Crate persy

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]);
    //....
}

Modules§

inspect

Structs§

ByteVec: Wrapper for Vec<u8> for use it in index keys or values
Config: Persy configuration structure.
IndexId: Unique identifier of an index
IndexInfo: Index definition details
IndexIter: Index Iterator implementation for iterating on a range of keys
OpenOptions: Options, flags, configs which can be used to configure how a persy database is opened.
Persy: Main structure to operate persy storage files
PersyId: Identifier of a persistent record, can be used for read, update or delete the record
Recover: Intermediate recover status to select witch transactions to commit or rollback and list witch transactions are in a intermediate state
SegmentId: Represents a looked-up segment
SegmentIter: Iterator implementation used to scan a segment
Snapshot: Read snapshot at a specific point in time.
SnapshotSegmentIter: Iterator implementation to scan a segment at the current snapshot state.
Transaction: Transaction container, it include all the changes done in a transaction.
TransactionConfig: Configure the parameters for the transaction on the begin of a new transaction.
TransactionFinalize: prepared transaction state
TxIndexIter: Index Iterator implementation for iterating on a range of keys considering changes in transaction
TxSegmentIter: Iterator implementation to scan a segment considering in transaction changes.
ValueIter: Iterator of values relative to an index key use by get and range functions

Enums§

BeginTransactionError
CreateError
CreateIndexError
CreateSegmentError
DeleteError
DropIndexError
DropSegmentError
GenericError
IndexChangeError
IndexError
IndexOpsError
IndexPutError
IndexTypeId: Enum of all the possible Key or Value types for indexes
InsertError
OpenError
OpenMemoryError
PE: Wrapper enum for all the possible Persy errors,
PersyError: Enum of all possible errors from Persy
PrepareError
ReadError
RecoverStatus: Possible state of a transaction in the log
SegmentError
TxStrategy: Concurrent Modification Strategy for resolution of conflict on commit.
UpdateError
ValueMode: Define the behavior of the index in case a key value pair already exists

Traits§

IndexType
ToIndexId
ToSegmentId

Type Aliases§

TransactionId: Custom identifier to track the transaction in the recover phase

Crate persyCopy item path