diff options
author | Hiltjo Posthuma <hiltjo@codemadness.org> | 2021-01-08 19:08:59 +0100 |
---|---|---|
committer | Hiltjo Posthuma <hiltjo@codemadness.org> | 2021-01-08 19:33:29 +0100 |
commit | 04b832539cd5b5392c56ef238ec9b42b689de3ae (patch) | |
tree | f934b2769023a800ee0befe7608bdf70642fd39f | |
parent | c7e3ec5f37738c43b3918cba6977fa51631a23af (diff) |
util.c: printutf8pad(): improve padded printing and printing invalid unicode characters
This affects sfeed_plain.
- Use unicode replacement character (codepoint 0xfffd) when a codepoint is
invalid and proceed printing the rest of the characters.
- When a codepoint is invalid reset the internal state of mbtowc(3), from the
OpenBSD man page:
" If a call to mbtowc() resulted in an undefined internal state, mbtowc()
must be called with s set to NULL to reset the internal state before it
can safely be used again."
- Optimize for the common ASCII case and use a macro to print the character
instead of a wasteful fwrite() function call. With 250k lines (+- 350MB) this
improves printing performance from 1.7s to 1.0s on my laptop. On an other
system it improved by +- 25%. Tested with clang and gcc and also tested the
worst-case (non-ASCII) with no penalty.
To test:
printf '0\tabc\xc3 def' | sfeed_plain
Before:
1970-01-01 01:00 abc
After:
1970-01-01 01:00 abc� def
-rw-r--r-- | util.c | 47 |
1 files changed, 33 insertions, 14 deletions
@@ -234,29 +234,48 @@ printutf8pad(FILE *fp, const char *s, size_t len, int pad) { wchar_t wc; size_t col = 0, i, slen; - int rl, w; + int rl, siz, w; if (!len) return; slen = strlen(s); - for (i = 0; i < slen; i += rl) { - rl = w = 1; - if ((unsigned char)s[i] < 32) - continue; - if ((unsigned char)s[i] >= 127) { - if ((rl = mbtowc(&wc, s + i, slen - i < 4 ? slen - i : 4)) <= 0) + for (i = 0; i < slen; i += siz) { + siz = 1; + if ((unsigned char)s[i] < 32) { + continue; /* skip control characters */ + } else if ((unsigned char)s[i] >= 127) { + rl = siz = mbtowc(&wc, s + i, slen - i < 4 ? slen - i : 4); + if (rl < 0) { + mbtowc(NULL, NULL, 0); /* reset state */ + siz = 1; /* next byte */ + w = 1; /* replacement char is one width */ + } else if ((w = wcwidth(wc)) == -1) { + continue; + } + + if (col + w > len || (col + w == len && s[i + siz])) { + fputs("\xe2\x80\xa6", fp); /* ellipsis */ + col++; break; - if ((w = wcwidth(wc)) == -1) + } else if (rl < 0) { + fputs("\xef\xbf\xbd", fp); /* replacement */ + col++; continue; - } - if (col + w > len || (col + w == len && s[i + rl])) { - fputs("\xe2\x80\xa6", fp); + } + fwrite(&s[i], 1, siz, fp); + col += w; + } else { + /* simple ASCII character */ + if (col + 1 > len || (col + 1 == len && s[i + 1])) { + fputs("\xe2\x80\xa6", fp); /* ellipsis */ + col++; + break; + } + putc(s[i], fp); col++; - break; } - fwrite(&s[i], 1, rl, fp); - col += w; + } for (; col < len; ++col) putc(pad, fp); |