/**************************************************************************************
* Function Name: FIFO
*
* Description:
* FIFO replacement strategy
*
* Parameters:
* BM_BufferPool * const bm: Buffer Pool Handler
* BM_PageHandle * const page: Buffer Page Handler
* PageNumber pageNum: the page number of the requested page
*
* Return:
* RC: return code
*
* Author:
* Xin Su <*****@*****.**>
*
* History:
* Date Name Content
* ---------- ---------------------------------- ------------------------
* 2015-03-15 Xin Su <*****@*****.**> Initialization.
**************************************************************************************/
RC FIFO(BM_BufferPool * const bm, BM_PageHandle * const page,
PageNumber pageNum) {
// First search the page in the queue
RC rc = -99; // init return code
rc = searchPage(bm, page, pageNum);
// If find the page, then simply return RC_OK
if (rc != RC_PAGE_NOT_FOUND) {
return rc;
}
/*
* If the code comes here, then the Buffer Manager doesn't have the page loaded.
* We have to read the page from the disk and load it into BM_PageHandle.
*/
PageList *queue = (PageList *) bm->mgmtData;
// If the Buffer Manager has vacancy for the requested page,
// then read the page from the disk and append it to the tail of the PageList
if (queue->size < bm->numPages) {
rc = -99; // reset return code
rc = appendPage(bm, page, pageNum);
return rc;
}
/*
* If the code comes here, then neither the Buffer Manager has the page loaded nor has vacancy for the requested page.
* The size of the PageList = bm->numPages
* We have to replace an existing page in the Buffer Manager with the requested page.
*/
// Find the first removable page, starting from head
// Set the current pointer to the head of the queue to start the traversal
queue->current = queue->head;
while (queue->current != queue->tail && queue->current->fixCount != 0) {
queue->current = queue->current->next;
}
// After the while loop, if the current pointer comes to the tail
// then we still need to determine if the tail's fixCount = 0
if (queue->current == queue->tail && queue->current->fixCount != 0) {
return RC_NO_REMOVABLE_PAGE;
}
/*
* If the code comes here, then a removable page is found, and the current pointer is pointing to it
*/
// Replace the removable page with the requested page
rc = -99; // reset the return value
rc = replacePage(bm, page, pageNum);
return rc;
}
DbRecord DbFile::getNewRecord(const char* key, const char* value, RecordType type)
{
size_t size = DbRecord::getSize(key, value, type);
// Try creating a record in one of pages
for (int i = pages.size() - 1; i >= 0; --i)
{
if (getPage(i).hasSpace(size))
return getPage(i).newRecord(key, value, type);
}
// Create the record in a new page
return appendPage()->newRecord(key, value, type);
}
std::shared_ptr<Page> Queue::writeFillToPage(AddressType Index,
AddressType& Address) {
while (Index > LastPage->Index) {
bool WriteFillNextPage = writeFill(LastPage->getMinAddress(), PageSize);
if (!WriteFillNextPage && Index > LastPage->Index) {
// This should only happen if we reach eof. Verify,
// If so, allow page wrap so that we can have a cursor pointing
// to the eof position.
if ((LastPage->getMinAddress() + PageSize != LastPage->getMaxAddress()) ||
!appendPage())
return failThenGetErrorPage(Address);
}
}
return getDefinedPage(Index, Address);
}
bool Queue::writeFill(AddressType Address, AddressType WantedSize) {
Address += WantedSize;
// Expand till page exists.
while (Address > LastPage->getMaxAddress()) {
if (EofFrozen)
return false;
AddressType MaxLimit = LastPage->getMinAddress() + PageSize;
if (Address >= MaxLimit) {
LastPage->setMaxAddress(MaxLimit);
if (!appendPage())
return false;
} else {
LastPage->setMaxAddress(Address);
}
}
return true;
}
OutputViewWidget::OutputViewWidget(QWidget * parent) :
TitledPanel(parent),
MESSAGES_PAGE("messages"),
LOG_PAGE("log"),
PREVIEW_PAGE("preview"),
SEARCH_RESULT_PAGE("search")
{
setSelectorStyle(TabSelector);
mToggleViewAction->setText(tr("Messages / Log File"));
mToggleViewAction->setIcon(getRealIcon("logpanel"));
// messages
QFontMetrics fm(QApplication::font());
OutputMessages = new LogEditor(this);
OutputMessages->setFocusPolicy(Qt::ClickFocus);
OutputMessages->setMinimumHeight(3*(fm.lineSpacing()+4));
OutputMessages->setReadOnly(true);
appendPage(new TitledPanelPage(OutputMessages, MESSAGES_PAGE, tr("Messages")), false);
// log / errors
logWidget = new LatexLogWidget(this);
TitledPanelPage *page = new TitledPanelPage(logWidget, LOG_PAGE, tr("Log"));
page->addToolbarActions(logWidget->displayActions());
appendPage(page, false);
// previewer
previewWidget = new PreviewWidget(this);
appendPage(new TitledPanelPage(previewWidget, PREVIEW_PAGE, tr("Preview")), false);
// global search results
searchResultModel = new SearchResultModel(this);
SearchTreeDelegate *searchDelegate=new SearchTreeDelegate(this);
QHBoxLayout *horz=new QHBoxLayout;
horz->setContentsMargins(4,2,4,2);
horz->setSpacing(8);
searchScopeBox=new QComboBox;
searchScopeBox->setEditable(false);
searchScopeBox->addItem(tr("Current Doc"));
searchScopeBox->addItem(tr("All Docs"));
searchScopeBox->addItem(tr("Project"));
connect(searchScopeBox,SIGNAL(currentIndexChanged(int)),SIGNAL(updateTheSearch(int)));
QLabel *lbl=new QLabel;
lbl->setText(tr("Search text:"));
searchTextLabel=new QLabel;
//searchTextEdit->setSizePolicy(QSizePolicy::Expanding,QSizePolicy::Fixed);
QPushButton *btn=new QPushButton(tr("Update Search"));
connect(btn,SIGNAL(clicked()),this,SLOT(updateSearch()));
QLabel *lbl2=new QLabel;
lbl2->setText(tr("Replace by:"));
replaceTextEdit=new QLineEdit;
connect(replaceTextEdit,SIGNAL(textChanged(QString)),this,SLOT(replaceTextChanged(QString)));
//replaceTextEdit->setSizePolicy(QSizePolicy::Maximum,QSizePolicy::Fixed);
QPushButton *btn2=new QPushButton(tr("Replace all"));
connect(btn2,SIGNAL(clicked()),this,SLOT(replaceAll()));
horz->addWidget(searchScopeBox);
horz->addWidget(lbl);
horz->addWidget(searchTextLabel,1);
horz->addWidget(btn);
horz->addWidget(lbl2);
horz->addWidget(replaceTextEdit,1);
horz->addWidget(btn2);
OutputSearchTree= new QTreeView(this);
OutputSearchTree->header()->hide();
OutputSearchTree->setUniformRowHeights(true);
OutputSearchTree->setModel(searchResultModel);
OutputSearchTree->setItemDelegate(searchDelegate);
OutputSearchTree->setFrameShape(QFrame::NoFrame);
QVBoxLayout *vert=new QVBoxLayout;
vert->setContentsMargins(0,0,0,0);
vert->setSpacing(0);
vert->addLayout(horz);
QFrame *hLine = new QFrame();
hLine->setFrameShape(QFrame::HLine);
vert->addWidget(hLine);
vert->addWidget(OutputSearchTree,1);
QWidget *wgt=new QWidget;
wgt->setLayout(vert);
connect(OutputSearchTree,SIGNAL(clicked(QModelIndex)),this,SLOT(clickedSearchResult(QModelIndex)));
//appendPage(new TitledPanelPage(OutputSearchTree, SEARCH_RESULT_PAGE, tr("Search Results")));
appendPage(new TitledPanelPage(wgt, SEARCH_RESULT_PAGE, tr("Search Results")));
}
/**************************************************************************************
* Function Name: CLOCK
*
* Description:
* CLOCK replacement strategy
*
* Parameters:
* BM_BufferPool * const bm: Buffer Pool Handler
* BM_PageHandle * const page: Buffer Page Handler
* PageNumber pageNum: the page number of the requested page
*
* Return:
* RC: return code
*
* Author:
* Xin Su <*****@*****.**>
*
* History:
* Date Name Content
* ---------- ---------------------------------- ------------------------
* 2015-03-15 Xin Su <*****@*****.**> Initialization.
**************************************************************************************/
RC CLOCK(BM_BufferPool * const bm, BM_PageHandle * const page,
PageNumber pageNum) {
PageList *queue = (PageList *) bm->mgmtData;
// First search the page in the queue.
RC rc = -99; // init return code
rc = searchPage(bm, page, pageNum);
// if find the page, set the current page's clockFlag to TRUE
// else if other errors happen, return rc
if (rc == RC_OK) {
queue->current->clockFlag = TRUE;
return rc;
} else if (rc != RC_PAGE_NOT_FOUND) {
return rc;
}
/*
* If the code comes here, then the Buffer Manager doesn't have the page loaded.
* We have to read the page from the disk and load it into BM_PageHandle.
*/
// If the Buffer Manager has vacancy for the requested page,
// then read the page from the disk and append it to the tail of the PageList
if (queue->size < bm->numPages) {
rc = -99; // reset return code
rc = appendPage(bm, page, pageNum);
if (rc == RC_OK) {
// Set the clock pointer to the next to the current pointer
// if the PageList is not full, set the clock pointer to the next to the current pointer
// else, set the clock pointer to the head
if (queue->size < bm->numPages) {
queue->clock = queue->current->next;
} else if (queue->size == bm->numPages) {
queue->clock = queue->head;
}
}
return rc;
}
/*
* If the code comes here, then neither the Buffer Manager has the page loaded nor has vacancy for the requested page.
* The size of the PageList = bm->numPages
* We have to replace an existing page in the Buffer Manager with the requested page.
*/
// Logic of CLOCK replacement strategy
// Now the current points to should point to the page that was requested last time
while (queue->clock->clockFlag != FALSE) {
queue->clock->clockFlag = FALSE;
if (queue->clock == queue->tail) {
queue->clock = queue->head;
} else {
queue->clock = queue->clock->next;
}
}
// We find the first PageFrame whose clockFlag is FALSE
// Set the current pointer to the clock pointer
queue->current = queue->clock;
/*RC*/rc = -99;// do not need to redefine RC
rc = replacePage(bm, page, pageNum);
if (rc == RC_OK) {
// After the replacement of the requested page, set its clockFlag to TRUE
queue->clock->clockFlag = TRUE;
// TO DO - Whether we need to set the clock pointer to the next to the current pointer?
if (queue->clock == queue->tail) {
queue->clock = queue->head;
} else {
queue->clock = queue->clock->next;
}
}
return rc;
}
/**************************************************************************************
* Function Name: CLOCK
*
* Description:
* CLOCK replacement strategy
*
* Parameters:
* BM_BufferPool * const bm: Buffer Pool Handler
* BM_PageHandle * const page: Buffer Page Handler
* PageNumber pageNum: the page number of the requested page
*
* Return:
* RC: return code
*
* Author:
* Xin Su <*****@*****.**>
*
* History:
* Date Name Content
* ---------- ---------------------------------- ------------------------
* 2015-03-15 Xin Su <*****@*****.**> Initialization
**************************************************************************************/
RC CLOCK(BM_BufferPool * const bm, BM_PageHandle * const page,
PageNumber pageNum) {
PageList *queue = (PageList *) bm->mgmtData;
RC rc; // init return code
// First search the page in the PageList
printf("searchPage: Page-%d\n", pageNum);
rc = -99;
rc = searchPage(bm, page, pageNum);
// if find the page, set the current page's clockFlag to TRUE
// else if other errors happen, return rc
if (rc == RC_PAGE_FOUND) {
queue->current->fixCount++;
queue->current->clockFlag = TRUE;
printf("Page-%d found\n", pageNum);
return rc;
} else if (rc != RC_PAGE_NOT_FOUND) {
return rc;
}
printf("Page-%d not found\n", pageNum);
/*
* If the code comes here, then the Buffer Manager doesn't have the page loaded.
* We have to read the page from the disk and load it into BM_PageHandle.
*/
// if the Buffer Manager has vacancy for the requested page,
// then read the page from the disk and append it to the next to the tail of the PageList
if (queue->size < bm->numPages) {
printf("appendPage: Page-%d\n", pageNum);
rc = -99; // reset return code
rc = appendPage(bm, page, pageNum);
// if the PageList is not full, set the clock pointer to the next to the current pointer
// else, now the current pointer points to the tail, then set the clock pointer points back to the head
if (rc == RC_OK) {
if (queue->size < bm->numPages) {
queue->clock = queue->current->next;
} else if (queue->size == bm->numPages) {
queue->clock = queue->head;
}
printf("Page-%d appended\n", pageNum);
}
return rc;
}
/*
* If the code comes here, then neither the Buffer Manager has the page loaded nor vacancy for the requested page
* Now the PageList is full: the size of the PageList = bm->numPages
* We have to replace an existing page in the Buffer Manager with the requested page
*/
// Logic of CLOCK replacement strategy
// Now the current pointer points to the page that was requested last time,
// and the clock pointer points to the next to the current pointer (or back to the head if the current pointers points to the tail)
// Find the first page with clockFlag = TRUE and fixCount = 0
while (queue->clock->clockFlag == TRUE || queue->clock->fixCount != 0
|| queue->clock->numReadIO != 0 || queue->clock->numWriteIO != 0) {
queue->clock->clockFlag = FALSE;
// Into the while loop means this page does not fit the requirement of the removable page
// Move the clock pointer to the next. If it points to the tail, move it back to the head
if (queue->clock == queue->tail) {
queue->clock = queue->head;
} else {
queue->clock = queue->clock->next;
}
}
// We find the first PageFrame whose clockFlag = FALSE and fixCount = 0
// Set the current pointer to the clock pointer, so that we can call replacePage
queue->current = queue->clock;
// Replace the removable page with the requested page
printf("replacePage: Page-%d\n", pageNum);
rc = -99;
rc = replacePage(bm, page, pageNum);
if (rc == RC_OK) {
// After the replacement of the requested page, set its clockFlag to TRUE
queue->clock->clockFlag = TRUE;
// Set the clock pointer to the next to the current pointer
if (queue->clock == queue->tail) {
queue->clock = queue->head;
} else {
queue->clock = queue->clock->next;
}
printf("Page-%d replaced\n", pageNum);
}
return rc;
} // CLOCK
/**************************************************************************************
* Function Name: FIFO
*
* Description:
* FIFO replacement strategy
*
* Parameters:
* BM_BufferPool * const bm: Buffer Pool Handler
* BM_PageHandle * const page: Buffer Page Handler
* PageNumber pageNum: the page number of the requested page
*
* Return:
* RC: return code
*
* Author:
* Xin Su <*****@*****.**>
*
* History:
* Date Name Content
* ---------- ---------------------------------- ------------------------
* 2015-03-15 Xin Su <*****@*****.**> Initialization.
**************************************************************************************/
RC FIFO(BM_BufferPool * const bm, BM_PageHandle * const page,
PageNumber pageNum) {
PageList *queue = (PageList *) bm->mgmtData;
RC rc; // init return code
// First search the requested page in the PageList
printf("searchPage: Page-%d\n", pageNum);
rc = -99;
rc = searchPage(bm, page, pageNum);
// First search the requested page in the queue
// if the requested page is found, then set statistics and return rc (RC_PAGE_FOUND)
// else if something unexpected error happens, then return rc
if (rc == RC_PAGE_FOUND) {
queue->current->fixCount++;
printf("Page-%d found\n", pageNum);
return rc;
} else if (rc != RC_PAGE_NOT_FOUND) {
return rc;
}
printf("Page-%d not found\n", pageNum);
/*
* If the code comes here, then the Buffer Manager doesn't have the requested page
* We have to read the page from the disk and load it into BM_PageHandle.
*/
// if the Buffer Manager has vacancy for the requested page,
// then read the page from the disk and append it to the next of the tail of the PageList
if (queue->size < bm->numPages) {
printf("appendPage: Page-%d\n", pageNum);
rc = -99; // reset return code
rc = appendPage(bm, page, pageNum);
if (rc == RC_OK) {
printf("Page-%d appended\n", pageNum);
}
return rc;
}
/*
* If the code comes here, then neither the Buffer Manager has the requested page loaded nor vacancy for the requested page
* Now the PageList is full: the size of the PageList = bm->numPages
* We have to replace an existing page in the Buffer Manager with the requested page
*/
// Find the first removable page, starting from head
// Set the current pointer to the head of the queue to start the traversal
queue->current = queue->head;
// Find the first page with fixCount = 0
while (queue->current != queue->tail
&& (queue->current->fixCount != 0 || queue->current->numReadIO != 0
|| queue->current->numWriteIO != 0)) {
queue->current = queue->current->next;
}
// After the while loop, if the current pointer comes to the tail,
// then we still need to determine if the tail's fixCount = 0
if (queue->current == queue->tail
&& (queue->current->fixCount != 0 || queue->current->numReadIO != 0
|| queue->current->numWriteIO != 0)) {
return RC_NO_REMOVABLE_PAGE;
}
/*
* If the code comes here, then a removable page is found
* The current pointer is pointing to it
*/
// Replace the removable page with the requested page
printf("replacePage: Page-%d\n", pageNum);
rc = -99; // reset the return value
rc = replacePage(bm, page, pageNum);
// if replacePage completes without error and the requested page is not in the tail spot
// then move it to the tail of the PageList
if (rc == RC_OK && queue->current != queue->tail) {
// Remove the current PageFrame
// The steps of the remove are different depending on if the requested page is the head or not
if (queue->current == queue->head) {
queue->head = queue->head->next;
queue->current->next->previous = NULL;
} else {
queue->current->previous->next = queue->current->next;
queue->current->next->previous = queue->current->previous;
}
// Add the requested page to the tail of the PageList
// step 1 - connect tail and current
queue->current->previous = queue->tail;
queue->tail->next = queue->current;
// step 2 - set current's next
queue->current->next = NULL;
// step 3 - set tail
queue->tail = queue->tail->next;
printf("Page-%d replaced\n", pageNum);
// Now the current pointer still points to the requested page
}
return rc;
} // FIFO