mentat/db/src/types.rs
Emily Toop ab957948b4 Move to using watcher.
Simplify.

This has a watcher collect txid -> AttributeSet mappings each time a
transact occurs. On commit we retrieve those mappings and hand them over
to the observer service, which filters them and packages them up for
dispatch.

Tidy up
2018-03-20 16:27:35 +00:00

106 lines
3.2 KiB
Rust

// Copyright 2016 Mozilla
//
// Licensed under the Apache License, Version 2.0 (the "License"); you may not use
// this file except in compliance with the License. You may obtain a copy of the
// License at http://www.apache.org/licenses/LICENSE-2.0
// Unless required by applicable law or agreed to in writing, software distributed
// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
// CONDITIONS OF ANY KIND, either express or implied. See the License for the
// specific language governing permissions and limitations under the License.
#![allow(dead_code)]
use std::collections::HashMap;
use std::collections::{
BTreeMap,
BTreeSet,
};
extern crate mentat_core;
pub use self::mentat_core::{
Attribute,
AttributeBitFlags,
DateTime,
Entid,
Schema,
TypedValue,
Utc,
ValueType,
};
/// Represents one partition of the entid space.
#[derive(Clone,Debug,Eq,Hash,Ord,PartialOrd,PartialEq)]
pub struct Partition {
/// The first entid in the partition.
pub start: i64,
/// The next entid to be allocated in the partition.
pub index: i64,
}
impl Partition {
pub fn new(start: i64, next: i64) -> Partition {
assert!(start <= next, "A partition represents a monotonic increasing sequence of entids.");
Partition { start: start, index: next }
}
pub fn contains_entid(&self, e: i64) -> bool {
(e >= self.start) && (e < self.index)
}
}
/// Map partition names to `Partition` instances.
pub type PartitionMap = BTreeMap<String, Partition>;
/// Represents the metadata required to query from, or apply transactions to, a Mentat store.
///
/// See https://github.com/mozilla/mentat/wiki/Thoughts:-modeling-db-conn-in-Rust.
#[derive(Clone,Debug,Default,Eq,Hash,Ord,PartialOrd,PartialEq)]
pub struct DB {
/// Map partition name->`Partition`.
///
/// TODO: represent partitions as entids.
pub partition_map: PartitionMap,
/// The schema of the store.
pub schema: Schema,
}
impl DB {
pub fn new(partition_map: PartitionMap, schema: Schema) -> DB {
DB {
partition_map: partition_map,
schema: schema
}
}
}
/// A pair [a v] in the store.
///
/// Used to represent lookup-refs and [TEMPID a v] upserts as they are resolved.
pub type AVPair = (Entid, TypedValue);
/// Map [a v] pairs to existing entids.
///
/// Used to resolve lookup-refs and upserts.
pub type AVMap<'a> = HashMap<&'a AVPair, Entid>;
// represents a set of entids that are correspond to attributes
pub type AttributeSet = BTreeSet<Entid>;
/// A transaction report summarizes an applied transaction.
#[derive(Clone, Debug, Eq, Hash, Ord, PartialOrd, PartialEq)]
pub struct TxReport {
/// The transaction ID of the transaction.
pub tx_id: Entid,
/// The timestamp when the transaction began to be committed.
pub tx_instant: DateTime<Utc>,
/// A map from string literal tempid to resolved or allocated entid.
///
/// Every string literal tempid presented to the transactor either resolves via upsert to an
/// existing entid, or is allocated a new entid. (It is possible for multiple distinct string
/// literal tempids to all unify to a single freshly allocated entid.)
pub tempids: BTreeMap<String, Entid>,
}