Struct BfTree

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pub struct BfTree { /* private fields */ }

Expand description

The bf-tree instance

Implementations§

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impl BfTree

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

Recovery a Bf-Tree from snapshot and WAL files. Incomplete function, internal use only

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

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

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pub fn snapshot(&self) -> PathBuf

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

Returns the snapshot file path

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impl BfTree

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

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).unwrap();

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

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

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

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.

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pub fn config(&self) -> &Config

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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.

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pub fn update_read_promotion_rate(&self, new_rate: usize)

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

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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 mut config = bf_tree::Config::default();
config.cb_min_record_size(4);
let tree = BfTree::with_config(config, None).unwrap();
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");

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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 mut config = bf_tree::Config::default();
config.cb_min_record_size(4);

let tree = BfTree::with_config(config, None).unwrap();
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");

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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);