use sled::{self, Config, Db};
use std::convert::TryFrom;
use std::str;
use thiserror::Error as ThisError;
#[cfg(not(feature = "alter-table"))]
use crate::AlterTable;
#[cfg(feature = "alter-table")]
use crate::AlterTableError;
use crate::{Error, Result, Schema};
#[cfg(feature = "alter-table")]
mod alter_table;
#[cfg(not(feature = "alter-table"))]
impl AlterTable for SledStorage {}
mod store;
#[derive(ThisError, Debug)]
enum StorageError {
#[cfg(feature = "alter-table")]
#[error(transparent)]
AlterTable(#[from] AlterTableError),
#[error(transparent)]
Sled(#[from] sled::Error),
#[error(transparent)]
Bincode(#[from] bincode::Error),
#[error(transparent)]
Str(#[from] str::Utf8Error),
}
impl Into<Error> for StorageError {
fn into(self) -> Error {
use StorageError::*;
match self {
Sled(e) => Error::Storage(Box::new(e)),
Bincode(e) => Error::Storage(e),
Str(e) => Error::Storage(Box::new(e)),
#[cfg(feature = "alter-table")]
AlterTable(e) => e.into(),
}
}
}
#[macro_export]
macro_rules! try_into {
($expr: expr) => {
$expr.map_err(|e| {
let e: StorageError = e.into();
let e: Error = e.into();
e
})?
};
($self: expr, $expr: expr) => {
match $expr {
Err(e) => {
let e: StorageError = e.into();
let e: Error = e.into();
return Err(($self, e));
}
Ok(v) => v,
}
};
}
#[derive(Debug)]
pub struct SledStorage {
tree: Db,
}
impl SledStorage {
pub fn new(filename: &str) -> Result<Self> {
let tree = try_into!(sled::open(filename));
Ok(Self { tree })
}
}
impl TryFrom<Config> for SledStorage {
type Error = Error;
fn try_from(config: Config) -> Result<Self> {
let tree = try_into!(config.open());
Ok(Self { tree })
}
}
fn fetch_schema(tree: &Db, table_name: &str) -> Result<(String, Option<Schema>)> {
let key = format!("schema/{}", table_name);
let value = try_into!(tree.get(&key.as_bytes()));
let schema = try_into!(value.map(|v| bincode::deserialize(&v)).transpose());
Ok((key, schema))
}