Bump to version 1.22.1

[platform/upstream/busybox.git] / libbb / get_line_from_file.c

diff --git a/libbb/get_line_from_file.c b/libbb/get_line_from_file.c
index 2c9608e..a98dd35 100644 (file)
--- a/libbb/get_line_from_file.c
+++ b/libbb/get_line_from_file.c
@@ -6,31 +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) {
-                       linebuf = xrealloc(linebuf, linebufsz += 80);
-               }
+               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)
@@ -42,22 +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);
@@ -67,3 +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