X-Git-Url: https://git.librecmc.org/?a=blobdiff_plain;f=libbb%2Fget_line_from_file.c;h=a98dd35eb2b8fdf9e17737cf5abd9215a139b455;hb=b05bcaf29c9008799aedb535cb42d2e60cc4cbb9;hp=1eb4af13c975990d73217ecae6f56bc20e0f6bf5;hpb=51742f4bb0c57a4d5063ece9437a2f34a42e52c8;p=oweals%2Fbusybox.git

diff --git a/libbb/get_line_from_file.c b/libbb/get_line_from_file.c
index 1eb4af13c..a98dd35eb 100644
--- a/libbb/get_line_from_file.c
+++ b/libbb/get_line_from_file.c
@@ -6,32 +6,25 @@
  * Copyright (C) 2004 Erik Andersen <andersen@codepoet.org>
  * Copyright (C) 2001 Matt Krai
  *
- * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
+ * Licensed under GPLv2 or later, see file LICENSE in this source tree.
  */
 
 #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
- * stored and 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 read is stored in it.
- * Return NULL if EOF/error */
-
-char *bb_get_chunk_from_file(FILE *file, int *end)
+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 += 80;
-			linebuf = xrealloc(linebuf, linebufsz);
-		}
+		if (!(idx & 0xff))
+			linebuf = xrealloc(linebuf, idx + 0x100);
 		linebuf[idx++] = (char) ch;
-		if (!ch || (end && ch == '\n'))
+		if (ch == '\0')
+			break;
+		if (end && ch == '\n')
 			break;
 	}
 	if (end)
@@ -43,22 +36,21 @@ char *bb_get_chunk_from_file(FILE *file, int *end)
 		//	free(linebuf);
 		//	return NULL;
 		//}
-		linebuf = xrealloc(linebuf, idx+1);
+		linebuf = xrealloc(linebuf, idx + 1);
 		linebuf[idx] = '\0';
 	}
 	return linebuf;
 }
 
 /* Get line, including trailing \n if any */
-char *xmalloc_fgets(FILE *file)
+char* FAST_FUNC xmalloc_fgets(FILE *file)
 {
 	int i;
 
 	return bb_get_chunk_from_file(file, &i);
 }
-
 /* Get line.  Remove trailing \n */
-char *xmalloc_getline(FILE *file)
+char* FAST_FUNC xmalloc_fgetline(FILE *file)
 {
 	int i;
 	char *c = bb_get_chunk_from_file(file, &i);
@@ -68,3 +60,121 @@ char *xmalloc_getline(FILE *file)
 
 	return c;
 }
+
+#if 0
+/* GNUism getline() should be faster (not tested) than a loop with fgetc */
+
+/* Get line, including trailing \n if any */
+char* FAST_FUNC xmalloc_fgets(FILE *file)
+{
+	char *res_buf = NULL;
+	size_t res_sz;
+
+	if (getline(&res_buf, &res_sz, file) == -1) {
+		free(res_buf); /* uclibc allocates a buffer even on EOF. WTF? */
+		res_buf = NULL;
+	}
+//TODO: trimming to res_sz?
+	return res_buf;
+}
+/* Get line.  Remove trailing \n */
+char* FAST_FUNC xmalloc_fgetline(FILE *file)
+{
+	char *res_buf = NULL;
+	size_t res_sz;
+
+	res_sz = getline(&res_buf, &res_sz, file);
+
+	if ((ssize_t)res_sz != -1) {
+		if (res_buf[res_sz - 1] == '\n')
+			res_buf[--res_sz] = '\0';
+//TODO: trimming to res_sz?
+	} else {
+		free(res_buf); /* uclibc allocates a buffer even on EOF. WTF? */
+		res_buf = NULL;
+	}
+	return res_buf;
+}
+
+#endif
+
+#if 0
+/* 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"...
+ * Ironically, grep can't use it because of NUL issue.
+ * We sorely need C lib to provide fgets which reports size!
+ *
+ * Update:
+ * Actually, uclibc and glibc have it. man getline. It's GNUism,
+ *   but very useful one (if it's as fast as this code).
+ * TODO:
+ * - currently, sed and sort use bb_get_chunk_from_file and heavily
+ *   depend on its "stop on \n or \0" behavior, and STILL they fail
+ *   to handle all cases with embedded NULs correctly. So:
+ * - audit sed and sort; convert them to getline FIRST.
+ * - THEN ditch bb_get_chunk_from_file, replace it with getline.
+ * - provide getline implementation for non-GNU systems.
+ */
+
+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)! */
+}
+
+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