1/* id.c : implements FSX-internal ID functions
2 *
3 * ====================================================================
4 *    Licensed to the Apache Software Foundation (ASF) under one
5 *    or more contributor license agreements.  See the NOTICE file
6 *    distributed with this work for additional information
7 *    regarding copyright ownership.  The ASF licenses this file
8 *    to you under the Apache License, Version 2.0 (the
9 *    "License"); you may not use this file except in compliance
10 *    with the License.  You may obtain a copy of the License at
11 *
12 *      http://www.apache.org/licenses/LICENSE-2.0
13 *
14 *    Unless required by applicable law or agreed to in writing,
15 *    software distributed under the License is distributed on an
16 *    "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
17 *    KIND, either express or implied.  See the License for the
18 *    specific language governing permissions and limitations
19 *    under the License.
20 * ====================================================================
21 */
22
23#include <assert.h>
24
25#include "id.h"
26#include "index.h"
27#include "util.h"
28
29#include "private/svn_string_private.h"
30
31
32
33svn_boolean_t
34svn_fs_x__is_txn(svn_fs_x__change_set_t change_set)
35{
36  return change_set < SVN_FS_X__INVALID_CHANGE_SET;
37}
38
39svn_boolean_t
40svn_fs_x__is_revision(svn_fs_x__change_set_t change_set)
41{
42  return change_set > SVN_FS_X__INVALID_CHANGE_SET;
43}
44
45svn_revnum_t
46svn_fs_x__get_revnum(svn_fs_x__change_set_t change_set)
47{
48  return svn_fs_x__is_revision(change_set)
49       ? (svn_revnum_t)change_set
50       : SVN_INVALID_REVNUM;
51}
52
53apr_int64_t
54svn_fs_x__get_txn_id(svn_fs_x__change_set_t change_set)
55{
56  return svn_fs_x__is_txn(change_set)
57       ? -change_set + SVN_FS_X__INVALID_CHANGE_SET -1
58       : SVN_FS_X__INVALID_TXN_ID;
59}
60
61
62svn_fs_x__change_set_t
63svn_fs_x__change_set_by_rev(svn_revnum_t revnum)
64{
65  assert(revnum >= SVN_FS_X__INVALID_CHANGE_SET);
66  return revnum;
67}
68
69svn_fs_x__change_set_t
70svn_fs_x__change_set_by_txn(apr_int64_t txn_id)
71{
72  assert(txn_id >= SVN_FS_X__INVALID_CHANGE_SET);
73  return -txn_id + SVN_FS_X__INVALID_CHANGE_SET -1;
74}
75
76
77/* Parse the NUL-terminated ID part at DATA and write the result into *PART.
78 * Return TRUE if no errors were detected. */
79static svn_boolean_t
80part_parse(svn_fs_x__id_t *part,
81           const char *data)
82{
83  part->number = svn__base36toui64(&data, data);
84  switch (data[0])
85    {
86      /* txn number? */
87      case '-': part->change_set = -svn__base36toui64(&data, data + 1);
88                return TRUE;
89
90      /* revision number? */
91      case '+': part->change_set = svn__base36toui64(&data, data + 1);
92                return TRUE;
93
94      /* everything else is forbidden */
95      default:  return FALSE;
96    }
97}
98
99/* Write the textual representation of *PART into P and return a pointer
100 * to the first position behind that string.
101 */
102static char *
103part_unparse(char *p,
104             const svn_fs_x__id_t *part)
105{
106  p += svn__ui64tobase36(p, part->number);
107  if (part->change_set >= 0)
108    {
109      *(p++) = '+';
110      p += svn__ui64tobase36(p, part->change_set);
111    }
112  else
113    {
114      *(p++) = '-';
115      p += svn__ui64tobase36(p, -part->change_set);
116    }
117
118  return p;
119}
120
121
122
123/* Operations on ID parts */
124
125svn_boolean_t
126svn_fs_x__id_is_root(const svn_fs_x__id_t* part)
127{
128  return part->change_set == 0 && part->number == 0;
129}
130
131svn_boolean_t
132svn_fs_x__id_eq(const svn_fs_x__id_t *lhs,
133                const svn_fs_x__id_t *rhs)
134{
135  return lhs->change_set == rhs->change_set && lhs->number == rhs->number;
136}
137
138svn_error_t *
139svn_fs_x__id_parse(svn_fs_x__id_t *part,
140                   const char *data)
141{
142  if (!part_parse(part, data))
143    return svn_error_createf(SVN_ERR_FS_MALFORMED_NODEREV_ID, NULL,
144                             "Malformed ID string");
145
146  return SVN_NO_ERROR;
147}
148
149svn_string_t *
150svn_fs_x__id_unparse(const svn_fs_x__id_t *id,
151                     apr_pool_t *result_pool)
152{
153  char string[2 * SVN_INT64_BUFFER_SIZE + 1];
154  char *p = part_unparse(string, id);
155
156  return svn_string_ncreate(string, p - string, result_pool);
157}
158
159void
160svn_fs_x__id_reset(svn_fs_x__id_t *part)
161{
162  part->change_set = SVN_FS_X__INVALID_CHANGE_SET;
163  part->number = 0;
164}
165
166svn_boolean_t
167svn_fs_x__id_used(const svn_fs_x__id_t *part)
168{
169  return part->change_set != SVN_FS_X__INVALID_CHANGE_SET;
170}
171
172void
173svn_fs_x__init_txn_root(svn_fs_x__id_t *noderev_id,
174                        svn_fs_x__txn_id_t txn_id)
175{
176  noderev_id->change_set = svn_fs_x__change_set_by_txn(txn_id);
177  noderev_id->number = SVN_FS_X__ITEM_INDEX_ROOT_NODE;
178}
179
180void
181svn_fs_x__init_rev_root(svn_fs_x__id_t *noderev_id,
182                        svn_revnum_t rev)
183{
184  noderev_id->change_set = svn_fs_x__change_set_by_rev(rev);
185  noderev_id->number = SVN_FS_X__ITEM_INDEX_ROOT_NODE;
186}
187
188int
189svn_fs_x__id_compare(const svn_fs_x__id_t *a,
190                     const svn_fs_x__id_t *b)
191{
192  if (a->change_set < b->change_set)
193    return -1;
194  if (a->change_set > b->change_set)
195    return 1;
196
197  return a->number < b->number ? -1 : a->number == b->number ? 0 : 1;
198}
199