mod_storage_sql: Reconnect in all cases, and rollback on error.

diff --git a/plugins/mod_storage_sql.lua b/plugins/mod_storage_sql.lua
index 3f28307d3046b34ad80746cf93d169bc14aff715..07735cb21a6f8e0b64daf639e34a4b58fb6c8bc6 100644 (file)
--- a/plugins/mod_storage_sql.lua
+++ b/plugins/mod_storage_sql.lua
@@ -28,14 +28,44 @@ local setmetatable = setmetatable;
 local xpcall = xpcall;
 local json = require "util.json";
 
+local DBI;
 local connection;
 local host,user,store = module.host;
 local params = module:get_option("sql");
 
 local resolve_relative_path = require "core.configmanager".resolve_relative_path;
 
+local function test_connection()
+       if not connection then return nil; end
+       if connection:ping() then
+               return true;
+       else
+               module:log("debug", "Database connection closed");
+               connection = nil;
+       end
+end
+local function connect()
+       if not test_connection() then
+               prosody.unlock_globals();
+               local dbh, err = DBI.Connect(
+                       params.driver, params.database,
+                       params.username, params.password,
+                       params.host, params.port
+               );
+               prosody.lock_globals();
+               if not dbh then
+                       module:log("debug", "Database connection failed: %s", tostring(err));
+                       return nil, err;
+               end
+               module:log("debug", "Successfully connected to database");
+               dbh:autocommit(false); -- don't commit automatically
+               connection = dbh;
+               return connection;
+       end
+end
+
 do -- process options to get a db connection
-       local DBI = require "DBI";
+       DBI = require "DBI";
 
        params = params or { driver = "SQLite3" };
        
@@ -45,17 +75,7 @@ do -- process options to get a db connection
        
        assert(params.driver and params.database, "Both the SQL driver and the database need to be specified");
        
-       prosody.unlock_globals();
-       local dbh, err = DBI.Connect(
-               params.driver, params.database,
-               params.username, params.password,
-               params.host, params.port
-       );
-       prosody.lock_globals();
-       assert(dbh, err);
-
-       dbh:autocommit(false); -- don't commit automatically
-       connection = dbh;
+       assert(connect());
        
        -- Automatically create table, ignore failure (table probably already exists)
        local create_sql = "CREATE TABLE `prosody` (`host` TEXT, `user` TEXT, `store` TEXT, `key` TEXT, `type` TEXT, `value` TEXT);";
@@ -101,9 +121,11 @@ local function getsql(sql, ...)
        end
        -- do prepared statement stuff
        local stmt, err = connection:prepare(sql);
+       if not stmt and not test_connection() then error("connection failed"); end
        if not stmt then module:log("error", "QUERY FAILED: %s %s", err, debug.traceback()); return nil, err; end
        -- run query
        local ok, err = stmt:execute(host or "", user or "", store or "", ...);
+       if not ok and not test_connection() then error("connection failed"); end
        if not ok then return nil, err; end
        
        return stmt;
@@ -117,7 +139,7 @@ local function transact(...)
        -- ...
 end
 local function rollback(...)
-       connection:rollback(); -- FIXME check for rollback error?
+       if connection then connection:rollback(); end -- FIXME check for rollback error?
        return ...;
 end
 local function commit(...)
@@ -127,7 +149,7 @@ end
 
 local function keyval_store_get()
        local stmt, err = getsql("SELECT * FROM `prosody` WHERE `host`=? AND `user`=? AND `store`=?");
-       if not stmt then return nil, err; end
+       if not stmt then return rollback(nil, err); end
        
        local haveany;
        local result = {};
@@ -147,6 +169,7 @@ local function keyval_store_get()
 end
 local function keyval_store_set(data)
        local affected, err = setsql("DELETE FROM `prosody` WHERE `host`=? AND `user`=? AND `store`=?");
+       if not affected then return rollback(affected, err); end
        
        if data and next(data) ~= nil then
                local extradata = {};
@@ -174,18 +197,26 @@ local keyval_store = {};
 keyval_store.__index = keyval_store;
 function keyval_store:get(username)
        user,store = username,self.store;
+       if not connection and not connect() then return nil, "Unable to connect to database"; end
        local success, ret, err = xpcall(keyval_store_get, debug.traceback);
+       if not connection and connect() then
+               success, ret, err = xpcall(keyval_store_get, debug.traceback);
+       end
        if success then return ret, err; else return rollback(nil, ret); end
 end
 function keyval_store:set(username, data)
        user,store = username,self.store;
+       if not connection and not connect() then return nil, "Unable to connect to database"; end
        local success, ret, err = xpcall(function() return keyval_store_set(data); end, debug.traceback);
+       if not connection and connect() then
+               success, ret, err = xpcall(function() return keyval_store_set(data); end, debug.traceback);
+       end
        if success then return ret, err; else return rollback(nil, ret); end
 end
 
 local function map_store_get(key)
        local stmt, err = getsql("SELECT * FROM `prosody` WHERE `host`=? AND `user`=? AND `store`=? AND `key`=?", key or "");
-       if not stmt then return nil, err; end
+       if not stmt then return rollback(nil, err); end
        
        local haveany;
        local result = {};
@@ -205,6 +236,7 @@ local function map_store_get(key)
 end
 local function map_store_set(key, data)
        local affected, err = setsql("DELETE FROM `prosody` WHERE `host`=? AND `user`=? AND `store`=? AND `key`=?", key or "");
+       if not affected then return rollback(affected, err); end
        
        if data and next(data) ~= nil then
                if type(key) == "string" and key ~= "" then