Expand description
Persy - Transactional Persistence Engine
Simple single file durable, isolated, consistent, and atomic persistence engine based on copy on write. It guarantee the persistence of data even in case of crash through a in file write ahead log, and provide simple rust APIs for store simple bytes or value associated (index) data, provide also memory management logic to keep the file size in check.
Example
use persy::{Persy,Config};
//...
Persy::create("./target/data.persy")?;
let persy = Persy::open("./target/data.persy",Config::new())?;
let mut tx = persy.begin()?;
tx.create_segment("seg")?;
let data = vec![1;20];
tx.insert("seg", &data)?;
let prepared = tx.prepare()?;
prepared.commit()?;
for (_id,content) in persy.scan("seg")? {
assert_eq!(content[0], 1);
//....
}Example Index
use persy::{Persy,Config, ValueMode};
//...
Persy::create("./target/index_data.persy")?;
let persy = Persy::open("./target/index_data.persy",Config::new())?;
let mut tx = persy.begin()?;
tx.create_index::<i32,i32>("index", ValueMode::Cluster)?;
tx.put("index", 10, 20)?;
let prepared = tx.prepare()?;
prepared.commit()?;
for (key,values) in persy.range::<i32,i32,_>("index", ..)? {
assert_eq!(key, 10);
assert_eq!(values.into_iter().collect::<Vec<_>>(), vec![20]);
//....
}Structs
Wrapper for Vec<u8> for use it in index keys or values
Persy configuration structure.
Unique identifier of an index
Index definition details
Index Iterator implementation for iterating on a range of keys
Options, flags, configs which can be used to configure how a persy database is opened.
Main structure to operate persy storage files
Identifier of a persistent record, can be used for read, update or delete the record
Intermediate recover status to select witch transactions to commit or rollback and list witch transactions are in a intermediate state
Represents a looked-up segment
Iterator implementation used to scan a segment
Read snapshot at a specific point in time.
Iterator implementation to scan a segment at the current snapshot state.
Transaction container, it include all the changes done in a transaction.
Configure the parameters for the transaction on the begin of a new transaction.
prepared transaction state
Index Iterator implementation for iterating on a range of keys considering changes in transaction
Iterator implementation to scan a segment considering in transaction changes.
Iterator of values relative to an index key use by get and range functions
Enums
Enum of all the possible Key or Value types for indexes
Wrapper enum for all the possible Persy errors,
Enum of all possible errors from Persy
Possible state of a transaction in the log
Concurrent Modification Strategy for resolution of conflict on commit.
Define the behavior of the index in case a key value pair already exists
Traits
Type Definitions
Custom identifier to track the transaction in the recover phase