This is all part of moving the entity builder away from building term
instances and toward building entity instances. One of the nice
things that the existing term interface does is allow consumers to use
lightweight reference counted tempid handles; I don't want to lose
that, so we'll build it into the entity data structures directly.
We haven't observed performance issues using `Arc` instead of `Rc`,
and we want to be able to include things that are interned (including,
soon, `TempId` instances) in errors coming out of the
transactor. (And `Rc` isn't `Sync`, so it can't be included in errors
directly.)
It's not great to keep lifting functionality higher and higher up the
crate hierarchy, but we really do want to intern while we parse.
Eventually, I expect that we will split the `edn` crate into `types`
and `parsing`, and the `types` crate can depend on a more efficient
interning dependency.
* Delete the (apparently unused) EntId
* Rename edn's Entid to EntidOrIdent to avoid confusion with the Entid that's actually an i64
* Fix travis beta bustage (This is actually unrelated to entids, but is a trivial fix nonetheless)
* 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.
This should address #663, by re-inserting type checking in the
transactor stack after the entry point used by the term builder.
Before this commit, we were using an SQLite UNIQUE index to assert
that no `[e a]` pair, with `a` a cardinality one attribute, was
asserted more than once. However, that's not in line with Datomic,
which treats transaction inputs as a set and allows a single datom
like `[e a v]` to appear multiple times. It's both awkward and not
particularly efficient to look for _distinct_ repetitions in SQL, so
we accept some runtime cost in order to check for repetitions in the
transactor. This will allow us to address #532, which is really about
whether we treat inputs as sets. A side benefit is that we can
provide more helpful error messages when the transactor does detect
that the input truly violates the cardinality constraints of the
schema.
This commit builds a trie while error checking and collecting final
terms, which should be fairly efficient. It also allows a simpler
expression of input-provided :db/txInstant datoms, which in turn
uncovered a small issue with the transaction watcher, where-by the
watcher would not see non-input-provided :db/txInstant datoms.
This transition to Datomic-like input-as-set semantics allows us to
address #532. Previously, two tempids that upserted to the same entid
would produce duplicate datoms, and that would have been rejected by
the transactor -- correctly, since we did not allow duplicate datoms
under the input-as-list semantics. With input-as-set semantics,
duplicate datoms are allowed; and that means that we must allow
tempids to be equivalent, i.e., to resolve to the same tempid.
To achieve this, we:
- index the set of tempids
- identify tempid indices that share an upsert
- map tempids to a dense set of contiguous integer labels
We use the well-known union-find algorithm, as implemented by
petgraph, to efficiently manage the set of equivalent tempids.
Along the way, I've fixed and added tests for two small errors in the
transactor. First, don't drop datoms resolved by upsert (#679).
Second, ensure that complex upserts are allocated.
I don't know quite what happened here. The Clojure implementation
correctly kept complex upserts that hadn't resolved as complex
upserts (see
9a9dfb502a/src/common/datomish/transact.cljc (L436))
and then allocated complex upserts if they didn't resolve (see
9a9dfb502a/src/common/datomish/transact.cljc (L509)).
Based on the code comments, I think the Rust implementation must have
incorrectly tried to optimize by handling all complex upserts in at
most a single generation of evolution, and that's just not correct.
We're effectively implementing a topological sort, using very specific
domain knowledge, and its not true that a node in a topological sort
can be considered only once!
* Make properties on NamespacedKeyword/NamespacedSymbol private
* Use only a single String for NamespacedKeyword/NamespacedSymbol
* Review comments.
* Remove unsafe code in namespaced_name.
Benchmarking shows approximately zero change.
* Allow the types of ns and name to differ when constructing a NamespacedName.
* Make symbol namespaces optional.
* Normalize names of keyword/symbol constructors.
This will make the subsequent refactor much less painful.
* Use expect not unwrap.
* Merge Keyword and NamespacedKeyword.
There are few reasons to do this:
- it's difficult to add symbol interning to combine-based parsers like
tx-parser -- literally every type changes to reflect the interner,
and that means every convenience macro we've built needs to chagne.
It's trivial to add interning to rust-peg-based parsers.
- combine has rolled forward to 3.2, and I spent a similar amount of
time investigating how to upgrade tx-parser (to take advantage of
the new parser! macros in combine that I think are necessary for
adapting to changing types) as I did just converting to rust-peg.
- it's easy to improve the error messages in rust-peg, where-as I have
tried twice to improve the nested error messages in combine and am
stumped.
- it's roughly 4x faster to parse strings directly as opposed to
edn::ValueAndSpan, and it'll be even better when we intern directly.
This is a stepping stone to transacting entities that are not based on
`edn::ValueAndSpan`. We need to turn some value places (general) into
entity places (restricted), and those restrictions are captured in
tx-parser right now. But for `TypedValue` value places, those
restrictions are encoded in the type itself. This lays the track to
accept other value types in value places, which is good for
programmatic builder interfaces.
* Refactor AttributeCache populator code for use from pull.
* Pre: add to_value_rc to Cloned.
* Pre: add From<StructuredMap> for Binding.
* Pre: clarify Store::open_empty.
* Pre: StructuredMap cleanup.
* Pre: clean up a doc test.
* Split projector crate. Pass schema to projector.
* CLI support for printing bindings.
* Add and use ConjoiningClauses::derive_types_from_find_spec.
* Define pull types.
* Implement pull on top of the attribute cache layer.
* Add pull support to the projector.
* Parse pull expressions.
* Add simple pull support to connection objects.
* Tests for pull.
* Compile with Rust 1.25.
The only choice involved in this commit is that of replacing the
anonymous lifetime '_ with a named lifetime for the cache; since we're
accepting a Known, which includes the cache in question, I think it's
clear that we expect the function to apply to any given cache
lifetime.
* Review comments.
* Bail on unnamed attribute.
* Make assert_parse_failure_contains safe to use.
* Rework query parser to report better errors for pull.
* Test for mixed wildcard and simple attribute.
This innocuous looking change (upserts_ev -> upserts_e -> resolved in
all situations, rather than upserts_ev -> resolved in some situations)
is a significant change in semantics and assumptions in the
transactor. Witness the large comment being removed about the same
tempid resolving in different generations!
To support this change, we provide more holistic errors for
conflicting upserts, which entails collecting some (relatively
expensive) diagnostic data.
I left in some debug logging, simply since it shouldn't hurt in
general, and will likely be useful for the next bug we see in the
transactor.
We don't yet have a logging system for production use, but I'd like to
start experimenting with log, which seems to be (close to) a Rust
standard. We're already using it in mentat_cli.
:db/tx (and Datomic's version, :datomic/tx) suffer from the same
ambiguities that [a v] lookup references do -- determining the type of
the result is context sensitive. (In this case, is :db/tx a reference
to the current transaction ID, or is it a valid keyword?) This commit
addresses the ambiguity by introducing a notion of a transaction
functions, and provides a little scaffolding for adding more (should
the need arise). I left the scaffolding in place rather than handling
just (transaction-tx) because I started trying to
implement (transaction-instant) as well, which is more difficult --
see the comments.
It's worth noting that this approach generalizes more or less directly
to ?input variables, since those can be eagerly bound like the
implemented transaction function (transaction-tx).
* Pre: eliminate some occurrences of Rc, largely through the magic of Into.
* Pre: introduce FromRc to convert between refcounted types.
* Introduce ValueRc as an abstraction over Rc/Arc choice.
* Move Cloned to core.
* Move CString-creation methods to TypedValue.
* Finish transition.
* Pre: clean up core/src/lib.rs.
* Pre: use indexmap 1.0 in db and query-projector.
* Change rel results to be a RelResult instance, not a Vec<Vec<TypedValue>>.
This avoids memory fragmentation and improves locality by using a single
heap-allocated vector for all bindings, rather than a separate
heap-allocated vector for each row.
We hide this abstraction behind the `RelResult` type, which tracks the
stride length (width) of each row.
* Don't allocate temporary vectors when projecting RelResults.
Some parts of the query engine and transactor need to know whether an
attribute is a component attribute, and sometimes want to do so in
a generated SQL query. This is one way to do that.
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
* Use fixed-size arrays for bootstrap datoms, not vecs.
* Wide-ranging cleanup.
This commit:
- Deletes some dead code.
- Marks some functions only used by tests as cfg(test).
- Adds pub(crate) to a bunch of functions.
- Cleans up a few other nits.
* Use the cache to make constant queries super fast.
* Fix translate tests to match: we no longer generate SQL for many of them!
* Accumulate additions and removals into the cache.
* Make attribute cache clone-on-write; store it in Metadata.
* Allow caching of fulltext attributes, interning strings.
This puts caching in mentat_db, adds a reverse lookup capability for
unique attributes, and populates bidirectional caches with a single
SQL cursor walk.
Differentiate between begin_read and begin_uncached_read.
Note that we still allow toggling within InProgress, because there might be
transient local state that makes starting a new transaction impossible.
You can use this in conjunction with setting SQLITE3_LIB_DIR to control which SQLite is used.
See https://github.com/jgallagher/rusqlite for more.
Also add recent contributors to the authors array.
* Nit: Alphabetical ordering of imports
* Create Cache and provide functions for calling it
* Get tests working. Move to using NamespacedKeyword over KnownEntid in function signature
* Add is_cached check to caching tests
* Move lazy and add/remove boolean flags to enums
* Move function definitions into generic trait and implement trait for AttributeCache
* Remove lazy cache and generalize cache
* Update tests
* Eager cache becomes simple key value store. AttributeMap handles attribute storing specifics
* Update tests to test presence of correct values in cache
* Move EagerCache, AttributeValueProvider and ValueProvider into mentat_db
* Add test for get_for_entid
* Add test for lookup attribute
* Make caches cloneable. Add value_for alongside values_for
* Use cache in attribute lookups
* Split test for values and value and add cardinality
* address review feedback r=rnewman
Also move `now` into core, implement microsecond truncation.
This is so we don't return a more granular -- and thus subtly different --
timestamp in a `TxReport` than we put into the store.
This includes two other changes:
* Split transact to expose an interface for TermWithTempIds.
* Return TxReport from each InProgress operation, not from commit.
Improve naming of read-only transactions.
Implement entid_for_type.
Simplify get_attribute.
Name ignored var in algebrizer.
Comment attribute_for_ident.
Make KnownEntid a core concept.
Expose lookup_value_for_attribute.
Implement HasSchema and a new query encapsulation on Conn.
Pre: export Queryable.
Pre: export AttributeBuilder from mentat_db.
Pre: fix module-level comment for tx/src/entities.rs.
Pre: rename some `to_` conversions to `into_`.
Pre: make AttributeBuilder::unique less verbose.
Pre: split out a HasSchema trait to abstract over Schema.
Pre: rename SchemaMap/schema_map to AttributeMap/attribute_map.
Pre: TypedValue/NamespacedKeyword conversions.
Pre: turn Unique and ValueType into TypedValue::Keyword.
Pre: export IntoResult.
Pre: export NamespacedKeyword from mentat_core.
Pre: use intern_set in tx.
Pre: add InternSet::len.
Pre: comment gardening.
Pre: remove inaccurate TODO from TxReport comment.
This was done using the following shell script:
```
find . -type f -not -path "*target*" \
'(' -name '*.rs' -o -name '*.md' -o -name '*.toml' ')' -print0 | \
xargs -0 sed -i '' -E 's/[[:space:]]*$//'
```
Which is admittedly imperfect, but manages to hit everything that was a problem in this repo.
* Pre: rename begin_transaction to begin_tx_application.
* Take an EXCLUSIVE transaction when bootstrapping, and an IMMEDIATE transaction when writing.
This avoids the remote possibility of another write sneaking in the door
while we're preparing to write, avoids us needing to upgrade locks, etc.
After a BEGIN IMMEDIATE, no other database connection will be able to write
to the database or do a BEGIN IMMEDIATE or BEGIN EXCLUSIVE. Other processes
can continue to read from the database, however.
An exclusive transaction causes EXCLUSIVE locks to be acquired on all
databases. After a BEGIN EXCLUSIVE, no other database connection except for
read_uncommitted connections will be able to read the database and no other
connection without exception will be able to write the database until the
transaction is complete.
* Hacky implementation of atomic multi-tx.
* Hold the last report, returning the InProgress from each operation.
* Rewrite transact in terms of InProgress.
* Test rollback.
* Remove unused imports.
* Don't use Rc for transaction reports.
* Pre: break out USER0 as a part boundary constant.
* Export TX0 and USER0 from mentat_db. This is for testing.
* Review comments: commenting.
* Test tempid allocation and rollback.
* Create mentat command line.
* Create tools directory containing new crate for mentat_cli.
* Add simple cli with mentat prompt.
* Remove rustc-serialize dependency
* Open DB inside CLI (#452) (#463)
* Open named database OR default to in memory database if no name provided
Rearrange workspace to allow import of mentat crate in cli crate
Create store object inside repl when started for connecting to mentat
Use provided DB name to open connection in store
Accept DB name as command line arg.
Open on CLI start
Implement '.open' command to open desired DB from inside CLI
* Implement Close command to close current DB.
* Closes existing open db and opens new in memory db
* Review comment: Use `combine` to parse arguments.
Move over to using Result rather than enums with err
* Accept and parse EDN Query and Transact commands (#453) (#465)
* Parse query and transact commands
* Implement is_complete for transactions and queries
* Improve query parser. Am still not happy with it though.
There must be some way that I can retain the eof() after the `then` that means I don't have to move the skip on spaces and eof
Make in process command storing clearer.
Add comments around in process commands.
Add alternative commands for transact/t and query/q
* Address review comments r=nalexander.
* Bump rust version number.
* Use `bail` when throwing errors.
* Improve edn parser.
* Remove references to unused `more` flag.
* Improve naming of query and transact commands.
* Send queries and transactions to mentat and output the results (#466)
* Send queries and transactions to mentat and output the results
move outputting query and transaction results out of store and into repl
* Add query and transact commands to help
* Execute queries and transacts passed in at startup
* Address review comments =nalexander.
* Bump rust version number.
* Use `bail` when throwing errors.
* Improve edn parser.
* Remove references to unused `more` flag.
* Improve naming of query and transact commands.
* Execute command line args in order
* Addressing rebase issues
* Exit CLI (#457) (#484) r-rnewman
* Implement exit command for cli tool
* Address review comments r=rnewman
* Include exit commands in help
* Show schema of current DB (#487)
* Fixing rebase issues
* addressing nit
* Match updated dependencies on CLI crate and remove unused import
* Update some dependencies.
* Update rusqlite to 0.12.
* Update error-chain to a forked version that implements Sync.
* Fix some compiler warnings.
* Remove unused imports in tests.
* Parse errors no longer naturally print with the expected symbol.
This commit adds a check to the partition map that a provided entity ID
has been mentioned (i.e., is present in the start:index range of one of
our partitions).
We introduce a newtype for known entity IDs, using this internally in
the tx expander to track user-provided entids that have passed the above
check (and IDs that we allocate as part of tempid processing). This
newtype is stripped prior to tx assertion.
In order that DB tests can continue to write
[:db/add 111 :foo/bar 222]
we add an additional fake partition to our test connections, ranging
from 100 to 1000.
This is an optimization that trades rejecting inputs earlier at the
cost of expressive error messages. It should be possible to recover
the error messages, however.
This will reject input like `[:db/{add,retract} v :attribute/_reversed NOT-AN-ENTITY]`.
There are two broad approaches:
1) Handle reverse attribute notation dynamically, in the style that
Datomic does. This is the most flexible, but it's not a good fit
given that we produce strongly typed output from the parser.
Strongly typed input to the transactor has had many benefits, so I
don't want to roll it back for a relatively unimportant feature
like reverse notation -- especially not since Mentat does not
require :db.install/_attribute to modify schema attributes.
2) Handle reverse attribute in the parser itself, so that we can
produce strongly typed parser output while restricting the input.
I implemented this first and discovered that it's very difficult to
give sensible error messages in common cases.
In any case, the bulk of the code is the same between the two
approaches, and I wrote the tests for the dynamic version (with error
output), so that's what I'm rolling with.
This patch preserves the existing indentation, to highlight the
differences. The next patch will indent.
This is a big commit, but it breaks into two conceptual pieces. The
first is to "parse without copying". We replace a stream of an owned
collection of edn::ValueAndSpan and instead have a stream of a
borrowed collection of &edn::ValueAndSpan references. (Generally,
this is represented as an iterator over a slice, but it can be over
other things too.) Cloning such iterators is constant time, which
improves on cloning an owned collection of edn::ValueAndSpan, which is
linear time in the length of the collection and additional time
depending on the complexity of the EDN values.
The second conceptual piece is to parse keyword maps using a special
parser and a macro to build the parser implementations. Before, we
created a new edn::ValueAndSpan::Map to represent a keyword map in
vector form; since we're working with &edn::ValueAndSpan references
now, we can't create an &edn::ValueAndSpan reference with an
appropriate lifetime. Therefore we generalize the concept of
iteration slightly and turn keyword maps in map form into linear
iterators by flattening the value maps. This is a potentially
obscuring transformation, so we have to take care to protect against
some failure cases. (See the comments and the tests in the code.)
After these changes, parsing using `combine` is linear time (and
reasonably fast).
* Pre: unused import in translate.rs.
* Part 2: take a dependency on rusqlite for query arguments.
* Part 1: flatten V2 schema into V1. Add UUID and URI.
Bump expected ident and bootstrap datom count in tests.
* Part 5: parse edn::Value::Uuid.
* Part 3: extend ValueType and TypedValue to include Uuid.
* Part 4: add Uuid to query arguments.
* Part 6: extend db to support Uuid.
* Part 8: add a tx-parser test for #f NaN and #uuid.
* Part 7: parse and algebrize UUIDs in queries.
* Part 1: parse #inst in EDN and throughout query engine.
* Part 3: handle instants in db.
* Part 2: instants never matches integers in queries.
* Part 4: use DateTime for tx_instants.
* Add a test for adding and querying UUIDs and instants.
* Review comments.
* Pre: Expose more in edn.
* Pre: Make it easier to work with ValueAndSpan.
with_spans() is a temporary hack, needed only because I don't care to
parse the bootstrap assertions from text right now.
* Part 1a: Add `value_and_span` for parsing nested `edn::ValueAndSpan` instances.
I wasn't able to abstract over `edn::Value` and `edn::ValueAndSpan`;
there are multiple obstacles. I chose to roll with
`edn::ValueAndSpan` since it exposes the additional span information
that we will want to form good error messages in the future.
* Part 1b: Add keyword_map() parsing an `edn::Value::Vector` into an `edn::Value::map`.
* Part 1c: Add `Log`/`.log(...)` for logging parser progress.
This is a terrible hack, but it sure helps to debug complicated nested
parsers. I don't even know what a principled approach would look
like; since our parser combinators are so frequently expressed in
code, it's hard to imagine a data-driven interpreter that can help
debug things.
* Part 2: Use `value_and_span` apparatus in tx-parser/.
I break an abstraction boundary by returning a value column
`edn::ValueAndSpan` rather than just an `edn::Value`. That is, the
transaction processor shouldn't care where the `edn::Value` it is
processing arose -- even we care to track that information we should
bake it into the `Entity` type. We do this because we need to
dynamically parse the value column to support nested maps, and parsing
requires a full `edn::ValueAndSpan`. Alternately, we could cheat and
fake the spans when parsing nested maps, but that's potentially
expensive.
* Part 3: Use `value_and_span` apparatus in query-parser/.
* Part 4: Use `value_and_span` apparatus in root crate.
* Review comment: Make Span and SpanPosition Copy.
* Review comment: nits.
* Review comment: Make `or` be `or_exactly`.
I baked the eof checking directly into the parser, rather than using
the skip and eof parsers. I also took the time to restore some tests
that were mistakenly commented out.
* Review comment: Extract and use def_matches_* macros.
* Review comment: .map() as late as possible.
Part 1, core: use Rc for String and Keyword.
Part 2, query: use Rc for Variable.
Part 3, sql: use Rc for args in SQLiteQueryBuilder.
Part 4, query-algebrizer: use Rc.
Part 5, db: use Rc.
Part 6, query-parser: use Rc.
Part 7, query-projector: use Rc.
Part 8, query-translator: use Rc.
Part 9, top level: use Rc.
Part 10: intern Ident and IdentOrKeyword.
* Part 1 - Create as_edn_value function.
* Do not include defaults inside output.
* Pretty-printed by default. Do we want to make that a flag?
* Includes simple test just to make sure it works.
* Part 2 - only include ident if available.
* Part 3 - Remove spacing and newlines as unnecessary.
* Update function to build edn::Value directly rather than parsing from string
* Update test to actually test the functionality.
* Address review comments ncalexan.
* Rename `as_edn_value` to `to_edn_value`.
* Move `db/src/values.rs` to `core/src/values.rs` so we can reference inside `core/src/ib.rs`.
* Add `lazy-static` crate to core `Cargo.toml`
* Expose `values` as a public module from `core`.
* Update references to values in `db/src/bootstrap.rs` & `db/src/lib.rs`.
* Add new static vars for `DB_FULLTEXT`, `DB_INDEX` & `DB_IS_COMPONENT`.
* Use static vars exposed in `values` inside `to_edn_value`.
* Remove `db/id` as key in attribute output and use `entid` as `db/ident` if no `ident` is found for that `entid`.
* Update test to match new expected output.
* Add doc comment for function
* Address review comments ncalexan.
* Update function docstring to give clearer description of function.
* Do not all entid at all to output.
* Clean up code fetching ident (make it rustier).
* Address review comments rnewman.
* Extract out to new `to_edn_value` functions code for creating `edn::Value`\'s for `ValueType` and `Attribute`.
* Use `map()` to create schema edn value rather than a loop.
* Address review comments rnewman.
* pass cloned instance of ident to `Attribute::get_edn_value`.
* update `use` import for `edn`.
* remove unnecessary call when using ident as key on `associate_ident`.
* Fixed bug whereby we didn't differentiate between `db.index/value` and `db.index/identity` when generating `edn::Value`
* Add extra assert at the end to ensure we get the same output when we convert the same schema to edn multiple times
* Move check for type of uniqueness to `match` statement.
* Also use `iter` instead of `into_iter` when iterating schema map.
* Pre: Fix error in parser macros.
* Pre: Make test unwrapping more verbose.
* Pre: Make lookup refs be (lookup-ref a v) in the entity position.
This has the advantage of being explicit in all situations and
unambiguous at parse-time. This choice agrees with the Clojure
implementation but not with Datomic. Datomic treats [a v] as a lookup
ref, is ambiguous at parse-time, and is disambiguated in ways I do not
understand at transaction time. We mooted making lookup refs [[a v]]
and outlawing nested value vectors in transactions, but after
implementing that approach I decided it was better to handle lookup
refs at parse time and therefore outlawing nested value vectors is not
necessary.
* Handle lookup refs in the entity and value columns. Fixes#183.
* Pre 0a: Use a stack instead of into_iter.
* Pre 0b: Dedent.
* Pre 0c: Handle `e` after `v`.
This allows to use the original `e` while handling `v`.
* Explode value lists for :db.cardinality/many attributes. Fixes#284.
* Parse and accept map notation. Fixes#180.
* Pre: Modernize add() and retract() into one add_or_retract().
* Pre: Add is_collection and is_atom to edn::Value.
* Pre: Differentiate atoms from lookup-refs in value position.
Initially, I expected to accept arbitrary edn::Value instances in the
value position, and to differentiate in the transactor. However, the
implementation quickly became a two-stage parser, since we always
wanted to parse the resulting value position into some other known
thing using the tx-parser. To save calls into the parser and to allow
the parser to move forward with a smaller API surface, I push as much
of this parsing as possible into the initial parse.
* Pre: Modernize entities().
* Pre: Quote edn::Value::Text in Display.
* Review comment: Add and use edn::Value::into_atom.
* Review comment: Use skip(eof()) throughout.
* Review comment: VecDeque instead of Vec.
* Review comment: Part 0: Rename TempId to TempIdHandle.
* Review comment: Part 1: Differentiate internal and external tempids.
This breaks an abstraction boundary by pushing the Internal/External
split up to the Entity level in tx/ and tx-parser/. This just makes
it easier to explode Entity map notation instances into Entity
instances, taking an existing External tempid :db/id or generating a
new Internal tempid as appropriate. To do this without breaking the
abstraction boundary would require adding flexibility to the
transaction processor: we'd need to be able to turn Entity instances
into some internal enum and handle the two cases independently. It
wouldn't be too hard, but this reduces the combinatorial type
explosion.
* Pre: Don't retract :db/ident in test.
Datomic (and eventually Mentat) don't allow to retract :db/ident in
this way, so this runs afoul of future work to support mutating
metadata.
* Pre: s/VALUETYPE/VALUE_TYPE/.
This is consistent with the capitalization (which is "valueType") and
the other identifier.
* Pre: Remove some single quotes from error output.
* Part 1: Make materialized views be uniform [e a v value_type_tag].
This looks ahead to a time when we could support arbitrary
user-defined materialized views. For now, the "idents" materialized
view is those datoms of the form [e :db/ident :namespaced/keyword] and
the "schema" materialized view is those datoms of the form [e a v]
where a is in a particular set of attributes that will become clear in
the following commits.
This change is not backwards compatible, so I'm removing the open
current (really, v2) test. It'll be re-instated when we get to
https://github.com/mozilla/mentat/issues/194.
* Pre: Map TypedValue::Ref to TypedValue::Keyword in debug output.
* Part 3: Separate `schema_to_mutate` from the `schema` used to interpret.
This is just to keep track of the expected changes during
bootstrapping. I want bootstrap metadata mutations to flow through
the same code path as metadata mutations during regular transactions;
by differentiating the schema used for interpretation from the schema
that will be updated I expect to be able to apply bootstrap metadata
mutations to an empty schema and have things like materialized views
created (using the regular code paths).
This commit has been re-ordered for conceptual clarity, but it won't
compile because it references the metadata module. It's possible to
make it compile -- the functionality is there in the schema module --
but it's not worth the rebasing effort until after review (and
possibly not even then, since we'll squash down to a single commit to
land).
* Part 2: Maintain entids separately from idents.
In order to support historical idents, we need to distinguish the
"current" map from entid -> ident from the "complete historical" map
ident -> entid. This is what Datomic does; in Datomic, an ident is
never retracted (although it can be replaced). This approach is an
important part of allowing multiple consumers to share a schema
fragment as it migrates forward.
This fixes a limitation of the Clojure implementation, which did not
handle historical idents across knowledge base close and re-open.
The "entids" materialized view is naturally a slice of the "datoms"
table. The "idents" materialized view is a slice of the
"transactions" table. I hope that representing in this way, and
casting the problem in this light, might generalize to future
materialized views.
* Pre: Add DiffSet.
* Part 4: Collect mutations to a `Schema`.
I haven't taken your review comment about consuming AttributeBuilder
during each fluent function. If you read my response and still want
this, I'm happy to do it in review.
* Part 5: Handle :db/ident and :db.{install,alter}/attribute.
This "loops" the committed datoms out of the SQL store and back
through the metadata (schema, but in future also partition map)
processor. The metadata processor updates the schema and produces a
report of what changed; that report is then used to update the SQL
store. That update includes:
- the materialized views ("entids", "idents", and "schema");
- if needed, a subset of the datoms themselves (as flags change).
I've left a TODO for handling attribute retraction in the cases that
it makes sense. I expect that to be straight-forward.
* Review comment: Rename DiffSet to AddRetractAlterSet.
Also adds a little more commentary and a simple test.
* Review comment: Use ToIdent trait.
* Review comment: partially revert "Part 2: Maintain entids separately from idents."
This reverts commit 23a91df9c35e14398f2ddbd1ba25315821e67401.
Following our discussion, this removes the "entids" materialized
view. The next commit will remove historical idents from the "idents"
materialized view.
* Post: Use custom Either rather than std::result::Result.
This is not necessary, but it was suggested that we might be paying an
overhead creating Err instances while using error_chain. That seems
not to be the case, but this change shows that we don't actually use
any of the Result helper methods, so there's no reason to overload
Result. This change might avoid some future confusion, so I'm going
to land it anyway.
Signed-off-by: Nick Alexander <nalexander@mozilla.com>
* Review comment: Don't preserve historical idents.
* Review comment: More prepared statements when updating materialized views.
* Post: Test altering :db/cardinality and :db/unique.
These tests fail due to a Datomic limitation, namely that the marker
flag :db.alter/attribute can only be asserted once for an attribute!
That is, [:db.part/db :db.alter/attribute :attribute] will only be
transacted at most once. Since older versions of Datomic required the
:db.alter/attribute flag, I can only imagine they either never wrote
:db.alter/attribute to the store, or they handled it specially. I'll
need to remove the marker flag system from Mentat in order to address
this fundamental limitation.
* Post: Remove some more single quotes from error output.
* Post: Add assert_transact! macro to unwrap safely.
I was finding it very difficult to track unwrapping errors while
making changes, due to an underlying Mac OS X symbolication issue that
makes running tests with RUST_BACKTRACE=1 so slow that they all time
out.
* Post: Don't expect or recognize :db.{install,alter}/attribute.
I had this all working... except we will never see a repeated
`[:db.part/db :db.alter/attribute :attribute]` assertion in the store!
That means my approach would let you alter an attribute at most one
time. It's not worth hacking around this; it's better to just stop
expecting (and recognizing) the marker flags. (We have all the data
to distinguish the various cases that we need without the marker
flags.)
This brings Mentat in line with the thrust of newer Datomic versions,
but isn't compatible with Datomic, because (if I understand correctly)
Datomic automatically adds :db.{install,alter}/attribute assertions to
transactions.
I haven't purged the corresponding :db/ident and schema fragments just
yet:
- we might want them back
- we might want them in order to upgrade v1 and v2 databases to the
new on-disk layout we're fleshing out (v3?).
* Post: Don't make :db/unique :db.unique/* imply :db/index true.
This patch avoids a potential bug with the "schema" materialized view.
If :db/unique :db.unique/value implies :db/index true, then what
happens when you _retract_ :db.unique/value? I think Datomic defines
this in some way, but I really want the "schema" materialized view to
be a slice of "datoms" and not have these sort of ambiguities and
persistent effects. Therefore, to ensure that we don't retract a
schema characteristic and accidentally change more than we intended
to, this patch stops having any schema characteristic imply any other
schema characteristic(s). To achieve that, I added an
Option<Unique::{Value,Identity}> type to Attribute; this helps with
this patch, and also looks ahead to when we allow to retract
:db/unique attributes.
* Post: Allow to retract :db/ident.
* Post: Include more details about invalid schema changes.
The tests use strings, so they hide the chained errors which do in
fact provide more detail.
* Review comment: Fix outdated comment.
* Review comment: s/_SET/_SQL_LIST/.
* Review comment: Use a sub-select for checking cardinality.
This might be faster in practice.
* Review comment: Put `attribute::Unique` into its own namespace.
* Test collecting tempids after upsert resolution. Fixes#299.
I just didn't finish and expose the tempid collection when I
implemented upsert resolution. Here it is!
* Review comment: Take ownership of temp_id_map; avoid contains_key().
* Pre: Order datoms deterministically in debug output.
This makes comparison much easier, and avoids a whole class of
difficult problems when introducing pattern matching with placeholder
values.
* Pre: Don't rewrite ?txN and ?msN in debug module into_edn() methods.
* Convert EDN transaction tests to Rust code. Fixes#271.
This implements
https://github.com/mozilla/mentat/issues/271#issuecomment-283125963.
I'm using the EDN pattern matching functionality
internally (extensively!), but specifically working around the tricky
edges we encountered. This should let us implement tests quickly (and
hopefully legibly) while not requiring us to encode as much behaviour
into non-standard EDN notations.
* Part 1: added limits feature to rusqlite dependencies.
* Part 2: replace references to SQLITE_MAX_VARIABLE_NUMBER with sqlite3_limit.
* Move assertion check for correct number of variables in repeat_values to before call as this is where the variable is defined.
* Part 3: add tests
* Add a failing test for EDN parsing '…'.
* Expose a SQLValueType trait to get value_type_tag values out of a ValueType.
* Add accessors to FindSpec.
* Implement querying.
* Implement rudimentary projection.
* Export mentat_db::new_connection.
* Export symbols from mentat.
* Add rudimentary end-to-end query tests.
* Add top-level `Conn`. Fixes#296.
This is a little different than the API rnewman and I originally
discussed in https://public.etherpad-mozilla.org/p/db-conn-thoughts.
A few notes:
- I was led to make a `Schema` instance the thing that is shared,
rather than a `db::DB`. It's possible that queries will want to
know the current transaction at some point (to prevent races, or to
query historical data), but that can be a future consideration.
- The generation number just allows for a cheap comparison. I don't
care to handle races to transact just yet; the long term plan might
be to make embedding applications responsible for avoiding races, or
we might handle queuing transactions and yielding report futures in
Mentat itself.
- The sharing of the partition maps is a little more subtle than
expected. Partition maps are volatile: a successful Mentat
transaction always advances the :db.part/tx partition, so it's not
worth passing references around. This means that consumers must
clone in order to maintain just a single clone per transaction.
Clean some cruft.
* Review comments.
* Pre: Drop unneeded tx0 from search results.
* Pre: Don't require a schema in some of the DB code.
The idea is to separate the transaction applying code, which is
schema-aware, from the concrete storage code, which is just concerned
with getting bits onto disk.
* Pre: Only reference Schema, not DB, in debug module.
This is part of a larger separation of the volatile PartitionMap,
which is modified every transaction, from the stable Schema, which is
infrequently modified.
* Pre: Fix indentation.
* Extract part of DB to new SchemaTypeChecking trait.
* Extract part of DB to new PartitionMapping trait.
* Pre: Don't expect :db.part/tx partition to advance when tx fails.
This fails right now, because we allocate tx IDs even when we shouldn't.
* Sketch a db interface without DB.
* Add ValueParseError; use error-chain in tx-parser.
This can be simplified when
https://github.com/Marwes/combine/issues/86 makes it to a published
release, but this unblocks us for now. This converts the `combine`
error type `ParseError<&'a [edn::Value]>` to a type with owned
`Vec<edn::Value>` collections, re-using `edn::Value::Vector` for
making them `Display`.
* Pre: Accept Borrow<Schema> instead of just &Schema in debug module.
This makes it easy to use Rc<Schema> or Arc<Schema> without inserting
&* sigils throughout the code.
* Use error-chain in query-parser.
There are a few things to point out here:
- the fine grained error types have been flattened into one crate-wide
error type; it's pretty easy to regain the granularity as needed.
- edn::ParseError is automatically lifted to
mentat_query_parser::errors::Error;
- we use mentat_parser_utils::ValueParser to maintain parsing error
information from `combine`.
* Patch up top-level.
* Review comment: Only `borrow()` once.
