lib/uuid.h

   1 /* Copyright (c) 2008, 2009, 2010, 2016, 2017 Nicira, Inc.
   2  *
   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 #ifndef UUID_H
  17 #define UUID_H 1
  18
  19 #include "openvswitch/uuid.h"
  20
  21 #ifdef __cplusplus
  22 extern "C" {
  23 #endif
  24
  25 /* An initializer or expression for an all-zero UUID. */
  26 #define UUID_ZERO ((struct uuid) { .parts = { 0, 0, 0, 0 } })
  27
  28 /* Formats a UUID as a string, in the conventional format.
  29  *
  30  * Example:
  31  *   struct uuid uuid = ...;
  32  *   printf("This UUID is "UUID_FMT"\n", UUID_ARGS(&uuid));
  33  *
  34  */
  35 #define UUID_LEN 36
  36 #define UUID_FMT "%08x-%04x-%04x-%04x-%04x%08x"
  37 #define UUID_ARGS(UUID)                             \
  38     ((unsigned int) ((UUID)->parts[0])),            \
  39     ((unsigned int) ((UUID)->parts[1] >> 16)),      \
  40     ((unsigned int) ((UUID)->parts[1] & 0xffff)),   \
  41     ((unsigned int) ((UUID)->parts[2] >> 16)),      \
  42     ((unsigned int) ((UUID)->parts[2] & 0xffff)),   \
  43     ((unsigned int) ((UUID)->parts[3]))
  44
  45 /* Returns a hash value for 'uuid'.  This hash value is the same regardless of
  46  * whether we are running on a 32-bit or 64-bit or big-endian or little-endian
  47  * architecture. */
  48 static inline size_t
  49 uuid_hash(const struct uuid *uuid)
  50 {
  51     return uuid->parts[0];
  52 }
  53
  54 /* Returns true if 'a == b', false otherwise. */
  55 static inline bool
  56 uuid_equals(const struct uuid *a, const struct uuid *b)
  57 {
  58     return (a->parts[0] == b->parts[0]
  59             && a->parts[1] == b->parts[1]
  60             && a->parts[2] == b->parts[2]
  61             && a->parts[3] == b->parts[3]);
  62 }
  63
  64 /* Returns the first 'n' hex digits of 'uuid', for 0 < 'n' <= 8.
  65  *
  66  * This is useful for displaying a few leading digits of the uuid, e.g. to
  67  * display 4 digits:
  68  *     printf("%04x", uuid_prefix(uuid, 4));
  69  */
  70 static inline unsigned int
  71 uuid_prefix(const struct uuid *uuid, int digits)
  72 {
  73     return (uuid->parts[0] >> (32 - 4 * digits));
  74 }
  75
  76 void uuid_init(void);
  77 void uuid_generate(struct uuid *);
  78 struct uuid uuid_random(void);
  79 void uuid_zero(struct uuid *);
  80 bool uuid_is_zero(const struct uuid *);
  81 int uuid_compare_3way(const struct uuid *, const struct uuid *);
  82 bool uuid_from_string(struct uuid *, const char *);
  83 bool uuid_from_string_prefix(struct uuid *, const char *);
  84 int uuid_is_partial_string(const char *);
  85 int uuid_is_partial_match(const struct uuid *, const char *match);
  86 void uuid_set_bits_v4(struct uuid *);
  87
  88 #ifdef __cplusplus
  89 }
  90 #endif
  91
  92 #endif /* uuid.h */