catboy/buffer.c

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/* Copyright (C) 2020 C. McEnroe <june@causal.agency>
*
* 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, either version 3 of the License, or
* (at your option) any later version.
*
* This program 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 this program. If not, see <https://www.gnu.org/licenses/>.
*
* Additional permission under GNU GPL version 3 section 7:
*
* If you modify this Program, or any covered work, by linking or
* combining it with OpenSSL (or a modified version of that library),
* containing parts covered by the terms of the OpenSSL License and the
* original SSLeay license, the licensors of this Program grant you
* additional permission to convey the resulting work. Corresponding
* Source for a non-source form of such a combination shall include the
* source code for the parts of OpenSSL used as well as that of the
* covered work.
*/
#include <err.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sysexits.h>
#include <time.h>
#include <wchar.h>
#include "chat.h"
struct Lines {
size_t len;
struct Line lines[BufferCap];
};
_Static_assert(!(BufferCap & (BufferCap - 1)), "BufferCap is power of two");
struct Buffer {
struct Lines soft;
struct Lines hard;
};
struct Buffer *bufferAlloc(void) {
struct Buffer *buffer = calloc(1, sizeof(*buffer));
if (!buffer) err(EX_OSERR, "calloc");
return buffer;
}
void bufferFree(struct Buffer *buffer) {
for (size_t i = 0; i < BufferCap; ++i) {
free(buffer->soft.lines[i].str);
free(buffer->hard.lines[i].str);
}
free(buffer);
}
static const struct Line *linesLine(const struct Lines *lines, size_t i) {
const struct Line *line = &lines->lines[(lines->len + i) % BufferCap];
return (line->str ? line : NULL);
}
static struct Line *linesNext(struct Lines *lines) {
struct Line *line = &lines->lines[lines->len++ % BufferCap];
free(line->str);
return line;
}
const struct Line *bufferSoft(const struct Buffer *buffer, size_t i) {
return linesLine(&buffer->soft, i);
}
const struct Line *bufferHard(const struct Buffer *buffer, size_t i) {
return linesLine(&buffer->hard, i);
}
enum { StyleCap = 10 };
static void styleCat(struct Cat *cat, struct Style style) {
catf(
cat, "%s%s%s%s",
(style.attr & Bold ? (const char []) { B, '\0' } : ""),
(style.attr & Reverse ? (const char []) { R, '\0' } : ""),
(style.attr & Italic ? (const char []) { I, '\0' } : ""),
(style.attr & Underline ? (const char []) { U, '\0' } : "")
);
if (style.fg != Default || style.bg != Default) {
catf(cat, "\3%02d,%02d", style.fg, style.bg);
}
}
static const wchar_t ZWS = L'\u200B';
static const wchar_t ZWNJ = L'\u200C';
static int flow(struct Lines *hard, int cols, const struct Line *soft) {
int flowed = 1;
struct Line *line = linesNext(hard);
line->heat = soft->heat;
line->time = soft->time;
line->str = strdup(soft->str);
if (!line->str) err(EX_OSERR, "strdup");
int width = 0;
int align = 0;
char *wrap = NULL;
struct Style style = StyleDefault;
for (char *str = line->str; *str;) {
size_t len = styleParse(&style, (const char **)&str);
if (!len) continue;
bool tab = (*str == '\t' && !align);
if (tab) *str = ' ';
wchar_t wc = L'\0';
int n = mbtowc(&wc, str, len);
if (n < 0) {
n = 1;
width++;
} else if (wc == ZWS || wc == ZWNJ) {
// XXX: ncurses likes to render these as spaces when they should be
// zero-width, so just remove them entirely.
memmove(str, &str[n], strlen(&str[n]) + 1);
continue;
} else if (wc < L' ') {
// XXX: ncurses will render these as "^A".
width += 2;
} else if (wcwidth(wc) > 0) {
width += wcwidth(wc);
}
if (width <= cols) {
if (tab && width < cols) align = width;
if (iswspace(wc) && !tab) wrap = str;
if (*str == '-') wrap = &str[1];
str += n;
continue;
}
if (!wrap) wrap = str;
n = mbtowc(&wc, wrap, strlen(wrap));
if (n < 0) {
n = 1;
} else if (!iswspace(wc)) {
n = 0;
}
flowed++;
line = linesNext(hard);
line->heat = soft->heat;
line->time = soft->time;
size_t cap = StyleCap + align + strlen(&wrap[n]) + 1;
line->str = malloc(cap);
if (!line->str) err(EX_OSERR, "malloc");
struct Cat cat = { line->str, cap, 0 };
styleCat(&cat, style);
str = &line->str[cat.len];
catf(&cat, "%*s%n%s", align, "", &width, &wrap[n]);
str += width;
*wrap = '\0';
wrap = NULL;
}
return flowed;
}
int bufferPush(
struct Buffer *buffer, int cols,
enum Heat heat, time_t time, const char *str
) {
struct Line *soft = linesNext(&buffer->soft);
soft->heat = heat;
soft->time = time;
soft->str = strdup(str);
if (!soft->str) err(EX_OSERR, "strdup");
return flow(&buffer->hard, cols, soft);
}
void bufferReflow(struct Buffer *buffer, int cols) {
buffer->hard.len = 0;
for (size_t i = 0; i < BufferCap; ++i) {
free(buffer->hard.lines[i].str);
buffer->hard.lines[i].str = NULL;
}
for (size_t i = 0; i < BufferCap; ++i) {
const struct Line *soft = bufferSoft(buffer, i);
if (soft) flow(&buffer->hard, cols, soft);
}
}