db.rs

  1mod kvp;
  2mod migrations;
  3
  4use std::fs;
  5use std::path::{Path, PathBuf};
  6use std::sync::Arc;
  7
  8use anyhow::Result;
  9use log::error;
 10use parking_lot::Mutex;
 11use rusqlite::Connection;
 12
 13use migrations::MIGRATIONS;
 14
 15#[derive(Clone)]
 16pub enum Db {
 17    Real(Arc<RealDb>),
 18    Null,
 19}
 20
 21pub struct RealDb {
 22    connection: Mutex<Connection>,
 23    path: Option<PathBuf>,
 24}
 25
 26impl Db {
 27    /// Open or create a database at the given directory path.
 28    pub fn open(db_dir: &Path, channel: &'static str) -> Self {
 29        // Use 0 for now. Will implement incrementing and clearing of old db files soon TM
 30        let current_db_dir = db_dir.join(Path::new(&format!("0-{}", channel)));
 31        fs::create_dir_all(&current_db_dir)
 32            .expect("Should be able to create the database directory");
 33        let db_path = current_db_dir.join(Path::new("db.sqlite"));
 34
 35        Connection::open(db_path)
 36            .map_err(Into::into)
 37            .and_then(|connection| Self::initialize(connection))
 38            .map(|connection| {
 39                Db::Real(Arc::new(RealDb {
 40                    connection,
 41                    path: Some(db_dir.to_path_buf()),
 42                }))
 43            })
 44            .unwrap_or_else(|e| {
 45                error!(
 46                    "Connecting to file backed db failed. Reverting to null db. {}",
 47                    e
 48                );
 49                Self::Null
 50            })
 51    }
 52
 53    /// Open a in memory database for testing and as a fallback.
 54    #[cfg(any(test, feature = "test-support"))]
 55    pub fn open_in_memory() -> Self {
 56        Connection::open_in_memory()
 57            .map_err(Into::into)
 58            .and_then(|connection| Self::initialize(connection))
 59            .map(|connection| {
 60                Db::Real(Arc::new(RealDb {
 61                    connection,
 62                    path: None,
 63                }))
 64            })
 65            .unwrap_or_else(|e| {
 66                error!(
 67                    "Connecting to in memory db failed. Reverting to null db. {}",
 68                    e
 69                );
 70                Self::Null
 71            })
 72    }
 73
 74    fn initialize(mut conn: Connection) -> Result<Mutex<Connection>> {
 75        MIGRATIONS.to_latest(&mut conn)?;
 76
 77        conn.pragma_update(None, "journal_mode", "WAL")?;
 78        conn.pragma_update(None, "synchronous", "NORMAL")?;
 79        conn.pragma_update(None, "foreign_keys", true)?;
 80        conn.pragma_update(None, "case_sensitive_like", true)?;
 81
 82        Ok(Mutex::new(conn))
 83    }
 84
 85    pub fn persisting(&self) -> bool {
 86        self.real().and_then(|db| db.path.as_ref()).is_some()
 87    }
 88
 89    pub fn real(&self) -> Option<&RealDb> {
 90        match self {
 91            Db::Real(db) => Some(&db),
 92            _ => None,
 93        }
 94    }
 95}
 96
 97impl Drop for Db {
 98    fn drop(&mut self) {
 99        match self {
100            Db::Real(real_db) => {
101                let lock = real_db.connection.lock();
102
103                let _ = lock.pragma_update(None, "analysis_limit", "500");
104                let _ = lock.pragma_update(None, "optimize", "");
105            }
106            Db::Null => {}
107        }
108    }
109}
110
111#[cfg(test)]
112mod tests {
113    use crate::migrations::MIGRATIONS;
114
115    #[test]
116    fn test_migrations() {
117        assert!(MIGRATIONS.validate().is_ok());
118    }
119}