06056a8468
The `core` create didn't exist when the `db` was started, but this type is clearly part of the public interface of Mentat.
111 lines
3.4 KiB
Rust
111 lines
3.4 KiB
Rust
// Copyright 2016 Mozilla
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//
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// Licensed under the Apache License, Version 2.0 (the "License"); you may not use
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// this file except in compliance with the License. You may obtain a copy of the
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// License at http://www.apache.org/licenses/LICENSE-2.0
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// Unless required by applicable law or agreed to in writing, software distributed
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// under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
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// CONDITIONS OF ANY KIND, either express or implied. See the License for the
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// specific language governing permissions and limitations under the License.
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#![allow(dead_code)]
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use std::collections::HashMap;
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use std::collections::{
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BTreeMap,
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BTreeSet,
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};
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extern crate mentat_core;
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pub use self::mentat_core::{
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Attribute,
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AttributeBitFlags,
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DateTime,
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Entid,
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Schema,
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TypedValue,
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Utc,
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ValueType,
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};
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use edn::entities::{
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EntityPlace,
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TempId,
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};
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use errors;
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/// Represents one partition of the entid space.
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#[derive(Clone,Debug,Eq,Hash,Ord,PartialOrd,PartialEq)]
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pub struct Partition {
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/// The first entid in the partition.
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pub start: i64,
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/// The next entid to be allocated in the partition.
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pub index: i64,
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}
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impl Partition {
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pub fn new(start: i64, next: i64) -> Partition {
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assert!(start <= next, "A partition represents a monotonic increasing sequence of entids.");
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Partition { start: start, index: next }
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}
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pub fn contains_entid(&self, e: i64) -> bool {
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(e >= self.start) && (e < self.index)
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}
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}
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/// Map partition names to `Partition` instances.
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pub type PartitionMap = BTreeMap<String, Partition>;
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/// Represents the metadata required to query from, or apply transactions to, a Mentat store.
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///
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/// See https://github.com/mozilla/mentat/wiki/Thoughts:-modeling-db-conn-in-Rust.
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#[derive(Clone,Debug,Default,Eq,Hash,Ord,PartialOrd,PartialEq)]
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pub struct DB {
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/// Map partition name->`Partition`.
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///
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/// TODO: represent partitions as entids.
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pub partition_map: PartitionMap,
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/// The schema of the store.
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pub schema: Schema,
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}
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impl DB {
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pub fn new(partition_map: PartitionMap, schema: Schema) -> DB {
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DB {
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partition_map: partition_map,
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schema: schema
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}
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}
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}
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/// A pair [a v] in the store.
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///
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/// Used to represent lookup-refs and [TEMPID a v] upserts as they are resolved.
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pub type AVPair = (Entid, TypedValue);
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/// Map [a v] pairs to existing entids.
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///
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/// Used to resolve lookup-refs and upserts.
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pub type AVMap<'a> = HashMap<&'a AVPair, Entid>;
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// represents a set of entids that are correspond to attributes
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pub type AttributeSet = BTreeSet<Entid>;
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/// The transactor is tied to `edn::ValueAndSpan` right now, but in the future we'd like to support
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/// `TypedValue` directly for programmatic use. `TransactableValue` encapsulates the interface
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/// value types (i.e., values in the value place) need to support to be transacted.
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pub trait TransactableValue: Clone {
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/// Coerce this value place into the given type. This is where we perform schema-aware
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/// coercion, for example coercing an integral value into a ref where appropriate.
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fn into_typed_value(self, schema: &Schema, value_type: ValueType) -> errors::Result<TypedValue>;
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/// Make an entity place out of this value place. This is where we limit values in nested maps
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/// to valid entity places.
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fn into_entity_place(self) -> errors::Result<EntityPlace<Self>>;
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fn as_tempid(&self) -> Option<TempId>;
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}
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