raze/source/common/filesystem/source/fs_stringpool.cpp
2023-12-17 12:48:03 +01:00

131 lines
3.5 KiB
C++

/*
** stringpool.cpp
** allocate static strings from larger blocks
**
**---------------------------------------------------------------------------
** Copyright 2010 Randy Heit
** Copyright 2023 Christoph Oelckers
** All rights reserved.
**
** Redistribution and use in source and binary forms, with or without
** modification, are permitted provided that the following conditions
** are met:
**
** 1. Redistributions of source code must retain the above copyright
** notice, this list of conditions and the following disclaimer.
** 2. Redistributions in binary form must reproduce the above copyright
** notice, this list of conditions and the following disclaimer in the
** documentation and/or other materials provided with the distribution.
** 3. The name of the author may not be used to endorse or promote products
** derived from this software without specific prior written permission.
**
** THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
** IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
** OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
** IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
** INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
** NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
** DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
** THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
** (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
** THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
**---------------------------------------------------------------------------
**
*/
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include "fs_stringpool.h"
namespace FileSys {
struct StringPool::Block
{
Block *NextBlock;
void *Limit; // End of this block
void *Avail; // Start of free space in this block
void *alignme; // align to 16 bytes.
void *Alloc(size_t size);
};
//==========================================================================
//
// StringPool Destructor
//
//==========================================================================
StringPool::~StringPool()
{
for (Block *next, *block = TopBlock; block != nullptr; block = next)
{
next = block->NextBlock;
free(block);
}
TopBlock = nullptr;
}
//==========================================================================
//
// StringPool :: Alloc
//
//==========================================================================
void *StringPool::Block::Alloc(size_t size)
{
if ((char *)Avail + size > Limit)
{
return nullptr;
}
void *res = Avail;
Avail = ((char *)Avail + size);
return res;
}
StringPool::Block *StringPool::AddBlock(size_t size)
{
size += sizeof(Block); // Account for header size
// Allocate a new block
if (size < BlockSize)
{
size = BlockSize;
}
auto mem = (Block *)malloc(size);
if (mem == nullptr)
{
}
mem->Limit = (uint8_t *)mem + size;
mem->Avail = &mem[1];
mem->NextBlock = TopBlock;
TopBlock = mem;
return mem;
}
void *StringPool::Alloc(size_t size)
{
Block *block;
size = (size + 7) & ~7;
for (block = TopBlock; block != nullptr; block = block->NextBlock)
{
void *res = block->Alloc(size);
if (res != nullptr)
{
return res;
}
}
block = AddBlock(size);
return block->Alloc(size);
}
const char* StringPool::Strdup(const char* str)
{
char* p = (char*)Alloc(strlen(str) + 1);
strcpy(p, str);
return p;
}
}