From 5e415c5b9565564c41c4f2f4144c6863c106bc46 Mon Sep 17 00:00:00 2001
From: madmaxoft <github@xoft.cz>
Date: Wed, 13 Aug 2014 12:33:31 +0200
Subject: RankMgr: Fixed multithreading issues.

Only one thread is allowed to interact with a SQLite::Database object at a time.
Additionally, improved performance of the migration by wrapping the entire thing in a transaction.
---
 src/RankManager.h | 32 +++++++++++++++++++++++++++++++-
 1 file changed, 31 insertions(+), 1 deletion(-)

(limited to 'src/RankManager.h')

diff --git a/src/RankManager.h b/src/RankManager.h
index ffe7638e1..3ccbd2fd4 100644
--- a/src/RankManager.h
+++ b/src/RankManager.h
@@ -9,6 +9,7 @@
 #pragma once
 
 #include "SQLiteCpp/Database.h"
+#include "SQLiteCpp/Transaction.h"
 
 
 
@@ -23,6 +24,29 @@ class cMojangAPI;
 class cRankManager
 {
 public:
+	/** Acquire this lock to perform mass changes.
+	Improves performance by wrapping everything into a transaction.
+	Makes sure that no other thread is accessing the DB. */
+	class cMassChangeLock
+	{
+	public:
+		cMassChangeLock(cRankManager & a_RankManager) :
+			m_Lock(a_RankManager.m_CS),
+			m_Transaction(a_RankManager.m_DB)
+		{
+		}
+		
+		~cMassChangeLock()
+		{
+			m_Transaction.commit();
+		}
+		
+	protected:
+		cCSLock m_Lock;
+		SQLite::Transaction m_Transaction;
+	};
+	
+	
 	/** Creates the rank manager. Needs to be initialized before other use. */
 	cRankManager(void);
 	
@@ -80,6 +104,9 @@ public:
 	/** Adds a new permission group. No action if such a group already exists. */
 	void AddGroup(const AString & a_GroupName);
 	
+	/** Bulk-adds groups. Group names that already exist are silently skipped. */
+	void AddGroups(const AStringVector & a_GroupNames);
+	
 	/** Adds the specified permission group to the specified rank.
 	Fails if the rank or group names are not found.
 	Returns true if successful, false on error. */
@@ -163,9 +190,12 @@ public:
 	
 protected:
 
-	/** The database storage for all the data. */
+	/** The database storage for all the data. Protected by m_CS. */
 	SQLite::Database m_DB;
 	
+	/** The mutex protecting m_DB against multi-threaded access. */
+	cCriticalSection m_CS;
+	
 	/** Set to true once the manager is initialized. */
 	bool m_IsInitialized;
 	
-- 
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