pub struct Persy { /* private fields */ }
Expand description

Main structure to operate persy storage files

Implementations

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())?;

Create a new database file.

Errors

Fails if the file already exists.

Open a database file.

The file should have been created with Persy::create

Errors

Fails if the file does not exist.

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.

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.

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.

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.

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(())
})?;

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()?;

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()?;

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")?);

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")?;

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")?;

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);

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);

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")?);

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 {
    //...
}

Get one value or none from a key.

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

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 {
        //...
    }
}

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()));

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()));

Create a read snapshot at the current data status.

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

Trait Implementations

Returns a copy of the value. Read more

Performs copy-assignment from source. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more

Immutably borrows from an owned value. Read more

Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The resulting type after obtaining ownership.

Creates owned data from borrowed data, usually by cloning. Read more

Uses borrowed data to replace owned data, usually by cloning. Read more

The type returned in the event of a conversion error.

Performs the conversion.

The type returned in the event of a conversion error.

Performs the conversion.