mentat/db/src/tx.rs

1157 lines
50 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)]
//! This module implements the transaction application algorithm described at
//! https://github.com/mozilla/mentat/wiki/Transacting and its children pages.
//!
//! The implementation proceeds in four main stages, labeled "Pipeline stage 1" through "Pipeline
//! stage 4". _Pipeline_ may be a misnomer, since the stages as written **cannot** be interleaved
//! in parallel. That is, a single transacted entity cannot flow through all the stages without its
//! sibling entities.
//!
//! This unintuitive architectural decision was made because the second and third stages (resolving
//! lookup refs and tempids, respectively) operate _in bulk_ to minimize the number of expensive
//! SQLite queries by processing many in one SQLite invocation. Pipeline stage 2 doesn't need to
//! operate like this: it is easy to handle each transacted entity independently of all the others
//! (and earlier, less efficient, implementations did this). However, Pipeline stage 3 appears to
//! require processing multiple elements at the same time, since there can be arbitrarily complex
//! graph relationships between tempids. Pipeline stage 4 (inserting elements into the SQL store)
//! could also be expressed as an independent operation per transacted entity, but there are
//! non-trivial uniqueness relationships inside a single transaction that need to enforced.
//! Therefore, some multi-entity processing is required, and a per-entity pipeline becomes less
//! attractive.
//!
//! A note on the types in the implementation. The pipeline stages are strongly typed: each stage
//! accepts and produces a subset of the previous. We hope this will reduce errors as data moves
//! through the system. In contrast the Clojure implementation rewrote the fundamental entity type
//! in place and suffered bugs where particular code paths missed cases.
//!
//! The type hierarchy accepts `Entity` instances from the transaction parser and flows `Term`
//! instances through the term-rewriting transaction applier. `Term` is a general `[:db/add e a v]`
//! with restrictions on the `e` and `v` components. The hierarchy is expressed using `Result` to
//! model either/or, and layers of `Result` are stripped -- we might say the `Term` instances are
//! _lowered_ as they flow through the pipeline. This type hierarchy could have been expressed by
//! combinatorially increasing `enum` cases, but this makes it difficult to handle the `e` and `v`
//! components symmetrically. Hence, layers of `Result` type aliases. Hopefully the explanatory
//! names -- `TermWithTempIdsAndLookupRefs`, anyone? -- and strongly typed stage functions will help
//! keep everything straight.
use std::borrow::Cow;
use std::collections::{BTreeMap, BTreeSet, VecDeque};
use std::iter::once;
use crate::db;
use crate::db::MentatStoring;
use crate::entids;
use crate::internal_types::{
replace_lookup_ref, AEVTrie, AddAndRetract, KnownEntidOr, LookupRef, LookupRefOrTempId,
TempIdHandle, TempIdMap, Term, TermWithTempIds, TermWithTempIdsAndLookupRefs,
TermWithoutTempIds, TypedValueOr,
};
use db_traits::errors;
use db_traits::errors::{DbErrorKind, Result};
use edn::{InternSet, Keyword};
use mentat_core::util::Either;
use core_traits::{attribute, now, Attribute, Entid, KnownEntid, TypedValue, ValueType};
use mentat_core::{DateTime, Schema, TxReport, Utc};
use crate::metadata;
use crate::schema::SchemaBuilding;
use crate::tx_checking;
use crate::types::{AVMap, AVPair, PartitionMap, TransactableValue};
use crate::upsert_resolution::{FinalPopulations, Generation};
use crate::watcher::TransactWatcher;
use edn::entities as entmod;
use edn::entities::{AttributePlace, Entity, OpType, TempId};
use rusqlite;
/// Defines transactor's high level behaviour.
pub(crate) enum TransactorAction {
/// Materialize transaction into 'datoms' and metadata
/// views, but do not commit it into 'transactions' table.
/// Use this if you need transaction's "side-effects", but
/// don't want its by-products to end-up in the transaction log,
/// e.g. when rewinding.
Materialize,
/// Materialize transaction into 'datoms' and metadata
/// views, and also commit it into the 'transactions' table.
/// Use this for regular transactions.
MaterializeAndCommit,
}
/// A transaction on its way to being applied.
#[derive(Debug)]
pub struct Tx<'conn, 'a, W>
where
W: TransactWatcher,
{
/// The storage to apply against. In the future, this will be a Mentat connection.
store: &'conn rusqlite::Connection, // TODO: db::MentatStoring,
/// The partition map to allocate entids from.
///
/// The partition map is volatile in the sense that every succesful transaction updates
/// allocates at least one tx ID, so we own and modify our own partition map.
partition_map: PartitionMap,
/// The schema to update from the transaction entities.
///
/// Transactions only update the schema infrequently, so we borrow this schema until we need to
/// modify it.
schema_for_mutation: Cow<'a, Schema>,
/// The schema to use when interpreting the transaction entities.
///
/// This schema is not updated, so we just borrow it.
schema: &'a Schema,
watcher: W,
/// The transaction ID of the transaction.
tx_id: Entid,
}
/// Remove any :db/id value from the given map notation, converting the returned value into
/// something suitable for the entity position rather than something suitable for a value position.
pub fn remove_db_id<V: TransactableValue>(
map: &mut entmod::MapNotation<V>,
) -> Result<Option<entmod::EntityPlace<V>>> {
// TODO: extract lazy defined constant.
let db_id_key = entmod::EntidOrIdent::Ident(Keyword::namespaced("db", "id"));
let db_id: Option<entmod::EntityPlace<V>> = if let Some(id) = map.remove(&db_id_key) {
match id {
entmod::ValuePlace::Entid(e) => Some(entmod::EntityPlace::Entid(e)),
entmod::ValuePlace::LookupRef(e) => Some(entmod::EntityPlace::LookupRef(e)),
entmod::ValuePlace::TempId(e) => Some(entmod::EntityPlace::TempId(e)),
entmod::ValuePlace::TxFunction(e) => Some(entmod::EntityPlace::TxFunction(e)),
entmod::ValuePlace::Atom(v) => Some(v.into_entity_place()?),
entmod::ValuePlace::Vector(_) | entmod::ValuePlace::MapNotation(_) => {
bail!(DbErrorKind::InputError(errors::InputError::BadDbId))
}
}
} else {
None
};
Ok(db_id)
}
impl<'conn, 'a, W> Tx<'conn, 'a, W>
where
W: TransactWatcher,
{
pub fn new(
store: &'conn rusqlite::Connection,
partition_map: PartitionMap,
schema_for_mutation: &'a Schema,
schema: &'a Schema,
watcher: W,
tx_id: Entid,
) -> Tx<'conn, 'a, W> {
Tx {
store,
partition_map,
schema_for_mutation: Cow::Borrowed(schema_for_mutation),
schema,
watcher,
tx_id,
}
}
/// Given a collection of tempids and the [a v] pairs that they might upsert to, resolve exactly
/// which [a v] pairs do upsert to entids, and map each tempid that upserts to the upserted
/// entid. The keys of the resulting map are exactly those tempids that upserted.
pub(crate) fn resolve_temp_id_avs<'b>(
&self,
temp_id_avs: &'b [(TempIdHandle, AVPair)],
) -> Result<TempIdMap> {
if temp_id_avs.is_empty() {
return Ok(TempIdMap::default());
}
// Map [a v]->entid.
let mut av_pairs: Vec<&AVPair> = vec![];
for temp_id_av in temp_id_avs {
av_pairs.push(&temp_id_av.1);
}
// Lookup in the store.
let av_map: AVMap = self.store.resolve_avs(&av_pairs[..])?;
debug!("looked up avs {:?}", av_map);
// Map id->entid.
let mut tempids: TempIdMap = TempIdMap::default();
// Errors. BTree* since we want deterministic results.
let mut conflicting_upserts: BTreeMap<TempId, BTreeSet<KnownEntid>> = BTreeMap::default();
for &(ref tempid, ref av_pair) in temp_id_avs {
trace!(
"tempid {:?} av_pair {:?} -> {:?}",
tempid,
av_pair,
av_map.get(&av_pair)
);
if let Some(entid) = av_map.get(&av_pair).cloned().map(KnownEntid) {
if let Some(previous) = tempids.insert(tempid.clone(), entid) {
if entid != previous {
conflicting_upserts
.entry((**tempid).clone())
.or_insert_with(|| once(previous).collect::<BTreeSet<_>>())
.insert(entid);
}
}
}
}
if !conflicting_upserts.is_empty() {
bail!(DbErrorKind::SchemaConstraintViolation(
errors::SchemaConstraintViolation::ConflictingUpserts {
conflicting_upserts
}
));
}
Ok(tempids)
}
/// Pipeline stage 1: convert `Entity` instances into `Term` instances, ready for term
/// rewriting.
///
/// The `Term` instances produce share interned TempId and LookupRef handles, and we return the
/// interned handle sets so that consumers can ensure all handles are used appropriately.
fn entities_into_terms_with_temp_ids_and_lookup_refs<I, V: TransactableValue>(
&self,
entities: I,
) -> Result<(
Vec<TermWithTempIdsAndLookupRefs>,
InternSet<TempId>,
InternSet<AVPair>,
)>
where
I: IntoIterator<Item = Entity<V>>,
{
struct InProcess<'a> {
partition_map: &'a PartitionMap,
schema: &'a Schema,
mentat_id_count: i64,
tx_id: KnownEntid,
temp_ids: InternSet<TempId>,
lookup_refs: InternSet<AVPair>,
}
impl<'a> InProcess<'a> {
fn with_schema_and_partition_map(
schema: &'a Schema,
partition_map: &'a PartitionMap,
tx_id: KnownEntid,
) -> InProcess<'a> {
InProcess {
partition_map,
schema,
mentat_id_count: 0,
tx_id,
temp_ids: InternSet::new(),
lookup_refs: InternSet::new(),
}
}
fn ensure_entid_exists(&self, e: Entid) -> Result<KnownEntid> {
if self.partition_map.contains_entid(e) {
Ok(KnownEntid(e))
} else {
bail!(DbErrorKind::UnallocatedEntid(e))
}
}
fn ensure_ident_exists(&self, e: &Keyword) -> Result<KnownEntid> {
self.schema.require_entid(e)
}
fn intern_lookup_ref<W: TransactableValue>(
&mut self,
lookup_ref: &entmod::LookupRef<W>,
) -> Result<LookupRef> {
let lr_a: i64 = match lookup_ref.a {
AttributePlace::Entid(entmod::EntidOrIdent::Entid(ref a)) => *a,
AttributePlace::Entid(entmod::EntidOrIdent::Ident(ref a)) => {
self.schema.require_entid(&a)?.into()
}
};
let lr_attribute: &Attribute = self.schema.require_attribute_for_entid(lr_a)?;
let lr_typed_value: TypedValue = lookup_ref
.v
.clone()
.into_typed_value(&self.schema, lr_attribute.value_type)?;
if lr_attribute.unique.is_none() {
bail!(DbErrorKind::NotYetImplemented(format!(
"Cannot resolve (lookup-ref {} {:?}) with attribute that is not :db/unique",
lr_a, lr_typed_value
)))
}
Ok(self.lookup_refs.intern((lr_a, lr_typed_value)))
}
/// Allocate private internal tempids reserved for Mentat. Internal tempids just need to be
/// unique within one transaction; they should never escape a transaction.
fn allocate_mentat_id<W: TransactableValue>(&mut self) -> entmod::EntityPlace<W> {
self.mentat_id_count += 1;
entmod::EntityPlace::TempId(TempId::Internal(self.mentat_id_count).into())
}
fn entity_e_into_term_e<W: TransactableValue>(
&mut self,
x: entmod::EntityPlace<W>,
) -> Result<KnownEntidOr<LookupRefOrTempId>> {
match x {
entmod::EntityPlace::Entid(e) => {
let e = match e {
entmod::EntidOrIdent::Entid(ref e) => self.ensure_entid_exists(*e)?,
entmod::EntidOrIdent::Ident(ref e) => self.ensure_ident_exists(&e)?,
};
Ok(Either::Left(e))
}
entmod::EntityPlace::TempId(e) => Ok(Either::Right(LookupRefOrTempId::TempId(
self.temp_ids.intern(e),
))),
entmod::EntityPlace::LookupRef(ref lookup_ref) => Ok(Either::Right(
LookupRefOrTempId::LookupRef(self.intern_lookup_ref(lookup_ref)?),
)),
entmod::EntityPlace::TxFunction(ref tx_function) => {
match tx_function.op.0.as_str() {
"transaction-tx" => Ok(Either::Left(self.tx_id)),
unknown => bail!(DbErrorKind::NotYetImplemented(format!(
"Unknown transaction function {}",
unknown
))),
}
}
}
}
fn entity_a_into_term_a(&mut self, x: entmod::EntidOrIdent) -> Result<Entid> {
let a = match x {
entmod::EntidOrIdent::Entid(ref a) => *a,
entmod::EntidOrIdent::Ident(ref a) => self.schema.require_entid(&a)?.into(),
};
Ok(a)
}
fn entity_e_into_term_v<W: TransactableValue>(
&mut self,
x: entmod::EntityPlace<W>,
) -> Result<TypedValueOr<LookupRefOrTempId>> {
self.entity_e_into_term_e(x)
.map(|r| r.map_left(|ke| TypedValue::Ref(ke.0)))
}
fn entity_v_into_term_e<W: TransactableValue>(
&mut self,
x: entmod::ValuePlace<W>,
backward_a: &entmod::EntidOrIdent,
) -> Result<KnownEntidOr<LookupRefOrTempId>> {
match backward_a.unreversed() {
None => {
bail!(DbErrorKind::NotYetImplemented("Cannot explode map notation value in :attr/_reversed notation for forward attribute".to_string()));
}
Some(forward_a) => {
let forward_a = self.entity_a_into_term_a(forward_a)?;
let forward_attribute =
self.schema.require_attribute_for_entid(forward_a)?;
if forward_attribute.value_type != ValueType::Ref {
bail!(DbErrorKind::NotYetImplemented(format!("Cannot use :attr/_reversed notation for attribute {} that is not :db/valueType :db.type/ref", forward_a)))
}
match x {
entmod::ValuePlace::Atom(v) => {
// Here is where we do schema-aware typechecking: we either assert
// that the given value is in the attribute's value set, or (in
// limited cases) coerce the value into the attribute's value set.
match v.as_tempid() {
Some(tempid) => Ok(Either::Right(LookupRefOrTempId::TempId(self.temp_ids.intern(tempid)))),
None => {
if let TypedValue::Ref(entid) = v.into_typed_value(&self.schema, ValueType::Ref)? {
Ok(Either::Left(KnownEntid(entid)))
} else {
// The given value is expected to be :db.type/ref, so this shouldn't happen.
bail!(DbErrorKind::NotYetImplemented(format!("Cannot use :attr/_reversed notation for attribute {} with value that is not :db.valueType :db.type/ref", forward_a)))
}
}
}
},
entmod::ValuePlace::Entid(entid) =>
Ok(Either::Left(KnownEntid(self.entity_a_into_term_a(entid)?))),
entmod::ValuePlace::TempId(tempid) =>
Ok(Either::Right(LookupRefOrTempId::TempId(self.temp_ids.intern(tempid)))),
entmod::ValuePlace::LookupRef(ref lookup_ref) =>
Ok(Either::Right(LookupRefOrTempId::LookupRef(self.intern_lookup_ref(lookup_ref)?))),
entmod::ValuePlace::TxFunction(ref tx_function) => {
match tx_function.op.0.as_str() {
"transaction-tx" => Ok(Either::Left(KnownEntid(self.tx_id.0))),
unknown=> bail!(DbErrorKind::NotYetImplemented(format!("Unknown transaction function {}", unknown))),
}
},
entmod::ValuePlace::Vector(_) =>
bail!(DbErrorKind::NotYetImplemented(format!("Cannot explode vector value in :attr/_reversed notation for attribute {}", forward_a))),
entmod::ValuePlace::MapNotation(_) =>
bail!(DbErrorKind::NotYetImplemented(format!("Cannot explode map notation value in :attr/_reversed notation for attribute {}", forward_a))),
}
}
}
}
}
let mut in_process = InProcess::with_schema_and_partition_map(
&self.schema,
&self.partition_map,
KnownEntid(self.tx_id),
);
// We want to handle entities in the order they're given to us, while also "exploding" some
// entities into many. We therefore push the initial entities onto the back of the deque,
// take from the front of the deque, and explode onto the front as well.
let mut deque: VecDeque<Entity<V>> = VecDeque::default();
deque.extend(entities);
let mut terms: Vec<TermWithTempIdsAndLookupRefs> = Vec::with_capacity(deque.len());
while let Some(entity) = deque.pop_front() {
match entity {
Entity::MapNotation(mut map_notation) => {
// :db/id is optional; if it's not given, we generate a special internal tempid
// to use for upserting. This tempid will not be reported in the TxReport.
let db_id: entmod::EntityPlace<V> = remove_db_id(&mut map_notation)?
.unwrap_or_else(|| in_process.allocate_mentat_id());
// We're not nested, so :db/isComponent is not relevant. We just explode the
// map notation.
for (a, v) in map_notation {
deque.push_front(Entity::AddOrRetract {
op: OpType::Add,
e: db_id.clone(),
a: AttributePlace::Entid(a),
v,
});
}
}
Entity::AddOrRetract { op, e, a, v } => {
let AttributePlace::Entid(a) = a;
if let Some(reversed_a) = a.unreversed() {
let reversed_e = in_process.entity_v_into_term_e(v, &a)?;
let reversed_a = in_process.entity_a_into_term_a(reversed_a)?;
let reversed_v = in_process.entity_e_into_term_v(e)?;
terms.push(Term::AddOrRetract(
OpType::Add,
reversed_e,
reversed_a,
reversed_v,
));
} else {
let a = in_process.entity_a_into_term_a(a)?;
let attribute = self.schema.require_attribute_for_entid(a)?;
let v = match v {
entmod::ValuePlace::Atom(v) => {
// Here is where we do schema-aware typechecking: we either assert
// that the given value is in the attribute's value set, or (in
// limited cases) coerce the value into the attribute's value set.
if attribute.value_type == ValueType::Ref {
match v.as_tempid() {
Some(tempid) => Either::Right(LookupRefOrTempId::TempId(
in_process.temp_ids.intern(tempid),
)),
None => v
.into_typed_value(&self.schema, attribute.value_type)
.map(Either::Left)?,
}
} else {
v.into_typed_value(&self.schema, attribute.value_type)
.map(Either::Left)?
}
}
entmod::ValuePlace::Entid(entid) => Either::Left(TypedValue::Ref(
in_process.entity_a_into_term_a(entid)?,
)),
entmod::ValuePlace::TempId(tempid) => Either::Right(
LookupRefOrTempId::TempId(in_process.temp_ids.intern(tempid)),
),
entmod::ValuePlace::LookupRef(ref lookup_ref) => {
if attribute.value_type != ValueType::Ref {
bail!(DbErrorKind::NotYetImplemented(format!("Cannot resolve value lookup ref for attribute {} that is not :db/valueType :db.type/ref", a)))
}
Either::Right(LookupRefOrTempId::LookupRef(
in_process.intern_lookup_ref(lookup_ref)?,
))
}
entmod::ValuePlace::TxFunction(ref tx_function) => {
let typed_value = match tx_function.op.0.as_str() {
"transaction-tx" => TypedValue::Ref(self.tx_id),
unknown => bail!(DbErrorKind::NotYetImplemented(format!(
"Unknown transaction function {}",
unknown
))),
};
// Here we do schema-aware typechecking: we assert that the computed
// value is in the attribute's value set. If and when we have
// transaction functions that produce numeric values, we'll have to
// be more careful here, because a function that produces an integer
// value can be used where a double is expected. See also
// `SchemaTypeChecking.to_typed_value(...)`.
if attribute.value_type != typed_value.value_type() {
bail!(DbErrorKind::NotYetImplemented(format!("Transaction function {} produced value of type {} but expected type {}",
tx_function.op.0.as_str(), typed_value.value_type(), attribute.value_type)));
}
Either::Left(typed_value)
}
entmod::ValuePlace::Vector(vs) => {
if !attribute.multival {
bail!(DbErrorKind::NotYetImplemented(format!("Cannot explode vector value for attribute {} that is not :db.cardinality :db.cardinality/many", a)));
}
for vv in vs {
deque.push_front(Entity::AddOrRetract {
op,
e: e.clone(),
a: AttributePlace::Entid(entmod::EntidOrIdent::Entid(a)),
v: vv,
});
}
continue;
}
entmod::ValuePlace::MapNotation(mut map_notation) => {
// TODO: consider handling this at the tx-parser level. That would be
// more strict and expressive, but it would lead to splitting
// AddOrRetract, which proliferates types and code, or only handling
// nested maps rather than map values, like Datomic does.
if op != OpType::Add {
bail!(DbErrorKind::NotYetImplemented(format!("Cannot explode nested map value in :db/retract for attribute {}", a)));
}
if attribute.value_type != ValueType::Ref {
bail!(DbErrorKind::NotYetImplemented(format!("Cannot explode nested map value for attribute {} that is not :db/valueType :db.type/ref", a)))
}
// :db/id is optional; if it's not given, we generate a special internal tempid
// to use for upserting. This tempid will not be reported in the TxReport.
let db_id: Option<entmod::EntityPlace<V>> =
remove_db_id(&mut map_notation)?;
let mut dangling = db_id.is_none();
let db_id: entmod::EntityPlace<V> =
db_id.unwrap_or_else(|| in_process.allocate_mentat_id());
// We're nested, so we want to ensure we're not creating "dangling"
// entities that can't be reached. If we're :db/isComponent, then this
// is not dangling. Otherwise, the resulting map needs to have a
// :db/unique :db.unique/identity [a v] pair, so that it's reachable.
// Per http://docs.datomic.com/transactions.html: "Either the reference
// to the nested map must be a component attribute, or the nested map
// must include a unique attribute. This constraint prevents the
// accidental creation of easily-orphaned entities that have no identity
// or relation to other entities."
if attribute.component {
dangling = false;
}
for (inner_a, inner_v) in map_notation {
if let Some(reversed_a) = inner_a.unreversed() {
// We definitely have a reference. The reference might be
// dangling (a bare entid, for example), but we don't yet
// support nested maps and reverse notation simultaneously
// (i.e., we don't accept {:reverse/_attribute {:nested map}})
// so we don't need to check that the nested map reference isn't
// dangling.
dangling = false;
let reversed_e =
in_process.entity_v_into_term_e(inner_v, &inner_a)?;
let reversed_a =
in_process.entity_a_into_term_a(reversed_a)?;
let reversed_v =
in_process.entity_e_into_term_v(db_id.clone())?;
terms.push(Term::AddOrRetract(
OpType::Add,
reversed_e,
reversed_a,
reversed_v,
));
} else {
let inner_a = in_process.entity_a_into_term_a(inner_a)?;
let inner_attribute =
self.schema.require_attribute_for_entid(inner_a)?;
if inner_attribute.unique
== Some(attribute::Unique::Identity)
{
dangling = false;
}
deque.push_front(Entity::AddOrRetract {
op: OpType::Add,
e: db_id.clone(),
a: AttributePlace::Entid(entmod::EntidOrIdent::Entid(
inner_a,
)),
v: inner_v,
});
}
}
if dangling {
bail!(DbErrorKind::NotYetImplemented(format!("Cannot explode nested map value that would lead to dangling entity for attribute {}", a)));
}
in_process.entity_e_into_term_v(db_id)?
}
};
let e = in_process.entity_e_into_term_e(e)?;
terms.push(Term::AddOrRetract(op, e, a, v));
}
}
}
}
Ok((terms, in_process.temp_ids, in_process.lookup_refs))
}
/// Pipeline stage 2: rewrite `Term` instances with lookup refs into `Term` instances without
/// lookup refs.
///
/// The `Term` instances produced share interned TempId handles and have no LookupRef references.
fn resolve_lookup_refs<I>(
&self,
lookup_ref_map: &AVMap,
terms: I,
) -> Result<Vec<TermWithTempIds>>
where
I: IntoIterator<Item = TermWithTempIdsAndLookupRefs>,
{
terms
.into_iter()
.map(
|term: TermWithTempIdsAndLookupRefs| -> Result<TermWithTempIds> {
match term {
Term::AddOrRetract(op, e, a, v) => {
let e = replace_lookup_ref(&lookup_ref_map, e, KnownEntid)?;
let v = replace_lookup_ref(&lookup_ref_map, v, TypedValue::Ref)?;
Ok(Term::AddOrRetract(op, e, a, v))
}
}
},
)
.collect::<Result<Vec<_>>>()
}
/// Transact the given `entities` against the store.
///
/// This approach is explained in https://github.com/mozilla/mentat/wiki/Transacting.
// TODO: move this to the transactor layer.
pub fn transact_entities<I, V: TransactableValue>(&mut self, entities: I) -> Result<TxReport>
where
I: IntoIterator<Item = Entity<V>>,
{
// Pipeline stage 1: entities -> terms with tempids and lookup refs.
let (terms_with_temp_ids_and_lookup_refs, tempid_set, lookup_ref_set) =
self.entities_into_terms_with_temp_ids_and_lookup_refs(entities)?;
// Pipeline stage 2: resolve lookup refs -> terms with tempids.
let lookup_ref_avs: Vec<&(i64, TypedValue)> =
lookup_ref_set.iter().map(|rc| &**rc).collect();
let lookup_ref_map: AVMap = self.store.resolve_avs(&lookup_ref_avs[..])?;
let terms_with_temp_ids =
self.resolve_lookup_refs(&lookup_ref_map, terms_with_temp_ids_and_lookup_refs)?;
self.transact_simple_terms_with_action(
terms_with_temp_ids,
tempid_set,
TransactorAction::MaterializeAndCommit,
)
}
pub fn transact_simple_terms<I>(
&mut self,
terms: I,
tempid_set: InternSet<TempId>,
) -> Result<TxReport>
where
I: IntoIterator<Item = TermWithTempIds>,
{
self.transact_simple_terms_with_action(
terms,
tempid_set,
TransactorAction::MaterializeAndCommit,
)
}
fn transact_simple_terms_with_action<I>(
&mut self,
terms: I,
tempid_set: InternSet<TempId>,
action: TransactorAction,
) -> Result<TxReport>
where
I: IntoIterator<Item = TermWithTempIds>,
{
// TODO: push these into an internal transaction report?
let mut tempids: BTreeMap<TempId, KnownEntid> = BTreeMap::default();
// Pipeline stage 3: upsert tempids -> terms without tempids or lookup refs.
// Now we can collect upsert populations.
let (mut generation, inert_terms) = Generation::from(terms, &self.schema)?;
// And evolve them forward.
while generation.can_evolve() {
debug!("generation {:?}", generation);
let tempid_avs = generation.temp_id_avs();
debug!("trying to resolve avs {:?}", tempid_avs);
// Evolve further.
let temp_id_map: TempIdMap = self.resolve_temp_id_avs(&tempid_avs[..])?;
debug!("resolved avs for tempids {:?}", temp_id_map);
generation = generation.evolve_one_step(&temp_id_map);
// Errors. BTree* since we want deterministic results.
let mut conflicting_upserts: BTreeMap<TempId, BTreeSet<KnownEntid>> =
BTreeMap::default();
// Report each tempid that resolves via upsert.
for (tempid, entid) in temp_id_map {
// Since `UpsertEV` instances always transition to `UpsertE` instances, it might be
// that a tempid resolves in two generations, and those resolutions might conflict.
if let Some(previous) = tempids.insert((*tempid).clone(), entid) {
if entid != previous {
conflicting_upserts
.entry((*tempid).clone())
.or_insert_with(|| once(previous).collect::<BTreeSet<_>>())
.insert(entid);
}
}
}
if !conflicting_upserts.is_empty() {
bail!(DbErrorKind::SchemaConstraintViolation(
errors::SchemaConstraintViolation::ConflictingUpserts {
conflicting_upserts
}
));
}
debug!("tempids {:?}", tempids);
}
generation.allocate_unresolved_upserts()?;
debug!("final generation {:?}", generation);
// Allocate entids for tempids that didn't upsert. BTreeMap so this is deterministic.
let unresolved_temp_ids: BTreeMap<TempIdHandle, usize> =
generation.temp_ids_in_allocations(&self.schema)?;
debug!("unresolved tempids {:?}", unresolved_temp_ids);
// TODO: track partitions for temporary IDs.
let entids = self
.partition_map
.allocate_entids(":db.part/user", unresolved_temp_ids.len());
let temp_id_allocations = unresolved_temp_ids
.into_iter()
.map(|(tempid, index)| (tempid, KnownEntid(entids.start + (index as i64))))
.collect();
debug!("tempid allocations {:?}", temp_id_allocations);
let final_populations = generation.into_final_populations(&temp_id_allocations)?;
// Report each tempid that is allocated.
for (tempid, &entid) in &temp_id_allocations {
// Every tempid should be allocated at most once.
assert!(!tempids.contains_key(&**tempid));
tempids.insert((**tempid).clone(), entid);
}
// Verify that every tempid we interned either resolved or has been allocated.
assert_eq!(tempids.len(), tempid_set.len());
for tempid in tempid_set.iter() {
assert!(tempids.contains_key(&**tempid));
}
// Any internal tempid has been allocated by the system and is a private implementation
// detail; it shouldn't be exposed in the final transaction report.
let tempids = tempids
.into_iter()
.filter_map(|(tempid, e)| tempid.into_external().map(|s| (s, e.0)))
.collect();
// A transaction might try to add or retract :db/ident assertions or other metadata mutating
// assertions , but those assertions might not make it to the store. If we see a possible
// metadata mutation, we will figure out if any assertions made it through later. This is
// strictly an optimization: it would be correct to _always_ check what made it to the
// store.
let mut tx_might_update_metadata = false;
// Mutable so that we can add the transaction :db/txInstant.
let mut aev_trie = into_aev_trie(&self.schema, final_populations, inert_terms)?;
let tx_instant;
{
// TODO: Don't use this block to scope borrowing the schema; instead, extract a helper function.
// Assertions that are :db.cardinality/one and not :db.fulltext.
let mut non_fts_one: Vec<db::ReducedEntity> = vec![];
// Assertions that are :db.cardinality/many and not :db.fulltext.
let mut non_fts_many: Vec<db::ReducedEntity> = vec![];
// Assertions that are :db.cardinality/one and :db.fulltext.
let mut fts_one: Vec<db::ReducedEntity> = vec![];
// Assertions that are :db.cardinality/many and :db.fulltext.
let mut fts_many: Vec<db::ReducedEntity> = vec![];
// We need to ensure that callers can't blindly transact entities that haven't been
// allocated by this store.
let errors = tx_checking::type_disagreements(&aev_trie);
if !errors.is_empty() {
bail!(DbErrorKind::SchemaConstraintViolation(
errors::SchemaConstraintViolation::TypeDisagreements {
conflicting_datoms: errors
}
));
}
let errors = tx_checking::cardinality_conflicts(&aev_trie);
if !errors.is_empty() {
bail!(DbErrorKind::SchemaConstraintViolation(
errors::SchemaConstraintViolation::CardinalityConflicts { conflicts: errors }
));
}
// Pipeline stage 4: final terms (after rewriting) -> DB insertions.
// Collect into non_fts_*.
tx_instant = get_or_insert_tx_instant(&mut aev_trie, &self.schema, self.tx_id)?;
for ((a, attribute), evs) in aev_trie {
if entids::might_update_metadata(a) {
tx_might_update_metadata = true;
}
let queue = match (attribute.fulltext, attribute.multival) {
(false, true) => &mut non_fts_many,
(false, false) => &mut non_fts_one,
(true, false) => &mut fts_one,
(true, true) => &mut fts_many,
};
for (e, ars) in evs {
for (added, v) in ars
.add
.into_iter()
.map(|v| (true, v))
.chain(ars.retract.into_iter().map(|v| (false, v)))
{
let op = if added { OpType::Add } else { OpType::Retract };
self.watcher.datom(op, e, a, &v);
queue.push((e, a, attribute, v, added));
}
}
}
if !non_fts_one.is_empty() {
self.store
.insert_non_fts_searches(&non_fts_one[..], db::SearchType::Inexact)?;
}
if !non_fts_many.is_empty() {
self.store
.insert_non_fts_searches(&non_fts_many[..], db::SearchType::Exact)?;
}
if !fts_one.is_empty() {
self.store
.insert_fts_searches(&fts_one[..], db::SearchType::Inexact)?;
}
if !fts_many.is_empty() {
self.store
.insert_fts_searches(&fts_many[..], db::SearchType::Exact)?;
}
match action {
TransactorAction::Materialize => {
self.store.materialize_mentat_transaction(self.tx_id)?;
}
TransactorAction::MaterializeAndCommit => {
self.store.materialize_mentat_transaction(self.tx_id)?;
self.store.commit_mentat_transaction(self.tx_id)?;
}
}
}
self.watcher.done(&self.tx_id, self.schema)?;
if tx_might_update_metadata {
// Extract changes to metadata from the store.
let metadata_assertions = match action {
TransactorAction::Materialize => self.store.resolved_metadata_assertions()?,
TransactorAction::MaterializeAndCommit => {
db::committed_metadata_assertions(self.store, self.tx_id)?
}
};
let mut new_schema = (*self.schema_for_mutation).clone(); // Clone the underlying Schema for modification.
let metadata_report = metadata::update_schema_from_entid_quadruples(
&mut new_schema,
metadata_assertions,
)?;
// We might not have made any changes to the schema, even though it looked like we
// would. This should not happen, even during bootstrapping: we mutate an empty
// `Schema` in this case specifically to run the bootstrapped assertions through the
// regular transactor code paths, updating the schema and materialized views uniformly.
// But, belt-and-braces: handle it gracefully.
if new_schema != *self.schema_for_mutation {
let old_schema = (*self.schema_for_mutation).clone(); // Clone the original Schema for comparison.
*self.schema_for_mutation.to_mut() = new_schema; // Store the new Schema.
db::update_metadata(
self.store,
&old_schema,
&*self.schema_for_mutation,
&metadata_report,
)?;
}
}
Ok(TxReport {
tx_id: self.tx_id,
tx_instant,
tempids,
})
}
}
/// Initialize a new Tx object with a new tx id and a tx instant. Kick off the SQLite conn, too.
fn start_tx<'conn, 'a, W>(
conn: &'conn rusqlite::Connection,
mut partition_map: PartitionMap,
schema_for_mutation: &'a Schema,
schema: &'a Schema,
watcher: W,
) -> Result<Tx<'conn, 'a, W>>
where
W: TransactWatcher,
{
let tx_id = partition_map.allocate_entid(":db.part/tx");
conn.begin_tx_application()?;
Ok(Tx::new(
conn,
partition_map,
schema_for_mutation,
schema,
watcher,
tx_id,
))
}
fn conclude_tx<W>(
tx: Tx<W>,
report: TxReport,
) -> Result<(TxReport, PartitionMap, Option<Schema>, W)>
where
W: TransactWatcher,
{
// If the schema has moved on, return it.
let next_schema = match tx.schema_for_mutation {
Cow::Borrowed(_) => None,
Cow::Owned(next_schema) => Some(next_schema),
};
Ok((report, tx.partition_map, next_schema, tx.watcher))
}
/// Transact the given `entities` against the given SQLite `conn`, using the given metadata.
/// If you want this work to occur inside a SQLite transaction, establish one on the connection
/// prior to calling this function.
///
/// This approach is explained in https://github.com/mozilla/mentat/wiki/Transacting.
// TODO: move this to the transactor layer.
pub fn transact<'conn, 'a, I, V, W>(
conn: &'conn rusqlite::Connection,
partition_map: PartitionMap,
schema_for_mutation: &'a Schema,
schema: &'a Schema,
watcher: W,
entities: I,
) -> Result<(TxReport, PartitionMap, Option<Schema>, W)>
where
I: IntoIterator<Item = Entity<V>>,
V: TransactableValue,
W: TransactWatcher,
{
let mut tx = start_tx(conn, partition_map, schema_for_mutation, schema, watcher)?;
let report = tx.transact_entities(entities)?;
conclude_tx(tx, report)
}
/// Just like `transact`, but accepts lower-level inputs to allow bypassing the parser interface.
pub fn transact_terms<'conn, 'a, I, W>(
conn: &'conn rusqlite::Connection,
partition_map: PartitionMap,
schema_for_mutation: &'a Schema,
schema: &'a Schema,
watcher: W,
terms: I,
tempid_set: InternSet<TempId>,
) -> Result<(TxReport, PartitionMap, Option<Schema>, W)>
where
I: IntoIterator<Item = TermWithTempIds>,
W: TransactWatcher,
{
transact_terms_with_action(
conn,
partition_map,
schema_for_mutation,
schema,
watcher,
terms,
tempid_set,
TransactorAction::MaterializeAndCommit,
)
}
#[allow(clippy::too_many_arguments)]
pub(crate) fn transact_terms_with_action<'conn, 'a, I, W>(
conn: &'conn rusqlite::Connection,
partition_map: PartitionMap,
schema_for_mutation: &'a Schema,
schema: &'a Schema,
watcher: W,
terms: I,
tempid_set: InternSet<TempId>,
action: TransactorAction,
) -> Result<(TxReport, PartitionMap, Option<Schema>, W)>
where
I: IntoIterator<Item = TermWithTempIds>,
W: TransactWatcher,
{
let mut tx = start_tx(conn, partition_map, schema_for_mutation, schema, watcher)?;
let report = tx.transact_simple_terms_with_action(terms, tempid_set, action)?;
conclude_tx(tx, report)
}
fn extend_aev_trie<'schema, I>(
schema: &'schema Schema,
terms: I,
trie: &mut AEVTrie<'schema>,
) -> Result<()>
where
I: IntoIterator<Item = TermWithoutTempIds>,
{
for Term::AddOrRetract(op, KnownEntid(e), a, v) in terms.into_iter() {
let attribute: &Attribute = schema.require_attribute_for_entid(a)?;
let a_and_r = trie
.entry((a, attribute))
.or_insert_with(BTreeMap::default)
.entry(e)
.or_insert_with(AddAndRetract::default);
match op {
OpType::Add => a_and_r.add.insert(v),
OpType::Retract => a_and_r.retract.insert(v),
};
}
Ok(())
}
pub(crate) fn into_aev_trie<'schema>(
schema: &'schema Schema,
final_populations: FinalPopulations,
inert_terms: Vec<TermWithTempIds>,
) -> Result<AEVTrie<'schema>> {
let mut trie = AEVTrie::default();
extend_aev_trie(schema, final_populations.resolved, &mut trie)?;
extend_aev_trie(schema, final_populations.allocated, &mut trie)?;
// Inert terms need to be unwrapped. It is a coding error if a term can't be unwrapped.
extend_aev_trie(
schema,
inert_terms.into_iter().map(|term| term.unwrap()),
&mut trie,
)?;
Ok(trie)
}
/// Transact [:db/add :db/txInstant tx_instant (transaction-tx)] if the trie doesn't contain it
/// already. Return the instant from the input or the instant inserted.
fn get_or_insert_tx_instant<'schema>(
aev_trie: &mut AEVTrie<'schema>,
schema: &'schema Schema,
tx_id: Entid,
) -> Result<DateTime<Utc>> {
let ars = aev_trie
.entry((
entids::DB_TX_INSTANT,
schema.require_attribute_for_entid(entids::DB_TX_INSTANT)?,
))
.or_insert_with(BTreeMap::default)
.entry(tx_id)
.or_insert_with(AddAndRetract::default);
if !ars.retract.is_empty() {
// Cannot retract :db/txInstant!
}
// Otherwise we have a coding error -- we should have cardinality checked this already.
assert!(ars.add.len() <= 1);
let first = ars.add.iter().next().cloned();
match first {
Some(TypedValue::Instant(instant)) => Ok(instant),
Some(_) => unreachable!(), // This is a coding error -- we should have typechecked this already.
None => {
let instant = now();
ars.add.insert(instant.into());
Ok(instant)
}
}
}