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authorDenys Vlasenko2011-06-17 03:37:43 +0200
committerDenys Vlasenko2011-06-17 03:37:43 +0200
commita1a448347e71c9899ad1500cbd8739fd82e1bb91 (patch)
treeb6f60da8a298eb37b672b68245e664dc04951d7f /libbb/get_line_from_file.c
parent901a53baecd5b8a580f63eb23d481f553de72634 (diff)
downloadbusybox-a1a448347e71c9899ad1500cbd8739fd82e1bb91.zip
busybox-a1a448347e71c9899ad1500cbd8739fd82e1bb91.tar.gz
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 <vda.linux@googlemail.com>
Diffstat (limited to 'libbb/get_line_from_file.c')
-rw-r--r--libbb/get_line_from_file.c42
1 files changed, 8 insertions, 34 deletions
diff --git a/libbb/get_line_from_file.c b/libbb/get_line_from_file.c
index 9be1068..a98dd35 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)
{