eqemu-server/common/memory_buffer.cpp

/*	EQEMu:  Everquest Server Emulator
	
	Copyright (C) 2001-2016 EQEMu Development Team (http://eqemulator.net)

	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 except by those people which sell it, which
	are required to give you total support for your newly bought product;
	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., 59 Temple Place, Suite 330, Boston, MA 02111-1307  USA
*/

#include "memory_buffer.h"


EQ::MemoryBuffer::MemoryBuffer()
{
	buffer_ = nullptr;
	size_ = 0;
	capacity_ = 0;
	read_pos_ = 0;
	write_pos_ = 0;
}

EQ::MemoryBuffer::MemoryBuffer(size_t sz)
{
	buffer_ = nullptr;
	size_ = 0;
	capacity_ = 0;
	read_pos_ = 0;
	write_pos_ = 0;
	Resize(sz);
}

EQ::MemoryBuffer::MemoryBuffer(const MemoryBuffer &other)
{
	if(other.capacity_) {
		buffer_ = new uchar[other.capacity_];
		memcpy(buffer_, other.buffer_, other.capacity_);
	} else {
		buffer_ = nullptr;
	}

	size_ = other.size_;
	capacity_ = other.capacity_;
	write_pos_ = other.write_pos_;
	read_pos_ = other.read_pos_;
}

EQ::MemoryBuffer::MemoryBuffer(MemoryBuffer &&other)
{
	uchar *tbuf = other.buffer_;
	size_t tsz = other.size_;
	size_t tcapacity = other.capacity_;
	size_t twrite_pos = other.write_pos_;
	size_t tread_pos = other.read_pos_;

	other.buffer_ = nullptr;
	other.size_ = 0;
	other.capacity_ = 0;
	other.read_pos_ = 0;
	other.write_pos_ = 0;

	buffer_ = tbuf;
	size_ = tsz;
	capacity_ = tcapacity;
	write_pos_ = twrite_pos;
	read_pos_ = tread_pos;
}

EQ::MemoryBuffer& EQ::MemoryBuffer::operator=(const MemoryBuffer &other)
{
	if(this == &other) {
		return *this;
	}

	if(buffer_) {
		delete[] buffer_;
	}

	if(other.capacity_) {
		buffer_ = new uchar[other.capacity_];
		memcpy(buffer_, other.buffer_, other.capacity_);
	}
	else {
		buffer_ = nullptr;
	}

	size_ = other.size_;
	capacity_ = other.capacity_;
	write_pos_ = other.write_pos_;
	read_pos_ = other.read_pos_;
	return *this;
}

EQ::MemoryBuffer& EQ::MemoryBuffer::operator=(MemoryBuffer &&other)
{
	uchar *tbuf = other.buffer_;
	size_t tsz = other.size_;
	size_t tcapacity = other.capacity_;
	size_t twrite_pos = other.write_pos_;
	size_t tread_pos = other.read_pos_;

	other.buffer_ = nullptr;
	other.size_ = 0;
	other.capacity_ = 0;
	other.read_pos_ = 0;
	other.write_pos_ = 0;

	buffer_ = tbuf;
	size_ = tsz;
	capacity_ = tcapacity;
	write_pos_ = twrite_pos;
	read_pos_ = tread_pos;
	return *this;
}

EQ::MemoryBuffer& EQ::MemoryBuffer::operator+=(const MemoryBuffer &rhs)
{
	if(!rhs.buffer_) {
		return *this;
	}

	if(buffer_) {
		size_t old_size = size_;
		Resize(size_ + rhs.size_);
		memcpy(&buffer_[old_size], rhs.buffer_, rhs.size_);
	} else {
		buffer_ = new uchar[rhs.capacity_];
		memcpy(buffer_, rhs.buffer_, rhs.capacity_);
		size_ = rhs.size_;
		capacity_ = rhs.capacity_;
	}

	return *this;
}

EQ::MemoryBuffer::~MemoryBuffer()
{
	Clear();
}

uchar& EQ::MemoryBuffer::operator[](size_t pos)
{
	return buffer_[pos];
}

const uchar& EQ::MemoryBuffer::operator[](size_t pos) const
{
	return buffer_[pos];
}

bool EQ::MemoryBuffer::Empty()
{
	return size_ == 0;
}

bool EQ::MemoryBuffer::Empty() const
{
	return size_ == 0;
}

size_t EQ::MemoryBuffer::Size()
{
	return size_;
}

size_t EQ::MemoryBuffer::Size() const
{
	return size_;
}

size_t EQ::MemoryBuffer::Capacity()
{
	return capacity_;
}

size_t EQ::MemoryBuffer::Capacity() const
{
	return capacity_;
}

void EQ::MemoryBuffer::Resize(size_t sz)
{
	if(!buffer_) {
		size_t new_size = sz + 64;
		buffer_ = new uchar[new_size];
		capacity_ = new_size;
		size_ = sz;
		memset(buffer_, 0, capacity_);
		return;
	}

	if(sz > capacity_) {
		size_t new_size = sz + 32;
		uchar *temp = new uchar[new_size];
		memcpy(temp, buffer_, capacity_);
		delete[] buffer_;
		buffer_ = temp;
		
		capacity_ = new_size;
		size_ = sz;
	}
	else {
		size_ = sz;
	}
}

void EQ::MemoryBuffer::Clear()
{
	if(buffer_) {
		delete[] buffer_;
		buffer_ = nullptr;
	}
	
	size_ = 0;
	capacity_ = 0;
	write_pos_ = 0;
	read_pos_ = 0;
}

void EQ::MemoryBuffer::Zero()
{
	if(buffer_) {
		memset(buffer_, 0, capacity_);
	}
}

void EQ::MemoryBuffer::Write(const char *val, size_t len)
{
	size_t size_needed = write_pos_ + len;
	Resize(size_needed);

	memcpy(&buffer_[write_pos_], val, len);
	write_pos_ += len;
}

void EQ::MemoryBuffer::Read(uchar *buf, size_t len)
{
	memcpy(buf, &buffer_[read_pos_], len);
	read_pos_ += len;
}

void EQ::MemoryBuffer::Read(char *str)
{
	size_t len = strlen((const char*)&buffer_[read_pos_]);
	memcpy(str, &buffer_[read_pos_], len);
	read_pos_ += len;
}

void EQ::OutBuffer::overwrite(OutBuffer::pos_type position, const char *_Str, std::streamsize _Count)
{
	auto last_pos = tellp();
	seekp(position);
	write(_Str, _Count);
	seekp(last_pos);
}

uchar* EQ::OutBuffer::detach()
{
	size_t buffer_size = tellp();
	if (buffer_size == 0)
		return nullptr;

	auto out_buffer = new uchar[buffer_size];
	memcpy(out_buffer, str().c_str(), buffer_size);
	flush();

	return out_buffer;
}