persy/
recover.rs

1use crate::{
2    error::{GenericError, PE},
3    journal::recover_impl::RecoverImpl,
4    persy::PersyImpl,
5    Persy, TransactionId,
6};
7use std::sync::Arc;
8
9/// Possible state of a transaction in the log
10#[derive(PartialEq, Eq, Debug, Clone)]
11pub enum RecoverStatus {
12    /// Can't find the start of the transaction so already completed  
13    Partial,
14    /// Started but not completed
15    Started,
16    /// Successfully prepared
17    PrepareCommit,
18    /// rollback-ed
19    Rollback,
20    /// Successfully committed after prepared
21    Commit,
22    /// Successfully cleaned up resources after commit
23    Cleanup,
24}
25
26/// Intermediate recover status to select witch transactions to commit or rollback and list witch
27/// transactions are in a intermediate state
28///
29/// # Example
30///
31///
32/// ```rust
33/// # use persy::{Persy,Config};
34/// # fn main() -> Result<(), Box<dyn std::error::Error>> {
35/// # Persy::create("./target/recover_example.persy")?;
36/// let mut recover = Persy::recover("./target/recover_example.persy", Config::new())?;
37/// for (tx_id,status) in recover.list_transactions() {
38///     // Check the transaction if can be committed using the tx_id
39///     if true {
40///         // if so commit the tx
41///         recover.commit(tx_id);
42///     } else {
43///         // otherwise roll back it
44///         recover.rollback(tx_id);
45///     }
46///     // finalize all the transaction marked to finalize and get a persy instance.
47/// }
48/// let persy = recover.finalize()?;
49/// # std::fs::remove_file("./target/recover_example.persy")?;
50/// # Ok(())
51/// # }
52/// ```
53pub struct Recover {
54    recover_impl: RecoverImpl,
55    persy_impl: Arc<PersyImpl>,
56}
57
58impl Recover {
59    pub(crate) fn new(recover_impl: RecoverImpl, persy_impl: Arc<PersyImpl>) -> Recover {
60        Recover {
61            recover_impl,
62            persy_impl,
63        }
64    }
65    /// List all the transactions found in the log with the current status
66    pub fn list_transactions(&self) -> Vec<(TransactionId, RecoverStatus)> {
67        self.recover_impl.list_transactions()
68    }
69    /// Mark to commit a transaction in the log with state prepared commit
70    pub fn commit(&mut self, tx_id: TransactionId) {
71        self.recover_impl.commit(tx_id)
72    }
73    /// Mark to rollback a transaction that is not yet committed
74    pub fn rollback(&mut self, tx_id: TransactionId) {
75        self.recover_impl.rollback(tx_id)
76    }
77    /// Read the status of a transaction in the log
78    pub fn status(&self, tx_id: TransactionId) -> Option<RecoverStatus> {
79        self.recover_impl.status(tx_id)
80    }
81    /// Recover all the prepared committed transactions that are not marked to rollback
82    pub fn finalize(self) -> Result<Persy, PE<GenericError>> {
83        self.persy_impl.final_recover(self.recover_impl)?;
84        Ok(Persy {
85            persy_impl: self.persy_impl,
86        })
87    }
88}
persy/recover.rs

persy/
recover.rs
