Документация для Модуль:Cache Перейти к коду ↴ [ править | очистить ]


This module provides a way of storing data between module invocations. Legal data types are strings, numbers and tables. The data gets stored as json in a variable named cargo_data. To see the stored raw json data, simply add {{#var:cargo_data}} at the end of the page.

This is useful for templates that tend to appear multiple times on the same page. Do not use this for modules that only appear a single time per page. It will lead to performance decreases.

Функции

Базовые

cache.auto

cache.auto(func, args, prefix)

The cache.auto function is the simplest way of implementing caching. It wraps the function supplying the value and automatically decides whether to execute the function or use a cached version.


It's parameters are:

  1. The function for which caching should be applied.
  2. A table holding the functions arguments.
  3. An optional prefix for the key under which the output will be stored (useful if multiple functions have the same arguments).

In pseudo-code it would look something like this:

function cache.auto(func, args, prefix)
  if prefix_args[1]_args[2].isCached() then
    return get_cache(prefix_args[1]_args[2])
  else
    return set_cache(prefix_args[1]_args[2], func(args))
  end
end

Дополнительные

Use these functions if you want to manually implement caching in your module.

cache.set

cache.set(args, value, prefix)

Stores content. Logs the stored content and the variable name. Returns the content.

cache.get

cache.get(args, prefix)

Retrieves content. Returns the content.

Использование

local p = {}
local cache = require('Модуль:Cache')


function p.example(args)
  -- First usage of p._example(); Executes the function and stores the value.
  cache.auto(p._example, args, 'example_prefix')

  -- Second usage; Uses the cached version.
  cache.auto(p._example, args, 'example_prefix')
end

function p._example(args)
  return args[1]
end


return p

Тесты

Yes check.svgД All tests passed.

Name Expected Actual
Yes check.svgД test_auto_boolean
Yes check.svgД test_auto_number
Yes check.svgД test_auto_string
Yes check.svgД test_auto_table
Yes check.svgД test_get_boolean
Yes check.svgД test_get_no_set
Yes check.svgД test_get_number
Yes check.svgД test_get_string
Yes check.svgД test_get_table
Yes check.svgД test_set_boolean
Yes check.svgД test_set_number
Yes check.svgД test_set_string
Yes check.svgД test_set_table

Зависимости

--------------------------------------------------------------------------------
-- Imports
--------------------------------------------------------------------------------

local libraryUtil = require( 'libraryUtil' )
local var = require( 'Модуль:Variables' ).var
local vardefine = require( 'Модуль:Variables' ).vardefine

--------------------------------------------------------------------------------
-- Strings
--------------------------------------------------------------------------------

local i18n = {
  error = {
    unsupported_type = 'Неподдерживаемый тип данных'
  },
  log = {
    caching = 'Не найдено кэшированной версии. Сбор данных.'
  }
}

--------------------------------------------------------------------------------
-- Helper functions
--------------------------------------------------------------------------------

local h = {}

--- Generate a variable unique key.
-- @param args (table): The template/module arguments.
-- @param prefix (string): A unique prefix for the cached template/module.
-- @return (string): A unique key.
function h.make_key( args, prefix )
  prefix = ( prefix or 'cache' )
  local key = { prefix }
  for _,arg in pairs( args ) do
    key[#key+1] = tostring( arg )
  end
  local key = table.concat( key, '_' )
  return mw.hash.hashValue( 'md5', key )
end

--- Convert a value into a string for caching.
-- @param value (string/number/bool/table/nil): The value to be converted
-- @return (string): The converted value.
-- @return (string): The original type.
function h.preprocess( value )
  local value_type = type( value )
  
  if value_type == 'number' or value_type == 'boolean' then
    value = tostring( value )
  elseif value_type == 'table' then
    -- Check the table for a metatable to detect mw.html and similar objects.
    local mt = getmetatable( value )
    if mt and mt.__tostring then
      value = tostring( value )
      value_type = 'string'
    else
      value = mw.text.jsonEncode( value )
    end
  elseif value_type ~= 'string' then
    error( i18n.error.unsupported_type )
  end

  return value, value_type
end

--- Convert a string value back to its original type.
-- @param value (string): The string value.
-- @param value_type (string): The original type.
-- @return (string/number/bool/table/nil): The value in its original type.
function h.process( value, value_type )
  if value_type == 'string' then
    return value
  elseif value_type == 'number' then
    return tonumber( value )
  elseif value_type == 'boolean' then
    return ( value == 'true' )
  elseif value_type == 'table' then
    return mw.text.jsonDecode( value )
  elseif not value_type then
    return
  else
    error( i18n.error.unsupported_type )
  end
end

--- Write a value to the cache.
-- @param key (string): The key under which the value will be stored.
-- @param value (string/number/bool/table/nil): The value to store.
-- @return (string/number/bool/table/nil): The value.
function h.write( key, value )
  local processed_value, value_type = h.preprocess( value )
  vardefine( key, processed_value )
  vardefine( key .. '__type', value_type )
  return value
end

--- Read a value from the cache.
-- @param key (string): The key from which to retrieve the value.
-- @return (string/number/bool/table/nil): The original value.
function h.read( key )
  local value = var( key )
  local value_type = var( key .. '__type' )

  return h.process( value, value_type )
end

--------------------------------------------------------------------------------
-- Functions
--------------------------------------------------------------------------------

local p = {}

function p.auto( func, args, prefix )
  libraryUtil.checkType( 'auto', 1, func, 'function' )
  libraryUtil.checkType( 'auto', 2, args, 'table' )
  libraryUtil.checkType( 'auto', 3, prefix, 'string', true )

  local key = h.make_key( args, prefix )
  local cached = h.read( key )
  if cached then
    return cached
  else
    mw.log( i18n.log.caching )
    return h.write( key, func( args ) )
  end
end

function p.set( args, value, prefix )
  libraryUtil.checkType( 'set', 1, args, 'table' )
  libraryUtil.checkTypeMulti( 'set', 2, value, { 'boolean', 'string', 'number', 'table' } )
  libraryUtil.checkType( 'set', 3, prefix, 'string', true )

  local key = h.make_key( args, prefix )

  return h.write( key, value )
end

function p.get( args, prefix )
  libraryUtil.checkType( 'get', 2, args, 'table' )
  libraryUtil.checkType( 'get', 3, prefix, 'string', true )

  local key = h.make_key( args, prefix )

  return h.read( key )
end

function p.key( args, prefix )
  return h.make_key( args, prefix )
end

--------------------------------------------------------------------------------
-- Return
--------------------------------------------------------------------------------

return p