LSST Applications 27.0.0,g0265f82a02+469cd937ee,g02d81e74bb+21ad69e7e1,g1470d8bcf6+cbe83ee85a,g2079a07aa2+e67c6346a6,g212a7c68fe+04a9158687,g2305ad1205+94392ce272,g295015adf3+81dd352a9d,g2bbee38e9b+469cd937ee,g337abbeb29+469cd937ee,g3939d97d7f+72a9f7b576,g487adcacf7+71499e7cba,g50ff169b8f+5929b3527e,g52b1c1532d+a6fc98d2e7,g591dd9f2cf+df404f777f,g5a732f18d5+be83d3ecdb,g64a986408d+21ad69e7e1,g858d7b2824+21ad69e7e1,g8a8a8dda67+a6fc98d2e7,g99cad8db69+f62e5b0af5,g9ddcbc5298+d4bad12328,ga1e77700b3+9c366c4306,ga8c6da7877+71e4819109,gb0e22166c9+25ba2f69a1,gb6a65358fc+469cd937ee,gbb8dafda3b+69d3c0e320,gc07e1c2157+a98bf949bb,gc120e1dc64+615ec43309,gc28159a63d+469cd937ee,gcf0d15dbbd+72a9f7b576,gdaeeff99f8+a38ce5ea23,ge6526c86ff+3a7c1ac5f1,ge79ae78c31+469cd937ee,gee10cc3b42+a6fc98d2e7,gf1cff7945b+21ad69e7e1,gfbcc870c63+9a11dc8c8f
LSST Data Management Base Package
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codec.h
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1/*
2 * This file is part of sphgeom.
3 *
4 * Developed for the LSST Data Management System.
5 * This product includes software developed by the LSST Project
6 * (http://www.lsst.org).
7 * See the COPYRIGHT file at the top-level directory of this distribution
8 * for details of code ownership.
9 *
10 * This software is dual licensed under the GNU General Public License and also
11 * under a 3-clause BSD license. Recipients may choose which of these licenses
12 * to use; please see the files gpl-3.0.txt and/or bsd_license.txt,
13 * respectively. If you choose the GPL option then the following text applies
14 * (but note that there is still no warranty even if you opt for BSD instead):
15 *
16 * This program is free software: you can redistribute it and/or modify
17 * it under the terms of the GNU General Public License as published by
18 * the Free Software Foundation, either version 3 of the License, or
19 * (at your option) any later version.
20 *
21 * This program is distributed in the hope that it will be useful,
22 * but WITHOUT ANY WARRANTY; without even the implied warranty of
23 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
24 * GNU General Public License for more details.
25 *
26 * You should have received a copy of the GNU General Public License
27 * along with this program. If not, see <http://www.gnu.org/licenses/>.
28 */
29
30#ifndef LSST_SPHGEOM_CODEC_H_
31#define LSST_SPHGEOM_CODEC_H_
32
33// Optimized path requires little endian arch and support for unaligned loads.
34#if defined(__x86_64__) or \
35 (defined(__aarch64__) and \
36 (defined(__LITTLE_ENDIAN__) or \
37 (defined(__BYTE_ORDER__) and __BYTE_ORDER__ == 1234)))
38#define OPTIMIZED_LITTLE_ENDIAN
39#endif
40
41#ifdef NO_OPTIMIZED_PATHS
42#undef OPTIMIZED_LITTLE_ENDIAN
43#endif
44
48
49#include <vector>
50
51namespace lsst {
52namespace sphgeom {
53
56inline void encodeDouble(double item, std::vector<uint8_t> & buffer) {
57#ifdef OPTIMIZED_LITTLE_ENDIAN
58 auto ptr = reinterpret_cast<uint8_t const *>(&item);
59 buffer.insert(buffer.end(), ptr, ptr + 8);
60#else
61 union { uint64_t u; double d; };
62 d = item;
63 buffer.push_back(static_cast<uint8_t>(u));
64 buffer.push_back(static_cast<uint8_t>(u >> 8));
65 buffer.push_back(static_cast<uint8_t>(u >> 16));
66 buffer.push_back(static_cast<uint8_t>(u >> 24));
67 buffer.push_back(static_cast<uint8_t>(u >> 32));
68 buffer.push_back(static_cast<uint8_t>(u >> 40));
69 buffer.push_back(static_cast<uint8_t>(u >> 48));
70 buffer.push_back(static_cast<uint8_t>(u >> 56));
71#endif
72}
73
76inline double decodeDouble(uint8_t const * buffer) {
77#ifdef OPTIMIZED_LITTLE_ENDIAN
78 return *reinterpret_cast<double const *>(buffer);
79#else
80 union { uint64_t u; double d; };
81 u = static_cast<uint64_t>(buffer[0]) +
82 (static_cast<uint64_t>(buffer[1]) << 8) +
83 (static_cast<uint64_t>(buffer[2]) << 16) +
84 (static_cast<uint64_t>(buffer[3]) << 24) +
85 (static_cast<uint64_t>(buffer[4]) << 32) +
86 (static_cast<uint64_t>(buffer[5]) << 40) +
87 (static_cast<uint64_t>(buffer[6]) << 48) +
88 (static_cast<uint64_t>(buffer[7]) << 56);
89 return d;
90#endif
91}
92
95inline void encodeU64(std::uint64_t item, std::vector<uint8_t> & buffer) {
96#ifdef OPTIMIZED_LITTLE_ENDIAN
97 auto ptr = reinterpret_cast<uint8_t const *>(&item);
98 buffer.insert(buffer.end(), ptr, ptr + 8);
99#else
100 union { uint64_t u; double d; };
101 d = item;
102 buffer.push_back(static_cast<uint8_t>(u));
103 buffer.push_back(static_cast<uint8_t>(u >> 8));
104 buffer.push_back(static_cast<uint8_t>(u >> 16));
105 buffer.push_back(static_cast<uint8_t>(u >> 24));
106 buffer.push_back(static_cast<uint8_t>(u >> 32));
107 buffer.push_back(static_cast<uint8_t>(u >> 40));
108 buffer.push_back(static_cast<uint8_t>(u >> 48));
109 buffer.push_back(static_cast<uint8_t>(u >> 56));
110#endif
111}
112
115inline std::uint64_t decodeU64(uint8_t const * buffer) {
116#ifdef OPTIMIZED_LITTLE_ENDIAN
117 return *reinterpret_cast<uint64_t const *>(buffer);
118#else
119 std::uint64_t u = static_cast<uint64_t>(buffer[0]) +
120 (static_cast<uint64_t>(buffer[1]) << 8) +
121 (static_cast<uint64_t>(buffer[2]) << 16) +
122 (static_cast<uint64_t>(buffer[3]) << 24) +
123 (static_cast<uint64_t>(buffer[4]) << 32) +
124 (static_cast<uint64_t>(buffer[5]) << 40) +
125 (static_cast<uint64_t>(buffer[6]) << 48) +
126 (static_cast<uint64_t>(buffer[7]) << 56);
127 return u;
128#endif
129}
130
131}} // namespace lsst::sphgeom
132
133#endif // LSST_SPHGEOM_CODEC_H_
uint64_t * ptr
Definition RangeSet.cc:95
T end(T... args)
T insert(T... args)
void encodeDouble(double item, std::vector< uint8_t > &buffer)
encodeDouble appends an IEEE double in little-endian byte order to the end of buffer.
Definition codec.h:56
void encodeU64(std::uint64_t item, std::vector< uint8_t > &buffer)
encodeU64 appends an uint64 in little-endian byte order to the end of buffer.
Definition codec.h:95
double decodeDouble(uint8_t const *buffer)
decodeDouble extracts an IEEE double from the 8 byte little-endian byte sequence in buffer.
Definition codec.h:76
std::uint64_t decodeU64(uint8_t const *buffer)
decodeU64 extracts an uint64 from the 8 byte little-endian byte sequence in buffer.
Definition codec.h:115
T push_back(T... args)