1
0
Fork 0
mirror of https://gitlab.com/sortix/sortix.git synced 2023-02-13 20:55:38 -05:00
sortix--sortix/kernel/linebuffer.cpp
Jonas 'Sortie' Termansen 2b72262b4f Relicense Sortix to the ISC license.
I hereby relicense all my work on Sortix under the ISC license as below.

All Sortix contributions by other people are already under this license,
are not substantial enough to be copyrightable, or have been removed.

All imported code from other projects is compatible with this license.

All GPL licensed code from other projects had previously been removed.

Copyright 2011-2016 Jonas 'Sortie' Termansen and contributors.

Permission to use, copy, modify, and distribute this software for any
purpose with or without fee is hereby granted, provided that the above
copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
2016-03-05 22:21:50 +01:00

144 lines
3.3 KiB
C++

/*
* Copyright (c) 2012, 2013, 2014 Jonas 'Sortie' Termansen.
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*
* linebuffer.cpp
* Provides a simple queue-like line buffering for terminals.
*/
#include <stddef.h>
#include <stdint.h>
#include <string.h>
#include <sortix/kernel/kernel.h>
#include "linebuffer.h"
namespace Sortix {
static size_t OffsetIndex(size_t offset, size_t index, size_t length)
{
// TODO: Possible overflow here.
return (offset + index) % length;
}
LineBuffer::LineBuffer()
{
buffer = NULL;
bufferlength = 0;
bufferoffset = 0;
buffercommitted = 0;
bufferfrozen = 0;
bufferused = 0;
}
LineBuffer::~LineBuffer()
{
delete[] buffer;
}
bool LineBuffer::Push(uint32_t unicode)
{
// Check if we need to allocate or resize the circular queue.
if ( bufferused == bufferlength )
{
size_t newbufferlength = (bufferlength) ? bufferlength * 2 : 32UL;
uint32_t* newbuffer = new uint32_t[newbufferlength];
if ( !newbuffer )
return false;
size_t elemsize = sizeof(*buffer);
size_t leadingavai = bufferlength-bufferoffset;
size_t leading = (leadingavai < bufferused) ? leadingavai : bufferused;
size_t trailing = bufferused - leading;
if ( buffer )
{
memcpy(newbuffer, buffer + bufferoffset, leading * elemsize);
memcpy(newbuffer + leading, buffer, trailing * elemsize);
delete[] buffer;
}
buffer = newbuffer;
bufferlength = newbufferlength;
bufferoffset = 0;
}
size_t index = OffsetIndex(bufferoffset, bufferused++, bufferlength);
buffer[index] = unicode;
return true;
}
uint32_t LineBuffer::Pop()
{
if ( !CanPop() )
return 0;
uint32_t result = Peek();
bufferoffset = (bufferoffset+1) % bufferlength;
buffercommitted--;
bufferfrozen--;
bufferused--;
return result;
}
uint32_t LineBuffer::Peek() const
{
if ( !CanPop() )
return 0;
size_t index = OffsetIndex(bufferoffset, 0, bufferlength);
return buffer[index];
}
uint32_t LineBuffer::Backspace()
{
if ( !CanBackspace() )
return 0;
size_t index = OffsetIndex(bufferoffset, --bufferused, bufferlength);
return buffer[index];
}
uint32_t LineBuffer::WouldBackspace() const
{
if ( !CanBackspace() )
return 0;
size_t index = OffsetIndex(bufferoffset, bufferused-1, bufferlength);
return buffer[index];
}
void LineBuffer::Commit()
{
buffercommitted = bufferfrozen = bufferused;
}
void LineBuffer::Freeze()
{
bufferfrozen = bufferused;
}
bool LineBuffer::CanPop() const
{
return buffercommitted;
}
bool LineBuffer::CanBackspace() const
{
return bufferused - bufferfrozen;
}
void LineBuffer::Flush()
{
bufferoffset = 0;
buffercommitted = 0;
bufferfrozen = 0;
bufferused = 0;
}
} // namespace Sortix