class Redis::Connection

Overview

The connection wraps the TCP connection to the Redis server.

Included Modules

Defined in:

connection.cr
graph.cr

Constructors

Macro Summary

Instance Method Summary

Instance methods inherited from module Redis::Commands

decr(key : String) decr, decrby(key : String, amount : Int | String) decrby, del(keys : Enumerable(String))
del(*keys : String)
del
, eval(script : String, keys : Enumerable(String) = EmptyEnumerable.new, args : Enumerable(String) = EmptyEnumerable.new) eval, eval_ro(script : String, keys : Enumerable(String) = EmptyEnumerable.new, args : Enumerable(String) = EmptyEnumerable.new) eval_ro, evalsha(sha : String, keys : Enumerable(String) = EmptyEnumerable.new, args : Enumerable(String) = EmptyEnumerable.new) evalsha, evalsha_ro(script : String, keys : Enumerable(String) = EmptyEnumerable.new, args : Enumerable(String) = EmptyEnumerable.new) evalsha_ro, exists(*keys : String) exists, expire(key : String, ttl : Time::Span)
expire(key : String, ttl : Int)
expire
, expireat(key : String, at : Time) expireat, flushall flushall, flushdb flushdb, ft ft, get(key : String) get, graph(key : String) graph, incr(key : String) incr, incrby(key : String, amount : Int | String) incrby, info info, json json, keys(pattern = "*") keys, mget(keys : Enumerable(String)) mget, mset(data : Hash(String, String)) mset, pexpire(key : String, ttl : Time::Span)
pexpire(key : String, ttl : Int)
pexpire
, pexpireat(key : String, at : Time) pexpireat, pttl(key : String) pttl, publish(channel : String, message : String) publish, run(command) run, scan(cursor : String = "0", match : String | Nil = nil, count : String | Int | Nil = nil, type : String | Nil = nil) scan, script_exists(shas : Enumerable(String))
script_exists(*shas : String)
script_exists
, script_flush(mode : ScriptFlushMode) script_flush, script_kill script_kill, script_load(script : String) script_load, set(key : String, value : String, ex : String | Int | Nil = nil, px : String | Int | Nil = nil, nx = false, xx = false, keepttl = false)
set(key, value, ex : Time, nx = false, xx = false, keepttl = false)
set(key, value, ex : Time::Span, nx = false, xx = false, keepttl = false)
set
, ts ts, ttl(key : String) ttl, type(key : String) type, unlink(keys : Enumerable(String))
unlink(*keys : String)
unlink

Instance methods inherited from module Redis::Commands::Stream

xack(key : String, group : String, id : String)
xack(key : String, group : String, ids : Enumerable(String))
xack
, xadd(key : String, id : String, maxlen, data : Hash(String, String))
xadd(key : String, id : String, data : Hash(String, String))
xadd(key : String, id : String, maxlen = nil, **data)
xadd
, xautoclaim(key : String, group : String, consumer : String, min_idle_time : Time::Span, start : String, count : Int | String | Nil = nil) xautoclaim, xdel(key : String, ids : Enumerable(String))
xdel(key : String, *ids : String)
xdel
, xgroup(command : String, key : String, groupname : String)
xgroup(command : XGroup, key : String, groupname : String, *, id : String | Nil = nil, mkstream = false, consumer_name : String | Nil = nil)
xgroup(command : String, key : String, groupname : String, *args : String)
xgroup
, xgroup_create(key : String, groupname : String, *, id : String = "$", mkstream = false) xgroup_create, xgroup_create_consumer(key : String, groupname : String, consumer_name : String) xgroup_create_consumer, xlen(key : String) xlen, xpending(key : String, group : String, start : String, end finish : String, count : String | Int, idle : String | Time::Span | Nil = nil)
xpending(key : String, group : String)
xpending
, xrange(key : String, start min, end max, count = nil) xrange, xreadgroup(group : String, consumer : String, count : String | Int | Nil = nil, block : Time::Span | String | Int | Nil = nil, no_ack = false, streams : ::Hash(String, String) = {} of String => String)
xreadgroup(group : String, consumer : String, count : String | Int | Nil = nil, block : Time::Span | String | Int | Nil = nil, no_ack = false, streams : NamedTuple = NamedTuple.new)
xreadgroup

Instance methods inherited from module Redis::Commands::SortedSet

zadd(key : String, score : String | Int64, value : String)
zadd(key : String, values : Enumerable(String))
zadd
, zcard(key : String) zcard, zcount(key : String, min : String, max : String) zcount, zrange(key : String, starting : String | Int64, ending : String | Int64, with_scores : Bool = false) zrange, zrangebyscore(key : String, low : String | Int64, high : String | Int64, limit : Enumerable(String) | Nil = nil) zrangebyscore, zrem(key : String, value : String)
zrem(key : String, values : Enumerable(String))
zrem(key : String, *values : String)
zrem
, zremrangebyrank(key : String, low : Int64, high : Int64) zremrangebyrank, zremrangebyscore(key : String, low : String | Int64, high : String | Int64) zremrangebyscore, zrevrange(key : String, starting : String | Int64, ending : String | Int64, with_scores : Bool = false) zrevrange, zscore(key : String, value : String) zscore

Instance methods inherited from module Redis::Commands::Set

sadd(key : String, *values : String) sadd, scard(key : String) scard, sdiff(first : String, second : String) sdiff, sinter(first : String, *others : String) sinter, sismember(key : String, value : String) sismember, smembers(key : String) smembers, srem(key : String, members : Enumerable(String))
srem(key : String, *values : String)
srem

Instance methods inherited from module Redis::Commands::List

blpop(keys : Enumerable(String), timeout : Time::Span)
blpop(*keys : String, timeout : Time::Span)
blpop(*keys : String, timeout : Int | Float)
blpop(*keys : String, timeout : String)
blpop
, brpop(keys : Enumerable(String), timeout : Int)
brpop(*keys : String, timeout : Time::Span)
brpop(*keys : String, timeout : Number)
brpop(*keys : String, timeout : String)
brpop
, llen(key : String) llen, lmove(from source : String, to destination : String, from_side source_side : Side, to_side destination_side : Side) lmove, lpop(key : String, count : String | Nil = nil) lpop, lpush(key : String, values : Enumerable(String))
lpush(key, *values : String)
lpush
, lrange(key : String, start : String | Int, finish : String | Int) lrange, lrem(key : String, count : Int, value : String) lrem, ltrim(key : String, start : String | Int, stop : String | Int)
ltrim(key : String, range : Range(String, String))
ltrim(key : String, range : Range(Int32, Int32))
ltrim
, rpop(key : String) rpop, rpoplpush(source : String, destination : String) rpoplpush, rpush(key : String, values : Enumerable(String))
rpush(key, *values : String)
rpush

Instance methods inherited from module Redis::Commands::Hash

hdel(key : String, fields : Enumerable(String))
hdel(key : String, *fields : String)
hdel
, hget(key : String, field : String) hget, hgetall(key : String) hgetall, hincrby(key : String, field : String, increment : Int | String) hincrby, hmget(key : String, fields : Enumerable(String))
hmget(key : String, *fields : String)
hmget
, hmset(key : String, data : ::Hash(String, String)) hmset, hscan(key : String, cursor : String, *, match pattern : String | Nil = nil, count : String | Int | Nil = nil) hscan, hset(key : String, fields : Enumerable(String))
hset(key : String, fields : ::Hash(String, String))
hset(key : String, *fields : String)
hset(key : String, **fields : String)
hset
, hsetnx(key : String, field : String, value : String) hsetnx

Constructor Detail

def self.new(uri : URI = URI.parse("redis:///")) #

We receive all connection information in the URI.

SSL connections require specifying the rediss:// scheme. Password authentication uses the URI password. DB selection uses the URI path.


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Macro Detail

macro set_return_types! #

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Instance Method Detail

def close #

Close the connection to the server.


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def encode(command) #

Send the given command over the wire without waiting for a reply. This is useful for query pipelining or sending commands that have no return value.

WARNING Be careful with this because you can get the client out of sync with the server. You should almost never have to use this, but it can be useful if a command like this has not been implemented yet.


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def flush #

Flush the connection buffer and make sure we've sent everything to the server.


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def hscan_each(key : String, match pattern : String | Nil = nil, count : String | Int | Nil = nil, &) : Nil #

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def multi(retries = 5, &) #

Execute a transaction within the server. The transaction is automatically committed at the end of the block or can be rolled back with Transaction#discard. Transactions are also rolled back if an exception is raised.

redis.multi do |redis|
  redis.set "foo", "bar"
  redis.incr "counter"
  raise "Oops!"
end

redis.get "foo"     # => nil
redis.get "counter" # => nil

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def pipeline(&) #

Execute a pipeline of commands. A pipeline sends all commands to the server before reading any of the results.

redis.pipeline do |redis|
  redis.set "foo", "bar"
  redis.incr "counter"
end

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def psubscribe(*channels : String, &block : Subscription, self -> ) #

Subscribe to the given pubsub channels. The block yields a subscription object and the connection. You can setup on_message, on_subscribe, and on_unsubscribe on the subscription.

redis.subscribe "channel1", "channel2" do |subscription, connection|
  subscription.on_message do |channel, message|
    if message == "unsubscribe"
      connection.unsubscribe channel
    end

    # ...
  end

  # Respond to new subscribers
  subscription.on_subscribe do |channel, sub_count|
    connection.set "sub_count:#{channel}", sub_count.to_s
  end

  # Respond to losing subscribers
  subscription.on_unsubscribe do |channel, sub_count|
    connection.set "sub_count:#{channel}", sub_count.to_s
  end
end

For more information, see the documentation for:


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def punsubscribe(*channels : String) #

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def read #

Read the next value from the server


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def read? #

Read the next value from the server, returning nil if the connection is closed.


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def readonly! : Nil #

Put this connection in a readonly state. This is typically used when talking to replicas, and used automatically by Cluster for cluster replicas.


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def run(command, retries = 5) : Value #

Execute the given command and return the result from the server. Commands must be an Enumerable.

run({"set", "foo", "bar"})

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def scan_each(match pattern : String | Nil = nil, count : String | Int | Nil = nil, type : String | Nil = nil, &) : Nil #

Iterate over keys that match the given pattern or all keys if no pattern is supplied, yielding each key to the block. This is a much more efficient way to iterate over keys than keys.each — it avoids loading every key in memory at the same time and also doesn't block the Redis server while it generates the array of all those keys.


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def subscribe(*channels : String, &block : Subscription, self -> ) #

Subscribe to the given pubsub channels. The block yields a subscription object and the connection. You can setup on_message, on_subscribe, and on_unsubscribe on the subscription.

redis.subscribe "channel1", "channel2" do |subscription, connection|
  subscription.on_message do |channel, message|
    if message == "unsubscribe"
      connection.unsubscribe channel
    end

    # ...
  end

  # Respond to new subscribers
  subscription.on_subscribe do |channel, sub_count|
    connection.set "sub_count:#{channel}", sub_count.to_s
  end

  # Respond to losing subscribers
  subscription.on_unsubscribe do |channel, sub_count|
    connection.set "sub_count:#{channel}", sub_count.to_s
  end
end

For more information, see the documentation for:


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def subscribe(*channels : String) #

Subscribe to the given channels without having to pass a block, which would block execution. This is useful to run inside of other subscription blocks to add new subscriptions.


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def unsubscribe #

Unsubscribe this connection from all subscriptions.


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def unsubscribe(*channels : String) #

Unsubscribe this connection the given channels.


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def url #

The URI


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