Defer
in package
This is a helper class for transactions. It will optimize the write going out and take care of rolling back.
Optimizations will be:
- multiple set() values (with the same expiration) will be applied in a single setMulti()
- for a set() followed by another set() on the same key, only the latter one will be applied
- same for an replace() followed by an increment(), or whatever operation happens on the same key: if we can pre-calculate the end result, we'll only execute 1 operation with the end result
- operations before a flush() will not be executed, they'll just be lost
Rollback strategy includes:
- fetching the original value of operations prone to fail (add, replace & cas) prior to executing them
- executing said operations before the others, to minimize changes of interfering concurrent writes
- if the commit fails, said original values will be restored in case the new value had already been stored
This class must never receive invalid data. E.g. a "replace" can never follow a "delete" of the same key. This should be guaranteed by whatever uses this class: there is no point in re-implementing these checks here. The only acceptable conflicts are when cache values have changed outside, from another process. Those will be handled by this class.
Tags
Table of Contents
Methods
- __construct() : mixed
- __destruct() : mixed
- add() : void
- cas() : void
- clear() : void
- Clears all scheduled writes.
- commit() : bool
- Commit all deferred writes to cache.
- decrement() : void
- delete() : void
- deleteMulti() : void
- flush() : void
- increment() : void
- replace() : void
- set() : void
- setMulti() : void
- touch() : void
Methods
__construct()
public
__construct(KeyValueStore $cache) : mixed
Parameters
- $cache : KeyValueStore
__destruct()
public
__destruct() : mixed
Tags
add()
public
add(string $key, mixed $value, int $expire) : void
Parameters
- $key : string
- $value : mixed
- $expire : int
cas()
public
cas(mixed $originalValue, string $key, mixed $value, int $expire) : void
Parameters
- $originalValue : mixed
-
No real CAS token, but the original value for this key
- $key : string
- $value : mixed
- $expire : int
clear()
Clears all scheduled writes.
public
clear() : void
commit()
Commit all deferred writes to cache.
public
commit() : bool
When the commit fails, no changes in this transaction will be applied (and those that had already been applied will be undone). False will be returned in that case.
Return values
booldecrement()
public
decrement(string $key, int $offset, int $initial, int $expire) : void
Parameters
- $key : string
- $offset : int
- $initial : int
- $expire : int
delete()
public
delete(string $key) : void
Parameters
- $key : string
deleteMulti()
public
deleteMulti(array<string|int, string> $keys) : void
Parameters
- $keys : array<string|int, string>
flush()
public
flush() : void
increment()
public
increment(string $key, int $offset, int $initial, int $expire) : void
Parameters
- $key : string
- $offset : int
- $initial : int
- $expire : int
replace()
public
replace(string $key, mixed $value, int $expire) : void
Parameters
- $key : string
- $value : mixed
- $expire : int
set()
public
set(string $key, mixed $value, int $expire) : void
Parameters
- $key : string
- $value : mixed
- $expire : int
setMulti()
public
setMulti(array<string|int, mixed> $items, int $expire) : void
Parameters
- $items : array<string|int, mixed>
- $expire : int
touch()
public
touch(string $key, int $expire) : void
Parameters
- $key : string
- $expire : int