Introduce DataPacks (bug 5885, r=ds)

amxmodx/CDataPack.cpp

@@ -0,0 +1,259 @@
+/**
+ * vim: set ts=4 :
+ * =============================================================================
+ * SourceMod
+ * Copyright (C) 2004-2008 AlliedModders LLC.  All rights reserved.
+ * =============================================================================
+ *
+ * This program is free software; you can redistribute it and/or modify it under
+ * the terms of the GNU General Public License, version 3.0, as published by the
+ * Free Software Foundation.
+ * 
+ * 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, see <http://www.gnu.org/licenses/>.
+ *
+ * As a special exception, AlliedModders LLC gives you permission to link the
+ * code of this program (as well as its derivative works) to "Half-Life 2," the
+ * "Source Engine," the "SourcePawn JIT," and any Game MODs that run on software
+ * by the Valve Corporation.  You must obey the GNU General Public License in
+ * all respects for all other code used.  Additionally, AlliedModders LLC grants
+ * this exception to all derivative works.  AlliedModders LLC defines further
+ * exceptions, found in LICENSE.txt (as of this writing, version JULY-31-2007),
+ * or <http://www.sourcemod.net/license.php>.
+ *
+ * Version: $Id$
+ */
+
+#include <stdlib.h>
+#include <string.h>
+#include "CDataPack.h"
+
+#define DATAPACK_INITIAL_SIZE		512
+
+CDataPack::CDataPack()
+{
+	m_pBase = (char *)malloc(DATAPACK_INITIAL_SIZE);
+	m_capacity = DATAPACK_INITIAL_SIZE;
+	Initialize();
+}
+
+CDataPack::~CDataPack()
+{
+	free(m_pBase);
+}
+
+void CDataPack::Initialize()
+{
+	m_curptr = m_pBase;
+	m_size = 0;
+}
+
+void CDataPack::CheckSize(size_t typesize)
+{
+	if (m_curptr - m_pBase + typesize <= m_capacity)
+	{
+		return;
+	}
+
+	size_t pos = m_curptr - m_pBase;
+	do
+	{
+		m_capacity *= 2;
+		m_pBase = (char *)realloc(m_pBase, m_capacity);
+		m_curptr = m_pBase + pos;
+	} while (m_curptr - m_pBase + typesize > m_capacity);
+}
+
+void CDataPack::ResetSize()
+{
+	m_size = 0;
+}
+
+size_t CDataPack::CreateMemory(size_t size, void **addr)
+{
+	CheckSize(sizeof(size_t) + size);
+	size_t pos = m_curptr - m_pBase;
+
+	*(size_t *)m_curptr = size;
+	m_curptr += sizeof(size_t);
+
+	if (addr)
+	{
+		*addr = m_curptr;
+	}
+
+	m_curptr += size;
+	m_size += sizeof(size_t) + size;
+
+	return pos;
+}
+
+void CDataPack::PackCell(cell cells)
+{
+	CheckSize(sizeof(size_t) + sizeof(cell));
+
+	*(size_t *)m_curptr = sizeof(cell);
+	m_curptr += sizeof(size_t);
+
+	*(cell *)m_curptr = cells;
+	m_curptr += sizeof(cell);
+
+	m_size += sizeof(size_t) + sizeof(cell);
+}
+
+void CDataPack::PackFloat(float val)
+{
+	CheckSize(sizeof(size_t) + sizeof(float));
+
+	*(size_t *)m_curptr = sizeof(float);
+	m_curptr += sizeof(size_t);
+
+	*(float *)m_curptr = val;
+	m_curptr += sizeof(float);
+
+	m_size += sizeof(size_t) + sizeof(float);
+}
+
+void CDataPack::PackString(const char *string)
+{
+	size_t len = strlen(string);
+	size_t maxsize = sizeof(size_t) + len + 1;
+	CheckSize(maxsize);
+
+	// Pack the string length first for buffer overrun checking.
+	*(size_t *)m_curptr = len;
+	m_curptr += sizeof(size_t);
+
+	// Now pack the string.
+	memcpy(m_curptr, string, len);
+	m_curptr[len] = '\0';
+	m_curptr += len + 1;
+
+	m_size += maxsize;
+}
+
+void CDataPack::Reset() const
+{
+	m_curptr = m_pBase;
+}
+
+size_t CDataPack::GetPosition() const
+{
+	return static_cast<size_t>(m_curptr - m_pBase);
+}
+
+bool CDataPack::SetPosition(size_t pos) const
+{
+	if (pos > m_size-1)
+	{
+		return false;
+	}
+	m_curptr = m_pBase + pos;
+
+	return true;
+}
+
+cell CDataPack::ReadCell() const
+{
+	if (!IsReadable(sizeof(size_t) + sizeof(cell)))
+	{
+		return 0;
+	}
+	if (*reinterpret_cast<size_t *>(m_curptr) != sizeof(cell))
+	{
+		return 0;
+	}
+
+	m_curptr += sizeof(size_t);
+
+	cell val = *reinterpret_cast<cell *>(m_curptr);
+	m_curptr += sizeof(cell);
+	return val;
+}
+
+float CDataPack::ReadFloat() const
+{
+	if (!IsReadable(sizeof(size_t) + sizeof(float)))
+	{
+		return 0;
+	}
+	if (*reinterpret_cast<size_t *>(m_curptr) != sizeof(float))
+	{
+		return 0;
+	}
+
+	m_curptr += sizeof(size_t);
+
+	float val = *reinterpret_cast<float *>(m_curptr);
+	m_curptr += sizeof(float);
+	return val;
+}
+
+bool CDataPack::IsReadable(size_t bytes) const
+{
+	return (bytes + (m_curptr - m_pBase) > m_size) ? false : true;
+}
+
+const char *CDataPack::ReadString(size_t *len) const
+{
+	if (!IsReadable(sizeof(size_t)))
+	{
+		return NULL;
+	}
+
+	size_t real_len = *(size_t *)m_curptr;
+
+	m_curptr += sizeof(size_t);
+	char *str = (char *)m_curptr;
+
+	if ((strlen(str) != real_len) || !(IsReadable(real_len+1)))
+	{
+		return NULL;
+	}
+
+	if (len)
+	{
+		*len = real_len;
+	}
+
+	m_curptr += real_len + 1;
+
+	return str;
+}
+
+void *CDataPack::GetMemory() const
+{
+	return m_curptr;
+}
+
+void *CDataPack::ReadMemory(size_t *size) const
+{
+	if (!IsReadable(sizeof(size_t)))
+	{
+		return NULL;
+	}
+
+	size_t bytecount = *(size_t *)m_curptr;
+	m_curptr += sizeof(size_t);
+
+	if (!IsReadable(bytecount))
+	{
+		return NULL;
+	}
+
+	void *ptr = m_curptr;
+
+	if (size)
+	{
+		*size = bytecount;
+	}
+
+	m_curptr += bytecount;
+
+	return ptr;
+}