84 lines
2.6 KiB
Lua
84 lines
2.6 KiB
Lua
-- See: https://github.com/bungle/lua-resty-tsort
|
|
--
|
|
-- Copyright (c) 2016, Aapo Talvensaari
|
|
-- All rights reserved.
|
|
--
|
|
-- Redistribution and use in source and binary forms, with or without modification,
|
|
-- are permitted provided that the following conditions are met:
|
|
--
|
|
-- * Redistributions of source code must retain the above copyright notice, this
|
|
-- list of conditions and the following disclaimer.
|
|
--
|
|
-- * Redistributions in binary form must reproduce the above copyright notice, this
|
|
-- list of conditions and the following disclaimer in the documentation and/or
|
|
-- other materials provided with the distribution.
|
|
--
|
|
-- THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
|
|
-- ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
|
|
-- WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
|
|
-- DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
|
|
-- ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
|
|
-- (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
|
|
-- LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
|
|
-- ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
|
-- (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
|
|
-- SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
|
|
|
local setmetatable = setmetatable
|
|
local pairs = pairs
|
|
local type = type
|
|
local function visit(k, n, m, s)
|
|
if m[k] == 0 then return 1 end
|
|
if m[k] == 1 then return end
|
|
m[k] = 0
|
|
local f = n[k]
|
|
for i=1, #f do
|
|
if visit(f[i], n, m, s) then return 1 end
|
|
end
|
|
m[k] = 1
|
|
s[#s+1] = k
|
|
end
|
|
local tsort = {}
|
|
tsort.__index = tsort
|
|
function tsort.new()
|
|
return setmetatable({ n = {} }, tsort)
|
|
end
|
|
function tsort:add(...)
|
|
local p = { ... }
|
|
local c = #p
|
|
if c == 0 then return self end
|
|
if c == 1 then
|
|
p = p[1]
|
|
if type(p) == "table" then
|
|
c = #p
|
|
else
|
|
p = { p }
|
|
end
|
|
end
|
|
local n = self.n
|
|
for i=1, c do
|
|
local f = p[i]
|
|
if n[f] == nil then n[f] = {} end
|
|
end
|
|
for i=2, c, 1 do
|
|
local f = p[i]
|
|
local t = p[i-1]
|
|
local o = n[f]
|
|
o[#o+1] = t
|
|
end
|
|
return self
|
|
end
|
|
function tsort:sort()
|
|
local n = self.n
|
|
local s = {}
|
|
local m = {}
|
|
for k in pairs(n) do
|
|
if m[k] == nil then
|
|
if visit(k, n, m, s) then
|
|
return nil, "There is a circular dependency in the graph. It is not possible to derive a topological sort."
|
|
end
|
|
end
|
|
end
|
|
return s
|
|
end
|
|
return tsort
|