Struct PageCache 

pub struct PageCache {
    pub root_pointer_buffer: ConcurrentHashMap<BTreePageID, Arc<RwLock<BTreeRootPointerPage>>>,
    pub internal_buffer: ConcurrentHashMap<BTreePageID, Arc<RwLock<BTreeInternalPage>>>,
    pub leaf_buffer: ConcurrentHashMap<BTreePageID, Arc<RwLock<BTreeLeafPage>>>,
    pub header_buffer: ConcurrentHashMap<BTreePageID, Arc<RwLock<BTreeHeaderPage>>>,
}

Fields

root_pointer_buffer: ConcurrentHashMap<BTreePageID, Arc<RwLock<BTreeRootPointerPage>>>

internal_buffer: ConcurrentHashMap<BTreePageID, Arc<RwLock<BTreeInternalPage>>>

leaf_buffer: ConcurrentHashMap<BTreePageID, Arc<RwLock<BTreeLeafPage>>>

header_buffer: ConcurrentHashMap<BTreePageID, Arc<RwLock<BTreeHeaderPage>>>

Implementations

impl PageCache

pub fn new() -> Self

pub fn clear(&self)

pub fn get_root_ptr_page( &self, tx: &Transaction, perm: Permission, key: &BTreePageID, ) -> ResultPod<BTreeRootPointerPage>

pub fn get_header_page( &self, tx: &Transaction, perm: Permission, key: &BTreePageID, ) -> ResultPod<BTreeHeaderPage>

pub fn get_internal_page( &self, tx: &Transaction, perm: Permission, key: &BTreePageID, ) -> ResultPod<BTreeInternalPage>

pub fn get_leaf_page( &self, tx: &Transaction, perm: Permission, key: &BTreePageID, ) -> ResultPod<BTreeLeafPage>

pub fn discard_page(&self, pid: &BTreePageID)

Remove the specific page id from the buffer pool. Needed by the recovery manager to ensure that the buffer pool doesn’t keep a rolled back page in its cache.

Also used by B+ tree files to ensure that deleted pages are removed from the cache so they can be reused safely

pub fn set_page_size(page_size: usize)

pub fn get_page_size() -> usize

pub fn flush_all_pages(&self, log_manager: &mut LogManager)

Flush all dirty pages to disk.

NB: Be careful using this routine – it writes dirty data to disk so will break small-db if running in NO STEAL mode.

TODO: does these pages belong to a single table?

pub fn flush_pages(&self, tx: &Transaction, log_manager: &mut LogManager)

Write all pages of the specified transaction to disk.

TODO: protest this function (mut self / or global lock)

pub fn tx_complete(&self, tx: &Transaction, commit: bool)

pub fn recover_page<PAGE: BTreePage>( &self, pid: &BTreePageID, page: PAGE, buffer: &ConcurrentHashMap<BTreePageID, Arc<RwLock<PAGE>>>, )