From a1a448347e71c9899ad1500cbd8739fd82e1bb91 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Fri, 17 Jun 2011 03:37:43 +0200 Subject: libbb: split bb_get_chunk_from_file and bb_get_chunk_with_continuation This also moves bb_get_chunk_with_continuation into its sole user, parse_config.c. This allows to optimize both functions separately, they need to be optimized for speed. (this need was highlighted by slow modprobe caused in part by slow bb_get_chunk_with_continuation in config parser). function old new delta bb_get_chunk_from_file 7 130 +123 config_read 457 558 +101 bb_get_chunk_with_continuation 194 - -194 ------------------------------------------------------------------------------ (add/remove: 0/1 grow/shrink: 2/0 up/down: 224/-194) Total: 30 bytes Signed-off-by: Denys Vlasenko --- libbb/get_line_from_file.c | 42 ++++++++---------------------------------- 1 file changed, 8 insertions(+), 34 deletions(-) (limited to 'libbb/get_line_from_file.c') diff --git a/libbb/get_line_from_file.c b/libbb/get_line_from_file.c index 9be10687b..a98dd35eb 100644 --- a/libbb/get_line_from_file.c +++ b/libbb/get_line_from_file.c @@ -11,45 +11,24 @@ #include "libbb.h" -/* This function reads an entire line from a text file, up to a newline - * or NUL byte, inclusive. It returns a malloc'ed char * which - * must be free'ed by the caller. If end is NULL '\n' isn't considered - * end of line. If end isn't NULL, length of the chunk is stored in it. - * If lineno is not NULL, *lineno is incremented for each line, - * and also trailing '\' is recognized as line continuation. - * - * Returns NULL if EOF/error. */ -char* FAST_FUNC bb_get_chunk_with_continuation(FILE *file, int *end, int *lineno) +char* FAST_FUNC bb_get_chunk_from_file(FILE *file, int *end) { int ch; - int idx = 0; + unsigned idx = 0; char *linebuf = NULL; - int linebufsz = 0; while ((ch = getc(file)) != EOF) { /* grow the line buffer as necessary */ - if (idx >= linebufsz) { - linebufsz += 256; - linebuf = xrealloc(linebuf, linebufsz); - } + if (!(idx & 0xff)) + linebuf = xrealloc(linebuf, idx + 0x100); linebuf[idx++] = (char) ch; - if (!ch) + if (ch == '\0') + break; + if (end && ch == '\n') break; - if (end && ch == '\n') { - if (lineno == NULL) - break; - (*lineno)++; - if (idx < 2 || linebuf[idx-2] != '\\') - break; - idx -= 2; - } } - if (end) { + if (end) *end = idx; - /* handle corner case when the file is not ended with '\n' */ - if (ch == EOF && lineno != NULL) - (*lineno)++; - } if (linebuf) { // huh, does fgets discard prior data on error like this? // I don't think so.... @@ -63,11 +42,6 @@ char* FAST_FUNC bb_get_chunk_with_continuation(FILE *file, int *end, int *lineno return linebuf; } -char* FAST_FUNC bb_get_chunk_from_file(FILE *file, int *end) -{ - return bb_get_chunk_with_continuation(file, end, NULL); -} - /* Get line, including trailing \n if any */ char* FAST_FUNC xmalloc_fgets(FILE *file) { -- cgit v1.2.3