monger/src/monger/core.clj

202 lines
7.3 KiB
Clojure

;; Copyright (c) 2011-2012 Michael S. Klishin
;;
;; The use and distribution terms for this software are covered by the
;; Eclipse Public License 1.0 (http://opensource.org/licenses/eclipse-1.0.php)
;; which can be found in the file epl-v10.html at the root of this distribution.
;; By using this software in any fashion, you are agreeing to be bound by
;; the terms of this license.
;; You must not remove this notice, or any other, from this software.
(ns ^{:author "Michael S. Klishin"
:doc "Thin idiomatic wrapper around MongoDB Java client. monger.core includes
fundamental functions that work with connections & databases. Most of functionality
is in the monger.collection namespace."}
monger.core
(:refer-clojure :exclude [count])
(:use [monger.conversion])
(:import [com.mongodb Mongo DB WriteConcern DBObject DBCursor CommandResult]
[com.mongodb.gridfs GridFS]
[java.util Map]))
;;
;; Defaults
;;
(def ^:dynamic ^String *mongodb-host* "localhost")
(def ^:dynamic ^long *mongodb-port* 27017)
(declare ^:dynamic ^Mongo *mongodb-connection*)
(declare ^:dynamic ^DB *mongodb-database*)
(def ^:dynamic ^WriteConcern *mongodb-write-concern* WriteConcern/SAFE)
(declare ^:dynamic ^GridFS *mongodb-gridfs*)
;;
;; API
;;
(defn ^Mongo connect
"Connects to MongoDB. When used without arguments, connects to
Arguments:
:host (*mongodb-host* by default)
:port (*mongodb-port* by default)
EXAMPLES
(monger.core/connect)
(monger.core/connect { :host \"db3.intranet.local\", :port 27787 })
"
([]
(Mongo.))
([{ :keys [host port] :or { host *mongodb-host*, port *mongodb-port* }}]
(Mongo. ^String host ^Long port)))
(defn ^DB get-db
"Get database reference by name.
EXAMPLES
(monger.core/get-db \"myapp_production\")
(monger.core/get-db connection \"myapp_production\")"
([^String name]
(.getDB *mongodb-connection* name))
([^Mongo connection, ^String name]
(.getDB connection name)))
(defn authenticate
([^String db ^String username ^chars password]
(authenticate *mongodb-connection* db username password))
([^Mongo connection ^String db ^String username ^chars password]
(.authenticate (.getDB connection db) username password)))
(defmacro with-connection
[conn & body]
`(binding [*mongodb-connection* ~conn]
(do ~@body)))
(defmacro with-db
[db & body]
`(binding [*mongodb-database* ~db]
(do ~@body)))
(defmacro with-gridfs
[fs & body]
`(binding [*mongodb-gridfs* ~fs]
(do ~@body)))
(defn connect!
"Connect to MongoDB, store connection in the *mongodb-connection* var"
^Mongo [& args]
(def ^:dynamic *mongodb-connection* (apply connect args)))
(defn set-db!
"Sets *mongodb-database* var to given db, updates *mongodb-gridfs* var state. Recommended to be used for
applications that only use one database."
[db]
(def ^:dynamic *mongodb-database* db)
(def ^:dynamic *mongodb-gridfs* (GridFS. db)))
(defn set-default-write-concern!
[wc]
"Set *mongodb-write-concert* var to :wc
Unlike the official Java driver, Monger uses WriteConcern/SAFE by default. We think defaults should be safe first
and WebScale fast second."
(def ^:dynamic *mongodb-write-concern* wc))
(defn ^CommandResult command
"Runs a database command (please check MongoDB documentation for the complete list of commands). Some common commands
are:
{ :buildinfo 1 } returns version number and build information about the current MongoDB server, should be executed via admin DB.
{ :collstats collection-name [ :scale scale ] } returns stats about given collection.
{ :dbStats 1 } returns the stats of current database
{ :dropDatabase 1 } deletes the current database
{ :findAndModify find-and-modify-config } runs find, modify and return for the given query.
Takes :query, :sory, :remove, :update, :new, :fields and :upsert arguments.
Please refer MongoDB documentation for details. http://www.mongodb.org/display/DOCS/findAndModify+Command
{ :fsync config } performs a full fsync, that flushes all pending writes to database, provides an optional write lock that will make
backups easier.
Please refer MongoDB documentation for details :http://www.mongodb.org/display/DOCS/fsync+Command
{ :getLastError 1 } returns the status of the last operation on current connection.
{ :group group-config } performs grouping aggregation, docs and support for grouping are TBD in Monger.
{ :listCommands 1 } displays the list of available commands.
{ :profile new-profile-level } sets the database profiler to profile level N.
{ :reIndex coll } performs re-index on a given collection.
{ :renameCollection old-name :to new-name } renames collection from old-name to new-name
{ :repairDatabase 1 } repair and compact the current database (may be very time-consuming, depending on DB size)
Replica set commands
{ :isMaster 1 } checks if this server is a master server.
{ :replSetGetStatus 1 } get the status of a replica set.
{ :replSetInitiate replica-config } initiate a replica set with given config.
{ :replSetReconfig replica-config } set a given config for replica set.
{ :replSetStepDown seconds } manually tell a member to step down as primary. It will become primary again after specified amount of seconds.
{ :replSetFreeze seconds } freeze state of member, call with 0 to unfreeze.
{ :resync 1 } start a full resync of a replica slave
For more information, please refer Mongodb Replica Set Command guide: http://www.mongodb.org/display/DOCS/Replica+Set+Commands
{ :serverStatus 1 } gets administrative statistics about the server.
{ :shutdown 1 } shuts the MongoDB server down.
{ :top 1 } get a breakdown of usage by collection.
{ :validate namespace-name } validate the namespace (collection or index). May be very time-consuming, depending on DB size.
For :distinct, :count, :drop, :dropIndexes, :mapReduce we suggest to use monger/collection #distinct, #count, #drop, #dropIndexes, :mapReduce respectively.
"
([^Map cmd]
(.command ^DB *mongodb-database* ^DBObject (to-db-object cmd)))
([^DB database ^Map cmd]
(.command ^DB database ^DBObject (to-db-object cmd)))
)
(defprotocol Countable
(count [this] "Returns size of the object"))
(extend-protocol Countable
DBCursor
(count [^DBCursor this]
(.count this)))
(defn ^DBObject get-last-error
"Returns the the error (if there is one) from the previous operation on this connection.
The result of this command looks like:
#<CommandResult { \"serverUsed\" : \"127.0.0.1:27017\" , \"n\" : 0 , \"connectionId\" : 66 , \"err\" : null , \"ok\" : 1.0}>\"
The value for err will be null if no error occurred, or a description otherwise.
Important note: when calling this method directly, it is undefined which connection \"getLastError\" is called on.
You may need to explicitly use a \"consistent Request\", see requestStart() For most purposes it is better not to call this method directly but instead use WriteConcern."
([]
(.getLastError ^DB *mongodb-database*))
([^DB database]
(.getLastError ^DB database))
([^DB database ^Integer w ^Integer wtimeout ^Boolean fsync]
(.getLastError ^DB database w wtimeout fsync))
([^DB database ^WriteConcern write-concern]
(.getLastError ^DB database write-concern)))