Capped collections support

src/monger/collection.clj

@@ -204,7 +204,7 @@
      (check-not-nil! id "id must not be nil")
      (from-db-object ^DBObject (find-one-as-map collection { :_id id }) true))
   ([^String collection id fields]
-     (check-not-nil! id "id must not be nil")  
+     (check-not-nil! id "id must not be nil")
      (from-db-object ^DBObject (find-one-as-map collection { :_id id } fields) true))
   ([^String collection id fields keywordize]
      (check-not-nil! id "id must not be nil")
@@ -546,3 +546,14 @@
   ([^DB db ^String collection ^String key ^Map query]
      (let [^DBCollection coll (.getCollection db collection)]
        (.distinct coll ^String (to-db-object key) ^DBObject (to-db-object query)))))
+
+
+;;
+;; create/capped collections
+;;
+
+(defn create
+  "Creates a collection. Options are: :capped (pass true to create a capped collection), :max (number of documents)
+   and :size (max allowed size of the collection, in bytes)."
+  [^String name options]
+  (.createCollection ^DB monger.core/*mongodb-database* name (to-db-object options)))

test/monger/test/capped_collections_test.clj

@@ -0,0 +1,38 @@
+(set! *warn-on-reflection* true)
+
+(ns monger.test.capped-collections-test
+  (:require [monger core util]
+            [monger.collection  :as mc]
+            [monger.result      :as mres]
+            [monger.test.helper :as helper])
+  (:use clojure.test
+        monger.operators
+        monger.test.fixtures))
+
+
+(helper/connect!)
+
+(use-fixtures :each purge-cached)
+
+(defn- megabytes
+  [^long n]
+  (* n 1024 1024))
+
+
+;;
+;; Tests
+;;
+
+(deftest test-inserting-into-capped-collection
+  (let [n     1000
+        cname "cached"
+        _     (mc/drop cname)
+        coll  (mc/create cname {:capped true :size (-> 16 megabytes) :max n})]
+    (is (= cname (.getName coll)))
+    (mc/insert-batch cname (for [i (range 0 (+ n 100))] {:i i}))
+    (is (= n (mc/count cname)))
+    ;; older elements get replaced by newer ones
+    (is (not (mc/any? cname {:i 1})))
+    (is (not (mc/any? cname {:i 5})))
+    (is (not (mc/any? cname {:i 9})))
+    (is (mc/any? cname {:i (+ n 80)}))))

test/monger/test/fixtures.clj

@@ -15,3 +15,5 @@
 (defcleaner domains   "domains")
 (defcleaner pages     "pages")
 
+(defcleaner cached    "cached")
+