librsync  2.3.4
util.c
1 /*= -*- c-basic-offset: 4; indent-tabs-mode: nil; -*-
2  *
3  * librsync -- the library for network deltas
4  *
5  * Copyright (C) 2000, 2001 by Martin Pool <mbp@sourcefrog.net>
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU Lesser General Public License as published by
9  * the Free Software Foundation; either version 2.1 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15  * GNU Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20  */
21 
22  /*=
23  | On heroin, I have all the answers.
24  */
25 
26 #include "config.h" /* IWYU pragma: keep */
27 #include <stdlib.h>
28 #include <string.h>
29 #include "librsync.h"
30 #include "util.h"
31 #include "trace.h"
32 
33 void rs_bzero(void *buf, size_t size)
34 {
35  memset(buf, 0, size);
36 }
37 
38 void *rs_alloc_struct0(size_t size, char const *name)
39 {
40  void *p;
41 
42  if (!(p = malloc(size))) {
43  rs_fatal("couldn't allocate instance of %s", name);
44  }
45  rs_bzero(p, size);
46  return p;
47 }
48 
49 void *rs_alloc(size_t size, char const *name)
50 {
51  void *p;
52 
53  if (!(p = malloc(size))) {
54  rs_fatal("couldn't allocate instance of %s", name);
55  }
56 
57  return p;
58 }
59 
60 void *rs_realloc(void *ptr, size_t size, char const *name)
61 {
62  void *p;
63 
64  if (!(p = realloc(ptr, size))) {
65  rs_fatal("couldn't reallocate instance of %s", name);
66  }
67  return p;
68 }
69 
70 int rs_long_ln2(rs_long_t v)
71 {
72  int n;
73 
74  /* Count the number of shifts to zero v. */
75  for (n = 0; (v >>= 1); n++) ;
76  return n;
77 }
78 
79 int rs_long_sqrt(rs_long_t v)
80 {
81  rs_long_t n, b;
82 
83  /* Find the most significant bit of the root. */
84  for (b = 1, n = v; (n >>= 2); b <<= 1) ;
85  /* Walk down the bits of the root. */
86  for (n = 0; b; b >>= 1) {
87  /* Set the bit in the answer n. */
88  n |= b;
89  /* If n^2 is too big, clear the bit. */
90  if (n * n > v)
91  n ^= b;
92  }
93  return (int)n;
94 }
Public header for librsync.
logging functions.
Misc utility functions used by librsync.