Cosmetic changes to better mimic Datomic API

CHANGELOG.md

@@ -1,3 +1,10 @@
+# 0.4.0
+
+Cosmetic changes to better mimic Datomic API. Useful for sharing code between Datomic and DataScript:
+
+- Added `tempid`, `resolve-tempid`, `db`, `transact`, `transact-async`, `index-range`, `squuid`, `squuid-time-millis`
+- [ BREAKING ] renamed `transact` to `with`, `with` to `db-with`
+
 # 0.3.1
 
 - Optimized speed of DB’s `equiv` and `hash`, Datom’s `hash`
@@ -9,7 +16,7 @@
 Proper entities implementation:
 
 - Entities are now lazy and implement usual Map protocols
-- When accessing attribute of `:db/valueType :db.type/ref`, its value will be automatically expanded to entites, allowing for recursive exploration of entities graphs (e.g. `(-> (d/entity db 42) :parent :parent :children)`)
+- [ BREAKING ] When accessing attribute of `:db/valueType :db.type/ref`, its value will be automatically expanded to entites, allowing for recursive exploration of entities graphs (e.g. `(-> (d/entity db 42) :parent :parent :children)`)
 - Entities support backwards navigation (e.g. `(:person/_friends (d/entity db 42))`)
 
 # 0.2.1

README.md

@@ -23,7 +23,7 @@ Also check out this blog post about [how DataScript fits into the current webdev
 :dependencies [
   [org.clojure/clojurescript "0.0-2311"]
   ...
-  [datascript "0.3.1"]
+  [datascript "0.4.0"]
 ]
 
 ;; for advanced optimizations externs are needed
@@ -103,10 +103,10 @@ Also check out this blog post about [how DataScript fits into the current webdev
 DataScript can be used from any JS engine without additional dependencies:
 
 ```html
-<script src="datascript-0.3.1.min.js"></script>
+<script src="datascript-0.4.0.min.js"></script>
 ```
 
-[Download datascript-0.3.1.min.js](https://github.com/tonsky/datascript/releases/download/0.3.1/datascript-0.3.1.min.js), 43k gzipped.
+[Download datascript-0.4.0.min.js](https://github.com/tonsky/datascript/releases/download/0.4.0/datascript-0.4.0.min.js), 43k gzipped.
 
 Queries:
 
@@ -122,12 +122,11 @@ Entities:
 Transactions:
 
 * Use strings such as `":db/id"`, `":db/add"`, etc. instead of db-namespaced keywords
-* Use regular JS arrays and objects to pass data to `transact` and `with_datoms`
+* Use regular JS arrays and objects to pass data to `transact` and `db_with`
 
 Transaction reports:
 
-* `report.tempids` has string keys (`"-1"` for entity tempid `-1`)
-* `report.tx_data` is list of objects with `e`, `a`, `v`, `tx` and `added` keys (instead of Datoms)
+* `report.tempids` has string keys (`"-1"` for entity tempid `-1`), use `resolve_tempid` set up a correspondence
 
 Check out [test/js/js.html](test/js/js.html) for usage examples.
 
@@ -164,12 +163,12 @@ Interface differences:
 * 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 (thx [@thegeez](https://github.com/thegeez))
 * Additional `:db.fn/retractAttribute` shortcut
-* `transact!` and `transact` return `TxReport`, `with` returns new DB value
 
 Expected soon:
 
 * Better error reporting
 * Support for components in schema
+* Support for `get-else`, `get-some`, `ground`, `missing?` query functions
 * Proper documentation
 
 ## Differences from Datomic

project.clj

@@ -1,4 +1,4 @@
-(defproject datascript "0.3.1"
+(defproject datascript "0.4.0"
   :description "An implementation of Datomic in-memory database and Datalog query engine in ClojureScript"
   :license {:name "Eclipse"
             :url "http://www.eclipse.org/legal/epl-v10.html"}

src/datascript.cljs

@@ -26,22 +26,22 @@
   (atom (empty-db schema)
         :meta { :listeners  (atom {}) }))
 
-(defn transact [db entities]
-  (dc/transact-entities (dc/TxReport. db db [] {}) entities))
+(defn with [db tx-data]
+  (dc/transact-tx-data (dc/TxReport. db db [] {}) tx-data))
 
-(defn with [db entities]
-  (:db-after (transact db entities)))
+(defn db-with [db tx-data]
+  (:db-after (with db tx-data)))
 
-(defn -transact! [conn entities]
+(defn -transact! [conn tx-data]
   (let [report (atom nil)]
     (swap! conn (fn [db]
-                  (let [r (transact db entities)]
+                  (let [r (with db tx-data)]
                     (reset! report r)
                     (:db-after r))))
     @report))
 
-(defn transact! [conn entities]
-  (let [report (-transact! conn entities)]
+(defn transact! [conn tx-data]
+  (let [report (-transact! conn tx-data)]
     (doseq [[_ callback] @(:listeners (meta conn))]
       (callback report))
     report))
@@ -67,6 +67,10 @@
 (defn seek-datoms [db index & cs]
   (btset/slice (get db index) (components->pattern index cs) (dc/Datom. nil nil nil nil nil)))
 
+(defn index-range [db attr start end]
+  (btset/slice (:avet db) (dc/Datom. nil attr start nil nil)
+                          (dc/Datom. nil attr end nil nil)))
+
 ;; printing and reading
 ;; #datomic/DB {:schema <map>, :datoms <vector of [e a v tx]>}
 
@@ -99,3 +103,60 @@
          (apply btset/btset-by dc/cmp-datoms-avet datoms)
          (reduce max 0 (map :e datoms))
          (reduce max tx0 (map :tx datoms)))))
+
+
+;; Datomic compatibility layer
+
+(def last-tempid (atom -1000000))
+(defn tempid
+  ([_part]  (swap! last-tempid dec))
+  ([_part x] x))
+(defn resolve-tempid [_db tempids tempid]
+  (get tempids tempid))
+
+(def db deref)
+
+(defn transact [conn tx-data]
+  (let [res (transact! conn tx-data)]
+    (reify
+      IDeref
+      (-deref [_] res)
+      IDerefWithTimeout
+      (-deref-with-timeout [_ _ _] res)
+      IPending
+      (-realized? [_] true))))
+
+;; ersatz future without proper blocking
+(defn- future-call [f]
+  (let [res      (atom nil)
+        realized (atom false)]
+    (js/setTimeout #(do (reset! res (f)) (reset! realized true)) 0)
+    (reify
+      IDeref
+      (-deref [_] @res)
+      IDerefWithTimeout
+      (-deref-with-timeout [_ _ timeout-val] (if @realized @res timeout-val))
+      IPending
+      (-realized? [_] @realized))))
+
+(defn transact-async [conn tx-data]
+  (future-call #(transact! conn tx-data)))
+
+(defn- rand-bits [pow]
+  (rand-int (bit-shift-left 1 pow)))
+
+(defn squuid []
+  (UUID.
+    (str
+          (-> (js/Date.) (.getTime) (/ 1000) (Math/round) (.toString 16))
+      "-" (-> (rand-bits 16) (.toString 16))
+      "-" (-> (rand-bits 16) (bit-and 0x0FFF) (bit-or 0x4000) (.toString 16))
+      "-" (-> (rand-bits 16) (bit-and 0x3FFF) (bit-or 0x8000) (.toString 16))
+      "-" (-> (rand-bits 16) (.toString 16))
+          (-> (rand-bits 16) (.toString 16))
+          (-> (rand-bits 16) (.toString 16)))))
+
+(defn squuid-time-millis [uuid]
+  (-> (subs (.-uuid uuid) 0 8)
+      (js/parseInt 16)
+      (* 1000)))

src/datascript/core.cljs

@@ -204,7 +204,7 @@
   (let [tx (current-tx report)]
     (transact-report report (Datom. (.-e d) (.-a d) (.-v d) tx false))))
 
-(defn- transact-entities [report [entity & entities :as es]]
+(defn- transact-tx-data [report [entity & entities :as es]]
   (let [db (:db-after report)]
     (cond
       (nil? entity)

src/datascript/externs.js

@@ -10,8 +10,8 @@ datascript.core.Datom.added = true;
 datascript.impl = {};
 datascript.impl.entity = {};
 datascript.impl.entity.Entity = {};
-datascript.impl.entity.Entity.prototype.db = {};
-datascript.impl.entity.Entity.prototype.eid = {};
+datascript.impl.entity.Entity.db = {};
+datascript.impl.entity.Entity.eid = {};
 
 datascript.impl.entity.Entity.prototype.keys      = function() {};
 datascript.impl.entity.Entity.prototype.entries   = function() {};

src/datascript/js.cljs

@@ -52,8 +52,8 @@
            (into-array tuple))
          (into-array))))
 
-(defn ^:export with_datoms [db entities]
-  (d/with db (entities->clj entities)))
+(defn ^:export db_with [db entities]
+  (d/db-with db (entities->clj entities)))
 
 (def ^:export entity    d/entity)
 (def ^:export touch     d/touch)
@@ -77,10 +77,22 @@
 
 (def ^:export unlisten d/unlisten!)
 
+(defn ^:export resolve_tempid [tempids tempid]
+  (aget tempids (str tempid)))
+
 (defn ^:export datoms [db index & components]
   (->> (apply d/datoms db (keywordize index) components)
        into-array))
 
 (defn ^:export seek_datoms [db index & components]
   (->> (apply d/seek-datoms db (keywordize index) components)
        into-array))
+
+(defn ^:export index_range [db attr start end]
+  (into-array (d/index-range db attr start end)))
+
+(defn ^:export squuid []
+  (.-uuid (d/squuid)))
+
+(defn ^:export squuid_time_millis [uuid]
+  (d/squuid-time-millis (UUID. uuid)))

src/datascript/preamble.js

@@ -1,5 +1,5 @@
 /**
- * Datascript v0.3.1
+ * Datascript v0.4.0
  *
  * Copyright 2014 Nikita Prokopov
  *

test/js/js.html

@@ -105,11 +105,11 @@
       var d = datascript.js;
       var tx0 =  0x20000000;
 
-      function test_with_datoms() {
+      function test_db_with() {
         var db = d.empty_db();
-        var db1 = d.with_datoms(db, [[":db/add", 1, "name", "Ivan"],
+        var db1 = d.db_with(db, [[":db/add", 1, "name", "Ivan"],
                                      [":db/add", 1, "age", 17]]);
-        var db2 = d.with_datoms(db1, [{":db/id": 2,
+        var db2 = d.db_with(db1, [{":db/id": 2,
                                        "name": "Igor",
                                        "age": 35}]);
         var q = '[:find ?n ?a :where [?e "name" ?n] [?e "age" ?a]]'; 
@@ -122,14 +122,14 @@
           return [[":db/add", e, "name", n],
                   [":db/add", e, "age", a]]; 
         }
-        var db = d.with_datoms(d.empty_db(), [[":db.fn/call", dbfn, 1, "Ilya", 44]]);
+        var db = d.db_with(d.empty_db(), [[":db.fn/call", dbfn, 1, "Ilya", 44]]);
         var q = '[:find ?n ?a :where [?e "name" ?n] [?e "age" ?a]]'; 
         assert_eq_set([["Ilya", 44]], d.q(q, db));
       }
 
       function test_schema() {
         var schema = {"aka": {":db/cardinality": ":db.cardinality/many"}};
-        var db = d.with_datoms(d.empty_db(schema), 
+        var db = d.db_with(d.empty_db(schema), 
                                [[":db/add", -1, "name", "Ivan"],
                                 [":db/add", -1, "aka", "X"],
                                 [":db/add", -1, "aka", "Y"],
@@ -151,14 +151,15 @@
                           {e: 1, a: "age", v: 17, tx: 536870913, added: true }],
                          tx_report.tx_data);
         assert_eq({"-1": 1}, tx_report.tempids);
+        assert_eq(1, d.resolve_tempid(tx_report.tempids, -1));
         assert_eq_datoms([{e: 1, a: "name", v: "Ivan", tx: 536870913, added: true },
                           {e: 1, a: "age", v: 17, tx: 536870913, added: true }],
                           log[0]);
       }
 
       function test_entity() {
         var schema = {"aka": {":db/cardinality": ":db.cardinality/many"}};
-        var db = d.with_datoms(d.empty_db(schema), 
+        var db = d.db_with(d.empty_db(schema), 
                                [{":db/id": 1,
                                  "name": "Ivan",
                                  "aka": ["X", "Y"]},
@@ -198,7 +199,7 @@
         var schema = {"father":   {":db/valueType":   ":db.type/ref"},
                       "children": {":db/valueType":   ":db.type/ref",
                                    ":db/cardinality": ":db.cardinality/many"}};
-        var db = d.with_datoms(d.empty_db(schema), 
+        var db = d.db_with(d.empty_db(schema), 
                                [{":db/id": 1,   "children": [10]},
                                 {":db/id": 10,  "father":   1, "children": [100, 101]},
                                 {":db/id": 100, "father":   10}]);
@@ -224,7 +225,7 @@
         assert_eq_refs([1],   e(100).get("_children")[0].get("_children"));
       }
 
-      var people_db = d.with_datoms(d.empty_db(),
+      var people_db = d.db_with(d.empty_db(),
                        [{ ":db/id": 1, "name": "Ivan", "age": 15 },
                         { ":db/id": 2, "name": "Petr", "age": 37 },
                         { ":db/id": 3, "name": "Ivan", "age": 37 }]);
@@ -287,7 +288,7 @@
       }
 
       function run_tests() {
-        return test_fns([ test_with_datoms,
+        return test_fns([ test_db_with,
                           test_dbfn_call,
                           test_schema,
                           test_tx_report,