the begginning

versioning/BRM/autoincrementmanager.cpp

@@ -0,0 +1,141 @@
+/* Copyright (C) 2014 InfiniDB, Inc.
+
+   This program is free software; you can redistribute it and/or
+   modify it under the terms of the GNU General Public License
+   as published by the Free Software Foundation; version 2 of
+   the License.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program; if not, write to the Free Software
+   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
+   MA 02110-1301, USA. */
+
+/*****************************************************************************
+ * $Id$
+ *
+ ****************************************************************************/
+
+#define BRMAUTOINCMGR_DLLEXPORT
+#include "autoincrementmanager.h"
+#undef BRMAUTOINCMGR_DLLEXPORT
+
+#include <math.h>
+#include <boost/date_time/posix_time/posix_time.hpp>
+
+using namespace std;
+using namespace boost;
+using namespace boost::posix_time;
+
+namespace BRM {
+
+AutoincrementManager::AutoincrementManager()
+{
+}
+
+AutoincrementManager::~AutoincrementManager()
+{
+}
+
+void AutoincrementManager::startSequence(uint32_t oid, uint64_t firstNum, uint32_t colWidth,
+                                         execplan::CalpontSystemCatalog::ColDataType colDataType)
+{
+	mutex::scoped_lock lk(lock);
+	map<uint64_t, sequence>::iterator it;
+	sequence s;
+
+	it = sequences.find(oid);
+	if (it != sequences.end())
+		return;
+
+	s.value = firstNum;
+    if (isUnsigned(colDataType))
+    {
+        s.overflow = (0xFFFFFFFFFFFFFFFFULL >> (64-colWidth*8)) - 1;
+    }
+    else
+    {
+        s.overflow = (1ULL << (colWidth*8-1));
+    }
+	sequences[oid] = s;
+}
+
+bool AutoincrementManager::getAIRange(uint32_t oid, uint64_t count, uint64_t *firstNum)
+{
+	mutex::scoped_lock lk(lock);
+	map<uint64_t, sequence>::iterator it;
+
+	it = sequences.find(oid);
+	if (it == sequences.end())
+		throw runtime_error("There is no sequence with that lock");
+	if ((count >= it->second.overflow ||
+	  count + it->second.value > it->second.overflow ||
+	  count + it->second.value <= it->second.value)
+	  && count != 0)
+		return false;
+	*firstNum = it->second.value;
+	it->second.value += count;
+	return true;
+}
+
+void AutoincrementManager::resetSequence(uint32_t oid, uint64_t value)
+{
+	mutex::scoped_lock lk(lock);
+	map<uint64_t, sequence>::iterator it;
+
+	it = sequences.find(oid);
+	if (it == sequences.end())
+		return;
+	it->second.value = value;
+}
+
+void AutoincrementManager::getLock(uint32_t oid)
+{
+	mutex::scoped_lock lk(lock);
+	map<uint64_t, sequence>::iterator it;
+	ptime stealTime = microsec_clock::local_time() + seconds(lockTime);
+
+	bool gotIt = false;
+
+	it = sequences.find(oid);
+	if (it == sequences.end())
+		throw runtime_error("There is no sequence with that lock");
+	lk.unlock();
+
+	while (!gotIt && microsec_clock::local_time() < stealTime) {
+		gotIt = it->second.lock.try_lock();
+		if (!gotIt)
+			usleep(100000);
+	}
+	// If !gotIt, take possession
+}
+
+void AutoincrementManager::releaseLock(uint32_t oid)
+{
+	mutex::scoped_lock lk(lock);
+	map<uint64_t, sequence>::iterator it;
+
+	it = sequences.find(oid);
+	if (it == sequences.end())
+		return;   // it's unlocked if the lock doesn't exist...
+	lk.unlock();
+
+	it->second.lock.unlock();
+}
+
+void AutoincrementManager::deleteSequence(uint32_t oid)
+{
+	mutex::scoped_lock lk(lock);
+	map<uint64_t, sequence>::iterator it;
+
+	it = sequences.find(oid);
+	if (it != sequences.end())
+		sequences.erase(it);
+}
+
+
+} /* namespace BRM */