summary refs log tree commit diff
path: root/buffer.c
blob: 7ac5c108fdddf75db4c957349262dd750e81d444 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
/* 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 <wctype.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 };
		catf(&cat, "%*s%n", align, "", &width);
		styleCat(&cat, style);
		str = &line->str[cat.len];
		catf(&cat, "%s", &wrap[n]);

		*wrap = '\0';
		wrap = NULL;
	}

	return flowed;
}

int bufferPush(
	struct Buffer *buffer, int cols, bool ignore,
	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");
	if (heat < Cold && ignore) return 0;
	return flow(&buffer->hard, cols, soft);
}

void bufferReflow(struct Buffer *buffer, int cols, bool ignore) {
	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) continue;
		if (soft->heat < Cold && ignore) continue;
		flow(&buffer->hard, cols, soft);
	}
}