mpv/common/common.c

255 lines
8.6 KiB
C

/*
* This file is part of MPlayer.
*
* MPlayer 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 2 of the License, or
* (at your option) any later version.
*
* MPlayer 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 MPlayer; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include <stdarg.h>
#include <assert.h>
#include <libavutil/common.h>
#include <libavutil/error.h>
#include "talloc.h"
#include "misc/bstr.h"
#include "common/common.h"
#define appendf(ptr, ...) \
do {(*(ptr)) = talloc_asprintf_append_buffer(*(ptr), __VA_ARGS__);} while(0)
// Return a talloc'ed string formatted according to the format string in fmt.
// On error, return NULL.
// Valid formats:
// %H, %h: hour (%H is padded with 0 to two digits)
// %M: minutes from 00-59 (hours are subtracted)
// %m: total minutes (includes hours, unlike %M)
// %S: seconds from 00-59 (minutes and hours are subtracted)
// %s: total seconds (includes hours and minutes)
// %f: like %s, but as float
// %T: milliseconds (000-999)
char *mp_format_time_fmt(const char *fmt, double time)
{
if (time == MP_NOPTS_VALUE)
return talloc_strdup(NULL, "unknown");
char *sign = time < 0 ? "-" : "";
time = time < 0 ? -time : time;
long long int itime = time;
long long int h, m, tm, s;
int ms;
s = itime;
tm = s / 60;
h = s / 3600;
s -= h * 3600;
m = s / 60;
s -= m * 60;
ms = (time - itime) * 1000;
char *res = talloc_strdup(NULL, "");
while (*fmt) {
if (fmt[0] == '%') {
fmt++;
switch (fmt[0]) {
case 'h': appendf(&res, "%s%lld", sign, h); break;
case 'H': appendf(&res, "%s%02lld", sign, h); break;
case 'm': appendf(&res, "%s%lld", sign, tm); break;
case 'M': appendf(&res, "%02lld", m); break;
case 's': appendf(&res, "%s%lld", sign, itime); break;
case 'S': appendf(&res, "%02lld", s); break;
case 'T': appendf(&res, "%03d", ms); break;
case '%': appendf(&res, "%s", "%"); break;
default: goto error;
}
fmt++;
} else {
appendf(&res, "%c", *fmt);
fmt++;
}
}
return res;
error:
talloc_free(res);
return NULL;
}
char *mp_format_time(double time, bool fractions)
{
return mp_format_time_fmt(fractions ? "%H:%M:%S.%T" : "%H:%M:%S", time);
}
// Set rc to the union of rc and rc2
void mp_rect_union(struct mp_rect *rc, const struct mp_rect *rc2)
{
rc->x0 = FFMIN(rc->x0, rc2->x0);
rc->y0 = FFMIN(rc->y0, rc2->y0);
rc->x1 = FFMAX(rc->x1, rc2->x1);
rc->y1 = FFMAX(rc->y1, rc2->y1);
}
// Set rc to the intersection of rc and src.
// Return false if the result is empty.
bool mp_rect_intersection(struct mp_rect *rc, const struct mp_rect *rc2)
{
rc->x0 = FFMAX(rc->x0, rc2->x0);
rc->y0 = FFMAX(rc->y0, rc2->y0);
rc->x1 = FFMIN(rc->x1, rc2->x1);
rc->y1 = FFMIN(rc->y1, rc2->y1);
return rc->x1 > rc->x0 && rc->y1 > rc->y0;
}
// This works like snprintf(), except that it starts writing the first output
// character to str[strlen(str)]. This returns the number of characters the
// string would have *appended* assuming a large enough buffer, will make sure
// str is null-terminated, and will never write to str[size] or past.
// Example:
// int example(char *buf, size_t buf_size, double num, char *str) {
// int n = 0;
// n += mp_snprintf_cat(buf, size, "%f", num);
// n += mp_snprintf_cat(buf, size, "%s", str);
// return n; }
// Note how this can be chained with functions similar in style.
int mp_snprintf_cat(char *str, size_t size, const char *format, ...)
{
size_t len = strnlen(str, size);
assert(!size || len < size); // str with no 0-termination is not allowed
int r;
va_list ap;
va_start(ap, format);
r = vsnprintf(str + len, size - len, format, ap);
va_end(ap);
return r;
}
// Encode the unicode codepoint as UTF-8, and append to the end of the
// talloc'ed buffer. All guarantees bstr_xappend() give applies, such as
// implicit \0-termination for convenience.
void mp_append_utf8_bstr(void *talloc_ctx, struct bstr *buf, uint32_t codepoint)
{
char data[8];
uint8_t tmp;
char *output = data;
PUT_UTF8(codepoint, tmp, *output++ = tmp;);
bstr_xappend(talloc_ctx, buf, (bstr){data, output - data});
}
// Parse a C-style escape beginning at code, and append the result to *str
// using talloc. The input string (*code) must point to the first character
// after the initial '\', and after parsing *code is set to the first character
// after the current escape.
// On error, false is returned, and all input remains unchanged.
static bool mp_parse_escape(void *talloc_ctx, bstr *dst, bstr *code)
{
if (code->len < 1)
return false;
char replace = 0;
switch (code->start[0]) {
case '"': replace = '"'; break;
case '\\': replace = '\\'; break;
case 'b': replace = '\b'; break;
case 'f': replace = '\f'; break;
case 'n': replace = '\n'; break;
case 'r': replace = '\r'; break;
case 't': replace = '\t'; break;
case 'e': replace = '\x1b'; break;
case '\'': replace = '\''; break;
}
if (replace) {
bstr_xappend(talloc_ctx, dst, (bstr){&replace, 1});
*code = bstr_cut(*code, 1);
return true;
}
if (code->start[0] == 'x' && code->len >= 3) {
bstr num = bstr_splice(*code, 1, 3);
char c = bstrtoll(num, &num, 16);
if (num.len)
return false;
bstr_xappend(talloc_ctx, dst, (bstr){&c, 1});
*code = bstr_cut(*code, 3);
return true;
}
if (code->start[0] == 'u' && code->len >= 5) {
bstr num = bstr_splice(*code, 1, 5);
int c = bstrtoll(num, &num, 16);
if (num.len)
return false;
mp_append_utf8_bstr(talloc_ctx, dst, c);
*code = bstr_cut(*code, 5);
return true;
}
return false;
}
// Like mp_append_escaped_string, but set *dst to sliced *src if no escape
// sequences have to be parsed (i.e. no memory allocation is required), and
// if dst->start was NULL on function entry.
bool mp_append_escaped_string_noalloc(void *talloc_ctx, bstr *dst, bstr *src)
{
bstr t = *src;
int cur = 0;
while (1) {
if (cur >= t.len || t.start[cur] == '"') {
*src = bstr_cut(t, cur);
t = bstr_splice(t, 0, cur);
if (dst->start == NULL) {
*dst = t;
} else {
bstr_xappend(talloc_ctx, dst, t);
}
return true;
} else if (t.start[cur] == '\\') {
bstr_xappend(talloc_ctx, dst, bstr_splice(t, 0, cur));
t = bstr_cut(t, cur + 1);
cur = 0;
if (!mp_parse_escape(talloc_ctx, dst, &t))
goto error;
} else {
cur++;
}
}
error:
return false;
}
// src is expected to point to a C-style string literal, *src pointing to the
// first char after the starting '"'. It will append the contents of the literal
// to *dst (using talloc_ctx) until the first '"' or the end of *str is found.
// See bstr_xappend() how data is appended to *dst.
// On success, *src will either start with '"', or be empty.
// On error, return false, and *dst will contain the string until the first
// error, *src is not changed.
// Note that dst->start will be implicitly \0-terminated on successful return,
// and if it was NULL or \0-terminated before calling the function.
// As mentioned above, the caller is responsible for skipping the '"' chars.
bool mp_append_escaped_string(void *talloc_ctx, bstr *dst, bstr *src)
{
if (mp_append_escaped_string_noalloc(talloc_ctx, dst, src)) {
// Guarantee copy (or allocation).
if (!dst->start || dst->start == src->start) {
bstr res = *dst;
*dst = (bstr){0};
bstr_xappend(talloc_ctx, dst, res);
}
return true;
}
return false;
}
// Behaves like strerror()/strerror_r(), but is thread- and GNU-safe.
char *mp_strerror_buf(char *buf, size_t buf_size, int errnum)
{
// This handles the nasty details of calling the right function for us.
av_strerror(AVERROR(errnum), buf, buf_size);
return buf;
}