/rxdb-1

Simple Key-Value in memory DB

Primary LanguageErlang

RxDB Databae Server

=====================

Welcome to the RxDB Database Server source code tree! RxDB is simple Key-Value store. It's supports basic Key Value operations via wellknown protocols, and something more.

Build and run

$ git clone git@github.com:dvarkin/rxdb.git

$ cd rxdb

$ make

$ make tests

$ make run

Generate souce code Docs

Edocs available in Markup format. To generate source code documenation type in shell:

  $ make edoc

By default RxDB aquire 3 ports:

  • 8080 for HTTP/REST

  • 4444 for UDP

  • 5555 for TCP

TODO: Move port configuration to .config file

Protocol Overview

RxDB binary protocol is JSON based.

Actions

You can send commands to RxDB via TCP/UDP protocols or use HTTP/REST.

GET

Get uniqe key from store:

  {
  "action": "get", "key": "myKey"
  }

PUT

Put unique key and value to store. If key is already exists in the store, it will be replaced with new value.

  {
  "action": "put", "key": "myKey", "value": "newValue"
  }

PUT with expire

Put key and value to store with expire in seconds. You can get this key after expiration.

  {
  "action": "put", "key": "myKey", "value": "newValue", "expire": 5
  }

DEL

Delete key from store

  {
  "action": "del", "key": "myKey"
  }

SUB (TCP only)

Subscribe to changes of particular key.

  {
  "action": "sub", "key": "myKey"
  }

UNSUB (TCP only)

Unsubscribe to changes of particular key

  {
  "action": "unsub", "key": "myKey"
  }

HTTP/Rest Protocol

RxDB supports Swagger notation for API. Swagger documentation and REST demo available on http://localhost:8080/api-docs/index.html.

Get Key

curl -X GET --header "Accept: text/plain" "http://localhost:8080/rest/MyKey"

Put Key and Value

curl -X PUT --header "Content-Type: text/plain" --header "Accept: text/plain" -d "KeyValueExample" "http://localhost:8080/rest/MyKey"

Put Key and Value with expiration.

Expiration is an optional argument.

curl -X PUT --header "Content-Type: application/json" --header "Accept: text/plain" -d "asd" "http://localhost:8080/rest/a?expire=5"

Delete Key

curl -X DELETE --header "Accept: text/plain" "http://localhost:8080/rest/MyKey"

UDP Protocol

For test propouses, RxDB contain simple UDP client. You can try to play with RxDB via test UDP client:

Get Key

(rxdb@127.0.0.1)1> rxdb_raw_client:udp(<<"{"key":"a","action":"get"}">>). <<"[]">>

Put Key

(rxdb@127.0.0.1)2> rxdb_raw_client:udp(<<"{\"value\":\"Val\",\"key\":\"a\",\"action\":\"put\"}">>).
<<"\"ok\"">>

Put with expiration

(rxdb@127.0.0.1)2> rxdb_raw_client:udp(<<"{\"expire\":1,\"value\":\"Val\",\"key\":\"a\",\"action\":\"put\"}">>).

Delete Key

(rxdb@127.0.0.1)4> rxdb_raw_client:udp(<<"{\"key\":\"a\",\"action\":\"del\"}">>).
<<"\"ok\"">>

TCP Protocol

You can try to insert Rx commands via telnet:

Put Key

$ telnet 127.0.0.1 5555
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
 

{"action":"put","key":"MyKey","value":"MyValue"}
"ok"

Get Key

Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
{"action":"get","key":"MyKey"}
{"value":"MyValue","key":"MyKey"}

Subscribtion

RxDB supports receiving updates of current Key via subscribtions.

Subscribtions supprots only with TCP protocol

Connected to localhost.
Escape character is '^]'.
{"action":"sub","key":"MyKey"}
"ok"

Now you can open another terminal, and Update "MyKey" value.

$ telnet localhost 5555
Trying ::1...
telnet: connect to address ::1: Connection refused
Trying 127.0.0.1...
Connected to localhost.
Escape character is '^]'.
{"action":"put","key":"MyKey","value":"Receive via subscribtion"}
"ok"

In first terminal you will get:

{"value":"Receive via subscribtion","key":"MyKey","action":"upd"}

And now you can unsubscribe:

{"action":"unsub","key":"MyKey"}
"ok"

TODO: monitor TCP sockets, and cleaning subscribtion table from dead ports.