blob: e3b7b415cb3b046e236bbae01ee07921fb5a2817 [file] [log] [blame]
Ed Warnickecb9cada2015-12-08 15:45:58 -07001/*
2 * Copyright (c) 2015 Cisco and/or its affiliates.
3 * Licensed under the Apache License, Version 2.0 (the "License");
4 * you may not use this file except in compliance with the License.
5 * You may obtain a copy of the License at:
6 *
7 * http://www.apache.org/licenses/LICENSE-2.0
8 *
9 * Unless required by applicable law or agreed to in writing, software
10 * distributed under the License is distributed on an "AS IS" BASIS,
11 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 * See the License for the specific language governing permissions and
13 * limitations under the License.
14 */
15/*
16 Copyright (c) 2001, 2002, 2003 Eliot Dresselhaus
17
18 Permission is hereby granted, free of charge, to any person obtaining
19 a copy of this software and associated documentation files (the
20 "Software"), to deal in the Software without restriction, including
21 without limitation the rights to use, copy, modify, merge, publish,
22 distribute, sublicense, and/or sell copies of the Software, and to
23 permit persons to whom the Software is furnished to do so, subject to
24 the following conditions:
25
26 The above copyright notice and this permission notice shall be
27 included in all copies or substantial portions of the Software.
28
29 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
30 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
31 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
32 NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
33 LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
34 OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
35 WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
36*/
37
38#include <vppinfra/cache.h>
39#include <vppinfra/fifo.h>
40#include <vppinfra/error.h>
41#include <vppinfra/string.h>
42
43/*
44 General first in/first out queues.
45 FIFOs can have arbitrary size and type.
46 Let T be any type (i.e. char, int, struct foo, etc.).
47
48 A null fifo is initialized:
49
50 T * f = 0;
51
52 For example, typedef struct { int a, b; } T;
53
54 Elements can be added in 3 ways.
55
56 #1 1 element is added:
57 T x;
58 x.a = 10; x.b = 20;
59 fifo_add1 (f, x);
60
61 #2 n elements are added
62 T buf[10];
63 initialize buf[0] .. buf[9];
64 fifo_add (f, buf, 10);
65
66 #3 1 element is added, pointer is returned
67 T * x;
68 fifo_add2 (f, x);
69 x->a = 10;
70 x->b = 20;
71
72 Elements are removed 1 at a time:
73 T x;
74 fifo_sub1 (f, x);
75
76 fifo_free (f) frees fifo.
77*/
78
Dave Barachc3799992016-08-15 11:12:27 -040079void *
80_clib_fifo_resize (void *v_old, uword n_new_elts, uword elt_bytes)
Ed Warnickecb9cada2015-12-08 15:45:58 -070081{
Dave Barachc3799992016-08-15 11:12:27 -040082 void *v_new, *end, *head;
Ed Warnickecb9cada2015-12-08 15:45:58 -070083 uword n_old_elts, header_bytes;
84 uword n_copy_bytes, n_zero_bytes;
Dave Barachc3799992016-08-15 11:12:27 -040085 clib_fifo_header_t *f_new, *f_old;
86
Ed Warnickecb9cada2015-12-08 15:45:58 -070087 n_old_elts = clib_fifo_elts (v_old);
88 n_new_elts += n_old_elts;
89 if (n_new_elts < 32)
90 n_new_elts = 32;
91 else
92 n_new_elts = max_pow2 (n_new_elts);
93
94 header_bytes = vec_header_bytes (sizeof (clib_fifo_header_t));
95
96 v_new = clib_mem_alloc_no_fail (n_new_elts * elt_bytes + header_bytes);
97 v_new += header_bytes;
98
99 f_new = clib_fifo_header (v_new);
100 f_new->head_index = 0;
101 f_new->tail_index = n_old_elts;
102 _vec_len (v_new) = n_new_elts;
103
104 /* Copy old -> new. */
105 n_copy_bytes = n_old_elts * elt_bytes;
106 if (n_copy_bytes > 0)
107 {
108 f_old = clib_fifo_header (v_old);
109 end = v_old + _vec_len (v_old) * elt_bytes;
110 head = v_old + f_old->head_index * elt_bytes;
111
112 if (head + n_copy_bytes >= end)
113 {
114 uword n = end - head;
Damjan Marionf1213b82016-03-13 02:22:06 +0100115 clib_memcpy (v_new, head, n);
116 clib_memcpy (v_new + n, v_old, n_copy_bytes - n);
Ed Warnickecb9cada2015-12-08 15:45:58 -0700117 }
118 else
Damjan Marionf1213b82016-03-13 02:22:06 +0100119 clib_memcpy (v_new, head, n_copy_bytes);
Ed Warnickecb9cada2015-12-08 15:45:58 -0700120 }
121
122 /* Zero empty space. */
123 n_zero_bytes = (n_new_elts - n_old_elts) * elt_bytes;
Dave Barachb7b92992018-10-17 10:38:51 -0400124 clib_memset (v_new + n_copy_bytes, 0, n_zero_bytes);
Ed Warnickecb9cada2015-12-08 15:45:58 -0700125
126 clib_fifo_free (v_old);
127
128 return v_new;
129}
Dave Barachc3799992016-08-15 11:12:27 -0400130
131/*
132 * fd.io coding-style-patch-verification: ON
133 *
134 * Local Variables:
135 * eval: (c-set-style "gnu")
136 * End:
137 */