armanayvazyan / redisserver

Redis implementation with Java

Implementation of redis server with Java

---

Description

Project was done for learning purposes, feel free for contribution

---

Command List

SET key value

Set key to hold the string value. If key already holds a value, it is overwritten, regardless of its type. Any previous time to live associated with the key is discarded on successful SET operation.

SETNX key value

Set key to hold string value if key does not exist. In that case, it is equal to SET. When key already holds a value, no operation is performed. SETNX is short for "SET if Not eXists".

SETEX key value

Set key to hold the string value and set key to timeout after a given number of seconds. This command is equivalent to executing the following commands:

MSET key value [key value...]

Sets the given keys to their respective values. MSET replaces existing values with new values, just as regular SET. See MSETNX if you don't want to overwrite existing values.

GET key

Get the value of key. If the key does not exist the special value nil is returned. An error is returned if the value stored at key is not a string, because GET only handles string values.

MGET key [key...]

Returns the values of all specified keys. For every key that does not hold a string value or does not exist, the special value nil is returned. Because of this, the operation never fails.

---

LPUSH key value [value...]

Insert all the specified values at the head of the list stored at key. If key does not exist, it is created as empty list before performing the push operations. When key holds a value that is not a list, an error is returned

RPUSH key value [value...]

Insert all the specified values at the tail of the list stored at key. If key does not exist, it is created as empty list before performing the push operation. When key holds a value that is not a list, an error is returned.

LRANGE key start end

Returns the specified elements of the list stored at key. The offsets start and stop are zero-based indexes, with 0 being the first element of the list (the head of the list), 1 being the next element and so on.

These offsets can also be negative numbers indicating offsets starting at the end of the list.

---

ZADD key score value [score value...]

Adds all the specified members with the specified scores to the sorted set stored at key. It is possible to specify multiple score / member pairs. If a specified member is already a member of the sorted set, the score is updated and the element reinserted at the right position to ensure the correct ordering.

ZPOPMAX key

Removes and returns up to count members with the highest scores in the sorted set stored at key.

ZPOPMIN key

Removes and returns up to count members with the lowest scores in the sorted set stored at key.

ZRANGE key start end

Returns the specified range of elements in the sorted set stored at .

ZRANGE can perform different types of range queries: by index (rank), by the score, or by lexicographical order.

ZRANGE key start end WITHSCORES

The optional WITHSCORES argument supplements the command's reply with the scores of elements returned. The returned list contains value1,score1,...,valueN,scoreN instead of value1,...,valueN. Client libraries are free to return a more appropriate data type (suggestion: an array with (value, score) arrays/tuples).

---

HSET key field value [field value...]

Sets field in the hash stored at key to value. If key does not exist, a new key holding a hash is created. If field already exists in the hash, it is overwritten.

HGET key field

Returns the value associated with field in the hash stored at key.

HSETNX key field value

Sets field in the hash stored at key to value, only if field does not yet exist. If key does not exist, a new key holding a hash is created. If field already exists, this operation has no effect.

HVALS key

Returns all values in the hash stored at key.

HDEL key field

Removes the specified fields from the hash stored at key. Specified fields that do not exist within this hash are ignored. If key does not exist, it is treated as an empty hash and this command returns 0.