Try Couchbase

Couchbase (카우치베이스 NoSQL서버)를 클로저에서 사용하기 위한 Wrapper입니다.
http://docs.couchbase.com/sdk-api/couchbase-java-client-2.4.2/

Usage

(:require [try-cb-clj.core :refer :all])

1. Connect to server

connect to localhost

(def cluster (connect "couchbase://localhost"))

connect to multiple server

(def cluster (connect "couchbase://10.1.1.1,10.1.1.2"))

2. open bucket

(def bucket (open-bucket cluster "myblog"))

open bucket with password

(def bucket (open-bucket cluster "myblog" "your password"))

3. Manuplate Document

Insert

insert map

;; blog-id is document id that must be a unique name from your bucket
;; if omit document id then uuid will be used instead of
(insert! bucket "blog-id" {:title "Hello first blogging!"
                           :content "Hi there bla bla bla..."
                           :create_on (java.util.Date.)})

and returns values
it has always id, cas, value

{:value  {:title "Hello first blogging!"
          :content "Hi there bla bla bla..."
          :create_on 149409102932}
 :id "blog-id"
 :cas 12309203920}

insert array

(insert! bucket "items" [ 1 2 3 4 5])

getting a document

with document id can get a document,
if document not found you get a nill

(get! "blog-id")

do not want to dealing with nil?
you can find out

(.exists bucket "abcd")
true

if document found
and returns

{:value  {:title "Hello first blogging!"
          :content "Hi there bla bla bla..."
          :create_on 149409102932}
 :id "blog-id"
 :cas 12309203920}

also supports lock

;;5secs (max: 30 secs)
(get! bucket "hello-world" {:locktime 5})
(upsert! bucket "hello-world" {:operated-by "daehee"})

;;OnNextValue 
;;OnError while
;;emitting onNext value:
;;com.couchbase.client.core.message.kv.UpsertResponse.class 
;;rx.exceptions.OnErrorThrowable.addValueAsLastCause (OnErrorThrowable.java:118)

document like array or long types
you must use get-as-[type]
for example

(get-as-array bucket "items")

(get-as-long bucket "order::id")

;;or
(get! bucket "items" {:as :array})

(get! bucket "order::id" {:as :long})

Upsert/Replace

(upsert! bucket "abcd" {:items [1 2 3 4 5]})

(replace! bucket "abcd" {})

Remove

return true or false

(remove! bucket "abcd")

4. Atomic operation

creating counter

;; create counter
(counter bucket "order::id" 1 1)

how to start counter from init value

couter will start from 10

(counter bucket "user:id" 0 10)

and increment by 1

(counter bucket "user:id" 1)

and returns

{:value 1
 :id "order::id"
 :cas 12323232 }

get counter

(get-as-long bucket "order::id")
;; or
(get! bucket "order::id" {:as :long})

5. Query

simple query

(query bucket ["select * from myblog"])

also supports parameters

(query bucket ["select * from myblog where user_id=$1 and email=$2" "abc" "clonekim@gmail.com"])

(query bucket ["select * from myblog where user_id=$user_id and age=$age"  {:user-id "abc" :age 12}])

query returns

({:myblog  {:name "kim"}}
           {:myblog  {:name "kim", :email "clonekim@gmail.com"}}
           {:myblog  {:user_id "user::1", :name "kim", :gender "male"}})

support metrics

it's very helpfull to pagination

(query bucket ["select * from myblog"] {:with-metrics true})

and returns with metrics

{:requestId "2dbaae07-0877-45de-89b5-8a2b334921c6",
  :errors [],
  :status "success",
  :metrics {:executionTime "26.509444ms",
             :resultCount 13,
             :sortCount 3,
             :resultSize 583,
             :elapsedTime "26.536883ms"},
 :results ({:myblog  {:name "kim"}}
           {:myblog  {:name "kim", :email "clonekim@gmail.com"}}
           {:myblog  {:user_id "user::1", :name "kim", :gender "male"}})}

Setting Durability

https://developer.couchbase.com/documentation/server/4.0/developer-guide/durability.html

(set-default-durability {:persis-to :ONE
                         :replicate-to :NONE
                         :scan-consistency :REQUEST_PLUS})

Async Bucket

single! or first! , last!
you feel async query is much like sync operation

(defn user-add [doc]
  (async-bucket [bc bucket]
    (-> (counter bc "user::id" 1 1)
      (to-map)
      (to-flat (fn [id]
                 (let [user-id (str "user::" id)]
                   (insert! bc user-id (assoc doc :user_id user-id)))))
      (single!))))`

(user-add {:name "kim" :gender "male"})

and returns

{:value {:user_id "user::1"
         :name "kim"
         :gender "male"}
 :cas "1479118072773672960"
 :id "user::1"}

you can run async query to be blocked explicitly
use param {:block true}

(let [result (async-bucket [bc bucket]
              (-> (query bc ["select * from users limit 1"] {:block true})))]

   (println result))

can also

(let [result (async-bucket [bc bucket]
              (-> (query bc ["select * from users limit 1"])
                  (to-map)
                  (to-flat (fn [x]
                           ;; your code here))]

   (println result)) ;; rx.Observable

conditional performs insert or get

(async-bucket [bc bucket]
  (-> (.exists bc "blog12")
      (to-flat (fn [found]
                (if-not found
                   (insert! bc "blog12" {:test "ok"})
	               (get! bc "blog12"))))
      (single!)))

License

Copyright © 2016 FIXME

Distributed under the Eclipse Public License either version 1.0 or (at your option) any later version.