true) {
// The page is pinned
if(bufDescTable[i].pinCnt > 0) {
throw PagePinnedException(bufDescTable[i].file->filename(), bufDescTable[i].pageNo, bufDescTable[i].frameNo);
}
// write to disk if dirty
if(bufDescTable[i].dirty == true) {
bufDescTable[i].file->writePage(bufPool[bufDescTable[i].frameNo]);
bufDescTable[i].dirty = false;
}
// delete from hashtable
hashTable->remove(bufDescTable[i].file, bufDescTable[i].pageNo);
// clear the frame
bufDescTable[i].Clear();
}
}
}
void BufMgr::flushFile(const File* file)
{
for(FrameId i = 0; i < numBufs; i++){
BufDesc* temp = &(bufDescTable[i]);
if (temp->file == file){
if(temp->pinCnt > 0){
throw PagePinnedException(file->filename(), temp->pageNo, temp->frameNo);
}
if(temp->valid == false){
temp->pinCnt = 0;
throw BadBufferException(temp->frameNo, temp->dirty, temp->valid, temp->refbit);
}
// (a)
if (temp->dirty){
temp->file -> writePage(bufPool[i]); // flushes the page to disk
temp->dirty = false; // sets dirty bit to false
}
//(b)
try{
hashTable->remove(file, bufDescTable[i].pageNo);
} catch(HashNotFoundException e){
return;
}
//(c)
temp->Clear(); // clears frame
//bufDescTable[i].valid = false;
//bufDescTable[i].pinCnt = 0;
}
}
}
/**
* Writes out all dirty pages of the file to disk.
* All the frames assigned to the file need to be unpinned from buffer pool before this function can be successfully called.
* Otherwise Error returned.
*
* @throws PagePinnedException If any page of the file is pinned in the buffer pool
* @throws BadBufferException If any frame allocated to the file is found to be invalid
*/
void BufMgr::flushFile(const File* file)
{
int pages_found = 0;
for(std::uint32_t i = 0; i<numBufs; i++){
if(bufDescTable[i].file == file){
pages_found++;
if(bufDescTable[i].pinCnt > 0){
throw PagePinnedException(bufDescTable[i].file->filename(), bufDescTable[i].pageNo, i);
}
else if(bufPool[i].page_number() != bufDescTable[i].pageNo || bufDescTable[i].valid == false){
throw BadBufferException(i, bufDescTable[i].dirty, bufDescTable[i].valid, bufDescTable[i].refbit);
}
if(bufDescTable[i].dirty == true){
bufDescTable[i].file->writePage(bufPool[i]);
}
hashTable->remove(file, bufDescTable[i].pageNo);
bufDescTable[i].Clear();
}
}
}
/**
* Writes out all dirty pages of the file to disk.
* All the frames assigned to the file need to be unpinned from buffer pool before this function can be successfully called.
* Otherwise Error returned.
*
* @param file File object
* @throws PagePinnedException If any page of the file is pinned in the buffer pool
* @throws BadBufferException If any frame allocated to the file is found to be invalid
*/
void BufMgr::flushFile(const File* file)
{
for(FrameId i = 0; i < numBufs; i++){
if(bufDescTable[i].file == file){
if(bufDescTable[i].pinCnt != 0){
//page is already pinned, throw an exception
throw PagePinnedException("pagePinned", bufDescTable[i].pageNo, i);
}
if(!bufDescTable[i].valid){
//Not a valid page, throw an exception
throw BadBufferException(i, bufDescTable[i].dirty, bufDescTable[i].valid, bufDescTable[i].refbit);
}
if(bufDescTable[i].dirty){
//write to disk if the frame is dirty
bufDescTable[i].file->writePage(bufPool[i]);
bufDescTable[i].dirty = false;
}
hashTable->remove(bufDescTable[i].file, bufDescTable[i].pageNo);
bufDescTable[i].Clear();
}
}
}
