Works same as <tt>ping()</tt> but returns argument message instead of <tt>PONG</tt>. @param message @return message
Set the string value as value of the key. The string can't be longer than 1073741824 bytes (1 GB). <p> Time complexity: O(1) @param key @param value @return Status code reply
Set the string value as value of the key. The string can't be longer than 1073741824 bytes (1 GB). @param key @param value @param params NX|XX, NX -- Only set the key if it does not already exist. XX -- Only set the key if it already exist. EX|PX, expire time units: EX = seconds; PX = milliseconds @return Status code reply
Get the value of the specified key. If the key does not exist null is returned. If the value stored at key is not a string an error is returned because GET can only handle string values. <p> Time complexity: O(1) @param key @return Bulk reply
Test if the specified keys exist. The command returns the number of keys exist. Time complexity: O(N) @param keys @return Integer reply, specifically: an integer greater than 0 if one or more keys exist, 0 if none of the specified keys exist.
Test if the specified key exists. The command returns true if the key exists, otherwise false is returned. Note that even keys set with an empty string as value will return true. Time complexity: O(1) @param key @return bool reply, true if the key exists, otherwise false
Remove the specified keys. If a given key does not exist no operation is performed for this key. The command returns the number of keys removed. Time complexity: O(1) @param keys @return Integer reply, specifically: an integer greater than 0 if one or more keys were removed 0 if none of the specified key existed
This command is very similar to DEL: it removes the specified keys. Just like DEL a key is ignored if it does not exist. However the command performs the actual memory reclaiming in a different thread, so it is not blocking, while DEL is. This is where the command name comes from: the command just unlinks the keys from the keyspace. The actual removal will happen later asynchronously. <p> Time complexity: O(1) for each key removed regardless of its size. Then the command does O(N) work in a different thread in order to reclaim memory, where N is the number of allocations the deleted objects where composed of. @param keys @return Integer reply: The number of keys that were unlinked
Return the type of the value stored at key in form of a string. The type can be one of "none", "string", "list", "set". "none" is returned if the key does not exist. Time complexity: O(1) @param key @return Status code reply, specifically: "none" if the key does not exist "string" if the key contains a string value "list" if the key contains a List value "set" if the key contains a Set value "zset" if the key contains a Sorted Set value "hash" if the key contains a Hash value
Return a randomly selected key from the currently selected DB. <p> Time complexity: O(1) @return Singe line reply, specifically the randomly selected key or an empty string is the database is empty
Atomically renames the key oldkey to newkey. If the source and destination name are the same an error is returned. If newkey already exists it is overwritten. <p> Time complexity: O(1) @param oldkey @param newkey @return Status code repy
Rename oldkey into newkey but fails if the destination key newkey already exists. <p> Time complexity: O(1) @param oldkey @param newkey @return Integer reply, specifically: 1 if the key was renamed 0 if the target key already exist
Set a timeout on the specified key. After the timeout the key will be automatically deleted by the server. A key with an associated timeout is said to be volatile in Redis terminology. <p> Volatile keys are stored on disk like the other keys, the timeout is persistent too like all the other aspects of the dataset. Saving a dataset containing expires and stopping the server does not stop the flow of time as Redis stores on disk the time when the key will no longer be available as Unix time, and not the remaining seconds. <p> Since Redis 2.1.3 you can update the value of the timeout of a key already having an expire set. It is also possible to undo the expire at all turning the key into a normal key using the {@link #persist(string) PERSIST} command. <p> Time complexity: O(1) @see <a href="http://redis.io/commands/expire">Expire Command</a> @param key @param seconds @return Integer reply, specifically: 1: the timeout was set. 0: the timeout was not set since the key already has an associated timeout (this may happen only in Redis versions < 2.1.3, Redis >= 2.1.3 will happily update the timeout), or the key does not exist.
EXPIREAT works exactly like {@link #expire(string, int) EXPIRE} but instead to get the number of seconds representing the Time To Live of the key as a second argument (that is a relative way of specifying the TTL), it takes an absolute one in the form of a UNIX timestamp (Number of seconds elapsed since 1 Gen 1970). <p> EXPIREAT was introduced in order to implement the Append Only File persistence mode so that EXPIRE commands are automatically translated into EXPIREAT commands for the append only file. Of course EXPIREAT can also used by programmers that need a way to simply specify that a given key should expire at a given time in the future. <p> Since Redis 2.1.3 you can update the value of the timeout of a key already having an expire set. It is also possible to undo the expire at all turning the key into a normal key using the {@link #persist(string) PERSIST} command. <p> Time complexity: O(1) @see <a href="http://redis.io/commands/expire">Expire Command</a> @param key @param unixTime @return Integer reply, specifically: 1: the timeout was set. 0: the timeout was not set since the key already has an associated timeout (this may happen only in Redis versions < 2.1.3, Redis >= 2.1.3 will happily update the timeout), or the key does not exist.
The TTL command returns the remaining time to live in seconds of a key that has an {@link #expire(string, int) EXPIRE} set. This introspection capability allows a Redis client to check how many seconds a given key will continue to be part of the dataset. @param key @return Integer reply, returns the remaining time to live in seconds of a key that has an EXPIRE. In Redis 2.6 or older, if the Key does not exists or does not have an associated expire, -1 is returned. In Redis 2.8 or newer, if the Key does not have an associated expire, -1 is returned or if the Key does not exists, -2 is returned.
Alters the last access time of a key(s). A key is ignored if it does not exist. Time complexity: O(N) where N is the number of keys that will be touched. @param keys @return Integer reply: The number of keys that were touched.
Move the specified key from the currently selected DB to the specified destination DB. Note that this command returns 1 only if the key was successfully moved, and 0 if the target key was already there or if the source key was not found at all, so it is possible to use MOVE as a locking primitive. @param key @param dbIndex @return Integer reply, specifically: 1 if the key was moved 0 if the key was not moved because already present on the target DB or was not found in the current DB.
GETSET is an atomic set this value and return the old value command. Set key to the string value and return the old value stored at key. The string can't be longer than 1073741824 bytes (1 GB). <p> Time complexity: O(1) @param key @param value @return Bulk reply
Get the values of all the specified keys. If one or more keys don't exist or is not of type string, a 'nil' value is returned instead of the value of the specified key, but the operation never fails. <p> Time complexity: O(1) for every key @param keys @return Multi bulk reply
SETNX works exactly like {@link #set(string, string) SET} with the only difference that if the key already exists no operation is performed. SETNX actually means "SET if Not eXists". <p> Time complexity: O(1) @param key @param value @return Integer reply, specifically: 1 if the key was set 0 if the key was not set
The command is exactly equivalent to the following group of commands: {@link #set(string, string) SET} + {@link #expire(string, int) EXPIRE}. The operation is atomic. <p> Time complexity: O(1) @param key @param seconds @param value @return Status code reply
Set the the respective keys to the respective values. MSET will replace old values with new values, while {@link #msetnx(string...) MSETNX} will not perform any operation at all even if just a single key already exists. <p> Because of this semantic MSETNX can be used in order to set different keys representing different fields of an unique logic object in a way that ensures that either all the fields or none at all are set. <p> Both MSET and MSETNX are atomic operations. This means that for instance if the keys A and B are modified, another client talking to Redis can either see the changes to both A and B at once, or no modification at all. @see #msetnx(string...) @param keysvalues @return Status code reply Basically +OK as MSET can't fail
Set the the respective keys to the respective values. {@link #mset(string...) MSET} will replace old values with new values, while MSETNX will not perform any operation at all even if just a single key already exists. <p> Because of this semantic MSETNX can be used in order to set different keys representing different fields of an unique logic object in a way that ensures that either all the fields or none at all are set. <p> Both MSET and MSETNX are atomic operations. This means that for instance if the keys A and B are modified, another client talking to Redis can either see the changes to both A and B at once, or no modification at all. @see #mset(string...) @param keysvalues @return Integer reply, specifically: 1 if the all the keys were set 0 if no key was set (at least one key already existed)
IDECRBY work just like {@link #decr(string) INCR} but instead to decrement by 1 the decrement is integer. <p> INCR commands are limited to 64 bit signed integers. <p> Note: this is actually a string operation, that is, in Redis there are not "integer" types. Simply the string stored at the key is parsed as a base 10 64 bit signed integer, incremented, and then converted back as a string. <p> Time complexity: O(1) @see #incr(string) @see #decr(string) @see #incrBy(string, long) @param key @param decrement @return Integer reply, this commands will reply with the new value of key after the increment.
Decrement the number stored at key by one. If the key does not exist or contains a value of a wrong type, set the key to the value of "0" before to perform the decrement operation. <p> INCR commands are limited to 64 bit signed integers. <p> Note: this is actually a string operation, that is, in Redis there are not "integer" types. Simply the string stored at the key is parsed as a base 10 64 bit signed integer, incremented, and then converted back as a string. <p> Time complexity: O(1) @see #incr(string) @see #incrBy(string, long) @see #decrBy(string, long) @param key @return Integer reply, this commands will reply with the new value of key after the increment.
INCRBY work just like {@link #incr(string) INCR} but instead to increment by 1 the increment is integer. <p> INCR commands are limited to 64 bit signed integers. <p> Note: this is actually a string operation, that is, in Redis there are not "integer" types. Simply the string stored at the key is parsed as a base 10 64 bit signed integer, incremented, and then converted back as a string. <p> Time complexity: O(1) @see #incr(string) @see #decr(string) @see #decrBy(string, long) @param key @param increment @return Integer reply, this commands will reply with the new value of key after the increment.
INCRBYFLOAT <p> INCRBYFLOAT commands are limited to double precision floating point values. <p> Note: this is actually a string operation, that is, in Redis there are not "double" types. Simply the string stored at the key is parsed as a base double precision floating point value, incremented, and then converted back as a string. There is no DECRYBYFLOAT but providing a negative value will work as expected. <p> Time complexity: O(1) @param key @param increment @return Double reply, this commands will reply with the new value of key after the increment.
Increment the number stored at key by one. If the key does not exist or contains a value of a wrong type, set the key to the value of "0" before to perform the increment operation. <p> INCR commands are limited to 64 bit signed integers. <p> Note: this is actually a string operation, that is, in Redis there are not "integer" types. Simply the string stored at the key is parsed as a base 10 64 bit signed integer, incremented, and then converted back as a string. <p> Time complexity: O(1) @see #incrBy(string, long) @see #decr(string) @see #decrBy(string, long) @param key @return Integer reply, this commands will reply with the new value of key after the increment.
If the key already exists and is a string, this command appends the provided value at the end of the string. If the key does not exist it is created and set as an empty string, so APPEND will be very similar to SET in this special case. <p> Time complexity: O(1). The amortized time complexity is O(1) assuming the appended value is small and the already present value is of any size, since the dynamic string library used by Redis will double the free space available on every reallocation. @param key @param value @return Integer reply, specifically the total length of the string after the append operation.
Return a subset of the string from offset start to offset end (both offsets are inclusive). Negative offsets can be used in order to provide an offset starting from the end of the string. So -1 means the last char, -2 the penultimate and so forth. <p> The function handles out of range requests without raising an error, but just limiting the resulting range to the actual length of the string. <p> Time complexity: O(start+n) (with start being the start index and n the total length of the requested range). Note that the lookup part of this command is O(1) so for small strings this is actually an O(1) command. @param key @param start @param end @return Bulk reply
Set the specified hash field to the specified value. <p> If key does not exist, a new key holding a hash is created. <p> <b>Time complexity:</b> O(1) @param key @param field @param value @return If the field already exists, and the HSET just produced an update of the value, 0 is returned, otherwise if a new field is created 1 is returned.
If key holds a hash, retrieve the value associated to the specified field. <p> If the field is not found or the key does not exist, a special 'nil' value is returned. <p> <b>Time complexity:</b> O(1) @param key @param field @return Bulk reply
Set the specified hash field to the specified value if the field not exists. <b>Time complexity:</b> O(1) @param key @param field @param value @return If the field already exists, 0 is returned, otherwise if a new field is created 1 is returned.
Set the respective fields to the respective values. HMSET replaces old values with new values. <p> If key does not exist, a new key holding a hash is created. <p> <b>Time complexity:</b> O(N) (with N being the number of fields) @param key @param hash @return Return OK or Exception if hash is empty
Retrieve the values associated to the specified fields. <p> If some of the specified fields do not exist, nil values are returned. Non existing keys are considered like empty hashes. <p> <b>Time complexity:</b> O(N) (with N being the number of fields) @param key @param fields @return Multi Bulk Reply specifically a list of all the values associated with the specified fields, in the same order of the request.
Increment the number stored at field in the hash at key by value. If key does not exist, a new key holding a hash is created. If field does not exist or holds a string, the value is set to 0 before applying the operation. Since the value argument is signed you can use this command to perform both increments and decrements. <p> The range of values supported by HINCRBY is limited to 64 bit signed integers. <p> <b>Time complexity:</b> O(1) @param key @param field @param value @return Integer reply The new value at field after the increment operation.
Increment the number stored at field in the hash at key by a double precision floating point value. If key does not exist, a new key holding a hash is created. If field does not exist or holds a string, the value is set to 0 before applying the operation. Since the value argument is signed you can use this command to perform both increments and decrements. <p> The range of values supported by HINCRBYFLOAT is limited to double precision floating point values. <p> <b>Time complexity:</b> O(1) @param key @param field @param value @return Double precision floating point reply The new value at field after the increment operation.
Test for existence of a specified field in a hash. <b>Time complexity:</b> O(1) @param key @param field @return Return true if the hash stored at key contains the specified field. Return false if the key is not found or the field is not present.
Remove the specified field from an hash stored at key. <p> <b>Time complexity:</b> O(1) @param key @param fields @return If the field was present in the hash it is deleted and 1 is returned, otherwise 0 is returned and no operation is performed.
Return the number of items in a hash. <p> <b>Time complexity:</b> O(1) @param key @return The number of entries (fields) contained in the hash stored at key. If the specified key does not exist, 0 is returned assuming an empty hash.
Return all the fields in a hash. <p> <b>Time complexity:</b> O(N), where N is the total number of entries @param key @return All the fields names contained into a hash.
Return all the values in a hash. <p> <b>Time complexity:</b> O(N), where N is the total number of entries @param key @return All the fields values contained into a hash.
Return all the fields and associated values in a hash. <p> <b>Time complexity:</b> O(N), where N is the total number of entries @param key @return All the fields and values contained into a hash.
Add the string value to the head (LPUSH) or tail (RPUSH) of the list stored at key. If the key does not exist an empty list is created just before the append operation. If the key exists but is not a List an error is returned. <p> Time complexity: O(1) @param key @param strings @return Integer reply, specifically, the number of elements inside the list after the push operation.
Add the string value to the head (LPUSH) or tail (RPUSH) of the list stored at key. If the key does not exist an empty list is created just before the append operation. If the key exists but is not a List an error is returned. <p> Time complexity: O(1) @param key @param strings @return Integer reply, specifically, the number of elements inside the list after the push operation.
Return the length of the list stored at the specified key. If the key does not exist zero is returned (the same behaviour as for empty lists). If the value stored at key is not a list an error is returned. <p> Time complexity: O(1) @param key @return The length of the list.
Return the specified elements of the list stored at the specified key. Start and end are zero-based indexes. 0 is the first element of the list (the list head), 1 the next element and so on. <p> For example LRANGE foobar 0 2 will return the first three elements of the list. <p> start and end can also be negative numbers indicating offsets from the end of the list. For example -1 is the last element of the list, -2 the penultimate element and so on. <p> <b>Consistency with range functions in various programming languages</b> <p> Note that if you have a list of numbers from 0 to 100, LRANGE 0 10 will return 11 elements, that is, rightmost item is included. This may or may not be consistent with behavior of range-related functions in your programming language of choice (think Ruby's Range.new, Array#slice or Python's range() function). <p> LRANGE behavior is consistent with one of Tcl. <p> <b>Out-of-range indexes</b> <p> Indexes out of range will not produce an error: if start is over the end of the list, or start > end, an empty list is returned. If end is over the end of the list Redis will threat it just like the last element of the list. <p> Time complexity: O(start+n) (with n being the length of the range and start being the start offset) @param key @param start @param stop @return Multi bulk reply, specifically a list of elements in the specified range.
Trim an existing list so that it will contain only the specified range of elements specified. Start and end are zero-based indexes. 0 is the first element of the list (the list head), 1 the next element and so on. <p> For example LTRIM foobar 0 2 will modify the list stored at foobar key so that only the first three elements of the list will remain. <p> start and end can also be negative numbers indicating offsets from the end of the list. For example -1 is the last element of the list, -2 the penultimate element and so on. <p> Indexes out of range will not produce an error: if start is over the end of the list, or start > end, an empty list is left as value. If end over the end of the list Redis will threat it just like the last element of the list. <p> Hint: the obvious use of LTRIM is together with LPUSH/RPUSH. For example: <p> {@code lpush("mylist", "someelement"); ltrim("mylist", 0, 99); * } <p> The above two commands will push elements in the list taking care that the list will not grow without limits. This is very useful when using Redis to store logs for example. It is important to note that when used in this way LTRIM is an O(1) operation because in the average case just one element is removed from the tail of the list. <p> Time complexity: O(n) (with n being len of list - len of range) @param key @param start @param stop @return Status code reply
Return the specified element of the list stored at the specified key. 0 is the first element, 1 the second and so on. Negative indexes are supported, for example -1 is the last element, -2 the penultimate and so on. <p> If the value stored at key is not of list type an error is returned. If the index is out of range a 'nil' reply is returned. <p> Note that even if the average time complexity is O(n) asking for the first or the last element of the list is O(1). <p> Time complexity: O(n) (with n being the length of the list) @param key @param index @return Bulk reply, specifically the requested element
Set a new value as the element at index position of the List at key. <p> Out of range indexes will generate an error. <p> Similarly to other list commands accepting indexes, the index can be negative to access elements starting from the end of the list. So -1 is the last element, -2 is the penultimate, and so forth. <p> <b>Time complexity:</b> <p> O(N) (with N being the length of the list), setting the first or last elements of the list is O(1). @see #lindex(string, long) @param key @param index @param value @return Status code reply
Remove the first count occurrences of the value element from the list. If count is zero all the elements are removed. If count is negative elements are removed from tail to head, instead to go from head to tail that is the normal behaviour. So for example LREM with count -2 and hello as value to remove against the list (a,b,c,hello,x,hello,hello) will leave the list (a,b,c,hello,x). The number of removed elements is returned as an integer, see below for more information about the returned value. Note that non existing keys are considered like empty lists by LREM, so LREM against non existing keys will always return 0. <p> Time complexity: O(N) (with N being the length of the list) @param key @param count @param value @return Integer Reply, specifically: The number of removed elements if the operation succeeded
Atomically return and remove the first (LPOP) or last (RPOP) element of the list. For example if the list contains the elements "a","b","c" LPOP will return "a" and the list will become "b","c". <p> If the key does not exist or the list is already empty the special value 'nil' is returned. @see #rpop(string) @param key @return Bulk reply
Atomically return and remove the first (LPOP) or last (RPOP) element of the list. For example if the list contains the elements "a","b","c" RPOP will return "c" and the list will become "a","b". <p> If the key does not exist or the list is already empty the special value 'nil' is returned. @see #lpop(string) @param key @return Bulk reply
Atomically return and remove the last (tail) element of the srckey list, and push the element as the first (head) element of the dstkey list. For example if the source list contains the elements "a","b","c" and the destination list contains the elements "foo","bar" after an RPOPLPUSH command the content of the two lists will be "a","b" and "c","foo","bar". <p> If the key does not exist or the list is already empty the special value 'nil' is returned. If the srckey and dstkey are the same the operation is equivalent to removing the last element from the list and pushing it as first element of the list, so it's a "list rotation" command. <p> Time complexity: O(1) @param srckey @param dstkey @return Bulk reply
Add the specified member to the set value stored at key. If member is already a member of the set no operation is performed. If key does not exist a new set with the specified member as sole member is created. If the key exists but does not hold a set value an error is returned. <p> Time complexity O(1) @param key @param members @return Integer reply, specifically: 1 if the new element was added 0 if the element was already a member of the set
Return all the members (elements) of the set value stored at key. This is just syntax glue for {@link #sinter(string...) SINTER}. <p> Time complexity O(N) @param key @return Multi bulk reply
Remove the specified member from the set value stored at key. If member was not a member of the set no operation is performed. If key does not hold a set value an error is returned. <p> Time complexity O(1) @param key @param members @return Integer reply, specifically: 1 if the new element was removed 0 if the new element was not a member of the set
Remove a random element from a Set returning it as return value. If the Set is empty or the key does not exist, a nil object is returned. <p> The {@link #srandmember(string)} command does a similar work but the returned element is not removed from the Set. <p> Time complexity O(1) @param key @return Bulk reply
Move the specified member from the set at srckey to the set at dstkey. This operation is atomic, in every given moment the element will appear to be in the source or destination set for accessing clients. <p> If the source set does not exist or does not contain the specified element no operation is performed and zero is returned, otherwise the element is removed from the source set and added to the destination set. On success one is returned, even if the element was already present in the destination set. <p> An error is raised if the source or destination keys contain a non Set value. <p> Time complexity O(1) @param srckey @param dstkey @param member @return Integer reply, specifically: 1 if the element was moved 0 if the element was not found on the first set and no operation was performed
Return the set cardinality (number of elements). If the key does not exist 0 is returned, like for empty sets. @param key @return Integer reply, specifically: the cardinality (number of elements) of the set as an integer.
Return true if member is a member of the set stored at key, otherwise false is returned. <p> Time complexity O(1) @param key @param member @return bool reply, specifically: true if the element is a member of the set false if the element is not a member of the set OR if the key does not exist
Return the members of a set resulting from the intersection of all the sets hold at the specified keys. Like in {@link #lrange(string, long, long) LRANGE} the result is sent to the client as a multi-bulk reply (see the protocol specification for more information). If just a single key is specified, then this command produces the same result as {@link #smembers(string) SMEMBERS}. Actually SMEMBERS is just syntax sugar for SINTER. <p> Non existing keys are considered like empty sets, so if one of the keys is missing an empty set is returned (since the intersection with an empty set always is an empty set). <p> Time complexity O(N*M) worst case where N is the cardinality of the smallest set and M the number of sets @param keys @return Multi bulk reply, specifically the list of common elements.
This command works exactly like {@link #sinter(string...) SINTER} but instead of being returned the resulting set is stored as dstkey. <p> Time complexity O(N*M) worst case where N is the cardinality of the smallest set and M the number of sets @param dstkey @param keys @return Status code reply
Return the members of a set resulting from the union of all the sets hold at the specified keys. Like in {@link #lrange(string, long, long) LRANGE} the result is sent to the client as a multi-bulk reply (see the protocol specification for more information). If just a single key is specified, then this command produces the same result as {@link #smembers(string) SMEMBERS}. <p> Non existing keys are considered like empty sets. <p> Time complexity O(N) where N is the total number of elements in all the provided sets @param keys @return Multi bulk reply, specifically the list of common elements.
This command works exactly like {@link #sunion(string...) SUNION} but instead of being returned the resulting set is stored as dstkey. Any existing value in dstkey will be over-written. <p> Time complexity O(N) where N is the total number of elements in all the provided sets @param dstkey @param keys @return Status code reply
Return the difference between the Set stored at key1 and all the Sets key2, ..., keyN <p> <b>Example:</b>
This command works exactly like {@link #sdiff(string...) SDIFF} but instead of being returned the resulting set is stored in dstkey. @param dstkey @param keys @return Status code reply
Return a random element from a Set, without removing the element. If the Set is empty or the key does not exist, a nil object is returned. <p> The SPOP command does a similar work but the returned element is popped (removed) from the Set. <p> Time complexity O(1) @param key @return Bulk reply
Add the specified member having the specified score to the sorted set stored at key. If member is already a member of the sorted set the score is updated, and the element reinserted in the right position to ensure sorting. If key does not exist a new sorted set with the specified member as sole member is created. If the key exists but does not hold a sorted set value an error is returned. <p> The score value can be the string representation of a double precision floating point number. <p> Time complexity O(log(N)) with N being the number of elements in the sorted set @param key @param score @param member @return Integer reply, specifically: 1 if the new element was added 0 if the element was already a member of the sorted set and the score was updated
Remove the specified member from the sorted set value stored at key. If member was not a member of the set no operation is performed. If key does not not hold a set value an error is returned. <p> Time complexity O(log(N)) with N being the number of elements in the sorted set @param key @param members @return Integer reply, specifically: 1 if the new element was removed 0 if the new element was not a member of the set
If member already exists in the sorted set adds the increment to its score and updates the position of the element in the sorted set accordingly. If member does not already exist in the sorted set it is added with increment as score (that is, like if the previous score was virtually zero). If key does not exist a new sorted set with the specified member as sole member is created. If the key exists but does not hold a sorted set value an error is returned. <p> The score value can be the string representation of a double precision floating point number. It's possible to provide a negative value to perform a decrement. <p> For an introduction to sorted sets check the Introduction to Redis data types page. <p> Time complexity O(log(N)) with N being the number of elements in the sorted set @param key @param increment @param member @return The new score
Return the rank (or index) of member in the sorted set at key, with scores being ordered from low to high. <p> When the given member does not exist in the sorted set, the special value 'nil' is returned. The returned rank (or index) of the member is 0-based for both commands. <p> <b>Time complexity:</b> <p> O(log(N)) @see #zrevrank(string, string) @param key @param member @return Integer reply or a nil bulk reply, specifically: the rank of the element as an integer reply if the element exists. A nil bulk reply if there is no such element.
Return the rank (or index) of member in the sorted set at key, with scores being ordered from high to low. <p> When the given member does not exist in the sorted set, the special value 'nil' is returned. The returned rank (or index) of the member is 0-based for both commands. <p> <b>Time complexity:</b> <p> O(log(N)) @see #zrank(string, string) @param key @param member @return Integer reply or a nil bulk reply, specifically: the rank of the element as an integer reply if the element exists. A nil bulk reply if there is no such element.
Return the sorted set cardinality (number of elements). If the key does not exist 0 is returned, like for empty sorted sets. <p> Time complexity O(1) @param key @return the cardinality (number of elements) of the set as an integer.
Return the score of the specified element of the sorted set at key. If the specified element does not exist in the sorted set, or the key does not exist at all, a special 'nil' value is returned. <p> <b>Time complexity:</b> O(1) @param key @param member @return the score
Sort a Set or a List. <p> Sort the elements contained in the List, Set, or Sorted Set value at key. By default sorting is numeric with elements being compared as double precision floating point numbers. This is the simplest form of SORT. @see #sort(string, string) @see #sort(string, SortingParams) @see #sort(string, SortingParams, string) @param key @return Assuming the Set/List at key contains a list of numbers, the return value will be the list of numbers ordered from the smallest to the biggest number.
Sort a Set or a List accordingly to the specified parameters. <p> <b>examples:</b> <p> Given are the following sets and key/values:
BLPOP (and BRPOP) is a blocking list pop primitive. You can see this commands as blocking versions of LPOP and RPOP able to block if the specified keys don't exist or contain empty lists. <p> The following is a description of the exact semantic. We describe BLPOP but the two commands are identical, the only difference is that BLPOP pops the element from the left (head) of the list, and BRPOP pops from the right (tail). <p> <b>Non blocking behavior</b> <p> When BLPOP is called, if at least one of the specified keys contain a non empty list, an element is popped from the head of the list and returned to the caller together with the name of the key (BLPOP returns a two elements array, the first element is the key, the second the popped value). <p> Keys are scanned from left to right, so for instance if you issue BLPOP list1 list2 list3 0 against a dataset where list1 does not exist but list2 and list3 contain non empty lists, BLPOP guarantees to return an element from the list stored at list2 (since it is the first non empty list starting from the left). <p> <b>Blocking behavior</b> <p> If none of the specified keys exist or contain non empty lists, BLPOP blocks until some other client performs a LPUSH or an RPUSH operation against one of the lists. <p> Once new data is present on one of the lists, the client finally returns with the name of the key unblocking it and the popped value. <p> When blocking, if a non-zero timeout is specified, the client will unblock returning a nil special value if the specified amount of seconds passed without a push operation against at least one of the specified keys. <p> The timeout argument is interpreted as an integer value. A timeout of zero means instead to block forever. <p> <b>Multiple clients blocking for the same keys</b> <p> Multiple clients can block for the same key. They are put into a queue, so the first to be served will be the one that started to wait earlier, in a first-blpopping first-served fashion. <p> <b>blocking POP inside a MULTI/EXEC transaction</b> <p> BLPOP and BRPOP can be used with pipelining (sending multiple commands and reading the replies in batch), but it does not make sense to use BLPOP or BRPOP inside a MULTI/EXEC block (a Redis transaction). <p> The behavior of BLPOP inside MULTI/EXEC when the list is empty is to return a multi-bulk nil reply, exactly what happens when the timeout is reached. If you like science fiction, think at it like if inside MULTI/EXEC the time will flow at infinite speed :) <p> Time complexity: O(1) @see #brpop(int, string...) @param timeout @param keys @return BLPOP returns a two-elements array via a multi bulk reply in order to return both the unblocking key and the popped value. <p> When a non-zero timeout is specified, and the BLPOP operation timed out, the return value is a nil multi bulk reply. Most client values will return false or nil accordingly to the programming language used.
Sort a Set or a List accordingly to the specified parameters and store the result at dstkey. @see #sort(string, SortingParams) @see #sort(string) @see #sort(string, string) @param key @param sortingParameters @param dstkey @return The number of elements of the list at dstkey.
Sort a Set or a List and Store the Result at dstkey. <p> Sort the elements contained in the List, Set, or Sorted Set value at key and store the result at dstkey. By default sorting is numeric with elements being compared as double precision floating point numbers. This is the simplest form of SORT. @see #sort(string) @see #sort(string, SortingParams) @see #sort(string, SortingParams, string) @param key @param dstkey @return The number of elements of the list at dstkey.
BLPOP (and BRPOP) is a blocking list pop primitive. You can see this commands as blocking versions of LPOP and RPOP able to block if the specified keys don't exist or contain empty lists. <p> The following is a description of the exact semantic. We describe BLPOP but the two commands are identical, the only difference is that BLPOP pops the element from the left (head) of the list, and BRPOP pops from the right (tail). <p> <b>Non blocking behavior</b> <p> When BLPOP is called, if at least one of the specified keys contain a non empty list, an element is popped from the head of the list and returned to the caller together with the name of the key (BLPOP returns a two elements array, the first element is the key, the second the popped value). <p> Keys are scanned from left to right, so for instance if you issue BLPOP list1 list2 list3 0 against a dataset where list1 does not exist but list2 and list3 contain non empty lists, BLPOP guarantees to return an element from the list stored at list2 (since it is the first non empty list starting from the left). <p> <b>Blocking behavior</b> <p> If none of the specified keys exist or contain non empty lists, BLPOP blocks until some other client performs a LPUSH or an RPUSH operation against one of the lists. <p> Once new data is present on one of the lists, the client finally returns with the name of the key unblocking it and the popped value. <p> When blocking, if a non-zero timeout is specified, the client will unblock returning a nil special value if the specified amount of seconds passed without a push operation against at least one of the specified keys. <p> The timeout argument is interpreted as an integer value. A timeout of zero means instead to block forever. <p> <b>Multiple clients blocking for the same keys</b> <p> Multiple clients can block for the same key. They are put into a queue, so the first to be served will be the one that started to wait earlier, in a first-blpopping first-served fashion. <p> <b>blocking POP inside a MULTI/EXEC transaction</b> <p> BLPOP and BRPOP can be used with pipelining (sending multiple commands and reading the replies in batch), but it does not make sense to use BLPOP or BRPOP inside a MULTI/EXEC block (a Redis transaction). <p> The behavior of BLPOP inside MULTI/EXEC when the list is empty is to return a multi-bulk nil reply, exactly what happens when the timeout is reached. If you like science fiction, think at it like if inside MULTI/EXEC the time will flow at infinite speed :) <p> Time complexity: O(1) @see #blpop(int, string...) @param timeout @param keys @return BLPOP returns a two-elements array via a multi bulk reply in order to return both the unblocking key and the popped value. <p> When a non-zero timeout is specified, and the BLPOP operation timed out, the return value is a nil multi bulk reply. Most client values will return false or nil accordingly to the programming language used.
Return the all the elements in the sorted set at key with a score between min and max (including elements with score equal to min or max). <p> The elements having the same score are returned sorted lexicographically as ASCII strings (this follows from a property of Redis sorted sets and does not involve further computation). <p> Using the optional {@link #zrangeByScore(string, double, double, int, int) LIMIT} it's possible to get only a range of the matching elements in an SQL-alike way. Note that if offset is large the commands needs to traverse the list for offset elements and this adds up to the O(M) figure. <p> The {@link #zcount(string, double, double) ZCOUNT} command is similar to {@link #zrangeByScore(string, double, double) ZRANGEBYSCORE} but instead of returning the actual elements in the specified interval, it just returns the number of matching elements. <p> <b>Exclusive intervals and infinity</b> <p> min and max can be -inf and +inf, so that you are not required to know what's the greatest or smallest element in order to take, for instance, elements "up to a given value". <p> Also while the interval is for default closed (inclusive) it's possible to specify open intervals prefixing the score with a "(" character, so for instance: <p> {@code ZRANGEBYSCORE zset (1.3 5} <p> Will return all the values with score > 1.3 and <= 5, while for instance: <p> {@code ZRANGEBYSCORE zset (5 (10} <p> Will return all the values with score > 5 and < 10 (5 and 10 excluded). <p> <b>Time complexity:</b> <p> O(log(N))+O(M) with N being the number of elements in the sorted set and M the number of elements returned by the command, so if M is constant (for instance you always ask for the first ten elements with LIMIT) you can consider it O(log(N)) @see #zrangeByScore(string, double, double) @see #zrangeByScore(string, double, double, int, int) @see #zrangeByScoreWithScores(string, double, double) @see #zrangeByScoreWithScores(string, string, string) @see #zrangeByScoreWithScores(string, double, double, int, int) @see #zcount(string, double, double) @param key @param min a double or Double.NEGATIVE_INFINITY for "-inf" @param max a double or Double.POSITIVE_INFINITY for "+inf" @return Multi bulk reply specifically a list of elements in the specified score range.
Return the all the elements in the sorted set at key with a score between min and max (including elements with score equal to min or max). <p> The elements having the same score are returned sorted lexicographically as ASCII strings (this follows from a property of Redis sorted sets and does not involve further computation). <p> Using the optional {@link #zrangeByScore(string, double, double, int, int) LIMIT} it's possible to get only a range of the matching elements in an SQL-alike way. Note that if offset is large the commands needs to traverse the list for offset elements and this adds up to the O(M) figure. <p> The {@link #zcount(string, double, double) ZCOUNT} command is similar to {@link #zrangeByScore(string, double, double) ZRANGEBYSCORE} but instead of returning the actual elements in the specified interval, it just returns the number of matching elements. <p> <b>Exclusive intervals and infinity</b> <p> min and max can be -inf and +inf, so that you are not required to know what's the greatest or smallest element in order to take, for instance, elements "up to a given value". <p> Also while the interval is for default closed (inclusive) it's possible to specify open intervals prefixing the score with a "(" character, so for instance: <p> {@code ZRANGEBYSCORE zset (1.3 5} <p> Will return all the values with score > 1.3 and <= 5, while for instance: <p> {@code ZRANGEBYSCORE zset (5 (10} <p> Will return all the values with score > 5 and < 10 (5 and 10 excluded). <p> <b>Time complexity:</b> <p> O(log(N))+O(M) with N being the number of elements in the sorted set and M the number of elements returned by the command, so if M is constant (for instance you always ask for the first ten elements with LIMIT) you can consider it O(log(N)) @see #zrangeByScore(string, double, double) @see #zrangeByScore(string, double, double, int, int) @see #zrangeByScoreWithScores(string, double, double) @see #zrangeByScoreWithScores(string, double, double, int, int) @see #zcount(string, double, double) @param key @param min @param max @param offset @param count @return Multi bulk reply specifically a list of elements in the specified score range.
Return the all the elements in the sorted set at key with a score between min and max (including elements with score equal to min or max). <p> The elements having the same score are returned sorted lexicographically as ASCII strings (this follows from a property of Redis sorted sets and does not involve further computation). <p> Using the optional {@link #zrangeByScore(string, double, double, int, int) LIMIT} it's possible to get only a range of the matching elements in an SQL-alike way. Note that if offset is large the commands needs to traverse the list for offset elements and this adds up to the O(M) figure. <p> The {@link #zcount(string, double, double) ZCOUNT} command is similar to {@link #zrangeByScore(string, double, double) ZRANGEBYSCORE} but instead of returning the actual elements in the specified interval, it just returns the number of matching elements. <p> <b>Exclusive intervals and infinity</b> <p> min and max can be -inf and +inf, so that you are not required to know what's the greatest or smallest element in order to take, for instance, elements "up to a given value". <p> Also while the interval is for default closed (inclusive) it's possible to specify open intervals prefixing the score with a "(" character, so for instance: <p> {@code ZRANGEBYSCORE zset (1.3 5} <p> Will return all the values with score > 1.3 and <= 5, while for instance: <p> {@code ZRANGEBYSCORE zset (5 (10} <p> Will return all the values with score > 5 and < 10 (5 and 10 excluded). <p> <b>Time complexity:</b> <p> O(log(N))+O(M) with N being the number of elements in the sorted set and M the number of elements returned by the command, so if M is constant (for instance you always ask for the first ten elements with LIMIT) you can consider it O(log(N)) @see #zrangeByScore(string, double, double) @see #zrangeByScore(string, double, double, int, int) @see #zrangeByScoreWithScores(string, double, double) @see #zrangeByScoreWithScores(string, double, double, int, int) @see #zcount(string, double, double) @param key @param min @param max @return Multi bulk reply specifically a list of elements in the specified score range.
Return the all the elements in the sorted set at key with a score between min and max (including elements with score equal to min or max). <p> The elements having the same score are returned sorted lexicographically as ASCII strings (this follows from a property of Redis sorted sets and does not involve further computation). <p> Using the optional {@link #zrangeByScore(string, double, double, int, int) LIMIT} it's possible to get only a range of the matching elements in an SQL-alike way. Note that if offset is large the commands needs to traverse the list for offset elements and this adds up to the O(M) figure. <p> The {@link #zcount(string, double, double) ZCOUNT} command is similar to {@link #zrangeByScore(string, double, double) ZRANGEBYSCORE} but instead of returning the actual elements in the specified interval, it just returns the number of matching elements. <p> <b>Exclusive intervals and infinity</b> <p> min and max can be -inf and +inf, so that you are not required to know what's the greatest or smallest element in order to take, for instance, elements "up to a given value". <p> Also while the interval is for default closed (inclusive) it's possible to specify open intervals prefixing the score with a "(" character, so for instance: <p> {@code ZRANGEBYSCORE zset (1.3 5} <p> Will return all the values with score > 1.3 and <= 5, while for instance: <p> {@code ZRANGEBYSCORE zset (5 (10} <p> Will return all the values with score > 5 and < 10 (5 and 10 excluded). <p> <b>Time complexity:</b> <p> O(log(N))+O(M) with N being the number of elements in the sorted set and M the number of elements returned by the command, so if M is constant (for instance you always ask for the first ten elements with LIMIT) you can consider it O(log(N)) @see #zrangeByScore(string, double, double) @see #zrangeByScore(string, double, double, int, int) @see #zrangeByScoreWithScores(string, double, double) @see #zrangeByScoreWithScores(string, double, double, int, int) @see #zcount(string, double, double) @param key @param min @param max @param offset @param count @return Multi bulk reply specifically a list of elements in the specified score range.
Remove all elements in the sorted set at key with rank between start and end. Start and end are 0-based with rank 0 being the element with the lowest score. Both start and end can be negative numbers, where they indicate offsets starting at the element with the highest rank. For
Remove all the elements in the sorted set at key with a score between min and max (including elements with score equal to min or max). <p> <b>Time complexity:</b> <p> O(log(N))+O(M) with N being the number of elements in the sorted set and M the number of elements removed by the operation @param key @param min @param max @return Integer reply, specifically the number of elements removed.
Creates a union or intersection of N sorted sets given by keys k1 through kN, and stores it at dstkey. It is mandatory to provide the number of input keys N, before passing the input keys and the other (optional) arguments. <p> As the terms imply, the {@link #zinterstore(string, string...) ZINTERSTORE} command requires an element to be present in each of the given inputs to be inserted in the result. The {@link #zunionstore(string, string...) ZUNIONSTORE} command inserts all elements across all inputs. <p> Using the WEIGHTS option, it is possible to add weight to each input sorted set. This means that the score of each element in the sorted set is first multiplied by this weight before being passed to the aggregation. When this option is not given, all weights default to 1. <p> With the AGGREGATE option, it's possible to specify how the results of the union or intersection are aggregated. This option defaults to SUM, where the score of an element is summed across the inputs where it exists. When this option is set to be either MIN or MAX, the resulting set will contain the minimum or maximum score of an element across the inputs where it exists. <p> <b>Time complexity:</b> O(N) + O(M log(M)) with N being the sum of the sizes of the input sorted sets, and M being the number of elements in the resulting sorted set @see #zunionstore(string, string...) @see #zunionstore(string, ZParams, string...) @see #zinterstore(string, string...) @see #zinterstore(string, ZParams, string...) @param dstkey @param sets @return Integer reply, specifically the number of elements in the sorted set at dstkey
Creates a union or intersection of N sorted sets given by keys k1 through kN, and stores it at dstkey. It is mandatory to provide the number of input keys N, before passing the input keys and the other (optional) arguments. <p> As the terms imply, the {@link #zinterstore(string, string...) ZINTERSTORE} command requires an element to be present in each of the given inputs to be inserted in the result. The {@link #zunionstore(string, string...) ZUNIONSTORE} command inserts all elements across all inputs. <p> Using the WEIGHTS option, it is possible to add weight to each input sorted set. This means that the score of each element in the sorted set is first multiplied by this weight before being passed to the aggregation. When this option is not given, all weights default to 1. <p> With the AGGREGATE option, it's possible to specify how the results of the union or intersection are aggregated. This option defaults to SUM, where the score of an element is summed across the inputs where it exists. When this option is set to be either MIN or MAX, the resulting set will contain the minimum or maximum score of an element across the inputs where it exists. <p> <b>Time complexity:</b> O(N) + O(M log(M)) with N being the sum of the sizes of the input sorted sets, and M being the number of elements in the resulting sorted set @see #zunionstore(string, string...) @see #zunionstore(string, ZParams, string...) @see #zinterstore(string, string...) @see #zinterstore(string, ZParams, string...) @param dstkey @param sets @param params @return Integer reply, specifically the number of elements in the sorted set at dstkey
Creates a union or intersection of N sorted sets given by keys k1 through kN, and stores it at dstkey. It is mandatory to provide the number of input keys N, before passing the input keys and the other (optional) arguments. <p> As the terms imply, the {@link #zinterstore(string, string...) ZINTERSTORE} command requires an element to be present in each of the given inputs to be inserted in the result. The {@link #zunionstore(string, string...) ZUNIONSTORE} command inserts all elements across all inputs. <p> Using the WEIGHTS option, it is possible to add weight to each input sorted set. This means that the score of each element in the sorted set is first multiplied by this weight before being passed to the aggregation. When this option is not given, all weights default to 1. <p> With the AGGREGATE option, it's possible to specify how the results of the union or intersection are aggregated. This option defaults to SUM, where the score of an element is summed across the inputs where it exists. When this option is set to be either MIN or MAX, the resulting set will contain the minimum or maximum score of an element across the inputs where it exists. <p> <b>Time complexity:</b> O(N) + O(M log(M)) with N being the sum of the sizes of the input sorted sets, and M being the number of elements in the resulting sorted set @see #zunionstore(string, string...) @see #zunionstore(string, ZParams, string...) @see #zinterstore(string, string...) @see #zinterstore(string, ZParams, string...) @param dstkey @param sets @return Integer reply, specifically the number of elements in the sorted set at dstkey
Creates a union or intersection of N sorted sets given by keys k1 through kN, and stores it at dstkey. It is mandatory to provide the number of input keys N, before passing the input keys and the other (optional) arguments. <p> As the terms imply, the {@link #zinterstore(string, string...) ZINTERSTORE} command requires an element to be present in each of the given inputs to be inserted in the result. The {@link #zunionstore(string, string...) ZUNIONSTORE} command inserts all elements across all inputs. <p> Using the WEIGHTS option, it is possible to add weight to each input sorted set. This means that the score of each element in the sorted set is first multiplied by this weight before being passed to the aggregation. When this option is not given, all weights default to 1. <p> With the AGGREGATE option, it's possible to specify how the results of the union or intersection are aggregated. This option defaults to SUM, where the score of an element is summed across the inputs where it exists. When this option is set to be either MIN or MAX, the resulting set will contain the minimum or maximum score of an element across the inputs where it exists. <p> <b>Time complexity:</b> O(N) + O(M log(M)) with N being the sum of the sizes of the input sorted sets, and M being the number of elements in the resulting sorted set @see #zunionstore(string, string...) @see #zunionstore(string, ZParams, string...) @see #zinterstore(string, string...) @see #zinterstore(string, ZParams, string...) @param dstkey @param sets @param params @return Integer reply, specifically the number of elements in the sorted set at dstkey
Undo a {@link #expire(string, int) expire} at turning the expire key into a normal key. <p> Time complexity: O(1) @param key @return Integer reply, specifically: 1: the key is now persist. 0: the key is not persist (only happens when key not set).
Pop a value from a list, push it to another list and return it; or block until one is available @param source @param destination @param timeout @return the element
Sets or clears the bit at offset in the string value stored at key @param key @param offset @param value @return
Returns the bit value at offset in the string value stored at key @param key @param offset @return
Retrieve the configuration of a running Redis server. Not all the configuration parameters are supported. <p> CONFIG GET returns the current configuration parameters. This sub command only accepts a single argument, that is glob style pattern. All the configuration parameters matching this parameter are reported as a list of key-value pairs. <p> <b>Example:</b>
Alter the configuration of a running Redis server. Not all the configuration parameters are supported. <p> The list of configuration parameters supported by CONFIG SET can be obtained issuing a {@link #configGet(string) CONFIG GET *} command. <p> The configuration set using CONFIG SET is immediately loaded by the Redis server that will start acting as specified starting from the next command. <p> <b>Parameters value format</b> <p> The value of the configuration parameter is the same as the one of the same parameter in the Redis configuration file, with the following exceptions: <p> <ul> <li>The save parameter is a list of space-separated integers. Every pair of integers specify the time and number of changes limit to trigger a save. For instance the command CONFIG SET save "3600 10 60 10000" will configure the server to issue a background saving of the RDB file every 3600 seconds if there are at least 10 changes in the dataset, and every 60 seconds if there are at least 10000 changes. To completely disable automatic snapshots just set the parameter as an empty string. <li>All the integer parameters representing memory are returned and accepted only using bytes as unit. </ul> @param parameter @param value @return Status code reply
<pre> redis 127.0.0.1:26381> sentinel masters 1) 1) "name" 2) "mymaster" 3) "ip" 4) "127.0.0.1" 5) "port" 6) "6379" 7) "runid" 8) "93d4d4e6e9c06d0eea36e27f31924ac26576081d" 9) "flags" 10) "master" 11) "pending-commands" 12) "0" 13) "last-ok-ping-reply" 14) "423" 15) "last-ping-reply" 16) "423" 17) "info-refresh" 18) "6107" 19) "num-slaves" 20) "1" 21) "num-other-sentinels" 22) "2" 23) "quorum" 24) "2"
<pre> redis 127.0.0.1:26381> sentinel get-master-addr-by-name mymaster 1) "127.0.0.1" 2) "6379" </pre> @param masterName @return two elements list of strings : host and port.
<pre> redis 127.0.0.1:26381> sentinel reset mymaster (integer) 1 </pre> @param pattern @return
<pre> redis 127.0.0.1:26381> sentinel slaves mymaster 1) 1) "name" 2) "127.0.0.1:6380" 3) "ip" 4) "127.0.0.1" 5) "port" 6) "6380" 7) "runid" 8) "d7f6c0ca7572df9d2f33713df0dbf8c72da7c039" 9) "flags" 10) "slave" 11) "pending-commands" 12) "0" 13) "last-ok-ping-reply" 14) "47" 15) "last-ping-reply" 16) "47" 17) "info-refresh" 18) "657" 19) "master-link-down-time" 20) "0" 21) "master-link-status" 22) "ok" 23) "master-host" 24) "localhost" 25) "master-port" 26) "6379" 27) "slave-priority" 28) "100" </pre> @param masterName @return
PSETEX works exactly like {@link #setex(string, int, string)} with the sole difference that the expire time is specified in milliseconds instead of seconds. Time complexity: O(1) @param key @param milliseconds @param value @return Status code reply
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