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VoxeLibre/mods/ITEMS/mcl_enchanting/groupcaps.lua

60 lines
2.1 KiB
Lua

local groupcaps_cache = {}
-- Compute a hash value.
function compute_hash(value)
-- minetest.get_password_hash is quite fast, even if it uses a
-- cryptographic hashing function (SHA-1). It is written in C++ and it
-- is probably hard to write a faster hashing function in Lua.
return string.sub(minetest.get_password_hash("ryvnf", minetest.serialize(value)), 1, 8)
end
-- Get the groupcaps and hash for an enchanted tool. If this function is called
-- repeatedly with the same values it will return data from a cache.
--
-- Parameters:
-- toolname - Name of the tool
-- level - The efficiency level of the tool
--
-- Returns a table with the following two fields:
-- values - The groupcaps table
-- hash - The hash of the groupcaps table
local function get_efficiency_groupcaps(toolname, level)
local toolcache = groupcaps_cache[toolname]
local level = level
if not toolcache then
toolcache = {}
groupcaps_cache[toolname] = toolcache
end
local levelcache = toolcache[level]
if not levelcache then
levelcache = {}
levelcache.values = mcl_autogroup.get_groupcaps(toolname, level)
levelcache.hash = compute_hash(levelcache.values)
toolcache[level] = levelcache
end
return levelcache
end
-- Update groupcaps of an enchanted tool. This function will be called
-- repeatedly to make sure the digging times stored in groupcaps stays in sync
-- when the digging times of nodes can change.
--
-- To make it more efficient it will first check a hash value to determine if
-- the tool needs to be updated.
function mcl_enchanting.update_groupcaps(itemstack)
local name = itemstack:get_name()
local level = mcl_enchanting.get_enchantment(itemstack, "efficiency")
local groupcaps = get_efficiency_groupcaps(name, level)
local hash = itemstack:get_meta():get_string("groupcaps_hash")
if not hash or hash ~= groupcaps.hash then
local tool_capabilities = itemstack:get_tool_capabilities()
tool_capabilities.groupcaps = groupcaps.values
itemstack:get_meta():set_tool_capabilities(tool_capabilities)
itemstack:get_meta():set_string("groupcaps_hash", groupcaps.hash)
end
end