badgerdb::PageIterator Class Reference

Iterator for iterating over the records in a page. More...

#include <page_iterator.h>

List of all members.

Public Member Functions
	PageIterator ()
	PageIterator (Page *page)
	PageIterator (Page *page, const RecordId &record_id)
PageIterator &	operator++ ()
PageIterator	operator++ (int)
bool	operator== (const PageIterator &rhs) const
bool	operator!= (const PageIterator &rhs) const
std::string	operator* () const
SlotId	getNextUsedSlot (const SlotId start) const

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Detailed Description

Iterator for iterating over the records in a page.

This class provides a forward-only iterator that iterates over all the records stored in a Page.

Definition at line 23 of file page_iterator.h.

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Constructor & Destructor Documentation

badgerdb::PageIterator::PageIterator

(

)

[inline]

Constructs an empty iterator.

Definition at line 28 of file page_iterator.h.

      : page_(NULL) {
    current_record_ = {Page::INVALID_NUMBER, Page::INVALID_SLOT};
  }

badgerdb::PageIterator::PageIterator

(

Page *

page

)

[inline]

Constructors an iterator over the records in the given page, starting at the first record. Page must not be null.

Parameters:

page	Page to iterate over.

Definition at line 39 of file page_iterator.h.

      : page_(page)  {
    assert(page_ != NULL);
    const SlotId used_slot = getNextUsedSlot(Page::INVALID_SLOT /* start */);
    current_record_ = {page_->page_number(), used_slot};
  }

badgerdb::PageIterator::PageIterator	(	Page *	page,
		const RecordId &	record_id
	)		[inline]

Constructs an iterator over the records in the given page, starting at the given record.

Parameters:

page	Page to iterate over.
record_id	ID of record to start iterator at.

Definition at line 53 of file page_iterator.h.

      : page_(page),
        current_record_(record_id) {
  }

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Member Function Documentation

SlotId badgerdb::PageIterator::getNextUsedSlot

(

const SlotId

start

)

const [inline]

Returns the next used slot in the page after the given slot or Page::INVALID_SLOT if no slots are used after the given slot.

Parameters:

start

Slot to start search at.

Returns:

Next used slot after given slot or Page::INVALID_SLOT.

Definition at line 111 of file page_iterator.h.

                                                   {
    SlotId slot_number = Page::INVALID_SLOT;
    for (SlotId i = start + 1; i <= page_->header_.num_slots; ++i) {
      const PageSlot* slot = page_->getSlot(i);
      if (slot->used) {
        slot_number = i;
        break;
      }
    }
    return slot_number;
  }

std::string badgerdb::PageIterator::operator*

(

)

const [inline]

Dereferences the iterator, returning a copy of the current record in the page.

Returns:

Record in page.

Definition at line 100 of file page_iterator.h.

                                     {
    return page_->getRecord(current_record_); 
  }

PageIterator& badgerdb::PageIterator::operator++

(

)

[inline]

Advances the iterator to the next record in the page.

Definition at line 61 of file page_iterator.h.

                                    {
    assert(page_ != NULL);
    const SlotId used_slot = getNextUsedSlot(current_record_.slot_number);
    current_record_ = {page_->page_number(), used_slot};

    return *this;
  }

bool badgerdb::PageIterator::operator==

(

const PageIterator &

rhs

)

const [inline]

Returns true if this iterator is equal to the given iterator.

Parameters:

rhs	Iterator to compare against.

Returns:

True if other iterator is equal to this one.

Definition at line 84 of file page_iterator.h.

                                                        {
    return page_->page_number() == rhs.page_->page_number() &&
        current_record_ == rhs.current_record_;
  }

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The documentation for this class was generated from the following file:

• /afs/cs.wisc.edu/p/course/cs564-jignesh/public/html/projects/BadgerDB/bufmgr/src/page_iterator.h