1 /*
2 Minetest
3 Copyright (C) 2010-2015 kwolekr, Ryan Kwolek <kwolekr@minetest.net>
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU Lesser General Public License as published by
7 the Free Software Foundation; either version 2.1 of the License, or
8 (at your option) any later version.
9
10 This program is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 GNU Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public License along
16 with this program; if not, write to the Free Software Foundation, Inc.,
17 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
18 */
19
20 #include "objdef.h"
21 #include "util/numeric.h"
22 #include "log.h"
23 #include "gamedef.h"
24
ObjDefManager(IGameDef * gamedef,ObjDefType type)25 ObjDefManager::ObjDefManager(IGameDef *gamedef, ObjDefType type)
26 {
27 m_objtype = type;
28 m_ndef = gamedef ? gamedef->getNodeDefManager() : NULL;
29 }
30
31
~ObjDefManager()32 ObjDefManager::~ObjDefManager()
33 {
34 for (size_t i = 0; i != m_objects.size(); i++)
35 delete m_objects[i];
36 }
37
38
add(ObjDef * obj)39 ObjDefHandle ObjDefManager::add(ObjDef *obj)
40 {
41 assert(obj);
42
43 if (obj->name.length() && getByName(obj->name))
44 return OBJDEF_INVALID_HANDLE;
45
46 u32 index = addRaw(obj);
47 if (index == OBJDEF_INVALID_INDEX)
48 return OBJDEF_INVALID_HANDLE;
49
50 obj->handle = createHandle(index, m_objtype, obj->uid);
51 return obj->handle;
52 }
53
54
get(ObjDefHandle handle) const55 ObjDef *ObjDefManager::get(ObjDefHandle handle) const
56 {
57 u32 index = validateHandle(handle);
58 return (index != OBJDEF_INVALID_INDEX) ? getRaw(index) : NULL;
59 }
60
61
set(ObjDefHandle handle,ObjDef * obj)62 ObjDef *ObjDefManager::set(ObjDefHandle handle, ObjDef *obj)
63 {
64 u32 index = validateHandle(handle);
65 if (index == OBJDEF_INVALID_INDEX)
66 return NULL;
67
68 ObjDef *oldobj = setRaw(index, obj);
69
70 obj->uid = oldobj->uid;
71 obj->index = oldobj->index;
72 obj->handle = oldobj->handle;
73
74 return oldobj;
75 }
76
77
addRaw(ObjDef * obj)78 u32 ObjDefManager::addRaw(ObjDef *obj)
79 {
80 size_t nobjects = m_objects.size();
81 if (nobjects >= OBJDEF_MAX_ITEMS)
82 return -1;
83
84 obj->index = nobjects;
85
86 // Ensure UID is nonzero so that a valid handle == OBJDEF_INVALID_HANDLE
87 // is not possible. The slight randomness bias isn't very significant.
88 obj->uid = myrand() & OBJDEF_UID_MASK;
89 if (obj->uid == 0)
90 obj->uid = 1;
91
92 m_objects.push_back(obj);
93
94 infostream << "ObjDefManager: added " << getObjectTitle()
95 << ": name=\"" << obj->name
96 << "\" index=" << obj->index
97 << " uid=" << obj->uid
98 << std::endl;
99
100 return nobjects;
101 }
102
103
getRaw(u32 index) const104 ObjDef *ObjDefManager::getRaw(u32 index) const
105 {
106 return m_objects[index];
107 }
108
109
setRaw(u32 index,ObjDef * obj)110 ObjDef *ObjDefManager::setRaw(u32 index, ObjDef *obj)
111 {
112 ObjDef *old_obj = m_objects[index];
113 m_objects[index] = obj;
114 return old_obj;
115 }
116
117
getByName(const std::string & name) const118 ObjDef *ObjDefManager::getByName(const std::string &name) const
119 {
120 for (size_t i = 0; i != m_objects.size(); i++) {
121 ObjDef *obj = m_objects[i];
122 if (obj && !strcasecmp(name.c_str(), obj->name.c_str()))
123 return obj;
124 }
125
126 return NULL;
127 }
128
129
clear()130 void ObjDefManager::clear()
131 {
132 for (size_t i = 0; i != m_objects.size(); i++)
133 delete m_objects[i];
134
135 m_objects.clear();
136 }
137
138
validateHandle(ObjDefHandle handle) const139 u32 ObjDefManager::validateHandle(ObjDefHandle handle) const
140 {
141 ObjDefType type;
142 u32 index;
143 u32 uid;
144
145 bool is_valid =
146 (handle != OBJDEF_INVALID_HANDLE) &&
147 decodeHandle(handle, &index, &type, &uid) &&
148 (type == m_objtype) &&
149 (index < m_objects.size()) &&
150 (m_objects[index]->uid == uid);
151
152 return is_valid ? index : -1;
153 }
154
155
createHandle(u32 index,ObjDefType type,u32 uid)156 ObjDefHandle ObjDefManager::createHandle(u32 index, ObjDefType type, u32 uid)
157 {
158 ObjDefHandle handle = 0;
159 set_bits(&handle, 0, 18, index);
160 set_bits(&handle, 18, 6, type);
161 set_bits(&handle, 24, 7, uid);
162
163 u32 parity = calc_parity(handle);
164 set_bits(&handle, 31, 1, parity);
165
166 return handle ^ OBJDEF_HANDLE_SALT;
167 }
168
169
decodeHandle(ObjDefHandle handle,u32 * index,ObjDefType * type,u32 * uid)170 bool ObjDefManager::decodeHandle(ObjDefHandle handle, u32 *index,
171 ObjDefType *type, u32 *uid)
172 {
173 handle ^= OBJDEF_HANDLE_SALT;
174
175 u32 parity = get_bits(handle, 31, 1);
176 set_bits(&handle, 31, 1, 0);
177 if (parity != calc_parity(handle))
178 return false;
179
180 *index = get_bits(handle, 0, 18);
181 *type = (ObjDefType)get_bits(handle, 18, 6);
182 *uid = get_bits(handle, 24, 7);
183 return true;
184 }
185
186 // Cloning
187
cloneTo(ObjDef * def) const188 void ObjDef::cloneTo(ObjDef *def) const
189 {
190 def->index = index;
191 def->uid = uid;
192 def->handle = handle;
193 def->name = name;
194 }
195
cloneTo(ObjDefManager * mgr) const196 void ObjDefManager::cloneTo(ObjDefManager *mgr) const
197 {
198 mgr->m_ndef = m_ndef;
199 mgr->m_objects.reserve(m_objects.size());
200 for (const auto &obj : m_objects)
201 mgr->m_objects.push_back(obj->clone());
202 mgr->m_objtype = m_objtype;
203 }
204