# Introduction

This subdirectory provides implementation for the commands which are implemented
as a [Redis modules](https://redis.io/topics/modules-intro).

# Commands

## SETIE key value oldvalue [expiration EX seconds|PX milliseconds]

Time complexity: O(1) + O(1)

Checks a String 'key' for 'oldvalue' equality and set key for 'value' with
optional expired.

```
Example:

redis> get mykey
(nil)
redis> setie mykey "Hello again" "Hello"
(nil)

redis> set mykey "Hello"
OK
redis> get mykey
"Hello"
redis> setie mykey "Hello again" "Hello"
"OK"
redis> get mykey
"Hello again"
redis> setie mykey "Hello 2" "Hello"
(nil)
redis> get mykey
"Hello again"
redis> setie mykey "Hello 2" "Hello again" ex 100
"OK"
redis> ttl mykey
(integer) 96
redis> get mykey
"Hello 2"
```

## SETNE key value oldvalue [expiration EX seconds|PX milliseconds]

Time complexity: O(1) + O(1)

Checks a String 'key' for 'oldvalue' not equality and set key for 'value' with optional expired.

Example:

```
redis> get mykey
(nil)
redis> setne mykey "Hello again" "Hello"
"OK"
redis> get mykey
"Hello again"
redis> setne mykey "Hello 2" "Hello again"
(nil)
redis> setne mykey "Hello 2" "Hello"
"OK"
redis> get mykey
"Hello 2"
redis> setne mykey "Hello 3" "Hello" ex 100
"OK"
redis> get mykey
"Hello 3"
redis> ttl mykey
(integer) 93
```

## DELIE key oldvalue

Time complexity: O(1) + O(1)

Checks a String 'key' for 'oldvalue' equality and delete the key.

```
Example:
redis> get mykey
(nil)
redis> set mykey "Hello"
"OK"
redis> get mykey
"Hello"
redis> delie mykey "Hello again"
(integer) 0
redis> get mykey
"Hello"
redis> delie mykey "Hello"
(integer) 1
redis> get mykey
(nil)
```

## DELNE key oldvalue

Time complexity: O(1) + O(1)

Checks a String 'key' for 'oldvalue' not equality and delete the key.

```
Example:
redis> get mykey
(nil)
redis> set mykey "Hello"
"OK"
redis> get mykey
"Hello"
redis> delne mykey "Hello"
(integer) 0
redis> get mykey
"Hello"
redis> delne mykey "Hello again"
(integer) 1
redis> get mykey
(nil)
```

## MSETPUB key value [key value...] channel message

Time complexity: O(N) where N is the number of keys to set + O(N+M) where N is the number of clients subscribed to the receiving channel and M is the total number of subscribed patterns (by any client)

Set the given keys to their respective values and post a message to the given channel

## SETXXPUB key value channel message

Time complexity: O(1) + O(1) + O(N+M) where N is the number of clients subscribed to the receiving channel and M is the total number of subscribed patterns (by any client)

Set key to hold string value if key already exist and post a message to the given channel if set key value successfully

## SETNXPUB key value channel message

Time complexity: O(1) + O(1) + O(N+M) where N is the number of clients subscribed to the receiving channel and M is the total number of subscribed patterns (by any client)

Set key to hold string value if key does not exist and post a message to the given channel if set key value successfully

## SETIEPUB key value oldvalue channel message

Time complexity: O(1) + O(1) + O(1) + O(N+M) where N is the number of clients subscribed to the receiving channel and M is the total number of subscribed patterns (by any client)

Checks a String 'key' for 'oldvalue' equality and set key for 'value'  and post a message to the given channel if set key value successfully

## SETNEPUB key value oldvalue channel message

Time complexity: O(1) + O(1) + O(1) + O(N+M) where N is the number of clients subscribed to the receiving channel and M is the total number of subscribed patterns (by any client)

Checks a String 'key' for 'oldvalue' not equality and set key for 'value'  and post a message to the given channel if set key value successfully

## DELPUB key [key...] channel message

Time complexity: O(N) where N is the number of keys that will be removed + O(N+M) where N is the number of clients subscribed to the receiving channel and M is the total number of subscribed patterns (by any client)

Removes the specified keys and post a message to the given channel if delete key successfully(return >0)

## DELIEPUB key oldvalue channel message

ime complexity: O(1) + O(1) + O(1) + O(N+M) where N is the number of clients subscribed to the receiving channel and M is the total number of subscribed patterns (by any client)

Checks a String 'key' for 'oldvalue' equality and delete the key and post a message to the given channel if delete key successfully(return 1)

## DELNEPUB key oldvalue channel message

Time complexity: O(1) + O(1) + O(1) + O(N+M) where N is the number of clients subscribed to the receiving channel and M is the total number of subscribed patterns (by any client)

Checks a String 'key' for 'oldvalue' not equality and delete the key and post a message to the given channel if delete key successfully(return 1)

## NGET pattern

Time complexity: O(N) with N being the number of keys in the instance + O(N) where N is the number of keys to retrieve

Returns all key-value pairs matching pattern.

```
example:

redis> nget mykey*
(empty list or set)

redis> set mykey1 "myvalue1"
OK
redis> set mykey2 "myvalue2"
OK
redis> set mykey3 "myvalue3"
OK
redis> set mykey4 "myvalue4"
OK
redis> nget mykey*
1) "mykey2"
2) "myvalue2"
3) "mykey1"
4) "myvalue1"
5) "mykey4"
6) "myvalue4"
7) "mykey3"
8) "myvalue3"
```

## NDEL pattern

Time complexity: O(N) with N being the number of keys in the instance + O(N) where N is the number of keys that will be removed

Remove all key-value pairs matching pattern.

```
example:

redis> nget mykey*
1) "mykey2"
2) "myvalue2"
3) "mykey1"
4) "myvalue1"
5) "mykey4"
6) "myvalue4"
7) "mykey3"
8) "myvalue3"

redis> ndel mykey*
(integer) 4

redis> ndel mykey*
(integer) 0
```