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Merge pull request #7 from thegeez/transact-fns
Add transaction functions
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tonsky committed Apr 29, 2014
2 parents 8e08c02 + 28ea7ad commit 54053beac3d2aea87114e04e9ce085c660181ae7
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Showing 4 changed files with 64 additions and 15 deletions.
@@ -1,3 +1,7 @@

- Transactor functions via :db.fn/call

# 0.1.3

- `entity` added
@@ -119,10 +119,13 @@ Interface differences:
* Custom query functions and aggregates should be passed as source instead of being referenced by symbol (due to lack of `resolve` in CLJS)
* Conn is just an atom storing last DB value, use `@conn` instead of `(d/db conn)`
* Instead of `#db/id[:db.part/user -100]` just use `-100` in place of `:db/id` or entity id
* Transactor functions can be called as `[:db.fn/call f args]` where `f` is a function reference and will take db as first argument
* Additional `:db.fn/retractAttribute` shortcut

Expected soon:

* Better error reporting
* Support for components in schema
* Direct access to indexes
* Passing DB to rule
* Moar speed
@@ -136,7 +139,6 @@ Expected soon:
* Any value can be used as entity id, attribute or value. It’s better if they are immutable and fast to compare
* No `db/ident` attributes, keywords are _literally_ attribute values, no integer id behind them
* AV index for all datoms
* No transactor functions besides `:db.fn/retractEntity` and `:db.fn/retractAttribute`
* No schema migrations
* No history support, though history can be implemented on top of immutable DB values
* No cache segments management, no laziness. Entire DB must reside in memory
@@ -81,7 +81,10 @@
[:db/add eid a v]))
(if (= (first entity) :db.fn/call)
(let [[_ f & args] entity]
(mapcat #(entity->ops db %) (apply f db args)))

(defn- op->tx-data [db [op e a v]]
(let [tx (inc (.-max-tx db))]
@@ -372,20 +375,29 @@
db-before (atom nil)
tx-data (atom nil)
tempids (atom nil)
error (atom nil)
db-after (swap! conn (fn [db]
(let [raw-datoms (mapcat #(entity->tx-data db %) entities)
datoms (map #(resolve-eid db %) raw-datoms)]
(reset! db-before db)
(reset! tx-data datoms)
(reset! tempids (->> raw-datoms
(filter #(neg? (.-e %)))
(map #(vector (.-e %) (-resolve-eid (.-e %) db)))
(into {})))
(-with db datoms))))
report (TxReport. @db-before db-after @tx-data)]
(doseq [[_ l] @(:listeners meta)]
(l report))
(assoc report :tempids @tempids)))
(let [raw-datoms (try (mapcat #(entity->tx-data db %) entities)
(catch js/Object e
(reset! error e)))
(if @error
(let [datoms (map #(resolve-eid db %) raw-datoms)]
(reset! db-before db)
(reset! tx-data datoms)
(reset! tempids (->> raw-datoms
(filter #(neg? (.-e %)))
(map #(vector (.-e %) (-resolve-eid (.-e %) db)))
(into {})))
(-with db datoms)))
(if-let [e @error]
(throw e)
(let [report (TxReport. @db-before db-after @tx-data)]
(doseq [[_ l] @(:listeners meta)]
(l report))
(assoc report :tempids @tempids)))))

(defn listen!
([conn callback] (listen! conn (rand) callback))
@@ -84,6 +84,35 @@
:where [1 :aka ?v]] @conn)
#{["Devil"] ["Tupen"]}))))

(deftest test-db-fn
(let [conn (d/create-conn {:aka { :cardinality :many }})
inc-age (fn [db name]
(if-let [[eid age] (first (d/q '{:find [?e ?age]
:in [$ ?name]
:where [[?e :name ?name]
[?e :age ?age]]}
db name))]
[{:db/id eid :age (inc age)} [:db/add eid :had-birthday true]]
(throw (js/Error. (str "No entity with name: " name)))
(d/transact! conn [{:db/id 1 :name "Ivan" :age 31}])
(d/transact! conn [[:db/add 1 :name "Petr"]])
(d/transact! conn [[:db/add 1 :aka "Devil"]])
(d/transact! conn [[:db/add 1 :aka "Tupen"]])
(is (= (d/q '[:find ?v ?a
:where [?e :name ?v]
[?e :age ?a]] @conn)
#{["Petr" 31]}))
(is (= (d/q '[:find ?v
:where [?e :aka ?v]] @conn)
#{["Devil"] ["Tupen"]}))
(is (thrown-with-msg? js/Error #"No entity with name: Bob"
(d/transact! conn [[:db.fn/call inc-age "Bob"]])))
(let [{:keys [db-after]} (d/transact! conn [[:db.fn/call inc-age "Petr"]])
e (d/entity db-after 1)]
(is (= (:age e) 32))
(is (:had-birthday e)))))

(deftest test-resolve-eid
(let [conn (d/create-conn)
@@ -457,6 +486,8 @@
#(reverse (sort %))))
#{[:red [5 4 3 2 1]] [:blue [8 7]]})))))

;; (t/test-ns 'test.datomicscript)

;; Performance

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