b2e98f44f6
* Part 3: Parameterize Entity by value type. This isn't quite right, because after parsing, we shouldn't care about` `edn::ValueAndSpan`, we should care only about edn::Value. However, I think we can drop `ValueAndSpan` entirely if we just use `rust-peg` (and its simpler error messages) rather than a mix of `rust-peg` and `combine`. In any case, this paves the way to transacting `Entity<TypedValue>`, which is a nice step towards building general entities. * Part 1: Add AttributePlace. * Part 2: Name other places EntityPlace and ValuePlace. Now we're consistent and closer to self-documenting. Both matter more as we expose `Entity` as the thing to build for programmatic usage. * Part 4: Allow Ident and TempId in ValuePlace. The parser will never produce these, since determining whether an integer/keyword or string is an ident or a tempid, respectively, in the value place requires the schema. But a builder that produces `Entity` instances directly will want to produce these.
128 lines
4.1 KiB
Rust
128 lines
4.1 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,
|
|
};
|
|
|
|
use mentat_tx::entities::{
|
|
EntityPlace,
|
|
TempId,
|
|
};
|
|
|
|
use errors;
|
|
|
|
/// 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>,
|
|
}
|
|
|
|
/// The transactor is tied to `edn::ValueAndSpan` right now, but in the future we'd like to support
|
|
/// `TypedValue` directly for programmatic use. `TransactableValue` encapsulates the interface
|
|
/// value types (i.e., values in the value place) need to support to be transacted.
|
|
pub trait TransactableValue: Clone {
|
|
/// Coerce this value place into the given type. This is where we perform schema-aware
|
|
/// coercion, for example coercing an integral value into a ref where appropriate.
|
|
fn into_typed_value(self, schema: &Schema, value_type: ValueType) -> errors::Result<TypedValue>;
|
|
|
|
/// Make an entity place out of this value place. This is where we limit values in nested maps
|
|
/// to valid entity places.
|
|
fn into_entity_place(self) -> errors::Result<EntityPlace<Self>>;
|
|
|
|
fn as_tempid(&self) -> Option<TempId>;
|
|
}
|