util.rb in redis_failover-0.9.0

- old
+ new
@@ -3,17 +3,63 @@
 module RedisFailover
   # Common utiilty methods and constants.
   module Util
     extend self
 
+    # Redis read operations that are automatically dispatched to slaves. Any
+    # operation not listed here will be dispatched to the master.
+    REDIS_READ_OPS = Set[
+      :echo,
+      :exists,
+      :get,
+      :getbit,
+      :getrange,
+      :hexists,
+      :hget,
+      :hgetall,
+      :hkeys,
+      :hlen,
+      :hmget,
+      :hvals,
+      :keys,
+      :lindex,
+      :llen,
+      :lrange,
+      :mapped_hmget,
+      :mapped_mget,
+      :mget,
+      :scard,
+      :sdiff,
+      :sinter,
+      :sismember,
+      :smembers,
+      :srandmember,
+      :strlen,
+      :sunion,
+      :type,
+      :zcard,
+      :zcount,
+      :zrange,
+      :zrangebyscore,
+      :zrank,
+      :zrevrange,
+      :zrevrangebyscore,
+      :zrevrank,
+      :zscore
+    ].freeze
+
+    # Unsupported Redis operations. These don't make sense in a client
+    # that abstracts the master/slave servers.
+    UNSUPPORTED_OPS = Set[:select, :dbsize].freeze
+
     # Default node in ZK that contains the current list of available redis nodes.
     DEFAULT_ZNODE_PATH = '/redis_failover_nodes'.freeze
 
     # Connectivity errors that the redis (<3.x) client raises.
     REDIS_ERRORS = Errno.constants.map { |c| Errno.const_get(c) }
 
     # Connectivity errors that the redis (>3.x) client raises.
-    REDIS_ERRORS << Redis::BaseError if Redis.const_defined?("BaseError")
+    REDIS_ERRORS << Redis::BaseError if Redis.const_defined?('BaseError')
     REDIS_ERRORS.freeze
 
     # Full set of errors related to connectivity.
     CONNECTIVITY_ERRORS = [
       RedisFailover::Error,