the begginning

utils/common/fixedallocator.cpp

@@ -0,0 +1,122 @@
+/* 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. */
+
+/******************************************************************************************
+* $Id$
+*
+******************************************************************************************/
+
+//This is one of the first files we compile, check the compiler...
+#if defined(__GNUC__)
+#if __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 1)
+#error "This is a very old GCC, and it's probably not going to work."
+#endif
+#elif defined(_MSC_VER)
+#else
+#error "This compiler is not known and it's probably not going to work."
+#endif
+
+#include <stdint.h>
+#include <iostream>
+
+#define FIXEDALLOCATOR_DLLEXPORT
+#include "fixedallocator.h"
+#undef FIXEDALLOCATOR_DLLEXPORT
+
+using namespace std;
+using namespace boost;
+
+namespace utils {
+
+FixedAllocator::FixedAllocator(const FixedAllocator &f)
+{
+	elementCount = f.elementCount;
+	elementSize = f.elementSize;
+	tmpSpace = f.tmpSpace;
+	capacityRemaining = 0;
+	currentlyStored = 0;
+}
+
+FixedAllocator & FixedAllocator::operator=(const FixedAllocator &f)
+{
+	elementCount = f.elementCount;
+	elementSize = f.elementSize;
+	tmpSpace = f.tmpSpace;
+	deallocateAll();
+	return *this;
+}
+
+void FixedAllocator::newBlock()
+{
+	shared_array<uint8_t> next;
+
+	capacityRemaining = elementCount * elementSize;
+	if (!tmpSpace || mem.size() == 0) {
+		next.reset(new uint8_t[elementCount * elementSize]);
+		mem.push_back(next);
+		nextAlloc = next.get();
+	}
+	else {
+		currentlyStored = 0;
+		nextAlloc = mem.front().get();
+	}
+}
+
+void * FixedAllocator::allocate()
+{
+	void *ret;
+	if (capacityRemaining < elementSize)
+		newBlock();
+	ret = nextAlloc;
+	nextAlloc += elementSize;
+	capacityRemaining -= elementSize;
+	currentlyStored += elementSize;
+	return ret;
+}
+
+void * FixedAllocator::allocate(uint32_t len)
+{
+	void *ret;
+	if (capacityRemaining < len)
+		newBlock();
+	ret = nextAlloc;
+	nextAlloc += len;
+	capacityRemaining -= len;
+	currentlyStored += len;
+	return ret;
+}
+
+void FixedAllocator::truncateBy(uint32_t amt)
+{
+	nextAlloc -= amt;
+	capacityRemaining += amt;
+	currentlyStored -= amt;
+}
+
+void FixedAllocator::deallocateAll()
+{
+	mem.clear();
+	currentlyStored = 0;
+	capacityRemaining = 0;
+}
+
+uint64_t FixedAllocator::getMemUsage() const 
+{
+	return (mem.size() * elementCount * elementSize);
+}
+
+}