mirrors/prosody
1
0
Fork 0
mirror of https://github.com/bjc/prosody.git synced 2025-04-03 21:27:38 +03:00
Code Issues Projects Releases Packages Wiki Activity Actions

util.cache: Small update to prefix private fields with an underscore, add a :count() method (same as util.queue) and add an optional on_evict callback

Browse source
This commit is contained in:
Matthew Wild 2015-11-26 00:07:48 +00:00
parent 13d34d918f
commit c81eea619a
1 changed files with 43 additions and 32 deletions
Download patch file Download diff file Expand all files Collapse all files

75
util/cache.lua
View file

@ -1,13 +1,3 @@
local cache_methods = {};
local cache_mt = { __index = cache_methods };
local function new(size)
size = assert(tonumber(size), "cache size must be a number");
size = math.floor(size);
assert(size > 0, "cache size must be greater than zero");
local data = {};
return setmetatable({ data = data, count = 0, size = size, head = nil, tail = nil }, cache_mt);
end
local function _remove(list, m)
if m.prev then
@ -16,29 +6,32 @@ local function _remove(list, m)
if m.next then
m.next.prev = m.prev;
end
if list.tail == m then
list.tail = m.prev;
if list._tail == m then
list._tail = m.prev;
end
if list.head == m then
list.head = m.next;
if list._head == m then
list._head = m.next;
end
list.count = list.count - 1;
list._count = list._count - 1;
end
local function _insert(list, m)
if list.head then
list.head.prev = m;
if list._head then
list._head.prev = m;
end
m.prev, m.next = nil, list.head;
list.head = m;
if not list.tail then
list.tail = m;
m.prev, m.next = nil, list._head;
list._head = m;
if not list._tail then
list._tail = m;
end
list.count = list.count + 1;
list._count = list._count + 1;
end
local cache_methods = {};
local cache_mt = { __index = cache_methods };
function cache_methods:set(k, v)
local m = self.data[k];
local m = self._data[k];
if m then
-- Key already exists
if v ~= nil then
@ -49,27 +42,33 @@ function cache_methods:set(k, v)
else
-- Remove from list
_remove(self, m);
self.data[k] = nil;
self._data[k] = nil;
end
return;
return true;
end
-- New key
if v == nil then
return;
return true;
end
-- Check whether we need to remove oldest k/v
if self.count == self.size then
self.data[self.tail.key] = nil;
_remove(self, self.tail);
if self._count == self.size then
local tail = self._tail;
local on_evict = self._on_evict;
if on_evict then
on_evict(tail.key, tail.value);
end
_remove(self, tail);
self._data[tail.key] = nil;
end
m = { key = k, value = v, prev = nil, next = nil };
self.data[k] = m;
self._data[k] = m;
_insert(self, m);
return true;
end
function cache_methods:get(k)
local m = self.data[k];
local m = self._data[k];
if m then
return m.value;
end
@ -77,7 +76,7 @@ function cache_methods:get(k)
end
function cache_methods:items()
local m = self.head;
local m = self._head;
return function ()
if not m then
return;
@ -88,6 +87,18 @@ function cache_methods:items()
end
end
function cache_methods:count()
return self._count;
end
local function new(size, on_evict)
size = assert(tonumber(size), "cache size must be a number");
size = math.floor(size);
assert(size > 0, "cache size must be greater than zero");
local data = {};
return setmetatable({ _data = data, _count = 0, size = size, _head = nil, _tail = nil, _on_evict = on_evict }, cache_mt);
end
return {
new = new;
}