os-k/kaleid/libbuf/bputc.c

147 lines
4.8 KiB
C

//----------------------------------------------------------------------------//
// OS on Kaleid //
// //
// Desc: Buffer library //
// //
// //
// Copyright © 2018-2020 The OS/K Team //
// //
// This file is part of OS/K. //
// //
// OS/K 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, either version 3 of the License, or //
// any later version. //
// //
// OS/K 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 OS/K. If not, see <https://www.gnu.org/licenses/>. //
//----------------------------------------------------------------------------//
#include <libbuf.h>
//
// Writes a character on a buffer
//
error_t BPutOnBuf(Buffer_t *buf, uchar ch)
{
error_t rc;
if (!buf) return EINVAL;
if (buf->state != BS_RDWR && buf->state != BS_WRONLY) {
return EBADF;
}
ExAcquireLock(&buf->lock);
rc = bputc(buf, ch);
ExReleaseLock(&buf->lock);
return rc;
}
//
// Internal, unlocked version of BPutOnBuf
//
error_t bputc(Buffer_t *buf, uchar ch)
{
error_t rc = EOK;
if (buf->flags & (BF_EOF|BF_ERR)) return EENDF;
// Implements playback / scrolling up when terminal buffering
// Note that '\n', '\r' and '\t' can never occur in the buffer
// That should change; there should be a flag for it
if (buf->flags & BF_TERM) {
// Deal with line feeds by filling the rest of the line with spaces
// We need a field for choosing a different filler, e.g. '\0'
if (ch == '\n') {
assert(buf->lastLF < buf->lineLen);
int off = buf->lineLen - buf->lastLF;
while (off > 0) {
*buf->wp++ = ' ';
off--;
}
buf->lastLF = 0;
// Auto-scrolling
if (buf->wp == buf->buf + buf->size && buf->flags&BF_AUTOSCROLL) {
bscrolldown(buf);
}
if (buf->flusher) buf->flusher(buf);
}
// Deal with carriage returns
else if (ch == '\r') {
buf->wp -= buf->lastLF;
buf->lastLF = 0;
assert(buf->wp >= buf->buf);
}
// Deal with tabs... should be dealt with elsewhere tho
// We assume tabs are 4 characters long for now
else if (ch == '\t') {
rc = bputc(buf, ' ');
while (buf->lastLF % 4 > 0) {
rc = bputc(buf, ' ');
}
}
// Just a regular character
else {
if (buf->wp == buf->buf + buf->size) {
buf->flags |= BF_EOF;
return EENDF;
}
// Write it
*buf->wp++ = ch;
// Did we reach the end of line?
if (++buf->lastLF == buf->lineLen) {
buf->lastLF = 0;
}
// Auto-scrolling
if (buf->wp == buf->buf + buf->size && buf->flags&BF_AUTOSCROLL) {
bscrolldown(buf);
}
}
}
// Not a terminal buffer
else {
if (buf->wp == buf->buf + buf->size) {
buf->flags |= BF_EOF;
return EENDF;
}
*buf->wp++ = ch;
if (buf->wp == buf->buf + buf->size) {
if (!(buf->flags & (BF_LINE|BF_FONCLOSE))) {
if (buf->flusher) buf->flusher(buf);
}
}
// Line-buffering
if (ch == '\n' && buf->flags & BF_LINE) {
if (buf->flusher) buf->flusher(buf);
}
}
if (rc != EOK) {
// buf->flags |= BF_ERR;
}
return rc;
}