forked from mtcontrib/colddb
89 lines
1.6 KiB
Lua
89 lines
1.6 KiB
Lua
local mp = require("MessagePack")
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local function isFile(path)
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local f = io.open(path, "r")
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if f then
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f:close()
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return true
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end
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return false
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end
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local function isDir(path)
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local tmp = path.."/"..os.tmpname()
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local f = io.open(tmp, "w")
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if f then
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f:close()
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os.remove(tmp)
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return true
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end
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return false
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end
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local function load_page(path)
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local ret
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local f = io.open(path, "rb")
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if f then
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ret = mp.unpack(f:read("*a"))
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f:close()
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end
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return ret
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end
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local function store_page(path, page)
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if type(page) == "table" then
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local f = io.open(path, "wb")
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if f then
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f:write(mp.pack(page))
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f:close()
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return true
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end
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end
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return false
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end
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local pool = {}
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local db_funcs = {
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save = function(db, p)
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if p then
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if type(p) == "string" and type(db[p]) == "table" then
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return store_page(pool[db].."/"..p, db[p])
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else
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return false
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end
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end
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for p, page in pairs(db) do
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if not store_page(pool[db].."/"..p, page) then
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return false
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end
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end
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return true
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end
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}
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local mt = {
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__index = function(db, k)
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if db_funcs[k] then return db_funcs[k] end
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if isFile(pool[db].."/"..k) then
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db[k] = load_page(pool[db].."/"..k)
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end
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return rawget(db, k)
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end
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}
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pool.hack = db_funcs
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return setmetatable(pool, {
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__mode = "kv",
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__call = function(pool, path)
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assert(isDir(path), path.." is not a directory.")
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if pool[path] then return pool[path] end
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local db = {}
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setmetatable(db, mt)
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pool[path] = db
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pool[db] = path
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return db
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end
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})
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