xapian-core/common/win32_uuid.cc

   1 /** @file win32_uuid.cc
   2  * @brief Provide UUID functions compatible with libuuid from util-linux-ng.
   3  */
   4 /* Copyright (C) 2008 Lemur Consulting Ltd
   5  * Copyright (C) 2013,2015,2016,2017 Olly Betts
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 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 General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301 USA
  20  */
  21
  22 #include <config.h>
  23
  24 #include "win32_uuid.h"
  25
  26 #include "xapian/error.h"
  27
  28 #include <cstring>
  29 #include "stringutils.h"
  30
  31 #ifdef __WIN32__
  32 # include "safewinsock2.h" // For htonl() and htons().
  33 #else
  34 // Cygwin:
  35 # include <arpa/inet.h> // For htonl() and htons().
  36 #endif
  37
  38 using namespace std;
  39
  40 /// The size of a UUID in bytes.
  41 const size_t UUID_SIZE = 16;
  42
  43 void
  44 uuid_generate(uuid_t uu)
  45 {
  46     UUID uuid;
  47     if (rare(UuidCreate(&uuid) != RPC_S_OK)) {
  48         // Throw a DatabaseCreateError, since we can't make a UUID.  The
  49         // windows API documentation is a bit unclear about the situations in
  50         // which this can happen, but if this behaviour causes a problem, an
  51         // alternative would be to create a UUID ourselves somehow in this
  52         // situation.
  53         throw Xapian::DatabaseCreateError("Cannot create UUID");
  54     }
  55     uuid.Data1 = htonl(uuid.Data1);
  56     uuid.Data2 = htons(uuid.Data2);
  57     uuid.Data3 = htons(uuid.Data3);
  58     memcpy(uu, &uuid, UUID_SIZE);
  59 }
  60
  61 int
  62 uuid_parse(const char * in, uuid_t uu)
  63 {
  64     for (unsigned i = 0; i != UUID_SIZE; ++i) {
  65         uu[i] = hex_digit(in[0]) << 4 | hex_digit(in[1]);
  66         in += ((0x2a8 >> i) & 1) | 2;
  67     }
  68     return 0;
  69 }
  70
  71 void uuid_unparse_lower(const uuid_t uu, char * out)
  72 {
  73     for (unsigned i = 0; i != UUID_SIZE; ++i) {
  74         unsigned char ch = uu[i];
  75         *out++ = "0123456789abcdef"[ch >> 4];
  76         *out++ = "0123456789abcdef"[ch & 0x0f];
  77         if ((0x2a8 >> i) & 1)
  78            *out++ = '-';
  79     }
  80     *out = '\0';
  81 }
  82
  83 void uuid_clear(uuid_t uu)
  84 {
  85     memset(uu, 0, UUID_SIZE);
  86 }
  87
  88 int uuid_is_null(const uuid_t uu)
  89 {
  90     unsigned i = 0;
  91     while (i < UUID_SIZE) {
  92         if (uu[i++])
  93             return 0;
  94     }
  95     return 1;
  96 }