Struct BTreeLeafPage 

pub struct BTreeLeafPage {
    pub slot_count: usize,
    pub tuple_scheme: Schema,
    /* private fields */
}

A leaf page in the B+ tree.

Binary Layout

• 4 bytes: page category
• 4 bytes: parent page index
• 4 bytes: left sibling page index
• 4 bytes: right sibling page index
• n bytes: header bytes, indicate whether every slot of the page is used or not.
• n bytes: tuple bytes

Fields

slot_count: usize

tuple_scheme: Schema

Implementations

impl BTreeLeafPage

pub fn set_right_pid(&mut self, pid: Option<BTreePageID>)

pub fn get_right_pid(&self) -> Option<BTreePageID>

pub fn set_left_pid(&mut self, pid: Option<BTreePageID>)

pub fn get_left_pid(&self) -> Option<BTreePageID>

pub fn get_slots_count(&self) -> usize

pub fn stable(&self) -> bool

stable means at least half of the page is occupied

pub fn empty_slots_count(&self) -> usize

pub fn tuples_count(&self) -> usize

Returns the number of tuples currently stored on this page

pub fn calculate_header_size(slot_count: usize) -> usize

pub fn insert_tuple(&mut self, tuple: &Tuple)

Adds the specified tuple to the page such that all records remain in sorted order; the tuple should be updated to reflect that it is now stored on this page. tuple: The tuple to add.

pub fn get_tuple(&self, slot_index: usize) -> Option<Tuple>

pub fn delete_tuple(&mut self, slot_index: usize)

pub fn is_slot_used(&self, slot_index: usize) -> bool

Returns true if associated slot on this page is filled.

pub fn mark_slot_status(&mut self, slot_index: usize, used: bool)

pub fn check_integrity( &self, parent_pid: &BTreePageID, lower_bound: Option<IntField>, upper_bound: Option<IntField>, check_occupancy: bool, depth: usize, )

pub fn iter(&self) -> BTreeLeafPageIterator<'_>

impl BTreeLeafPage

pub fn calculate_slots_count(scheme: &Schema) -> usize

Retrieve the maximum number of tuples this page can hold.

Trait Implementations

impl BTreePage for BTreeLeafPage

fn get_page_data(&self) -> Vec<u8>

Generates a byte array representing the contents of this page. Used to serialize this page to disk.

The invariant here is that it should be possible to pass the byte array generated by get_page_data to the BTreeLeafPage constructor and have it produce an identical BTreeLeafPage object.

fn new( pid: &BTreePageID, bytes: &[u8], tuple_scheme: &Schema, key_field: usize, ) -> Self

fn get_pid(&self) -> BTreePageID

fn get_parent_pid(&self) -> BTreePageID

fn set_parent_pid(&mut self, pid: &BTreePageID)

fn set_before_image(&mut self)

fn get_before_image(&self) -> Vec<u8>

Provide a representation of this page before any modifications were made to it. Used by recovery.

fn peek(&self)