diff options
Diffstat (limited to 'util')
| -rw-r--r-- | util/sql.lua | 340 |
1 files changed, 340 insertions, 0 deletions
diff --git a/util/sql.lua b/util/sql.lua new file mode 100644 index 00000000..f360d6d0 --- /dev/null +++ b/util/sql.lua @@ -0,0 +1,340 @@ + +local setmetatable, getmetatable = setmetatable, getmetatable; +local ipairs, unpack, select = ipairs, unpack, select; +local tonumber, tostring = tonumber, tostring; +local assert, xpcall, debug_traceback = assert, xpcall, debug.traceback; +local t_concat = table.concat; +local s_char = string.char; +local log = require "util.logger".init("sql"); + +local DBI = require "DBI"; +-- This loads all available drivers while globals are unlocked +-- LuaDBI should be fixed to not set globals. +DBI.Drivers(); +local build_url = require "socket.url".build; + +module("sql") + +local column_mt = {}; +local table_mt = {}; +local query_mt = {}; +--local op_mt = {}; +local index_mt = {}; + +function is_column(x) return getmetatable(x)==column_mt; end +function is_index(x) return getmetatable(x)==index_mt; end +function is_table(x) return getmetatable(x)==table_mt; end +function is_query(x) return getmetatable(x)==query_mt; end +--function is_op(x) return getmetatable(x)==op_mt; end +--function expr(...) return setmetatable({...}, op_mt); end +function Integer(n) return "Integer()" end +function String(n) return "String()" end + +--[[local ops = { + __add = function(a, b) return "("..a.."+"..b..")" end; + __sub = function(a, b) return "("..a.."-"..b..")" end; + __mul = function(a, b) return "("..a.."*"..b..")" end; + __div = function(a, b) return "("..a.."/"..b..")" end; + __mod = function(a, b) return "("..a.."%"..b..")" end; + __pow = function(a, b) return "POW("..a..","..b..")" end; + __unm = function(a) return "NOT("..a..")" end; + __len = function(a) return "COUNT("..a..")" end; + __eq = function(a, b) return "("..a.."=="..b..")" end; + __lt = function(a, b) return "("..a.."<"..b..")" end; + __le = function(a, b) return "("..a.."<="..b..")" end; +}; + +local functions = { + +}; + +local cmap = { + [Integer] = Integer(); + [String] = String(); +};]] + +function Column(definition) + return setmetatable(definition, column_mt); +end +function Table(definition) + local c = {} + for i,col in ipairs(definition) do + if is_column(col) then + c[i], c[col.name] = col, col; + elseif is_index(col) then + col.table = definition.name; + end + end + return setmetatable({ __table__ = definition, c = c, name = definition.name }, table_mt); +end +function Index(definition) + return setmetatable(definition, index_mt); +end + +function table_mt:__tostring() + local s = { 'name="'..self.__table__.name..'"' } + for i,col in ipairs(self.__table__) do + s[#s+1] = tostring(col); + end + return 'Table{ '..t_concat(s, ", ")..' }' +end +table_mt.__index = {}; +function table_mt.__index:create(engine) + return engine:_create_table(self); +end +function table_mt:__call(...) + -- TODO +end +function column_mt:__tostring() + return 'Column{ name="'..self.name..'", type="'..self.type..'" }' +end +function index_mt:__tostring() + local s = 'Index{ name="'..self.name..'"'; + for i=1,#self do s = s..', "'..self[i]:gsub("[\\\"]", "\\%1")..'"'; end + return s..' }'; +-- return 'Index{ name="'..self.name..'", type="'..self.type..'" }' +end +-- + +local function urldecode(s) return s and (s:gsub("%%(%x%x)", function (c) return s_char(tonumber(c,16)); end)); end +local function parse_url(url) + local scheme, secondpart, database = url:match("^([%w%+]+)://([^/]*)/?(.*)"); + assert(scheme, "Invalid URL format"); + local username, password, host, port; + local authpart, hostpart = secondpart:match("([^@]+)@([^@+])"); + if not authpart then hostpart = secondpart; end + if authpart then + username, password = authpart:match("([^:]*):(.*)"); + username = username or authpart; + password = password and urldecode(password); + end + if hostpart then + host, port = hostpart:match("([^:]*):(.*)"); + host = host or hostpart; + port = port and assert(tonumber(port), "Invalid URL format"); + end + return { + scheme = scheme:lower(); + username = username; password = password; + host = host; port = port; + database = #database > 0 and database or nil; + }; +end + +--[[local session = {}; + +function session.query(...) + local rets = {...}; + local query = setmetatable({ __rets = rets, __filters }, query_mt); + return query; +end +-- + +local function db2uri(params) + return build_url{ + scheme = params.driver, + user = params.username, + password = params.password, + host = params.host, + port = params.port, + path = params.database, + }; +end]] + +local engine = {}; +function engine:connect() + if self.conn then return true; end + + local params = self.params; + assert(params.driver, "no driver") + local dbh, err = DBI.Connect( + params.driver, params.database, + params.username, params.password, + params.host, params.port + ); + if not dbh then return nil, err; end + dbh:autocommit(false); -- don't commit automatically + self.conn = dbh; + self.prepared = {}; + return true; +end +function engine:execute(sql, ...) + local success, err = self:connect(); + if not success then return success, err; end + local prepared = self.prepared; + + local stmt = prepared[sql]; + if not stmt then + local err; + stmt, err = self.conn:prepare(sql); + if not stmt then return stmt, err; end + prepared[sql] = stmt; + end + + local success, err = stmt:execute(...); + if not success then return success, err; end + return stmt; +end + +local result_mt = { __index = { + affected = function(self) return self.__affected; end; + rowcount = function(self) return self.__rowcount; end; +} }; + +function engine:execute_query(sql, ...) + if self.params.driver == "PostgreSQL" then + sql = sql:gsub("`", "\""); + end + local stmt = assert(self.conn:prepare(sql)); + assert(stmt:execute(...)); + return stmt:rows(); +end +function engine:execute_update(sql, ...) + if self.params.driver == "PostgreSQL" then + sql = sql:gsub("`", "\""); + end + local prepared = self.prepared; + local stmt = prepared[sql]; + if not stmt then + stmt = assert(self.conn:prepare(sql)); + prepared[sql] = stmt; + end + assert(stmt:execute(...)); + return setmetatable({ __affected = stmt:affected(), __rowcount = stmt:rowcount() }, result_mt); +end +engine.insert = engine.execute_update; +engine.select = engine.execute_query; +engine.delete = engine.execute_update; +engine.update = engine.execute_update; +function engine:_transaction(func, ...) + if not self.conn then + local a,b = self:connect(); + if not a then return a,b; end + end + --assert(not self.__transaction, "Recursive transactions not allowed"); + local args, n_args = {...}, select("#", ...); + local function f() return func(unpack(args, 1, n_args)); end + self.__transaction = true; + local success, a, b, c = xpcall(f, debug_traceback); + self.__transaction = nil; + if success then + log("debug", "SQL transaction success [%s]", tostring(func)); + local ok, err = self.conn:commit(); + if not ok then return ok, err; end -- commit failed + return success, a, b, c; + else + log("debug", "SQL transaction failure [%s]: %s", tostring(func), a); + if self.conn then self.conn:rollback(); end + return success, a; + end +end +function engine:transaction(...) + local a,b = self:_transaction(...); + if not a then + local conn = self.conn; + if not conn or not conn:ping() then + self.conn = nil; + a,b = self:_transaction(...); + end + end + return a,b; +end +function engine:_create_index(index) + local sql = "CREATE INDEX `"..index.name.."` ON `"..index.table.."` ("; + for i=1,#index do + sql = sql.."`"..index[i].."`"; + if i ~= #index then sql = sql..", "; end + end + sql = sql..");" + if self.params.driver == "PostgreSQL" then + sql = sql:gsub("`", "\""); + elseif self.params.driver == "MySQL" then + sql = sql:gsub("`([,)])", "`(20)%1"); + end + --print(sql); + return self:execute(sql); +end +function engine:_create_table(table) + local sql = "CREATE TABLE `"..table.name.."` ("; + for i,col in ipairs(table.c) do + sql = sql.."`"..col.name.."` "..col.type; + if col.nullable == false then sql = sql.." NOT NULL"; end + if i ~= #table.c then sql = sql..", "; end + end + sql = sql.. ");" + if self.params.driver == "PostgreSQL" then + sql = sql:gsub("`", "\""); + end + local success,err = self:execute(sql); + if not success then return success,err; end + for i,v in ipairs(table.__table__) do + if is_index(v) then + self:_create_index(v); + end + end + return success; +end +local engine_mt = { __index = engine }; + +local function db2uri(params) + return build_url{ + scheme = params.driver, + user = params.username, + password = params.password, + host = params.host, + port = params.port, + path = params.database, + }; +end +local engine_cache = {}; -- TODO make weak valued +function create_engine(self, params) + local url = db2uri(params); + if not engine_cache[url] then + local engine = setmetatable({ url = url, params = params }, engine_mt); + engine_cache[url] = engine; + end + return engine_cache[url]; +end + + +--[[Users = Table { + name="users"; + Column { name="user_id", type=String(), primary_key=true }; +}; +print(Users) +print(Users.c.user_id)]] + +--local engine = create_engine('postgresql://scott:tiger@localhost:5432/mydatabase'); +--[[local engine = create_engine{ driver = "SQLite3", database = "./alchemy.sqlite" }; + +local i = 0; +for row in assert(engine:execute("select * from sqlite_master")):rows(true) do + i = i+1; + print(i); + for k,v in pairs(row) do + print("",k,v); + end +end +print("---") + +Prosody = Table { + name="prosody"; + Column { name="host", type="TEXT", nullable=false }; + Column { name="user", type="TEXT", nullable=false }; + Column { name="store", type="TEXT", nullable=false }; + Column { name="key", type="TEXT", nullable=false }; + Column { name="type", type="TEXT", nullable=false }; + Column { name="value", type="TEXT", nullable=false }; + Index { name="prosody_index", "host", "user", "store", "key" }; +}; +--print(Prosody); +assert(engine:transaction(function() + assert(Prosody:create(engine)); +end)); + +for row in assert(engine:execute("select user from prosody")):rows(true) do + print("username:", row['username']) +end +--result.close();]] + +return _M; |