From 387e6e7ffa747a27412c66c7efca6fde4abc6169 Mon Sep 17 00:00:00 2001
From: Dorian Wouters <elementw@openmailbox.org>
Date: Sat, 3 Jun 2017 22:58:42 -0400
Subject: [PATCH] Initial commit

---
 .gitmodules |   3 +
 README.md   | 108 ++++++++++++++++++++++++++++++
 init.lua    | 186 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 mysql       |   1 +
 4 files changed, 298 insertions(+)
 create mode 100644 .gitmodules
 create mode 100644 README.md
 create mode 100644 init.lua
 create mode 160000 mysql

diff --git a/.gitmodules b/.gitmodules
new file mode 100644
index 0000000..065a19b
--- /dev/null
+++ b/.gitmodules
@@ -0,0 +1,3 @@
+[submodule "mysql"]
+	path = mysql
+	url = https://github.com/luapower/mysql.git
diff --git a/README.md b/README.md
new file mode 100644
index 0000000..56cd50b
--- /dev/null
+++ b/README.md
@@ -0,0 +1,108 @@
+# mysql_base
+
+Base Minetest mod to connect to a MySQL database. Used by other mods to read/write data.
+
+# Installing
+
+Get this repository's contents using `git`, and make sure to fetch submodules
+(`git submodule update --init`).
+
+# Configuration
+
+First, if mod security is enabled (`secure.enable_security = true`), this mod must be added as
+a trusted mod (in the `secure.trusted_mods` config entry). There is **no** other solution to
+make it work under mod security.
+
+By default `mysql_base` doesn't run in singleplayer. This can be overriden by setting
+`mysql_base.enable_singleplayer` to `true`.
+
+Configuration may be done as regular Minetest settings entries, or using a config file, allowing
+for more configuration options; to do so specify the path as `mysql_base.cfgfile`. This config
+must contain a Lua table that can be read by `minetest.deserialize`, i.e. a regular table
+definition follwing a `return` statement (see the example below).
+
+When using flat Minetest configuation entries, all the following option names must be prefixed
+with `mysql_base.`. When using a config file, entries are to be hierarchised as per the dot
+separator.
+
+Values written next to option names are default values.
+
+## Database connection
+
+### Minetest flat config file
+
+Values after the  "`=`" are the default values used if unspecified.
+```
+mysql_base.db.host = 'localhost'
+mysql_base.db.user = nil -- MySQL connector defaults to current username
+mysql_base.db.pass = nil -- Using password: NO
+mysql_base.db.port = nil -- MySQL connector defaults to either 3306, or no port if using localhost/unix socket
+mysql_base.db.db = nil -- <== Setting this is required
+```
+
+### Lua table config file
+
+Connection options are passed as a table through the `db.connopts` entry.
+Its format must be the same as [LuaPower's MySQL module `mysql.connect(options_t)` function][mycn],
+that is (all members are optional);
+
+```lua
+return {
+  db = {
+    connopts = {
+      host = ...,
+      user = ...,
+      pass = ...,
+      db = ...,
+      port = ...,
+      unix_socket = ...,
+      flags = { ... },
+      options = { ... },
+      attrs = { ... },
+      -- Also key, cert, ca, cpath, cipher
+    }
+  }
+}
+```
+
+## Examples
+
+### Example 1
+
+#### Using a Lua config file
+
+`minetest.conf`:
+```
+mysql_auth.cfgfile = /srv/minetest/skyblock/mysql_auth_config
+```
+
+`/srv/minetest/skyblock/mysql_auth_config`:
+```lua
+return {
+  db = {
+    connopts = {
+      user = 'minetest',
+      pass = 'BQy77wK$Um6es3Bi($iZ*w3N',
+      db = 'minetest'
+    },
+  }
+}
+```
+
+#### Using only Minetest config entries
+
+`minetest.conf`:
+```
+mysql_auth.db.user = minetest
+mysql_auth.db.pass = BQy77wK$Um6es3Bi($iZ*w3N
+mysql_auth.db.db = minetest
+```
+
+# License
+
+`mysql_base` is licensed under [LGPLv3](https://www.gnu.org/licenses/lgpl.html).
+
+Using the Public Domain-licensed LuaPower `mysql` module.
+
+
+[mycn]: https://luapower.com/mysql#mysql.connectoptions_t---conn
diff --git a/init.lua b/init.lua
new file mode 100644
index 0000000..c0f0591
--- /dev/null
+++ b/init.lua
@@ -0,0 +1,186 @@
+local modname = minetest.get_current_modname()
+local modpath = minetest.get_modpath(modname) 
+
+local thismod = {
+  enabled = false,
+}
+_G[modname] = thismod
+
+local singleplayer = minetest.is_singleplayer() -- Caching is OK since you can't open a game to
+-- multiplayer unless you restart it.
+if not minetest.setting_get(modname .. '.enable_singleplayer') and singleplayer then
+  minetest.log('action', modname .. ": Not enabling because of singleplayer game")
+  return
+end
+
+thismod.enabled = true
+
+local function setoverlay(tab, orig)
+  local mt = getmetatable(tab) or {}
+  mt.__index = function (tab, key)
+    if rawget(tab, key) ~= nil then
+      return rawget(tab, key)
+    else
+      return orig[key]
+    end
+  end
+  setmetatable(tab, mt)
+end
+
+local function string_splitdots(s)
+  local temp = {}
+  local index = 0
+  local last_index = string.len(s)
+  while true do
+    local i, e = string.find(s, '%.', index)
+    if i and e then
+      local next_index = e + 1
+      local word_bound = i - 1
+      table.insert(temp, string.sub(s, index, word_bound))
+      index = next_index
+    else            
+      if index > 0 and index <= last_index then
+        table.insert(temp, string.sub(s, index, last_index))
+      elseif index == 0 then
+        temp = nil
+      end
+      break
+    end
+  end
+  return temp
+end
+
+local mysql
+do -- MySQL module loading
+  local env = {
+    require = function (module)
+      if module == 'mysql_h' then
+        return dofile(modpath .. '/mysql/mysql_h.lua')
+      else
+        return require(module)
+      end
+    end
+  }
+  setoverlay(env, _G)
+  local fn, msg = loadfile(modpath .. '/mysql/mysql.lua')
+  if not fn then error(msg) end
+  setfenv(fn, env)
+  local status
+  status, mysql = pcall(fn, {})
+  if not status then
+    error(modname .. ' failed to load MySQL FFI interface: ' .. tostring(mysql))
+  end
+  thismod.mysql = mysql
+end
+
+function thismod.mkget(modname)
+  local get = function (name) return minetest.setting_get(modname .. '.' .. name) end
+  local cfgfile = get('cfgfile')
+  if type(cfgfile) == 'string' and cfgfile ~= '' then
+    local file = io.open(cfgfile, 'rb')
+    if not file then
+      error(modname .. ' failed to load specified config file at ' .. cfgfile)
+    end
+    local cfg, msg = minetest.deserialize(file:read('*a'))
+    file:close()
+    if not cfg then
+      error(modname .. ' failed to parse specified config file at ' .. cfgfile .. ': ' .. msg)
+    end
+    get = function (name)
+      if type(name) ~= 'string' or name == '' then
+        return nil
+      end
+      local parts = string_splitdots(name)
+      if not parts then
+        return cfg[name]
+      end
+      local tbl = cfg[parts[1]]
+      for n = 2, #parts do
+        if tbl == nil then
+          return nil
+        end
+        tbl = tbl[parts[n]]
+      end
+      return tbl
+    end
+  end
+  return get
+end
+
+local get = thismod.mkget(modname)
+do
+  local conn, dbname
+  -- MySQL API backend
+  mysql.config(get('db.api'))
+
+  local connopts = get('db.connopts')
+  if (get('db.db') == nil) and (type(connopts) == 'table' and connopts.db == nil) then
+    error(modname .. ": missing database name parameter")
+  end
+  if type(connopts) ~= 'table' then
+    connopts = {}
+    -- Traditional connection parameters
+    connopts.host, connopts.user, connopts.port, connopts.pass, connopts.db =
+      get('db.host') or 'localhost', get('db.user'), get('db.port'), get('db.pass'), get('db.db')
+  end
+  connopts.charset = 'utf8'
+  connopts.options = connopts.options or {}
+  connopts.options.MYSQL_OPT_RECONNECT = true
+  conn = mysql.connect(connopts)
+  dbname = connopts.db
+  minetest.log('action', modname .. ": Connected to MySQL database " .. dbname)
+  thismod.conn = conn
+  thismod.dbname = dbname
+
+  -- LuaPower's MySQL interface throws an error when the connection fails, no need to check if
+  -- it succeeded.
+
+  -- Ensure UTF-8 is in use.
+  -- If you use another encoding, kill yourself (unless it's UTF-32).
+  conn:query("SET NAMES 'utf8'")
+  conn:query("SET CHARACTER SET utf8")
+  conn:query("SET character_set_results = 'utf8', character_set_client = 'utf8'," ..
+                  "character_set_connection = 'utf8', character_set_database = 'utf8'," ..
+                  "character_set_server = 'utf8'")
+
+  local set = function(setting, val) conn:query('SET ' .. setting .. '=' .. val) end
+  pcall(set, 'wait_timeout', 3600)
+  pcall(set, 'autocommit', 1)
+  pcall(set, 'max_allowed_packet', 67108864)
+end
+
+local function ping()
+  if thismod.conn then
+    if not thismod.conn:ping() then
+      minetest.log('error', modname .. ": failed to ping database")
+    end
+  end
+  minetest.after(1800, ping)
+end
+minetest.after(10, ping)
+
+local shutdown_callbacks = {}
+function thismod.register_on_shutdown(func)
+  table.insert(shutdown_callbacks, func)
+end
+
+minetest.register_on_shutdown(function()
+  if thismod.conn then
+    minetest.log('action', modname .. ": Shutting down, running callbacks")
+    for _, func in ipairs(shutdown_callbacks) do
+      func()
+    end
+    thismod.conn:close()
+    thismod.conn = nil
+    minetest.log('action', modname .. ": Cosed database connection")
+  end
+end)
+
+function thismod.table_exists(name)
+  thismod.conn:query("SHOW TABLES LIKE '" .. name .. "'")
+  local res = thismod.conn:store_result()
+  local exists = (res:row_count() ~= 0)
+  res:free()
+  return exists
+end
+
diff --git a/mysql b/mysql
new file mode 160000
index 0000000..4bc8277
--- /dev/null
+++ b/mysql
@@ -0,0 +1 @@
+Subproject commit 4bc82774707695bf934682eb401ed44ab06d63d5