diff options
Diffstat (limited to 'stdio/linewrap.c')
| -rw-r--r-- | stdio/linewrap.c | 176 |
1 files changed, 122 insertions, 54 deletions
diff --git a/stdio/linewrap.c b/stdio/linewrap.c index 7f6576f..e22640d 100644 --- a/stdio/linewrap.c +++ b/stdio/linewrap.c @@ -50,6 +50,32 @@ unwrap_stream (FILE *stream, struct line_wrap_data *d) stream->__io_funcs.__fileno = d->fileno; stream->__io_funcs.__seek = d->seek; } + +/* If WRAPPER_COOKIE points to a 0 pointer, then STREAM is assumed to be + wrapped, and will be unwrapped, storing the wrapper cookie into + WRAPPER_COOKIE. Otherwise, nothing is done. */ +static inline void +ensure_unwrapped (FILE *stream, struct line_wrap_data **wrapper_cookie) +{ + if (*wrapper_cookie == 0) + { + *wrapper_cookie = stream->__cookie; + unwrap_stream (stream, *wrapper_cookie); + } +} + +/* If WRAPPER_COOKIE points to a non-0 pointer, then STREAM is assumed to + *have been unwrapped with ensure_unwrapped, will be wrapped with + *WRAPPER_COOKIE, and *WRAPPER_COOKIE zeroed. Otherwise, nothing is done. */ +static inline void +ensure_wrapped (FILE *stream, struct line_wrap_data **wrapper_cookie) +{ + if (*wrapper_cookie) + { + wrap_stream (stream, *wrapper_cookie); + *wrapper_cookie = 0; + } +} /* Cookie io functions that might get called on a wrapped stream. Must pass the original cookie to the original functions. */ @@ -68,26 +94,26 @@ lwfileno (void *cookie) return (*d->fileno) (d->cookie); } -/* This function is called when STREAM must be flushed. - C is EOF or a character to be appended to the buffer contents. */ -void -__line_wrap_output (FILE *stream, int c) +/* Process STREAM's buffer so that line wrapping is done from POINT_OFFS to + the end of its buffer. If WRAPPER_COOKIE is 0, and it's necessary to + flush some data, STREAM is unwrapped, and the line wrap stdio cookie + stored in WRAPPER_COOKIE; otherwise, stream is assumed to already be + unwrapped, and WRAPPER_COOKIE to point to the line wrap data. Returns C + or EOF if C was output. */ +static inline int +lwupdate (FILE *stream, int c, struct line_wrap_data **wrapper_cookie) { char *buf, *nl; size_t len; - - /* Extract our data and restore the stream's original cookie - and output function so writes we do really go out. */ - struct line_wrap_data *d = stream->__cookie; - unwrap_stream (stream, d); + struct line_wrap_data *d = *wrapper_cookie ?: stream->__cookie; /* Scan the buffer for newlines. */ - buf = stream->__buffer; + buf = stream->__buffer + d->point_offs; while ((buf < stream->__bufp || (c != EOF && c != '\n')) && !stream->__error) { size_t r; - if (d->point == 0 && d->lmargin != 0) + if (d->point_col == 0 && d->lmargin != 0) { /* We are starting a new line. Print spaces to the left margin. */ const size_t pad = d->lmargin; @@ -106,16 +132,18 @@ __line_wrap_output (FILE *stream, int c) size_t i; char *olimit; + ensure_unwrapped (stream, wrapper_cookie); + len = stream->__bufp - buf; olimit = stream->__put_limit; stream->__bufp = stream->__put_limit = buf; for (i = 0; i < pad; ++i) (*d->output) (stream, ' '); stream->__put_limit = olimit; - memcpy (stream->__bufp, buf, len); + memmove (stream->__bufp, buf, len); stream->__bufp += len; } - d->point = pad; + d->point_col = pad; } len = stream->__bufp - buf; @@ -125,12 +153,12 @@ __line_wrap_output (FILE *stream, int c) { /* The buffer ends in a partial line. */ - if (d->point + len + (c != EOF && c != '\n') <= d->rmargin) + if (d->point_col + len + (c != EOF && c != '\n') <= d->rmargin) { /* The remaining buffer text is a partial line and fits within the maximum line width. Advance point for the characters to be written and stop scanning. */ - d->point += len; + d->point_col += len; break; } else @@ -138,11 +166,11 @@ __line_wrap_output (FILE *stream, int c) the end of the buffer. */ nl = stream->__bufp; } - else if (d->point + (nl - buf) <= d->rmargin) + else if (d->point_col + (nl - buf) <= d->rmargin) { /* The buffer contains a full line that fits within the maximum line width. Reset point and scan the next line. */ - d->point = 0; + d->point_col = 0; buf = nl + 1; continue; } @@ -156,10 +184,10 @@ __line_wrap_output (FILE *stream, int c) newline and anything after it in the buffer. */ if (nl < stream->__bufp) { - memcpy (buf + (r - d->point), nl, stream->__bufp - nl); - stream->__bufp -= buf + (r - d->point) - nl; + memmove (buf + (r - d->point_col), nl, stream->__bufp - nl); + stream->__bufp -= buf + (r - d->point_col) - nl; /* Reset point for the next line and start scanning it. */ - d->point = 0; + d->point_col = 0; buf += r + 1; /* Skip full line plus \n. */ } else @@ -167,8 +195,8 @@ __line_wrap_output (FILE *stream, int c) /* The buffer ends with a partial line that is beyond the maximum line width. Advance point for the characters written, and discard those past the max from the buffer. */ - d->point += len; - stream->__bufp -= d->point - r; + d->point_col += len; + stream->__bufp -= d->point_col - r; if (c != '\n') /* Swallow the extra character too. */ c = EOF; @@ -184,7 +212,7 @@ __line_wrap_output (FILE *stream, int c) char *p, *nextline; int i; - p = buf + (r + 1 - d->point); + p = buf + (r + 1 - d->point_col); while (p >= buf && !isblank (*p)) --p; nextline = p + 1; /* This will begin the next line. */ @@ -201,7 +229,7 @@ __line_wrap_output (FILE *stream, int c) { /* A single word that is greater than the maximum line width. Oh well. Put it on an overlong line by itself. */ - p = buf + (r + 1 - d->point); + p = buf + (r + 1 - d->point_col); /* Find the end of the long word. */ do ++p; @@ -209,7 +237,7 @@ __line_wrap_output (FILE *stream, int c) if (p == nl) { /* It already ends a line. No fussing required. */ - d->point = 0; + d->point_col = 0; buf = nl + 1; continue; } @@ -228,14 +256,17 @@ __line_wrap_output (FILE *stream, int c) if (nextline - (nl + 1) < d->wmargin) /* The margin needs more blanks than we removed. Output the first line so we can use the space. */ - (*d->output) (stream, '\n'); + { + ensure_unwrapped (stream, wrapper_cookie); + (*d->output) (stream, '\n'); + } else /* We can fit the newline and blanks in before the next word. */ *stream->__bufp++ = '\n'; /* Reset the counter of what has been output this line. */ - d->point = 0; + d->point_col = 0; /* Add blanks up to the wrap margin column. */ for (i = 0; i < d->wmargin; ++i) @@ -244,7 +275,7 @@ __line_wrap_output (FILE *stream, int c) /* Copy the tail of the original buffer into the current buffer position. */ if (stream->__bufp != nextline) - memcpy (stream->__bufp, nextline, buf + len - nextline); + memmove (stream->__bufp, nextline, buf + len - nextline); len -= nextline - buf; /* Continue the scan on the remaining lines in the buffer. */ @@ -255,16 +286,33 @@ __line_wrap_output (FILE *stream, int c) } } + /* Remember that we've scanned as far as the end of the buffer. */ + d->point_offs = stream->__bufp - stream->__buffer; + + return c; +} + +/* This function is called when STREAM must be flushed. + C is EOF or a character to be appended to the buffer contents. */ +void +__line_wrap_output (FILE *stream, int c) +{ + struct line_wrap_data *d = 0; + + c = lwupdate (stream, c, &d); + if (!stream->__error) { + ensure_unwrapped (stream, &d); (*d->output) (stream, c); + d->point_offs = 0; /* The buffer now holds nothing. */ if (c == '\n') - d->point = 0; + d->point_col = 0; else if (c != EOF) - ++d->point; + ++d->point_col; } - wrap_stream (stream, d); + ensure_wrapped (stream, &d); } /* Modify STREAM so that it prefixes lines written on it with LMARGIN spaces @@ -285,7 +333,8 @@ line_wrap_stream (FILE *stream, size_t lmargin, size_t rmargin, size_t wmargin) fflush (stream); /* Initialize our wrapping state. */ - d->point = 0; + d->point_col = 0; + d->point_offs = 0; /* Save the original cookie and output and close hooks. */ d->cookie = stream->__cookie; @@ -326,8 +375,28 @@ line_wrapped (FILE *stream) return (stream->__room_funcs.__output == &__line_wrap_output); } +/* If STREAM is not line-wrapped, return 0. Otherwise all pending text + buffered text in STREAM so that the POINT_OFFS field refers to the last + position in the stdio buffer, and return the line wrap state object for + STREAM. Since all text has been processed, this means that (1) the + POINT_COL field refers to the column at which any new text would be added, + and (2) any changes to the margin parameters will only affect new text. */ +struct line_wrap_data * +__line_wrap_update (FILE *stream) +{ + if (line_wrapped (stream)) + { + struct line_wrap_data *d = stream->__cookie, *wc = 0; + lwupdate (stream, EOF, &wc); + ensure_wrapped (stream, &wc); + return d; + } + else + return 0; +} + /* If STREAM is not line-wrapped return -1, else return its left margin. */ -size_t +inline size_t line_wrap_lmargin (FILE *stream) { if (! line_wrapped (stream)) @@ -337,22 +406,22 @@ line_wrap_lmargin (FILE *stream) /* If STREAM is not line-wrapped return -1, else set its left margin to LMARGIN and return the old value. */ -size_t +inline size_t line_wrap_set_lmargin (FILE *stream, size_t lmargin) { - if (! line_wrapped (stream)) - return -1; - else + struct line_wrap_data *d = __line_wrap_update (stream); + if (d) { - struct line_wrap_data *d = stream->__cookie; size_t old = d->lmargin; d->lmargin = lmargin; return old; } + else + return -1; } /* If STREAM is not line-wrapped return -1, else return its left margin. */ -size_t +inline size_t line_wrap_rmargin (FILE *stream) { if (! line_wrapped (stream)) @@ -362,22 +431,22 @@ line_wrap_rmargin (FILE *stream) /* If STREAM is not line-wrapped return -1, else set its right margin to RMARGIN and return the old value. */ -size_t +inline size_t line_wrap_set_rmargin (FILE *stream, size_t rmargin) { - if (! line_wrapped (stream)) - return -1; - else + struct line_wrap_data *d = __line_wrap_update (stream); + if (d) { - struct line_wrap_data *d = stream->__cookie; size_t old = d->rmargin; d->rmargin = rmargin; return old; } + else + return -1; } /* If STREAM is not line-wrapped return -1, else return its wrap margin. */ -size_t +inline size_t line_wrap_wmargin (FILE *stream) { if (! line_wrapped (stream)) @@ -387,28 +456,27 @@ line_wrap_wmargin (FILE *stream) /* If STREAM is not line-wrapped return -1, else set its left margin to WMARGIN and return the old value. */ -size_t +inline size_t line_wrap_set_wmargin (FILE *stream, size_t wmargin) { - if (! line_wrapped (stream)) - return -1; - else + struct line_wrap_data *d = __line_wrap_update (stream); + if (d) { - struct line_wrap_data *d = stream->__cookie; size_t old = d->wmargin; d->wmargin = wmargin; return old; } + else + return -1; } /* If STREAM is not line-wrapped return -1, else return the column number of the current output point. */ -size_t +inline size_t line_wrap_point (FILE *stream) { - if (! line_wrapped (stream)) - return -1; - return ((struct line_wrap_data *)stream->__cookie)->point; + struct line_wrap_data *d = __line_wrap_update (stream); + return d ? d->point_col : -1; } #ifdef TEST |