Struct persy::Persy

pub struct Persy { /* private fields */ }

Main structure to operate persy storage files

Implementations

impl Persy

pub fn create<P: AsRef<Path>>(path: P) -> Result<(), PE<CreateError>>

Create a new database file.

Errors

Fails if the file already exists.

Example

use std::path::Path;
use persy::{Persy, Config};

let path = Path::new("target/created.db");
Persy::create(path)?;
let persy = Persy::open(path, Config::new())?;

pub fn create_from_file(file: File) -> Result<(), PE<CreateError>>

Create a new database file.

Errors

Fails if the file already exists.

pub fn open<P: AsRef<Path>>(
path: P,
config: Config
) -> Result<Persy, PE<OpenError>>

Open a database file.

The file should have been created with Persy::create

Errors

Fails if the file does not exist.

pub fn open_with_recover<P: AsRef<Path>, C>(
path: P,
config: Config,
recover: C
) -> Result<Persy, PE<OpenError>>where
C: Fn(&TransactionId) -> bool,

Open a database file from a path with a recover function.

The file should have been created with Persy::create

Errors

Fails if the file does not exist.

pub fn recover<P: AsRef<Path>>(
path: P,
config: Config
) -> Result<Recover, PE<OpenError>>

Open a database file from a path and return a recover structure that allow to select the transactions to commit and recover them.

The file should have been created with Persy::create

Errors

Fails if the file does not exist.

pub fn open_from_file(path: File, config: Config) -> Result<Persy, PE<OpenError>>

Open a database file from a direct file handle.

The file should have been created with Persy::create

Errors

Fails if the file does not exist.

pub fn open_from_file_with_recover<C>(
file: File,
config: Config,
recover: C
) -> Result<Persy, PE<OpenError>>where
C: Fn(&TransactionId) -> bool,

Open a database file, from a direct file handle and a transaction recover function.

The file should have been created with Persy::create

Errors

Fails if the file does not exist.

pub fn open_or_create_with<P, F>(
path: P,
config: Config,
prepare: F
) -> Result<Persy, PE<OpenError>>where
P: AsRef<Path>,
F: FnOnce(&Persy) -> Result<(), Box<dyn Error>> + 'static,

Open an existing database or create it if it does not exist yet, calling the prepare function just after the creation.

Example

use std::path::Path;
use persy::{Persy, Config, PersyId, ValueMode};

let path = Path::new("target/open_or_create.db");
let config = Config::new();

let persy = Persy::open_or_create_with(path, config, |persy| {
    // this closure is only called on database creation
    let mut tx = persy.begin()?;
    tx.create_segment("data")?;
    tx.create_index::<u64, PersyId>("index", ValueMode::Replace)?;
    let prepared = tx.prepare()?;
    prepared.commit()?;
    println!("Segment and Index successfully created");
    Ok(())
})?;

pub fn begin(&self) -> Result<Transaction, PE<BeginTransactionError>>

Begin a new transaction.

The transaction isolation level is ‘read_committed’. for commit call prepare and commit

Example

let mut tx = persy.begin()?;
// ...
tx.prepare()?.commit()?;

pub fn begin_with(
&self,
config: TransactionConfig
) -> Result<Transaction, PE<BeginTransactionError>>

Begin a new transaction specifying parameters for the transaction.

The transaction isolation level is ‘read_committed’. for commit call prepare and commit

Example

let tx_id = vec![2;2];
let mut tx = persy.begin_with(TransactionConfig::new().set_transaction_id(tx_id))?;
// ...
tx.prepare()?.commit()?;

pub fn exists_segment(&self, segment: &str) -> Result<bool, PE<GenericError>>

Check if a segment already exist in the storage

Example

let mut tx = persy.begin()?;
tx.create_segment("my_new_segment")?;
let prepared = tx.prepare()?;
prepared.commit()?;
assert!(persy.exists_segment("my_new_segment")?);

pub fn solve_segment_id(
&self,
segment: impl ToSegmentId
) -> Result<SegmentId, PE<SegmentError>>

Resolves the segment to a SegmentId

Example

let mut tx = persy.begin()?;
tx.create_segment("my_new_segment")?;
let prepared = tx.prepare()?;
prepared.commit()?;
let segment_id = persy.solve_segment_id("my_new_segment")?;

pub fn solve_index_id(
&self,
index: impl ToIndexId
) -> Result<IndexId, PE<IndexError>>

Resolves the index to a IndexId, this has no public use as today, may be used in future.

Example

let mut tx = persy.begin()?;
tx.create_index::<u8,u8>("my_new_index", ValueMode::Cluster)?;
let prepared = tx.prepare()?;
prepared.commit()?;
let index_id = persy.solve_index_id("my_new_index")?;

pub fn read(
&self,
segment: impl ToSegmentId,
id: &PersyId
) -> Result<Option<Vec<u8>>, PE<ReadError>>

Read the record content from persistent data.

Example

let mut tx = persy.begin()?;
let data = vec![1;20];
let id = tx.insert("seg", &data)?;
let prepared = tx.prepare()?;
prepared.commit()?;
let read = persy.read("seg", &id)?.expect("record exits");
assert_eq!(data,read);

pub fn scan(
&self,
segment: impl ToSegmentId
) -> Result<SegmentIter, PE<SegmentError>>

Scan a segment for persistent records

Example

let mut tx = persy.begin()?;
let data = vec![1;20];
let id = tx.insert("seg", &data)?;
let prepared = tx.prepare()?;
prepared.commit()?;
let mut count = 0;
for (id,content) in persy.scan("seg")? {
    println!("record size:{}",content.len());
    count+=1;
}
assert_eq!(count,1);

pub fn exists_index(&self, index_name: &str) -> Result<bool, PE<GenericError>>

Check if a segment already exist in the storage

Example

let mut tx = persy.begin()?;
tx.create_index::<u8,u8>("my_new_index", ValueMode::Replace)?;
let prepared = tx.prepare()?;
prepared.commit()?;
assert!(persy.exists_index("my_new_index")?);

pub fn get<K, V>(
&self,
index_name: &str,
k: &K
) -> Result<ValueIter<V>, PE<IndexOpsError>>where
K: IndexType,
V: IndexType,

Get a value or a group of values from a key.

Example

let values = persy.get::<u8,u8>("my_new_index",&10)?;
for value in values {
    //...
}

pub fn one<K, V>(
&self,
index_name: &str,
k: &K
) -> Result<Option<V>, PE<IndexOpsError>>where
K: IndexType,
V: IndexType,

Get one value or none from a key.

Example

if let Some(value) = persy.one::<u8,u8>("my_new_index",&10)? {
    //...
}

pub fn range<K, V, R>(
&self,
index_name: &str,
range: R
) -> Result<IndexIter<K, V>, PE<IndexOpsError>>where
K: IndexType,
V: IndexType,
R: RangeBounds<K>,

Browse a range of keys and values from and index.

Example

let iter:IndexIter<u8,u8> = persy.range("my_new_index",10..12)?;
for (k,values) in iter  {
    for value in values {
        //...
    }
}

pub fn list_segments(
&self
) -> Result<Vec<(String, SegmentId)>, PE<GenericError>>

List all the existing segments.

Example

let mut tx = persy.begin()?;
tx.create_segment("seg")?;
let prepared = tx.prepare()?;
prepared.commit()?;
let segments = persy.list_segments()?;
let names = segments.into_iter().map(|(name,_id)|name).collect::<Vec<String>>();
assert!(names.contains(&"seg".to_string()));

pub fn list_indexes(&self) -> Result<Vec<(String, IndexInfo)>, PE<GenericError>>

List all the existing indexes.

Example

let mut tx = persy.begin()?;
tx.create_index::<u8,u8>("index", ValueMode::Cluster)?;
let prepared = tx.prepare()?;
prepared.commit()?;
let indexes = persy.list_indexes()?;
let names = indexes.into_iter().map(|(name,_info)|name).collect::<Vec<String>>();
assert!(names.contains(&"index".to_string()));

pub fn snapshot(&self) -> Result<Snapshot, PE<GenericError>>

Create a read snapshot at the current data status.

// ... More logic
let snapshot = persy.snapshot()?;
// .. Access data from the snapshot

Trait Implementations

impl Clone for Persy

fn clone(&self) -> Persy

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.