1 #ifndef OSMIUM_OSM_CRC_HPP
2 #define OSMIUM_OSM_CRC_HPP
3 
4 /*
5 
6 This file is part of Osmium (https://osmcode.org/libosmium).
7 
8 Copyright 2013-2020 Jochen Topf <jochen@topf.org> and others (see README).
9 
10 Boost Software License - Version 1.0 - August 17th, 2003
11 
12 Permission is hereby granted, free of charge, to any person or organization
13 obtaining a copy of the software and accompanying documentation covered by
14 this license (the "Software") to use, reproduce, display, distribute,
15 execute, and transmit the Software, and to prepare derivative works of the
16 Software, and to permit third-parties to whom the Software is furnished to
17 do so, all subject to the following:
18 
19 The copyright notices in the Software and this entire statement, including
20 the above license grant, this restriction and the following disclaimer,
21 must be included in all copies of the Software, in whole or in part, and
22 all derivative works of the Software, unless such copies or derivative
23 works are solely in the form of machine-executable object code generated by
24 a source language processor.
25 
26 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
27 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
28 FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
29 SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
30 FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
31 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
32 DEALINGS IN THE SOFTWARE.
33 
34 */
35 
36 #include <osmium/osm/area.hpp>
37 #include <osmium/osm/box.hpp>
38 #include <osmium/osm/changeset.hpp>
39 #include <osmium/osm/item_type.hpp>
40 #include <osmium/osm/location.hpp>
41 #include <osmium/osm/node.hpp>
42 #include <osmium/osm/node_ref.hpp>
43 #include <osmium/osm/node_ref_list.hpp>
44 #include <osmium/osm/object.hpp>
45 #include <osmium/osm/relation.hpp>
46 #include <osmium/osm/tag.hpp>
47 #include <osmium/osm/timestamp.hpp>
48 #include <osmium/osm/way.hpp>
49 #include <osmium/util/endian.hpp>
50 
51 #include <cstdint>
52 
53 namespace osmium {
54 
55     inline namespace util {
56 
byte_swap_16(uint16_t value)57         inline uint16_t byte_swap_16(uint16_t value) noexcept {
58 #if defined(__GNUC__) || defined(__clang__)
59             return __builtin_bswap16(value);
60 #else
61             return (value >> 8) | (value << 8);
62 #endif
63         }
64 
byte_swap_32(uint32_t value)65         inline uint32_t byte_swap_32(uint32_t value) noexcept {
66 #if defined(__GNUC__) || defined(__clang__)
67             return __builtin_bswap32(value);
68 #else
69             return  (value >> 24) |
70                    ((value >>  8) & 0x0000FF00) |
71                    ((value <<  8) & 0x00FF0000) |
72                     (value << 24);
73 #endif
74         }
75 
byte_swap_64(uint64_t value)76         inline uint64_t byte_swap_64(uint64_t value) noexcept {
77 #if defined(__GNUC__) || defined(__clang__)
78             return __builtin_bswap64(value);
79 #else
80             const uint64_t val1 = byte_swap_32(value & 0xFFFFFFFF);
81             const uint64_t val2 = byte_swap_32(value >> 32);
82             return (val1 << 32) | val2;
83 #endif
84         }
85 
86     } // namespace util
87 
88     /**
89      * Framework for computing a checksum from OSM data. This class must be
90      * instantiated with a policy class that does the actual CRC calculations.
91      * It must have the process_byte(), process_bytes(), and checksum()
92      * member functions implemented according to the description in Boost
93      * (https://www.boost.org/doc/libs/release/libs/crc/crc.html).
94      *
95      * Typically you will either use the boost::crc_32_type from the Boost
96      * CRC library or the osmium::CRC_zlib class which uses the zlib library
97      * for this, but other checksums are possible.
98      *
99      * @tparam TCRC A CRC type.
100      */
101     template <typename TCRC>
102     class CRC {
103 
104         TCRC m_crc;
105 
106     public:
107 
operator ()()108         TCRC& operator()() noexcept {
109             return m_crc;
110         }
111 
operator ()() const112         const TCRC& operator()() const noexcept {
113             return m_crc;
114         }
115 
update_bool(const bool value)116         void update_bool(const bool value) noexcept {
117             m_crc.process_byte(value);
118         }
119 
update_int8(const uint8_t value)120         void update_int8(const uint8_t value) noexcept {
121             m_crc.process_byte(value);
122         }
123 
update_int16(const uint16_t value)124         void update_int16(const uint16_t value) noexcept {
125 #if __BYTE_ORDER == __LITTLE_ENDIAN
126             m_crc.process_bytes(&value, sizeof(uint16_t));
127 #else
128             const uint16_t v = osmium::byte_swap_16(value);
129             m_crc.process_bytes(&v, sizeof(uint16_t));
130 #endif
131         }
132 
update_int32(const uint32_t value)133         void update_int32(const uint32_t value) noexcept {
134 #if __BYTE_ORDER == __LITTLE_ENDIAN
135             m_crc.process_bytes(&value, sizeof(uint32_t));
136 #else
137             const uint32_t v = osmium::byte_swap_32(value);
138             m_crc.process_bytes(&v, sizeof(uint32_t));
139 #endif
140         }
141 
update_int64(const uint64_t value)142         void update_int64(const uint64_t value) noexcept {
143 #if __BYTE_ORDER == __LITTLE_ENDIAN
144             m_crc.process_bytes(&value, sizeof(uint64_t));
145 #else
146             const uint64_t v = osmium::byte_swap_64(value);
147             m_crc.process_bytes(&v, sizeof(uint64_t));
148 #endif
149         }
150 
update_string(const char * str)151         void update_string(const char* str) noexcept {
152             while (*str) {
153                 m_crc.process_byte(*str++);
154             }
155         }
156 
update(const Timestamp & timestamp)157         void update(const Timestamp& timestamp) noexcept {
158             update_int32(uint32_t(timestamp));
159         }
160 
update(const osmium::Location & location)161         void update(const osmium::Location& location) noexcept {
162             update_int32(location.x());
163             update_int32(location.y());
164         }
165 
update(const osmium::Box & box)166         void update(const osmium::Box& box) noexcept {
167             update(box.bottom_left());
168             update(box.top_right());
169         }
170 
update(const NodeRef & node_ref)171         void update(const NodeRef& node_ref) noexcept {
172             update_int64(node_ref.ref());
173             update(node_ref.location());
174         }
175 
update(const NodeRefList & node_refs)176         void update(const NodeRefList& node_refs) noexcept {
177             for (const NodeRef& node_ref : node_refs) {
178                 update(node_ref);
179             }
180         }
181 
update(const TagList & tags)182         void update(const TagList& tags) noexcept {
183             for (const Tag& tag : tags) {
184                 update_string(tag.key());
185                 update_string(tag.value());
186             }
187         }
188 
update(const osmium::RelationMember & member)189         void update(const osmium::RelationMember& member) noexcept {
190             update_int64(member.ref());
191             update_int16(uint16_t(member.type()));
192             update_string(member.role());
193         }
194 
update(const osmium::RelationMemberList & members)195         void update(const osmium::RelationMemberList& members) noexcept {
196             for (const RelationMember& member : members) {
197                 update(member);
198             }
199         }
200 
update(const osmium::OSMObject & object)201         void update(const osmium::OSMObject& object) noexcept {
202             update_int64(object.id());
203             update_bool(object.visible());
204             update_int32(object.version());
205             update(object.timestamp());
206             update_int32(object.uid());
207             update_string(object.user());
208             update(object.tags());
209         }
210 
update(const osmium::Node & node)211         void update(const osmium::Node& node) noexcept {
212             update(static_cast<const osmium::OSMObject&>(node));
213             update(node.location());
214         }
215 
update(const osmium::Way & way)216         void update(const osmium::Way& way) noexcept {
217             update(static_cast<const osmium::OSMObject&>(way));
218             update(way.nodes());
219         }
220 
update(const osmium::Relation & relation)221         void update(const osmium::Relation& relation) noexcept {
222             update(static_cast<const osmium::OSMObject&>(relation));
223             update(relation.members());
224         }
225 
update(const osmium::Area & area)226         void update(const osmium::Area& area) noexcept {
227             update(static_cast<const osmium::OSMObject&>(area));
228             for (const auto& subitem : area) {
229                 if (subitem.type() == osmium::item_type::outer_ring ||
230                     subitem.type() == osmium::item_type::inner_ring) {
231                     update(static_cast<const osmium::NodeRefList&>(subitem));
232                 }
233             }
234         }
235 
update(const osmium::ChangesetDiscussion & discussion)236         void update(const osmium::ChangesetDiscussion& discussion) noexcept {
237             for (const auto& comment : discussion) {
238                 update(comment.date());
239                 update_int32(comment.uid());
240                 update_string(comment.user());
241                 update_string(comment.text());
242             }
243         }
244 
update(const osmium::Changeset & changeset)245         void update(const osmium::Changeset& changeset) noexcept {
246             update_int64(changeset.id());
247             update(changeset.created_at());
248             update(changeset.closed_at());
249             update(changeset.bounds());
250             update_int32(changeset.num_changes());
251             update_int32(changeset.num_comments());
252             update_int32(changeset.uid());
253             update_string(changeset.user());
254             update(changeset.tags());
255             update(changeset.discussion());
256         }
257 
258     }; // class CRC
259 
260 } // namespace osmium
261 
262 #endif // OSMIUM_OSM_CRC_HPP
263