diff options
| -rw-r--r-- | include/libbb.h | 6 | ||||
| -rw-r--r-- | libbb/get_line_from_file.c | 70 |
2 files changed, 75 insertions, 1 deletions
diff --git a/include/libbb.h b/include/libbb.h index 671584b..2bd614c 100644 --- a/include/libbb.h +++ b/include/libbb.h @@ -607,6 +607,8 @@ extern void xopen_xwrite_close(const char* file, const char *str) FAST_FUNC; /* Reads and prints to stdout till eof, then closes FILE. Exits on error: */ extern void xprint_and_close_file(FILE *file) FAST_FUNC; + +extern char *bb_get_chunk_from_file(FILE *file, int *end) FAST_FUNC; /* Reads up to (and including) TERMINATING_STRING: */ extern char *xmalloc_fgets_str(FILE *file, const char *terminating_string) FAST_FUNC; /* Chops off TERMINATING_STRING from the end: */ @@ -615,7 +617,9 @@ extern char *xmalloc_fgetline_str(FILE *file, const char *terminating_string) FA extern char *xmalloc_fgets(FILE *file) FAST_FUNC; /* Chops off '\n' from the end, unlike fgets: */ extern char *xmalloc_fgetline(FILE *file) FAST_FUNC; -extern char *bb_get_chunk_from_file(FILE *file, int *end) FAST_FUNC; +/* Same, but doesn't try to conserve space (may have some slack after the end) */ +extern char *xmalloc_fgetline_fast(FILE *file) FAST_FUNC; + extern void die_if_ferror(FILE *file, const char *msg) FAST_FUNC; extern void die_if_ferror_stdout(void) FAST_FUNC; extern void xfflush_stdout(void) FAST_FUNC; diff --git a/libbb/get_line_from_file.c b/libbb/get_line_from_file.c index 3a76f49..7b65ced 100644 --- a/libbb/get_line_from_file.c +++ b/libbb/get_line_from_file.c @@ -67,3 +67,73 @@ char* FAST_FUNC xmalloc_fgetline(FILE *file) return c; } + +/* Faster routines (~twice as fast). +170 bytes. Unused as of 2008-07. + * + * NB: they stop at NUL byte too. + * Performance is important here. Think "grep 50gigabyte_file"... + * Iironically, grep can't use it because of NUL issue. + * We sorely need C lib to provide fgets which reports size! + */ + +static char* xmalloc_fgets_internal(FILE *file, int *sizep) +{ + int len; + int idx = 0; + char *linebuf = NULL; + + while (1) { + char *r; + + linebuf = xrealloc(linebuf, idx + 0x100); + r = fgets(&linebuf[idx], 0x100, file); + if (!r) { + /* need to terminate in case this is error + * (EOF puts NUL itself) */ + linebuf[idx] = '\0'; + break; + } + /* stupid. fgets knows the len, it should report it somehow */ + len = strlen(&linebuf[idx]); + idx += len; + if (len != 0xff || linebuf[idx - 1] == '\n') + break; + } + *sizep = idx; + if (idx) { + /* xrealloc(linebuf, idx + 1) is up to caller */ + return linebuf; + } + free(linebuf); + return NULL; +} + +/* Get line, remove trailing \n */ +char* FAST_FUNC xmalloc_fgetline_fast(FILE *file) +{ + int sz; + char *r = xmalloc_fgets_internal(file, &sz); + if (r && r[sz - 1] == '\n') + r[--sz] = '\0'; + return r; /* not xrealloc(r, sz + 1)! */ +} + +#if 0 +char* FAST_FUNC xmalloc_fgets(FILE *file) +{ + int sz; + return xmalloc_fgets_internal(file, &sz); +} + +/* Get line, remove trailing \n */ +char* FAST_FUNC xmalloc_fgetline(FILE *file) +{ + int sz; + char *r = xmalloc_fgets_internal(file, &sz); + if (!r) + return r; + if (r[sz - 1] == '\n') + r[--sz] = '\0'; + return xrealloc(r, sz + 1); +} +#endif |