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Handy protocols for working with Datomic
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| ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; | |
| ;;; Connection | |
| (defprotocol DatomicConnection | |
| (as-conn [_])) | |
| (extend-protocol DatomicConnection | |
| datomic.Connection | |
| (as-conn [c] c) | |
| datomic.db.Db | |
| (as-conn ([db] (-> db :id str as-conn))) | |
| java.lang.String | |
| (as-conn [db-uri] (d/connect db-uri))) | |
| ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; | |
| ;;; Transaction Log | |
| (defprotocol DatomicTransactionLog | |
| (as-tx-log [_])) | |
| (extend-protocol DatomicTransactionLog | |
| datomic.Connection | |
| (as-tx-log [c] (d/log c)) | |
| datomic.db.Db | |
| (as-tx-log [db] (-> db as-conn as-tx-log)) | |
| java.lang.String | |
| (as-tx-log [s] (-> s as-conn as-tx-log))) | |
| ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; | |
| ;;; Database | |
| (defprotocol DatabaseReference | |
| (as-db [_] [_ _])) | |
| (def sync-timeout-ms (* 10 1000)) | |
| (extend-protocol DatabaseReference | |
| datomic.db.Db | |
| (as-db | |
| ([db] db)) | |
| datomic.Connection | |
| (as-db | |
| ([conn] (d/db conn)) | |
| ([conn t] (let [db-value-or-timeout (-> (d/sync conn t) | |
| (deref sync-timeout-ms :timeout))] | |
| (cond | |
| (= (type db-value-or-timeout) datomic.db.Db) | |
| db-value-or-timeout | |
| (= db-value-or-timeout :timeout) | |
| (throw | |
| (ex-info "Datomic timed out during sync attempt." | |
| {:waited-ms sync-timeout-ms})) | |
| :else | |
| (throw | |
| (ex-info "An unknown error occured while Datomic was trying to sync." | |
| {})))))) | |
| java.lang.String | |
| (as-db | |
| ([db-uri] (as-db (as-conn db-uri))) | |
| ([db-uri t] (as-db (as-conn db-uri) t)))) | |
| ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; | |
| ;;; Entity | |
| (defprotocol EntityReference | |
| (id [_]) | |
| (entity [_ db])) | |
| (extend-protocol EntityReference | |
| datomic.query.EntityMap | |
| (id [e] (:db/id e)) | |
| (entity [e db] e) | |
| java.lang.Long | |
| (id [id] id) | |
| (entity [id db] (d/entity (as-db db) id)) | |
| ;; these two are for working with maps composed for a transaction | |
| clojure.lang.PersistentArrayMap | |
| (id [m] (:db/id m)) | |
| (entity [m db] (entity (id m) (as-db db))) | |
| clojure.lang.PersistentHashMap | |
| (id [m] (:db/id m)) | |
| (entity [m db] (entity (id m) (as-db db))) | |
| ;; nice for when working with the output of d/datoms and d/seek-datoms | |
| datomic.db.Datum | |
| (id [[e]] e) | |
| (entity [[e] db] (entity e (as-db db))) | |
| ;; nice for reaching schema or enum entities quickly, | |
| ;; however doesn't return a numeral for id like the rest do | |
| clojure.lang.Keyword | |
| (id [kw] kw) | |
| (entity [kw db] (let [db (as-db db)] | |
| (entity (d/entid db kw) (as-db db)))) | |
| ;; these two are when you have a naked entity (or schema entity) id | |
| java.lang.Long | |
| (id [id] id) | |
| (entity [id db] (d/entity (as-db db) id)) | |
| java.lang.Integer | |
| (id [id] id) | |
| (entity [id db] (d/entity (as-db db) id)) | |
| ;; lookup refs. doesn't work with id, because we don't get the db there. | |
| clojure.lang.PersistentVector | |
| (id [lookup] (throw "Can't infer id for lookup.")) | |
| (entity [lookup db] (d/entity (as-db db) lookup))) |
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