Part 1: Hacking up <transact!.

This commit is contained in:
Nick Alexander 2016-07-14 11:09:17 -07:00
parent 2b705019a7
commit 5202b147ee
4 changed files with 472 additions and 4 deletions

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@ -8,6 +8,7 @@
[datomish.pair-chan :refer [go-pair <?]] [datomish.pair-chan :refer [go-pair <?]]
[cljs.core.async.macros :refer [go]])) [cljs.core.async.macros :refer [go]]))
(:require (:require
[honeysql.core :as sql]
[datomish.util :as util :refer [raise]] [datomish.util :as util :refer [raise]]
[datomish.sqlite :as s] [datomish.sqlite :as s]
[datomish.sqlite-schema :as sqlite-schema] [datomish.sqlite-schema :as sqlite-schema]
@ -21,12 +22,342 @@
[db] [db]
"Close this database. Returns a pair channel of [nil error].")) "Close this database. Returns a pair channel of [nil error]."))
(defrecord DB [sqlite-connection] (defrecord DB [sqlite-connection max-tx]
IDB IDB
(close [db] (close (.-sqlite-connection db)))) (close [db] (s/close (.-sqlite-connection db))))
(def tx0 0x2000000)
(defn <with-sqlite-connection [sqlite-connection] (defn <with-sqlite-connection [sqlite-connection]
(go-pair (go-pair
(when-not (= sqlite-schema/current-version (<? (sqlite-schema/<ensure-current-version sqlite-connection))) (when-not (= sqlite-schema/current-version (<? (sqlite-schema/<ensure-current-version sqlite-connection)))
(raise "Could not ensure current SQLite schema version.")) (raise "Could not ensure current SQLite schema version."))
(->DB sqlite-connection))) (map->DB {:sqlite-connection sqlite-connection
:current-tx (atom (dec tx0))}))) ;; TODO: get rid of dec.
(defn- #?@(:clj [^Boolean tx-id?]
:cljs [^boolean tx-id?])
[e]
(or (= e :db/current-tx)
(= e ":db/current-tx"))) ;; for datascript.js interop
(defrecord TxReport [;; db-before db-after
tx-data tempids tx-meta])
#?(:clj
(defmacro cond-let [& clauses]
(when-let [[test expr & rest] clauses]
`(~(if (vector? test) 'if-let 'if) ~test
~expr
(cond-let ~@rest)))))
(defn <allocate-tx [db]
(go-pair
(swap! (:current-tx db) inc)))
(deftype Datom [e a v tx added])
;; printing and reading
;; #datomic/DB {:schema <map>, :datoms <vector of [e a v tx]>}
;; (defn ^Datom datom-from-reader [vec]
;; (apply datom vec))
#?(:clj
(defmethod print-method Datom [^Datom d, ^java.io.Writer w]
(.write w (str "#datomish/Datom "))
(binding [*out* w]
(pr [(.-e d) (.-a d) (.-v d) (.-tx d) (.-added d)]))))
(defn- validate-eid [eid at]
(when-not (number? eid)
(raise "Bad entity id " eid " at " at ", expected number"
{:error :transact/syntax, :entity-id eid, :context at})))
(defn- validate-attr [attr at]
(when-not (or (keyword? attr) (string? attr))
(raise "Bad entity attribute " attr " at " at ", expected keyword or string"
{:error :transact/syntax, :attribute attr, :context at})))
(defn- validate-val [v at]
(when (nil? v)
(raise "Cannot store nil as a value at " at
{:error :transact/syntax, :value v, :context at})))
(defn multival? [db attr] false)
(defn ref? [db attr] false)
(defn <entid [db eid]
;; {:pre [(db? db)]}
(go-pair
(cond
(number? eid) eid
;; (sequential? eid)
;; (cond
;; (not= (count eid) 2)
;; (raise "Lookup ref should contain 2 elements: " eid
;; {:error :lookup-ref/syntax, :entity-id eid})
;; (not (is-attr? db (first eid) :db.unique/identity))
;; (raise "Lookup ref attribute should be marked as :db.unique/identity: " eid
;; {:error :lookup-ref/unique
;; :entity-id eid})
;; (nil? (second eid))
;; nil
;; :else
;; (:e (first (-datoms db :avet eid))))
:else
(raise "Expected number or lookup ref for entity id, got " eid
{:error :entity-id/syntax
:entity-id eid}))))
(defn <entid-strict [db eid]
(go-pair
(or (<? (<entid db eid))
(raise "Nothing found for entity id " eid
{:error :entity-id/missing
:entity-id eid}))))
(defn <entid-some [db eid]
(go-pair
(when eid
(<? (<entid-strict db eid)))))
;; TODO: handle _?
(defn search->sql-clause [pattern]
(merge
{:select [:e :a :v :tx] ;; TODO: generalize columns.
:from [:datoms]}
(if-not (empty? pattern)
{:where (cons :and (map #(vector := %1 (if (keyword? %2) (str %2) %2)) [:e :a :v :tx] pattern))} ;; TODO: use schema to intern a and v.
{})))
(defn <search [db pattern]
(go-pair
;; TODO: find a better expression of this pattern.
(let [rows (<? (->>
(search->sql-clause pattern)
(sql/format)
(s/all-rows (:sqlite-connection db))))]
(map #(Datom. (:e %) (:a %) (:v %) (:tx %) true) rows))))
(defn- <transact-report [db report datom]
(go-pair
(let [exec (partial s/execute! (:sqlite-connection db))]
;; Append to transaction log.
(<? (exec
["INSERT INTO transactions VALUES (?, ?, ?, ?, ?)" (.-e datom) (str (.-a datom)) (.-v datom) (.-tx datom) (.-added datom)]))
;; Update materialized datom view.
(if (.-added datom)
(<? (exec
;; TODO: use schema to insert correct indexing flags.
["INSERT INTO datoms VALUES (?, ?, ?, ?, 0, 0)" (.-e datom) (str (.-a datom)) (.-v datom) (.-tx datom)]))
(<? (exec
;; TODO: verify this is correct.
["DELETE FROM datoms WHERE (e = ? AND a = ? AND v = ?)" (.-e datom) (.-a datom) (.-v datom)])))
(-> report
(update-in [:tx-data] conj datom)))))
(defn- <transact-add [db report [_ e a v tx :as entity]]
(go-pair
(validate-attr a entity)
(validate-val v entity)
(let [tx (or tx (:current-tx report))
e (<? (<entid-strict db e))
v (if (ref? db a) (<? (<entid-strict db v)) v)
datom (Datom. e a v tx true)]
(if (multival? db a)
;; TODO: consider adding a UNIQUE CONSTRAINT and using INSERT OR IGNORE.
(if (empty? (<? (<search db [e a v])))
(<? (<transact-report db report datom))
report)
(if-let [^Datom old-datom (first (<? (<search db [e a])))]
(if (= (.-v old-datom) v)
report
(let [ra (<? (<transact-report db report (Datom. e a (.-v old-datom) tx false)))
rb (<? (<transact-report db ra datom))]
rb)) ;; TODO: express this better.
(<? (<transact-report db report datom)))))))
(defn- <transact-retract [db report [_ e a v _ :as entity]] ;; TODO: think about retracting with tx.
(go-pair
(let [tx (:current-tx report)]
(if-let [e (<? (<entid db e))]
(let [v (if (ref? db a) (<? (<entid-strict db v)) v)]
(validate-attr a entity)
(validate-val v entity)
(if-let [old-datom (first (<? (<search db [e a v])))]
(<? (<transact-report db report (Datom. e a v tx false)))
report))
report))))
(defn <transact-tx-data
[db now initial-report initial-es]
(go-pair
(when-not (or (nil? initial-es)
(sequential? initial-es))
(raise "Bad transaction data " initial-es ", expected sequential collection"
{:error :transact/syntax, :tx-data initial-es}))
(loop [report initial-report
es initial-es]
(let [[entity & entities] es]
(cond
(nil? entity)
(let [current-tx (:current-tx report)]
(<? (<transact-report db report (Datom. current-tx :db/txInstant now current-tx true)))
(-> report
(assoc-in [:tempids :db/current-tx] current-tx)))
;; (map? entity)
;; (let [old-eid (:db/id entity)]
;; (cond-let
;; ;; :db/current-tx => tx
;; (tx-id? old-eid)
;; (let [id (current-tx report)]
;; (recur (allocate-eid report old-eid id)
;; (cons (assoc entity :db/id id) entities)))
;; ;; lookup-ref => resolved | error
;; (sequential? old-eid)
;; (let [id (entid-strict db old-eid)]
;; (recur report
;; (cons (assoc entity :db/id id) entities)))
;; ;; upserted => explode | error
;; [upserted-eid (upsert-eid db entity)]
;; (if (and (neg-number? old-eid)
;; (contains? (:tempids report) old-eid)
;; (not= upserted-eid (get (:tempids report) old-eid)))
;; (retry-with-tempid initial-report initial-es old-eid upserted-eid)
;; (recur (allocate-eid report old-eid upserted-eid)
;; (concat (explode db (assoc entity :db/id upserted-eid)) entities)))
;; ;; resolved | allocated-tempid | tempid | nil => explode
;; (or (number? old-eid)
;; (nil? old-eid))
;; (let [new-eid (cond
;; (nil? old-eid) (next-eid db)
;; (neg? old-eid) (or (get (:tempids report) old-eid)
;; (next-eid db))
;; :else old-eid)
;; new-entity (assoc entity :db/id new-eid)]
;; (recur (allocate-eid report old-eid new-eid)
;; (concat (explode db new-entity) entities)))
;; ;; trash => error
;; :else
;; (raise "Expected number or lookup ref for :db/id, got " old-eid
;; { :error :entity-id/syntax, :entity entity })))
(sequential? entity)
(let [[op e a v] entity]
(cond
;; (= op :db.fn/call)
;; (let [[_ f & args] entity]
;; (recur report (concat (apply f db args) entities)))
;; (= op :db.fn/cas)
;; (let [[_ e a ov nv] entity
;; e (entid-strict db e)
;; _ (validate-attr a entity)
;; ov (if (ref? db a) (entid-strict db ov) ov)
;; nv (if (ref? db a) (entid-strict db nv) nv)
;; _ (validate-val nv entity)
;; datoms (<searchdb [e a])]
;; (if (multival? db a)
;; (if (some (fn [^Datom d] (= (.-v d) ov)) datoms)
;; (recur (transact-add report [:db/add e a nv]) entities)
;; (raise ":db.fn/cas failed on datom [" e " " a " " (map :v datoms) "], expected " ov
;; {:error :transact/cas, :old datoms, :expected ov, :new nv}))
;; (let [v (:v (first datoms))]
;; (if (= v ov)
;; (recur (transact-add report [:db/add e a nv]) entities)
;; (raise ":db.fn/cas failed on datom [" e " " a " " v "], expected " ov
;; {:error :transact/cas, :old (first datoms), :expected ov, :new nv })))))
(tx-id? e)
(recur report (cons [op (:current-tx report) a v] entities))
;; (and (ref? db a) (tx-id? v))
;; (recur report (cons [op e a (current-tx report)] entities))
;; (neg-number? e)
;; (if (not= op :db/add)
;; (raise "Negative entity ids are resolved for :db/add only"
;; {:error :transact/syntax
;; :op entity })
;; (let [upserted-eid (when (is-attr? db a :db.unique/identity)
;; (:e (first (-datoms db :avet [a v]))))
;; allocated-eid (get-in report [:tempids e])]
;; (if (and upserted-eid allocated-eid (not= upserted-eid allocated-eid))
;; (retry-with-tempid initial-report initial-es e upserted-eid)
;; (let [eid (or upserted-eid allocated-eid (next-eid db))]
;; (recur (allocate-eid report e eid) (cons [op eid a v] entities))))))
;; (and (ref? db a) (neg-number? v))
;; (if-let [vid (get-in report [:tempids v])]
;; (recur report (cons [op e a vid] entities))
;; (recur (allocate-eid report v (next-eid db)) es))
(= op :db/add)
(recur (<? (<transact-add db report entity)) entities)
(= op :db/retract)
(recur (<? (<transact-retract db report entity)) entities)
;; (= op :db.fn/retractAttribute)
;; (if-let [e (entid db e)]
;; (let [_ (validate-attr a entity)
;; datoms (<search db [e a])]
;; (recur (reduce transact-retract-datom report datoms)
;; (concat (retract-components db datoms) entities)))
;; (recur report entities))
;; (= op :db.fn/retractEntity)
;; (if-let [e (entid db e)]
;; (let [e-datoms (<search db [e])
;; v-datoms (mapcat (fn [a] (<search db [nil a e])) (-attrs-by db :db.type/ref))]
;; (recur (reduce transact-retract-datom report (concat e-datoms v-datoms))
;; (concat (retract-components db e-datoms) entities)))
;; (recur report entities))
:else
(raise "Unknown operation at " entity ", expected :db/add, :db/retract, :db.fn/call, :db.fn/retractAttribute or :db.fn/retractEntity"
{:error :transact/syntax, :operation op, :tx-data entity})))
;; (datom? entity)
;; (let [[e a v tx added] entity]
;; (if added
;; (recur (transact-add report [:db/add e a v tx]) entities)
;; (recur report (cons [:db/retract e a v] entities))))
:else
(raise "Bad entity type at " entity ", expected map or vector"
{:error :transact/syntax, :tx-data entity})
)))))
(defn <transact!
([db tx-data]
(<transact! db tx-data nil 0xdeadbeef)) ;; TODO: timestamp!
([db tx-data tx-meta now]
;; {:pre [(db/db? db)]}
(go-pair
(let [current-tx (<? (<allocate-tx db))]
(<? (<transact-tx-data db now
(map->TxReport
{:current-tx current-tx
:tx-data []
:tempids {}
:tx-meta tx-meta}) tx-data))))))
#_ (a/<!! (<transact! db []))
#_ .
#_ (def db (<?? (<with-sqlite-connection (<?? (s/<sqlite-connection "/Users/nalexander/test5.db")))))
#_ (<?? (<transact! db [[:db/add 0 1 "test"]]))
#_ (<?? (<transact! db [[:db/retract 0 1 "test"]]))

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src/datomish/repl.clj Normal file
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@ -0,0 +1,41 @@
;; This Source Code Form is subject to the terms of the Mozilla Public
;; License, v. 2.0. If a copy of the MPL was not distributed with this
;; file, You can obtain one at http://mozilla.org/MPL/2.0/.
(ns datomish.repl
(:require
[datomish.db :as db]
[datomish.util :as util :refer [raise]]
[datomish.sqlite :as s]
[datomish.jdbc-sqlite :as j]
[tempfile.core]
[datomish.pair-chan :refer [go-pair <?]]
[clojure.core.async :as a :refer [go <! >! <!! >!!]]))
(defn <?? [pair-chan]
(datomish.pair-chan/consume-pair (<!! pair-chan)))
(defn debug-db [db]
(<??
(go-pair
(let [ds (<? (s/all-rows (:sqlite-connection db) ["SELECT e, a, v, tx FROM datoms"]))]
(println (count ds) "datoms.")
(doseq [d ds] (println d)))
(let [ts (<? (s/all-rows (:sqlite-connection db) ["SELECT * FROM transactions"]))]
(println (count ts) "transactions.")
(doseq [t ts] (println t)))))
db)
(defn reset-db! [db]
(<??
(go-pair
(<? (s/execute! (:sqlite-connection db) ["DELETE FROM datoms"]))
(<? (s/execute! (:sqlite-connection db) ["DELETE FROM transactions"]))))
db)
(defn db-with [datoms]
(go-pair
(let [c (<? (s/<sqlite-connection (tempfile.core/tempfile)))
d (<? (db/<with-sqlite-connection c))]
(<? (db/<transact! d datoms))
d)))

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@ -24,7 +24,7 @@
"CREATE INDEX avet ON datoms (a, v, e) WHERE index_avet = 1" ;; Opt-in index: only if a has :db/index true. "CREATE INDEX avet ON datoms (a, v, e) WHERE index_avet = 1" ;; Opt-in index: only if a has :db/index true.
"CREATE INDEX vaet ON datoms (v, a, e) WHERE index_vaet = 1" ;; Opt-in index: only if a has :db/valueType :db.type/ref "CREATE INDEX vaet ON datoms (v, a, e) WHERE index_vaet = 1" ;; Opt-in index: only if a has :db/valueType :db.type/ref
"CREATE TABLE transactions (e INTEGER NOT NULL, a SMALLINT NOT NULL, v BLOB NOT NULL, tx INTEGER NOT NULL, added TINYINT NOT NULL DEFAULT 1)" "CREATE TABLE transactions (e INTEGER NOT NULL, a SMALLINT NOT NULL, v BLOB NOT NULL, tx INTEGER NOT NULL, added TINYINT NOT NULL DEFAULT 1)"
"CREATE INDEX tx ON transactions (tx)" "CREATE INDEX tx ON transactions (tx, e, a)" ;; Allow to find a previous value relatively efficiently.
"CREATE TABLE attributes (name TEXT NOT NULL PRIMARY KEY, a INTEGER UNIQUE NOT NULL)"]) "CREATE TABLE attributes (name TEXT NOT NULL PRIMARY KEY, a INTEGER UNIQUE NOT NULL)"])
(defn <create-current-version (defn <create-current-version

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;; This Source Code Form is subject to the terms of the Mozilla Public
;; License, v. 2.0. If a copy of the MPL was not distributed with this
;; file, You can obtain one at http://mozilla.org/MPL/2.0/.
(ns datomish.db-test
#?(:cljs
(:require-macros
[datomish.pair-chan :refer [go-pair <?]]
[datomish.node-tempfile-macros :refer [with-tempfile]]
[cljs.core.async.macros :as a :refer [go]]))
(:require
[datomish.util :as util :refer [raise]]
[datomish.sqlite :as s]
[datomish.db :as db]
#?@(:clj [[datomish.pair-chan :refer [go-pair <?]]
[tempfile.core :refer [tempfile with-tempfile]]
[datomish.test-macros :refer [deftest-async]]
[clojure.test :as t :refer [is are deftest testing]]
[clojure.core.async :refer [go <! >!]]])
#?@(:cljs [[datomish.pair-chan]
[datomish.test-macros :refer-macros [deftest-async]]
[datomish.node-tempfile :refer [tempfile]]
[cljs.test :as t :refer-macros [is are deftest testing async]]
[cljs.core.async :as a :refer [<! >!]]])))
(defn <datoms [db]
(go-pair
(->>
(<? (s/all-rows (:sqlite-connection db) ["SELECT e, a, v, tx FROM datoms ORDER BY tx ASC, e, a, v"]))
(mapv #(vector (:e %) (:a %) (:v %) (:tx %) true)))))
(defn <transactions [db]
(go-pair
(->>
(<? (s/all-rows (:sqlite-connection db) ["SELECT e, a, v, tx, added FROM transactions ORDER BY tx ASC, e, a, v, added"]))
(mapv #(vector (:e %) (:a %) (:v %) (:tx %) (:added %))))))
(deftest-async test-add-one
(with-tempfile [t (tempfile)]
(let [c (<? (s/<sqlite-connection t))
db (<? (db/<with-sqlite-connection c))]
(try
(let [now -1
report (<? (db/<transact! db [[:db/add 0 :a "value"]] nil now))
current-tx (:current-tx report)]
(is (= current-tx db/tx0))
(is (= (<? (<datoms db))
[[0 ":a" "value" db/tx0 true]
[db/tx0 ":db/txInstant" now db/tx0 true]]))
(is (= (<? (<transactions db))
[[0 ":a" "value" db/tx0 1] ;; TODO: true, not 1.
[db/tx0 ":db/txInstant" now db/tx0 1]])))
(finally
(<? (db/close db)))))))
(deftest-async test-add-two
(with-tempfile [t (tempfile)]
(let [c (<? (s/<sqlite-connection t))
db (<? (db/<with-sqlite-connection c))]
(try
(let [now -1
report (<? (db/<transact! db [[:db/add 0 :a "valuea"] [:db/add 1 :b "valueb"]] nil now))
current-tx (:current-tx report)]
(is (= current-tx db/tx0))
(is (= (<? (<datoms db))
[[0 ":a" "valuea" db/tx0 true]
[1 ":b" "valueb" db/tx0 true]
[db/tx0 ":db/txInstant" now db/tx0 true]]))
(is (= (<? (<transactions db))
[[0 ":a" "valuea" db/tx0 1] ;; TODO: true, not 1.
[1 ":b" "valueb" db/tx0 1]
[db/tx0 ":db/txInstant" now db/tx0 1]])))
(finally
(<? (db/close db)))))))
;; TODO: test multipe :add and :retract of the same datom in the same transaction.
(deftest-async test-retract
(with-tempfile [t (tempfile)]
(let [c (<? (s/<sqlite-connection t))
db (<? (db/<with-sqlite-connection c))]
(try
(let [now -1
ra (<? (db/<transact! db [[:db/add 0 :a "value"]] nil now))
rb (<? (db/<transact! db [[:db/retract 0 :a "value"]] nil now))
txa (:current-tx ra)
txb (:current-tx rb)]
(is (= (<? (<datoms db))
[[txa ":db/txInstant" now txa true]
[txb ":db/txInstant" now txb true]]))
(is (= (<? (<transactions db))
[[0 ":a" "value" txa 1] ;; TODO: true, not 1.
[txa ":db/txInstant" -1 txa 1]
[0 ":a" "value" txb 0]
[txb ":db/txInstant" -1 txb 1]])))
(finally
(<? (db/close db)))))))