diff options
Diffstat (limited to 'plugins/storage/sqlbasic.lib.lua')
-rw-r--r-- | plugins/storage/sqlbasic.lib.lua | 97 |
1 files changed, 97 insertions, 0 deletions
diff --git a/plugins/storage/sqlbasic.lib.lua b/plugins/storage/sqlbasic.lib.lua new file mode 100644 index 00000000..ab3648f9 --- /dev/null +++ b/plugins/storage/sqlbasic.lib.lua @@ -0,0 +1,97 @@ + +-- Basic SQL driver +-- This driver stores data as simple key-values + +local ser = require "util.serialization".serialize; +local envload = require "util.envload".envload; +local deser = function(data) + module:log("debug", "deser: %s", tostring(data)); + if not data then return nil; end + local f = envload("return "..data, nil, {}); + if not f then return nil; end + local s, d = pcall(f); + if not s then return nil; end + return d; +end; + +local driver = {}; +driver.__index = driver; + +driver.item_table = "item"; +driver.list_table = "list"; + +function driver:prepare(sql) + module:log("debug", "query: %s", sql); + local err; + if not self.sqlcache then self.sqlcache = {}; end + local r = self.sqlcache[sql]; + if r then return r; end + r, err = self.connection:prepare(sql); + if not r then error("Unable to prepare SQL statement: "..err); end + self.sqlcache[sql] = r; + return r; +end + +function driver:load(username, host, datastore) + local select = self:prepare("select data from "..self.item_table.." where username=? and host=? and datastore=?"); + select:execute(username, host, datastore); + local row = select:fetch(); + return row and deser(row[1]) or nil; +end + +function driver:store(username, host, datastore, data) + if not data or next(data) == nil then + local delete = self:prepare("delete from "..self.item_table.." where username=? and host=? and datastore=?"); + delete:execute(username, host, datastore); + return true; + else + local d = self:load(username, host, datastore); + if d then -- update + local update = self:prepare("update "..self.item_table.." set data=? where username=? and host=? and datastore=?"); + return update:execute(ser(data), username, host, datastore); + else -- insert + local insert = self:prepare("insert into "..self.item_table.." values (?, ?, ?, ?)"); + return insert:execute(username, host, datastore, ser(data)); + end + end +end + +function driver:list_append(username, host, datastore, data) + if not data then return; end + local insert = self:prepare("insert into "..self.list_table.." values (?, ?, ?, ?)"); + return insert:execute(username, host, datastore, ser(data)); +end + +function driver:list_store(username, host, datastore, data) + -- remove existing data + local delete = self:prepare("delete from "..self.list_table.." where username=? and host=? and datastore=?"); + delete:execute(username, host, datastore); + if data and next(data) ~= nil then + -- add data + for _, d in ipairs(data) do + self:list_append(username, host, datastore, ser(d)); + end + end + return true; +end + +function driver:list_load(username, host, datastore) + local select = self:prepare("select data from "..self.list_table.." where username=? and host=? and datastore=?"); + select:execute(username, host, datastore); + local r = {}; + for row in select:rows() do + table.insert(r, deser(row[1])); + end + return r; +end + +local _M = {}; +function _M.new(dbtype, dbname, ...) + local d = {}; + setmetatable(d, driver); + local dbh = get_database(dbtype, dbname, ...); + --d:set_connection(dbh); + d.connection = dbh; + return d; +end +return _M; |