Persy 0.2

Persy is a storage based on a single file where data can stored in sub-containers called "segment", so as first step let's create a file the basic file add on it a segment and insert on it some raw data.

    //Create the file
    Persy::create("./storage.persy")?;
    //Open the file for operations
    let persy = Persy::open("./storage.persy",Config::new())?;
    //Start a transaction all the operations in persy are done inside a transaction.
    let mut tx = persy.begin()?;
    //Create a segment called "seg" using the started tx.
    persy.create_segment(&mut tx, "seg")?;
    //Prepere some raw data
    let data = vec![1;20];
    //Insert the data inside the segment with the current tx.
    let id = persy.insert_record(&mut tx, "seg", &data)?;
    //Commit the tx.
    let prepared = persy.prepare_commit(tx)?;
    persy.commit(prepared)?;

To notice that the transaction is a two phase transaction to allow to implement complex use cases.

be aware that file locking is not present in persy 0.2 so there is no controll if two process try to access the same file

Next step read scan the data that we just insert this can be done without a transaction

   let id = None;
   let to_find = vec![1;20];
   for record in persy.scan_records("seg")? {
        //.... do something with the record.id and record.content
        if record.content == to_find {
            id = Some(record.id);
            break;
        }
    }

Update the record to another content

    let update_id = //.... get from insert or from a scan.
    //Begin a transaction
    let mut tx = persy.begin()?;
    let new_data = vec![2;20];
    // Update the record with new data
    persy.update_record(&mut tx, "seg", &update_id, &new_data)?;
    //Commit the tx.
    let prepared = persy.prepare_commit(tx)?;
    persy.commit(prepared)?;

finally delete the record

    let delete_id = //.... get from insert or from a scan.
    //Begin a transaction
    let mut tx = persy.begin()?;
    // delete the record
    persy.delete_record(&mut tx, "seg", &delete_id)?;
    //Commit the tx.
    let prepared = persy.prepare_commit(tx)?;
    persy.commit(prepared)?;

For a full overview of the capabilities of persy, check the docs