minetest-mm/mods/Minetest-WorldEdit/worldedit/serialization.lua
2020-10-26 17:38:53 +01:00

255 lines
8.5 KiB
Lua

--- Schematic serialization and deserialiation.
-- @module worldedit.serialization
worldedit.LATEST_SERIALIZATION_VERSION = 5
local LATEST_SERIALIZATION_HEADER = worldedit.LATEST_SERIALIZATION_VERSION .. ":"
--[[
Serialization version history:
1: Original format. Serialized Lua table with a weird linked format...
2: Position and node seperated into sub-tables in fields `1` and `2`.
3: List of nodes, one per line, with fields seperated by spaces.
Format: <X> <Y> <Z> <Name> <Param1> <Param2>
4: Serialized Lua table containing a list of nodes with `x`, `y`, `z`,
`name`, `param1`, `param2`, and `meta` fields.
5: Added header and made `param1`, `param2`, and `meta` fields optional.
Header format: <Version>,<ExtraHeaderField1>,...:<Content>
--]]
--- Reads the header of serialized data.
-- @param value Serialized WorldEdit data.
-- @return The version as a positive natural number, or 0 for unknown versions.
-- @return Extra header fields as a list of strings, or nil if not supported.
-- @return Content (data after header).
function worldedit.read_header(value)
if value:find("^[0-9]+[,:]") then
local header_end = value:find(":", 1, true)
local header = value:sub(1, header_end - 1):split(",")
local version = tonumber(header[1])
table.remove(header, 1)
local content = value:sub(header_end + 1)
return version, header, content
end
-- Old versions that didn't include a header with a version number
if value:find("([+-]?%d+)%s+([+-]?%d+)%s+([+-]?%d+)") and not value:find("%{") then -- List format
return 3, nil, value
elseif value:find("^[^\"']+%{%d+%}") then
if value:find("%[\"meta\"%]") then -- Meta flat table format
return 2, nil, value
end
return 1, nil, value -- Flat table format
elseif value:find("%{") then -- Raw nested table format
return 4, nil, value
end
return nil
end
--- Converts the region defined by positions `pos1` and `pos2`
-- into a single string.
-- @return The serialized data.
-- @return The number of nodes serialized.
function worldedit.serialize(pos1, pos2)
pos1, pos2 = worldedit.sort_pos(pos1, pos2)
worldedit.keep_loaded(pos1, pos2)
local get_node, get_meta, hash_node_position =
minetest.get_node, minetest.get_meta, minetest.hash_node_position
-- Find the positions which have metadata
local has_meta = {}
local meta_positions = minetest.find_nodes_with_meta(pos1, pos2)
for i = 1, #meta_positions do
has_meta[hash_node_position(meta_positions[i])] = true
end
local pos = {x=pos1.x, y=0, z=0}
local count = 0
local result = {}
while pos.x <= pos2.x do
pos.y = pos1.y
while pos.y <= pos2.y do
pos.z = pos1.z
while pos.z <= pos2.z do
local node = get_node(pos)
if node.name ~= "air" and node.name ~= "ignore" then
count = count + 1
local meta
if has_meta[hash_node_position(pos)] then
meta = get_meta(pos):to_table()
-- Convert metadata item stacks to item strings
for _, invlist in pairs(meta.inventory) do
for index = 1, #invlist do
local itemstack = invlist[index]
if itemstack.to_string then
invlist[index] = itemstack:to_string()
end
end
end
end
result[count] = {
x = pos.x - pos1.x,
y = pos.y - pos1.y,
z = pos.z - pos1.z,
name = node.name,
param1 = node.param1 ~= 0 and node.param1 or nil,
param2 = node.param2 ~= 0 and node.param2 or nil,
meta = meta,
}
end
pos.z = pos.z + 1
end
pos.y = pos.y + 1
end
pos.x = pos.x + 1
end
-- Serialize entries
result = minetest.serialize(result)
return LATEST_SERIALIZATION_HEADER .. result, count
end
-- Contains code based on [table.save/table.load](http://lua-users.org/wiki/SaveTableToFile)
-- by ChillCode, available under the MIT license.
local function deserialize_workaround(content)
local nodes
if not jit then
nodes = minetest.deserialize(content, true)
else
-- XXX: This is a filthy hack that works surprisingly well
-- in LuaJIT, `minetest.deserialize` will fail due to the register limit
nodes = {}
content = content:gsub("^%s*return%s*{", "", 1):gsub("}%s*$", "", 1) -- remove the starting and ending values to leave only the node data
-- remove string contents strings while preserving their length
local escaped = content:gsub("\\\\", "@@"):gsub("\\\"", "@@"):gsub("(\"[^\"]*\")", function(s) return string.rep("@", #s) end)
local startpos, startpos1 = 1, 1
local endpos
while true do -- go through each individual node entry (except the last)
startpos, endpos = escaped:find("},%s*{", startpos)
if not startpos then
break
end
local current = content:sub(startpos1, startpos)
local entry = minetest.deserialize("return " .. current, true)
table.insert(nodes, entry)
startpos, startpos1 = endpos, endpos
end
local entry = minetest.deserialize("return " .. content:sub(startpos1), true) -- process the last entry
table.insert(nodes, entry)
end
return nodes
end
--- Loads the schematic in `value` into a node list in the latest format.
-- @return A node list in the latest format, or nil on failure.
local function load_schematic(value)
local version, header, content = worldedit.read_header(value)
local nodes = {}
if version == 1 or version == 2 then -- Original flat table format
local tables = minetest.deserialize(content, true)
if not tables then return nil end
-- Transform the node table into an array of nodes
for i = 1, #tables do
for j, v in pairs(tables[i]) do
if type(v) == "table" then
tables[i][j] = tables[v[1]]
end
end
end
nodes = tables[1]
if version == 1 then --original flat table format
for i, entry in ipairs(nodes) do
local pos = entry[1]
entry.x, entry.y, entry.z = pos.x, pos.y, pos.z
entry[1] = nil
local node = entry[2]
entry.name, entry.param1, entry.param2 = node.name, node.param1, node.param2
entry[2] = nil
end
end
elseif version == 3 then -- List format
for x, y, z, name, param1, param2 in content:gmatch(
"([+-]?%d+)%s+([+-]?%d+)%s+([+-]?%d+)%s+" ..
"([^%s]+)%s+(%d+)%s+(%d+)[^\r\n]*[\r\n]*") do
param1, param2 = tonumber(param1), tonumber(param2)
table.insert(nodes, {
x = tonumber(x),
y = tonumber(y),
z = tonumber(z),
name = name,
param1 = param1 ~= 0 and param1 or nil,
param2 = param2 ~= 0 and param2 or nil,
})
end
elseif version == 4 or version == 5 then -- Nested table format
nodes = deserialize_workaround(content)
else
return nil
end
return nodes
end
--- Determines the volume the nodes represented by string `value` would occupy
-- if deserialized at `origin_pos`.
-- @return Low corner position.
-- @return High corner position.
-- @return The number of nodes.
function worldedit.allocate(origin_pos, value)
local nodes = load_schematic(value)
if not nodes or #nodes == 0 then return nil end
return worldedit.allocate_with_nodes(origin_pos, nodes)
end
-- Internal
function worldedit.allocate_with_nodes(origin_pos, nodes)
local huge = math.huge
local pos1x, pos1y, pos1z = huge, huge, huge
local pos2x, pos2y, pos2z = -huge, -huge, -huge
local origin_x, origin_y, origin_z = origin_pos.x, origin_pos.y, origin_pos.z
for i, entry in ipairs(nodes) do
local x, y, z = origin_x + entry.x, origin_y + entry.y, origin_z + entry.z
if x < pos1x then pos1x = x end
if y < pos1y then pos1y = y end
if z < pos1z then pos1z = z end
if x > pos2x then pos2x = x end
if y > pos2y then pos2y = y end
if z > pos2z then pos2z = z end
end
local pos1 = {x=pos1x, y=pos1y, z=pos1z}
local pos2 = {x=pos2x, y=pos2y, z=pos2z}
return pos1, pos2, #nodes
end
--- Loads the nodes represented by string `value` at position `origin_pos`.
-- @return The number of nodes deserialized.
function worldedit.deserialize(origin_pos, value)
local nodes = load_schematic(value)
if not nodes then return nil end
if #nodes == 0 then return #nodes end
local pos1, pos2 = worldedit.allocate_with_nodes(origin_pos, nodes)
worldedit.keep_loaded(pos1, pos2)
local origin_x, origin_y, origin_z = origin_pos.x, origin_pos.y, origin_pos.z
local count = 0
local add_node, get_meta = minetest.add_node, minetest.get_meta
for i, entry in ipairs(nodes) do
entry.x, entry.y, entry.z = origin_x + entry.x, origin_y + entry.y, origin_z + entry.z
-- Entry acts as both position and node
add_node(entry, entry)
if entry.meta then
get_meta(entry):from_table(entry.meta)
end
end
return #nodes
end