Struct BfTree 

pub struct BfTree { /* private fields */ }

The bf-tree instance

Implementations

impl BfTree

pub fn recovery( config_file: impl AsRef<Path>, wal_file: impl AsRef<Path>, buffer_ptr: Option<*mut u8>, )

pub fn new_from_snapshot( bf_tree_config: Config, buffer_ptr: Option<*mut u8>, ) -> Self

Instead of creating a new Bf-Tree instance, it loads a Bf-Tree snapshot file and resume from there.

pub fn snapshot(&self) -> PathBuf

Stop the world and take a snapshot of the current state.

Returns the snapshot file path

impl BfTree

pub fn new(file_path: impl AsRef<Path>, cache_size_byte: usize) -> Self

Create a new bf-tree instance with customized storage backend and circular buffer size

For in-memory tree, use :memory: as file path. For cache-only tree, use :cache: as file path For disk tree, file_path is the path to the index file

Mini page cache must be at least 8192 bytes for practical workloads.

use bf_tree::BfTree;
let tree = BfTree::new(":memory:", 8192);

pub fn new_with_config_file<P: AsRef<Path>>(config_file_path: P) -> Self

Create a new bf-tree instance with customized configuration based on a config file

pub fn with_config(config: Config, buffer_ptr: Option<*mut u8>) -> Self

Initialize the bf-tree with provided config. For advanced user only. An optional pre-allocated buffer pointer can be provided to use as the buffer pool memory.

pub fn get_buffer_metrics(&self) -> CircularBufferMetrics

Get the buffer metrics of the circular buffer. This is a blocking call, will stop all other buffer operations, use it wisely.

pub fn update_read_promotion_rate(&self, new_rate: usize)

Chance% to promote a base read record to mini page.

pub fn insert(&self, key: &[u8], value: &[u8]) -> LeafInsertResult

Insert a key-value pair to the system, overrides existing value if present.

use bf_tree::BfTree;
use bf_tree::LeafReadResult;

let tree = BfTree::default();
tree.insert(b"key", b"value");
let mut buffer = [0u8; 1024];
let read_size = tree.read(b"key", &mut buffer);

assert_eq!(read_size, LeafReadResult::Found(5));
assert_eq!(&buffer[..5], b"value");

pub fn read(&self, key: &[u8], out_buffer: &mut [u8]) -> LeafReadResult

Read a record from the tree. Returns the number of bytes read.

TODO: don’t panic if the out_buffer is too small, instead returns a error.

use bf_tree::BfTree;
use bf_tree::LeafReadResult;

let tree = BfTree::default();
tree.insert(b"key", b"value");
let mut buffer = [0u8; 1024];
let read_size = tree.read(b"key", &mut buffer);
assert_eq!(read_size, LeafReadResult::Found(5));
assert_eq!(&buffer[..5], b"value");

pub fn delete(&self, key: &[u8])

Delete a record from the tree.

use bf_tree::BfTree;
use bf_tree::LeafReadResult;

let tree = BfTree::default();
tree.insert(b"key", b"value");
tree.delete(b"key");
let mut buffer = [0u8; 1024];
let rt = tree.read(b"key", &mut buffer);
assert_eq!(rt, LeafReadResult::Deleted);

pub fn scan<'a>(&'a self, key: &'a [u8], cnt: usize) -> ScanIter<'a, 'a>

Scan records in the tree, with starting key and desired scan count. Returns a iterator that yields key-value pairs.

pub fn get_metrics(&mut self) -> Option<Value>

Collect all metrics and reset the metric recorder The caller needs to ensure there are no references to the bf-tree’s metrics recorder anymore.

Trait Implementations

impl Default for BfTree

fn default() -> Self

Returns the “default value” for a type.

impl Drop for BfTree

fn drop(&mut self)

Executes the destructor for this type.

impl Send for BfTree

impl Sync for BfTree