Add d/{ident,entid} for mapping between keyword idents and integer entids.

src/datomish/db.cljc

@@ -8,6 +8,7 @@
       [datomish.pair-chan :refer [go-pair <?]]
       [cljs.core.async.macros :refer [go]]))
   (:require
+   [clojure.set]
    [datomish.query.context :as context]
    [datomish.query.projection :as projection]
    [datomish.query.source :as source]
@@ -15,7 +16,6 @@
    [datomish.datom :as dd :refer [datom datom? #?@(:cljs [Datom])]]
    [datomish.util :as util #?(:cljs :refer-macros :clj :refer) [raise raise-str cond-let]]
    [datomish.schema :as ds]
-   [datomish.schema-changes]
    [datomish.sqlite :as s]
    [datomish.sqlite-schema :as sqlite-schema]
    #?@(:clj [[datomish.pair-chan :refer [go-pair <?]]
@@ -74,9 +74,13 @@
     [db]
     "Return the schema of this database.")
 
-  (idents
+  (entid
-    [db]
+    [db ident]
-    "Return the known idents of this database, as a map from keyword idents to entids.")
+    "Returns the entity id associated with a symbolic keyword, or the id itself if passed.")
+
+  (ident
+    [db eid]
+    "Returns the keyword associated with an id, or the key itself if passed.")
 
   (current-tx
     [db]
@@ -101,12 +105,12 @@
     "Apply datoms to the store.")
 
   (<apply-db-ident-assertions
-    [db added-idents]
+    [db added-idents merge]
-    "Apply added idents to the store.")
+    "Apply added idents to the store, using `merge` as a `merge-with` function.")
 
   (<apply-db-install-assertions
-    [db fragment]
+    [db fragment merge]
-    "Apply added schema fragment to the store.")
+    "Apply added schema fragment to the store, using `merge` as a `merge-with` function.")
 
   (<advance-tx
     [db]
@@ -140,14 +144,25 @@
           ]
       rowid)))
 
-(defrecord DB [sqlite-connection schema idents current-tx]
+(defrecord DB [sqlite-connection schema entids ident-map current-tx]
-  ;; idents is map {ident -> entid} of known idents.  See http://docs.datomic.com/identity.html#idents.
+  ;; ident-map maps between keyword idents and integer entids.  The set of idents and entids is
+  ;; disjoint, so we represent both directions of the mapping in the same map for simplicity.  Also
+  ;; for simplicity, we assume that an entid has at most one associated ident, and vice-versa.  See
+  ;; http://docs.datomic.com/identity.html#idents.
   IDB
   (query-context [db] (context/->Context (source/datoms-source db) nil nil))
 
   (schema [db] (.-schema db))
 
-  (idents [db] (.-idents db))
+  (entid [db ident]
+    (if (keyword? ident)
+      (get (.-ident-map db) ident ident)
+      ident))
+
+  (ident [db eid]
+    (if-not (keyword? eid)
+      (get (.-ident-map db) eid eid)
+      eid))
 
   (current-tx
     [db]
@@ -231,7 +246,7 @@
         ;; TODO: handle exclusion across transactions here.
         (update db :current-tx inc))))
 
-  (<apply-db-ident-assertions [db added-idents]
+  (<apply-db-ident-assertions [db added-idents merge]
     (go-pair
       (let [->SQLite (get-in ds/value-type-map [:db.type/keyword :->SQLite]) ;; TODO: make this a protocol.
             exec     (partial s/execute! (:sqlite-connection db))]
@@ -239,9 +254,12 @@
         (doseq [[ident entid] added-idents]
           (<? (exec
                 ["INSERT INTO idents VALUES (?, ?)" (->SQLite ident) entid]))))
-      db))
 
-  (<apply-db-install-assertions [db fragment]
+      (let [db (update db :ident-map #(merge-with merge % added-idents))
+            db (update db :ident-map #(merge-with merge % (clojure.set/map-invert added-idents)))]
+        db)))
+
+  (<apply-db-install-assertions [db fragment merge]
     (go-pair
       (let [->SQLite (get-in ds/value-type-map [:db.type/keyword :->SQLite]) ;; TODO: make this a protocol.
             exec     (partial s/execute! (:sqlite-connection db))]
@@ -250,7 +268,12 @@
           (doseq [[attr value] attr-map]
             (<? (exec
                   ["INSERT INTO schema VALUES (?, ?, ?)" (->SQLite ident) (->SQLite attr) (->SQLite value)])))))
-      db))
+
+      (let [symbolic-schema (merge-with merge (:symbolic-schema db) fragment)
+            schema          (ds/schema (into {} (map (fn [[k v]] [(entid db k) v]) symbolic-schema)))]
+        (assoc db
+               :symbolic-schema symbolic-schema
+               :schema schema))))
 
   (close-db [db] (s/close (.-sqlite-connection db)))
 
@@ -261,6 +284,23 @@
        :cljs
        (.getTime (js/Date.)))))
 
+(defn with-ident [db ident entid]
+  (update db :ident-map #(assoc % ident entid, entid ident)))
+
+(defn db [sqlite-connection idents schema current-tx]
+  {:pre [(map? idents)
+         (every? keyword? (keys idents))
+         (map? schema)
+         (every? keyword? (keys schema))]}
+  (let [entid-schema (ds/schema (into {} (map (fn [[k v]] [(k idents) v]) schema))) ;; TODO: fail if ident missing.
+        ident-map    (into idents (clojure.set/map-invert idents))]
+    (map->DB
+      {:sqlite-connection sqlite-connection
+       :ident-map         ident-map
+       :symbolic-schema   schema
+       :schema            entid-schema
+       :current-tx        current-tx})))
+
 ;; TODO: factor this into the overall design.
 (defn <?run
   "Execute the provided query on the provided DB.

src/datomish/db_factory.cljc

@@ -97,12 +97,7 @@
                                                (raise "Altering schema attributes is not yet supported, got " new " altering existing schema attribute " old
                                                       {:error :schema/alter-schema :old old :new new})
                                                new))]
-          (-> (db/map->DB
+          (-> (db/db sqlite-connection bootstrap/idents bootstrap/symbolic-schema current-tx)
-                {:sqlite-connection sqlite-connection
-                 :idents            bootstrap/idents
-                 :symbolic-schema   bootstrap/symbolic-schema
-                 :schema            (ds/schema (into {} (map (fn [[k v]] [(k bootstrap/idents) v]) bootstrap/symbolic-schema))) ;; TODO: fail if ident missing.
-                 :current-tx        current-tx})
               ;; We use <with-internal rather than <transact! to apply the bootstrap transaction
               ;; data but to not follow the regular schema application process.  We can't apply the
               ;; schema changes, since the applied datoms would conflict with the bootstrapping
@@ -127,9 +122,4 @@
                    {:error :bootstrap/bad-symbolic-schema,
                     :new symbolic-schema :old bootstrap/symbolic-schema
                     })))
-        (db/map->DB
+        (db/db sqlite-connection idents symbolic-schema (inc current-tx))))))
-          {:sqlite-connection sqlite-connection
-           :idents            idents
-           :symbolic-schema   symbolic-schema
-           :schema            (ds/schema (into {} (map (fn [[k v]] [(k idents) v]) symbolic-schema))) ;; TODO: fail if ident missing.
-           :current-tx        (inc current-tx)})))))

src/datomish/schema_changes.cljc

@@ -6,9 +6,6 @@
   (:require
    [datomish.util :as util #?(:cljs :refer-macros :clj :refer) [raise raise-str cond-let]]))
 
-(defn- is-install? [db [_ a & _]]
-  (= a (get-in db [:idents :db.install/attribute])))
-
 (defn datoms->schema-fragment
   "Turn [[:db.part/db :db.install/attribute e] [e :db/ident :attr]] into {:attr {:db/* v}}.
 

src/datomish/transact.cljc

@@ -106,11 +106,11 @@
     entity))
 
 (defn maybe-ident->entid [db [op e a v tx :as orig]]
-  (let [e (get (db/idents db) e e) ;; TODO: use ident, entid here.
+  (let [e (db/entid db e)
-        a (get (db/idents db) a a)
+        a (db/entid db a)
         v (if (ds/kw? (db/schema db) a) ;; TODO: decide if this is best.  We could also check for ref and numeric types.
             v
-            (get (db/idents db) v v))]
+            (db/entid db v))]
     [op e a v tx]))
 
 (defrecord Transaction [db tempids entities])
@@ -120,7 +120,7 @@
   (let [tx        (:tx report)
         txInstant (:txInstant report)]
     ;; n.b., this must not be symbolic -- it's inserted after we map idents -> entids.
-    [:db/add tx (get-in db [:idents :db/txInstant]) txInstant]))
+    [:db/add tx (db/entid db :db/txInstant) txInstant]))
 
 (defn ensure-entity-form [[op e a v & rest :as entity]]
   (cond
@@ -153,8 +153,8 @@
 
 (defn- tx-instant? [db [op e a & _]]
   (and (= op :db/add)
-       (= e (get-in db [:idents :db/tx]))
+       (= (db/entid db e) (db/entid db :db/tx))
-       (= a (get-in db [:idents :db/txInstant]))))
+       (= (db/entid db a) (db/entid db :db/txInstant))))
 
 (defn- update-txInstant [db report]
   "Extract [:db/add :db/tx :db/txInstant ...], and update :txInstant with that value."
@@ -175,7 +175,7 @@
         ;; to unify all id-literals in :db.part/tx to the current transaction value, but also seems
         ;; inconsistent.
         tx         (:tx report)
-        db*        (assoc-in db [:idents :db/tx] tx)]
+        db*        (db/with-ident db :db/tx tx)]
     (when-not (sequential? initial-es)
       (raise "Bad transaction data " initial-es ", expected sequential collection"
              {:error :transact/syntax, :tx-data initial-es}))
@@ -453,7 +453,7 @@
 ;; Upsert or allocate id-literals.
 
 (defn- is-ident? [db [_ a & _]]
-  (= a (get-in db [:idents :db/ident])))
+  (= a (db/entid db :db/ident)))
 
 (defn collect-db-ident-assertions
   "Transactions may add idents, install new partitions, and install new schema attributes.
@@ -486,15 +486,13 @@
                      {:error :schema/idents
                       :op    ia }))))))))
 
-(defn- symbolicate-datom [db [e a v added]]
+(defn- symbolicate-datom [db [e a v tx added]]
-  (let [entids (zipmap (vals (db/idents db)) (keys (db/idents db)))
-        symbolicate (fn [x]
-                      (get entids x x))]
   (datom
-      (symbolicate e)
+    (db/ident db e)
-      (symbolicate a)
+    (db/ident db a)
-      (symbolicate v)
+    (db/ident db v)
-      added)))
+    tx
+    added))
 
 (defn collect-db-install-assertions
   "Transactions may add idents, install new partitions, and install new schema attributes.
@@ -534,26 +532,18 @@
                    (collect-db-ident-assertions db)
 
                    (collect-db-install-assertions db))
-          idents          (merge-with merge-ident (:idents db) (:added-idents report))
-          symbolic-schema (merge-with merge-attr (:symbolic-schema db) (:added-attributes report))
-          schema          (ds/schema (into {} (map (fn [[k v]] [(k idents) v]) symbolic-schema)))
           db-after        (->
                             db
 
                             (db/<apply-datoms (:tx-data report))
                             (<?)
 
-                            (db/<apply-db-ident-assertions (:added-idents report))
+                            (db/<apply-db-ident-assertions (:added-idents report) merge-ident)
                             (<?)
 
-                            (db/<apply-db-install-assertions (:added-attributes report))
+                            (db/<apply-db-install-assertions (:added-attributes report) merge-attr)
                             (<?)
 
-                            ;; TODO: abstract this.
-                            (assoc :idents idents
-                                   :symbolic-schema symbolic-schema
-                                   :schema schema)
-
                             (db/<advance-tx)
                             (<?))]
       (-> report

src/datomish/transact/explode.cljc

@@ -34,14 +34,14 @@
 (declare explode-entity)
 
 (defn- explode-entity-a-v [db entity eid a v]
-  ;; a should be symbolic at this point.  Map it.  TODO: use ident/entid to ensure we have a symbolic attr.
+  (let [a           (db/ident db a) ;; We expect a to be an ident, but it's legal to provide an entid.
-  (let [reverse?    (reverse-ref? a)
+        a*          (db/entid db a)
+        reverse?    (reverse-ref? a)
         straight-a  (if reverse? (reverse-ref a) a)
-        straight-a* (get-in db [:idents straight-a] straight-a)
+        straight-a* (db/entid db straight-a)
         _           (when (and reverse? (not (ds/ref? (db/schema db) straight-a*)))
                       (raise "Bad attribute " a ": reverse attribute name requires {:db/valueType :db.type/ref} in schema"
-                             {:error :transact/syntax, :attribute a, :op entity}))
+                             {:error :transact/syntax, :attribute a, :op entity}))]
-        a*          (get-in db [:idents a] a)]
     (cond
       reverse?
       (explode-entity-a-v db entity v straight-a eid)

test/datomish/api.cljc

@@ -33,3 +33,7 @@
 (def id-literal db/id-literal)
 
 (def db transact/db)
+
+(def entid db/entid)
+
+(def ident db/ident)

test/datomish/db_test.cljc

@@ -14,7 +14,6 @@
    [datomish.sqlite :as s]
    [datomish.sqlite-schema]
    [datomish.datom]
-   [datomish.db :as db]
    #?@(:clj [[datomish.pair-chan :refer [go-pair <?]]
              [tempfile.core :refer [tempfile with-tempfile]]
              [datomish.test-macros :refer [deftest-async]]
@@ -37,35 +36,32 @@
   (into {} (map (juxt (comp :idx first) second) (:tempids tx))))
 
 (defn- <datoms-after [db tx]
-  (let [entids (zipmap (vals (db/idents db)) (keys (db/idents db)))]
   (go-pair
     (->>
       (s/all-rows (:sqlite-connection db) ["SELECT e, a, v, tx FROM datoms WHERE tx > ?" tx])
       (<?)
-        (mapv #(vector (:e %) (get entids (:a %) (str "fail" (:a %))) (:v %)))
+      (mapv #(vector (:e %) (d/ident db (:a %)) (:v %)))
       (filter #(not (= :db/txInstant (second %))))
-        (set)))))
+      (set))))
 
 (defn- <datoms [db]
   (<datoms-after db 0))
 
 (defn- <shallow-entity [db eid]
   ;; TODO: make this actually be <entity.  Handle :db.cardinality/many and :db/isComponent.
-  (let [entids (zipmap (vals (db/idents db)) (keys (db/idents db)))]
   (go-pair
     (->>
       (s/all-rows (:sqlite-connection db) ["SELECT a, v FROM datoms WHERE e = ?" eid])
       (<?)
-        (mapv #(vector (entids (:a %)) (:v %)))
+      (mapv #(vector (d/ident db (:a %)) (:v %)))
-        (reduce conj {})))))
+      (reduce conj {}))))
 
 (defn- <transactions-after [db tx]
-  (let [entids (zipmap (vals (db/idents db)) (keys (db/idents db)))]
   (go-pair
     (->>
       (s/all-rows (:sqlite-connection db) ["SELECT e, a, v, tx, added FROM transactions WHERE tx > ? ORDER BY tx ASC, e, a, v, added" tx])
       (<?)
-        (mapv #(vector (:e %) (entids (:a %)) (:v %) (:tx %) (:added %)))))))
+      (mapv #(vector (:e %) (d/ident db (:a %)) (:v %) (:tx %) (:added %))))))
 
 (defn- <transactions [db]
   (<transactions-after db 0))
@@ -381,10 +377,12 @@
   (with-tempfile [t (tempfile)]
     (let [conn (<? (d/<connect t))]
       (try
+        (is (= :test/ident (d/entid (d/db conn) :test/ident)))
+
         (let [report   (<? (d/<transact! conn [[:db/add (d/id-literal :db.part/db -1) :db/ident :test/ident]]))
-              db-after (:db-after report)
+              eid      (get-in report [:tempids (d/id-literal :db.part/db -1)])]
-              tx       (:tx db-after)]
+          (is (= eid (d/entid (d/db conn) :test/ident)))
-          (is (= (:test/ident (db/idents db-after)) (get-in report [:tempids (d/id-literal :db.part/db -1)]))))
+          (is (= :test/ident (d/ident (d/db conn) eid))))
 
         ;; TODO: This should fail, but doesn't, due to stringification of :test/ident.
         ;; (is (thrown-with-msg?
@@ -417,7 +415,7 @@
               tx       (:tx db-after)]
 
           (testing "New ident is allocated"
-            (is (some? (get-in db-after [:idents :test/attr]))))
+            (is (some? (d/entid db-after :test/attr))))
 
           (testing "Schema is modified"
             (is (= (get-in db-after [:symbolic-schema :test/attr])