libreoffice-online/net/Buffer.hpp
Michael Meeks 4082975330 Fix unit test to not rely on under-defined behavior.
Change-Id: I4ad9ce7710f7f25884ca2ab31aabd82e2dc5be8e
Signed-off-by: Michael Meeks <michael.meeks@collabora.com>
2020-11-29 19:27:23 -05:00

89 lines
2.3 KiB
C++

/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4; fill-column: 100 -*- */
/*
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/.
*/
#pragma once
#include <assert.h>
#include <ostream>
#include <vector>
#include <Util.hpp>
// Blocks -> we can share from client -> server ... etc.
// headers / and a 'writeV' etc. =)
/**
* Encapsulate data we need to write.
*/
class Buffer
{
std::size_t _size;
std::size_t _offset;
std::vector<char> _buffer;
public:
Buffer() : _size(0), _offset(0)
{
}
std::size_t size() const { return _size; }
bool empty() const { return _size == 0; }
const char *getBlock() const
{
if (_size)
return &_buffer[_offset];
return nullptr;
}
std::size_t getBlockSize() const
{
return _size;
}
void eraseFirst(std::size_t len)
{
if (len <= 0)
return;
assert(_offset + len <= _buffer.size());
assert(_offset + _size == _buffer.size());
len = std::min(len, _size); // Avoid accidental damage.
// avoid regular shuffling down larger chunks of data
if (_buffer.size() > 16384 && // lots of queued data
len < _buffer.size() && // not a complete erase
_offset < 16384 * 64 && // do cleanup a Mb at a time or so:
_size > 512) // early cleanup if what remains is small.
{
_offset += len;
_size -= len;
return;
}
_buffer.erase(_buffer.begin(), _buffer.begin() + _offset + len);
_offset = 0;
_size = _buffer.size();
}
void append(const char *data, const int len)
{
_buffer.insert(_buffer.end(), data, data + len);
_size = _buffer.size() - _offset;
}
void dumpHex(std::ostream &os, const char *legend, const char *prefix) const
{
if (_size > 0 || _offset > 0)
os << prefix << "Buffer size: " << _size << " offset: " << _offset << '\n';
if (_buffer.size() > 0)
Util::dumpHex(os, legend, prefix, _buffer);
}
};
/* vim:set shiftwidth=4 softtabstop=4 expandtab: */