diff options
Diffstat (limited to 'lib/readtokens.c')
| -rw-r--r-- | lib/readtokens.c | 137 |
1 files changed, 64 insertions, 73 deletions
diff --git a/lib/readtokens.c b/lib/readtokens.c index 28aafa9..5933120 100644 --- a/lib/readtokens.c +++ b/lib/readtokens.c @@ -1,11 +1,12 @@ /* readtokens.c -- Functions for reading tokens from an input stream. - Copyright (C) 1990-1991, 1999-2004, 2006 Free Software Foundation, Inc. + Copyright (C) 1990-1991, 1999-2004, 2006, 2009-2016 Free Software + Foundation, Inc. - This program is free software; you can redistribute it and/or modify + 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 2, or (at your option) - any later version. + 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 @@ -13,12 +14,11 @@ 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, write to the Free Software Foundation, - Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. + along with this program. If not, see <http://www.gnu.org/licenses/>. Written by Jim Meyering. */ -/* This almost supercedes xreadline stuff -- using delim="\n" +/* This almost supersedes xreadline stuff -- using delim="\n" gives the same functionality, except that these functions would never return empty lines. */ @@ -26,6 +26,7 @@ #include "readtokens.h" +#include <limits.h> #include <stdio.h> #include <stdlib.h> #include <string.h> @@ -37,9 +38,6 @@ # include "unlocked-io.h" #endif -#define STREQ(a,b) ((a) == (b) || ((a) && (b) && *(a) == *(b) \ - && strcmp(a, b) == 0)) - /* Initialize a tokenbuffer. */ void @@ -49,6 +47,22 @@ init_tokenbuffer (token_buffer *tokenbuffer) tokenbuffer->buffer = NULL; } +typedef size_t word; +enum { bits_per_word = sizeof (word) * CHAR_BIT }; + +static bool +get_nth_bit (size_t n, word const *bitset) +{ + return bitset[n / bits_per_word] >> n % bits_per_word & 1; +} + +static void +set_nth_bit (size_t n, word *bitset) +{ + size_t one = 1; + bitset[n / bits_per_word] |= one << n % bits_per_word; +} + /* Read a token from STREAM into TOKENBUFFER. A token is delimited by any of the N_DELIM bytes in DELIM. Upon return, the token is in tokenbuffer->buffer and @@ -60,53 +74,28 @@ init_tokenbuffer (token_buffer *tokenbuffer) by testing ferror (STREAM). This function works properly on lines containing NUL bytes - and on files do not end with a delimiter. */ + and on files that do not end with a delimiter. */ size_t readtoken (FILE *stream, - const char *delim, - size_t n_delim, - token_buffer *tokenbuffer) + const char *delim, + size_t n_delim, + token_buffer *tokenbuffer) { char *p; int c; size_t i, n; - static const char *saved_delim = NULL; - static char isdelim[256]; - bool same_delimiters; - - if (delim == NULL && saved_delim == NULL) - abort (); - - same_delimiters = false; - if (delim != saved_delim && saved_delim != NULL) - { - same_delimiters = true; - for (i = 0; i < n_delim; i++) - { - if (delim[i] != saved_delim[i]) - { - same_delimiters = false; - break; - } - } - } + word isdelim[(UCHAR_MAX + bits_per_word) / bits_per_word]; - if (!same_delimiters) + memset (isdelim, 0, sizeof isdelim); + for (i = 0; i < n_delim; i++) { - size_t j; - saved_delim = delim; - memset (isdelim, 0, sizeof isdelim); - for (j = 0; j < n_delim; j++) - { - unsigned char ch = delim[j]; - isdelim[ch] = 1; - } + unsigned char ch = delim[i]; + set_nth_bit (ch, isdelim); } - /* FIXME: don't fool with this caching. Use strchr instead. */ /* skip over any leading delimiters */ - for (c = getc (stream); c >= 0 && isdelim[c]; c = getc (stream)) + for (c = getc (stream); c >= 0 && get_nth_bit (c, isdelim); c = getc (stream)) { /* empty */ } @@ -117,21 +106,21 @@ readtoken (FILE *stream, for (;;) { if (c < 0 && i == 0) - return -1; + return -1; if (i == n) - p = x2nrealloc (p, &n, sizeof *p); + p = x2nrealloc (p, &n, sizeof *p); if (c < 0) - { - p[i] = 0; - break; - } - if (isdelim[c]) - { - p[i] = 0; - break; - } + { + p[i] = 0; + break; + } + if (get_nth_bit (c, isdelim)) + { + p[i] = 0; + break; + } p[i++] = c; c = getc (stream); } @@ -146,15 +135,15 @@ readtoken (FILE *stream, All storage is obtained through calls to xmalloc-like functions. %%% Question: is it worth it to do a single - %%% realloc() of `tokens' just before returning? */ + %%% realloc() of 'tokens' just before returning? */ size_t readtokens (FILE *stream, - size_t projected_n_tokens, - const char *delim, - size_t n_delim, - char ***tokens_out, - size_t **token_lengths) + size_t projected_n_tokens, + const char *delim, + size_t n_delim, + char ***tokens_out, + size_t **token_lengths) { token_buffer tb, *token = &tb; char **tokens; @@ -165,7 +154,7 @@ readtokens (FILE *stream, if (projected_n_tokens == 0) projected_n_tokens = 64; else - projected_n_tokens++; /* add one for trailing NULL pointer */ + projected_n_tokens++; /* add one for trailing NULL pointer */ sz = projected_n_tokens; tokens = xnmalloc (sz, sizeof *tokens); @@ -178,18 +167,18 @@ readtokens (FILE *stream, char *tmp; size_t token_length = readtoken (stream, delim, n_delim, token); if (n_tokens >= sz) - { - tokens = x2nrealloc (tokens, &sz, sizeof *tokens); - lengths = xnrealloc (lengths, sz, sizeof *lengths); - } + { + tokens = x2nrealloc (tokens, &sz, sizeof *tokens); + lengths = xnrealloc (lengths, sz, sizeof *lengths); + } if (token_length == (size_t) -1) - { - /* don't increment n_tokens for NULL entry */ - tokens[n_tokens] = NULL; - lengths[n_tokens] = 0; - break; - } + { + /* don't increment n_tokens for NULL entry */ + tokens[n_tokens] = NULL; + lengths[n_tokens] = 0; + break; + } tmp = xnmalloc (token_length + 1, sizeof *tmp); lengths[n_tokens] = token_length; tokens[n_tokens] = memcpy (tmp, token->buffer, token_length + 1); @@ -200,5 +189,7 @@ readtokens (FILE *stream, *tokens_out = tokens; if (token_lengths != NULL) *token_lengths = lengths; + else + free (lengths); return n_tokens; } |