minor refactoring to lapis.db.mysql, use metatable to inherit base db

Author: leafo

lapis/db/mysql.lua

@@ -6,15 +6,15 @@ end
 local concat
 concat = table.concat
 local unpack = unpack or table.unpack
-local FALSE, NULL, TRUE, build_helpers, format_date, is_raw, raw, is_list, list, is_encodable, clause, is_clause
+local NULL, build_helpers, is_raw, is_list
 do
   local _obj_0 = require("lapis.db.base")
-  FALSE, NULL, TRUE, build_helpers, format_date, is_raw, raw, is_list, list, is_encodable, clause, is_clause = _obj_0.FALSE, _obj_0.NULL, _obj_0.TRUE, _obj_0.build_helpers, _obj_0.format_date, _obj_0.is_raw, _obj_0.raw, _obj_0.is_list, _obj_0.list, _obj_0.is_encodable, _obj_0.clause, _obj_0.is_clause
+  NULL, build_helpers, is_raw, is_list = _obj_0.NULL, _obj_0.build_helpers, _obj_0.is_raw, _obj_0.is_list
 end
 local logger = require("lapis.logging")
-local conn
-local BACKENDS, set_raw_query, get_raw_query, escape_literal, escape_identifier, connect, raw_query, interpolate_query, encode_values, encode_assigns, encode_clause, append_all, add_cond, query, _select, _insert, _update, _delete, _truncate
-BACKENDS = {
+local active_connection
+local connect, raw_query
+local BACKENDS = {
   luasql = function()
     local config = require("lapis.config").get()
     local mysql_config = assert(config.mysql, "missing mysql configuration")
@@ -30,14 +30,14 @@ BACKENDS = {
         table.insert(conn_opts, mysql_config.port)
       end
     end
-    conn = assert(luasql:connect(unpack(conn_opts)))
+    active_connection = assert(luasql:connect(unpack(conn_opts)))
     return function(q)
       logger.query(q)
-      local cur = assert(conn:execute(q))
+      local cur = assert(active_connection:execute(q))
       local has_rows = type(cur) ~= "number"
       local result = {
         affected_rows = has_rows and cur:numrows() or cur,
-        last_auto_id = conn:getlastautoid()
+        last_auto_id = active_connection:getlastautoid()
       }
       if has_rows then
         local colnames = cur:getcolnames()
@@ -156,19 +156,22 @@ BACKENDS = {
     end
   end
 }
+local set_raw_query
 set_raw_query = function(fn)
   raw_query = fn
 end
+local get_raw_query
 get_raw_query = function()
   return raw_query
 end
+local escape_literal
 escape_literal = function(val)
   local _exp_0 = type(val)
   if "number" == _exp_0 then
     return tostring(val)
   elseif "string" == _exp_0 then
-    if conn then
-      return "'" .. tostring(conn:escape(val)) .. "'"
+    if active_connection then
+      return "'" .. tostring(active_connection:escape(val)) .. "'"
     else
       if ngx then
         return ngx.quote_sql_str(val)
@@ -206,6 +209,7 @@ escape_literal = function(val)
   end
   return error("don't know how to escape value: " .. tostring(val))
 end
+local escape_identifier
 escape_identifier = function(ident)
   if is_raw(ident) then
     return ident[1]
@@ -234,12 +238,14 @@ raw_query = function(...)
   connect()
   return raw_query(...)
 end
-interpolate_query, encode_values, encode_assigns, encode_clause = build_helpers(escape_literal, escape_identifier)
+local interpolate_query, encode_values, encode_assigns, encode_clause = build_helpers(escape_literal, escape_identifier)
+local append_all
 append_all = function(t, ...)
   for i = 1, select("#", ...) do
     t[#t + 1] = select(i, ...)
   end
 end
+local add_cond
 add_cond = function(buffer, cond, ...)
   append_all(buffer, " WHERE ")
   local _exp_0 = type(cond)
@@ -249,15 +255,18 @@ add_cond = function(buffer, cond, ...)
     return append_all(buffer, interpolate_query(cond, ...))
   end
 end
+local query
 query = function(str, ...)
   if select("#", ...) > 0 then
     str = interpolate_query(str, ...)
   end
   return raw_query(str)
 end
+local _select
 _select = function(str, ...)
   return query("SELECT " .. str, ...)
 end
+local _insert
 _insert = function(tbl, values, ...)
   local buff = {
     "INSERT INTO ",
@@ -267,6 +276,7 @@ _insert = function(tbl, values, ...)
   encode_values(values, buff)
   return raw_query(concat(buff))
 end
+local _update
 _update = function(table, values, cond, ...)
   local buff = {
     "UPDATE ",
@@ -279,6 +289,7 @@ _update = function(table, values, cond, ...)
   end
   return raw_query(concat(buff))
 end
+local _delete
 _delete = function(table, cond, ...)
   local buff = {
     "DELETE FROM ",
@@ -289,30 +300,20 @@ _delete = function(table, cond, ...)
   end
   return raw_query(concat(buff))
 end
+local _truncate
 _truncate = function(table)
   return raw_query("TRUNCATE " .. escape_identifier(table))
 end
-return {
+return setmetatable({
   __type = "mysql",
   connect = connect,
-  NULL = NULL,
-  TRUE = TRUE,
-  FALSE = FALSE,
-  raw = raw,
-  is_raw = is_raw,
-  list = list,
-  is_list = is_list,
-  clause = clause,
-  is_clause = is_clause,
-  is_encodable = is_encodable,
   encode_values = encode_values,
   encode_assigns = encode_assigns,
   encode_clause = encode_clause,
   interpolate_query = interpolate_query,
   query = query,
   escape_literal = escape_literal,
   escape_identifier = escape_identifier,
-  format_date = format_date,
   set_raw_query = set_raw_query,
   get_raw_query = get_raw_query,
   parse_clause = function()
@@ -324,4 +325,6 @@ return {
   delete = _delete,
   truncate = _truncate,
   BACKENDS = BACKENDS
-}
+}, {
+  __index = require("lapis.db.base")
+})

lapis/db/mysql.moon

@@ -5,24 +5,19 @@ import concat from table
 unpack = unpack or table.unpack
 
 import
-  FALSE
   NULL
-  TRUE
   build_helpers
-  format_date
   is_raw
-  raw
   is_list
-  list
-  is_encodable
-  clause
-  is_clause
   from require "lapis.db.base"
 
 logger = require "lapis.logging"
 
-local conn
-local *
+-- NOTE: active connection only stored in local with luasql, otherwise request
+-- context is used to store connection
+local active_connection
+
+local connect, raw_query
 
 BACKENDS = {
   luasql: ->
@@ -35,16 +30,20 @@ BACKENDS = {
       table.insert conn_opts, mysql_config.host
       if mysql_config.port then table.insert conn_opts, mysql_config.port
 
-    conn = assert luasql\connect unpack(conn_opts)
+    -- Note that connection is established up front. This is
+    -- necessary since connection is used for escaping literal when
+    -- using lua sql. This is distinct from ngx mode which lazily
+    -- establishes connection on first query
+    active_connection = assert luasql\connect unpack(conn_opts)
 
     (q) ->
       logger.query q
-      cur = assert conn\execute q
+      cur = assert active_connection\execute q
       has_rows = type(cur) != "number"
 
       result = {
         affected_rows: has_rows and cur\numrows! or cur
-        last_auto_id: conn\getlastautoid!
+        last_auto_id: active_connection\getlastautoid!
       }
 
       if has_rows
@@ -152,8 +151,8 @@ escape_literal = (val) ->
     when "number"
       return tostring val
     when "string"
-      if conn
-        return "'#{conn\escape val}'"
+      if active_connection
+        return "'#{active_connection\escape val}'"
       else if ngx
         return ngx.quote_sql_str(val)
       else
@@ -268,17 +267,17 @@ _truncate = (table) ->
 -- 
 -- }
 
-{
+setmetatable {
   __type: "mysql"
 
   :connect
-  :NULL, :TRUE, :FALSE
-
-  :raw, :is_raw
-  :list, :is_list
-  :clause, :is_clause
 
-  :is_encodable
+  -- :NULL, :TRUE, :FALSE
+  -- :raw, :is_raw
+  -- :list, :is_list
+  -- :clause, :is_clause
+  -- :format_date
+  -- :is_encodable
 
   :encode_values
   :encode_assigns
@@ -289,8 +288,6 @@ _truncate = (table) ->
   :escape_literal
   :escape_identifier
 
-  :format_date
-
   :set_raw_query
   :get_raw_query
 
@@ -303,4 +300,5 @@ _truncate = (table) ->
   truncate: _truncate
 
   :BACKENDS
-}
+}, __index: require "lapis.db.base"
+

lapis/spec/db.moon

@@ -1,6 +1,6 @@
 
--- NOTE: do not require lapis.db, etc. on the top level as it will try to bind
--- to the connection type to the closure.
+-- NOTE: do not require config dependent modules on the top level here, eg.
+-- lapis.db
 
 import assert_env from require "lapis.environment"
 

spec/mysql_spec.moon

@@ -15,6 +15,10 @@ value_table = { hello: db.FALSE, age: 34 }
 
 TESTS = {
   -- lapis.db.mysql
+  {
+    -> db.format_date 0
+    "1970-01-01 00:00:00"
+  }
   {
     -> db.escape_identifier "dad"
     '`dad`'

spec/postgres_spec.moon

@@ -11,6 +11,10 @@ import sorted_pairs from require "spec.helpers"
 
 TESTS = {
   -- lapis.db.postgres
+  {
+    -> db.format_date 0
+    "1970-01-01 00:00:00"
+  }
   {
     -> db.escape_identifier "dad"
     '"dad"'