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wisc_db
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Class which represents a fixed-size database page containing records. More...
#include <page.h>
Public Member Functions | |
| Page () | |
| RecordId | insertRecord (const char *record_data) |
| std::string | getRecord (const RecordId &record_id) const |
| void | updateRecord (const RecordId &record_id, const char *record_data) |
| void | deleteRecord (const RecordId &record_id) |
| bool | hasSpaceForRecord (const char *record_data) const |
| std::uint16_t | getFreeSpace () const |
| PageId | page_number () const |
| PageId | next_page_number () const |
| PageIterator | begin () |
| PageIterator | end () |
| void | print () |
Public Attributes | |
| PageHeader | header |
Static Public Attributes | |
| static const std::size_t | SIZE |
| static const std::size_t | DATA_SIZE = SIZE - sizeof(PageHeader) |
| static const PageId | INVALID_NUMBER = 0 |
| static const SlotId | INVALID_SLOT = 0 |
Friends | |
| class | File |
| class | PageIterator |
| class | PageTest |
| class | BufferTest |
Class which represents a fixed-size database page containing records.
This Page is heap-ordered, and handles variable-length records using slots. Slot meta-data is stored at the end of the file. A page is a fixed-size unit of data storage. Each page holds zero or more records, which consist of arbitrary binary data. Records are placed into slots and identified by a RecordId. Although a record's actual contents may be moved on the page, accessing a record by its slot is consistent.
| wiscdb::Page::Page | ( | ) |
Constructs a new, uninitialized page.
| PageIterator wiscdb::Page::begin | ( | ) |
Returns an iterator at the first record in the page.
| void wiscdb::Page::deleteRecord | ( | const RecordId & | record_id | ) |
Deletes the record with the given ID. Page is compacted upon delete to ensure that data of all records is contiguous. Slot array is compacted if the slot deleted is at the end of the slot array.
| record_id | ID of the record to delete. |
| InvalidRecordException | if passed record_id is invalid |
| PageIterator wiscdb::Page::end | ( | ) |
Returns an iterator representing the record after the last record in the page. This iterator should not be dereferenced.
| std::uint16_t wiscdb::Page::getFreeSpace | ( | ) | const |
Returns this page's free space in bytes.
| std::string wiscdb::Page::getRecord | ( | const RecordId & | record_id | ) | const |
Returns the record with the given ID. Returned data is a copy of what is stored on the page; use updateRecord to change it.
| record_id | ID of the record to return. |
| InvalidRecordException | if passed record_id is invalid |
| bool wiscdb::Page::hasSpaceForRecord | ( | const char * | record_data | ) | const |
Returns true if the page has enough free space to hold the given data.
| record_data | Bytes that compose the record. |
| RecordId wiscdb::Page::insertRecord | ( | const char * | record_data | ) |
Inserts a new record into the page.
| record_data | Bytes that compose the record. |
| InsufficientSpaceException | if not enough space on page for record |
| PageId wiscdb::Page::next_page_number | ( | ) | const |
Returns the number of the next used page this page in its file.
| PageId wiscdb::Page::page_number | ( | ) | const |
Returns this page's number in its file.
| void wiscdb::Page::print | ( | ) |
For debugging purposes; prints the contents of a page
| void wiscdb::Page::updateRecord | ( | const RecordId & | record_id, |
| const char * | record_data | ||
| ) |
Updates the record with the given ID, replacing its data with a new version. This is equivalent to deleting the old record and inserting a new one, with the exception that the record ID will not change.
| record_id | ID of record to update. |
| record_data | Updated bytes that compose the record. |
| InvalidRecordException | if passed record_id is invalid |
| InsufficientSpaceException | if the the new data for the recorde cannot fit in the page |
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| PageHeader wiscdb::Page::header |
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1.8.11
