1/**
2 * Licensed to the Apache Software Foundation (ASF) under one
3 * or more contributor license agreements. See the NOTICE file
4 * distributed with this work for additional information
5 * regarding copyright ownership. The ASF licenses this file
6 * to you under the Apache License, Version 2.0 (the
7 * "License"); you may not use this file except in compliance
8 * with the License. You may obtain a copy of the License at
9 *
10 * http://www.apache.org/licenses/LICENSE-2.0
11 *
12 * Unless required by applicable law or agreed to in writing, software
13 * distributed under the License is distributed on an "AS IS" BASIS,
14 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
15 * See the License for the specific language governing permissions and
16 * limitations under the License.
17 */
18
19#ifndef TIMEZONE_HH
20#define TIMEZONE_HH
21
22// This file is for timezone routines.
23
24#include "Adaptor.hh"
25
26#include <memory>
27#include <stdexcept>
28#include <stdint.h>
29#include <string>
30#include <vector>
31
32namespace orc {
33
34 static const int64_t SECONDS_PER_HOUR = 60 * 60;
35 static const int64_t SECONDS_PER_DAY = SECONDS_PER_HOUR * 24;
36
37 /**
38 * A variant (eg. PST or PDT) of a timezone (eg. America/Los_Angeles).
39 */
40 struct TimezoneVariant {
41 int64_t gmtOffset;
42 bool isDst;
43 std::string name;
44
45 std::string toString() const;
46 };
47
48 /**
49 * A region that shares the same legal rules for wall clock time and
50 * day light savings transitions. They are typically named for the largest
51 * city in the region (eg. America/Los_Angeles or America/Mexico_City).
52 */
53 class Timezone {
54 public:
55 virtual ~Timezone();
56
57 /**
58 * Get the variant for the given time (time_t).
59 */
60 virtual const TimezoneVariant& getVariant(int64_t clk) const = 0;
61
62 /**
63 * Get the number of seconds between the ORC epoch in this timezone
64 * and Unix epoch.
65 * ORC epoch is 1 Jan 2015 00:00:00 local.
66 * Unix epoch is 1 Jan 1970 00:00:00 UTC.
67 */
68 virtual int64_t getEpoch() const = 0;
69
70 /**
71 * Print the timezone to the stream.
72 */
73 virtual void print(std::ostream&) const = 0;
74
75 /**
76 * Get the version of the zone file.
77 */
78 virtual uint64_t getVersion() const =0;
79
80 /**
81 * Convert wall clock time of current timezone to UTC timezone
82 */
83 virtual int64_t convertToUTC(int64_t clk) const = 0;
84 };
85
86 /**
87 * Get the local timezone.
88 * Results are cached.
89 */
90 const Timezone& getLocalTimezone();
91
92 /**
93 * Get a timezone by name (eg. America/Los_Angeles).
94 * Results are cached.
95 */
96 const Timezone& getTimezoneByName(const std::string& zone);
97
98 /**
99 * Parse a set of bytes as a timezone file as if they came from filename.
100 */
101 std::unique_ptr<Timezone> getTimezone(const std::string& filename,
102 const std::vector<unsigned char>& b);
103
104 class TimezoneError: public std::runtime_error {
105 public:
106 TimezoneError(const std::string& what);
107 TimezoneError(const TimezoneError&);
108 virtual ~TimezoneError() ORC_NOEXCEPT;
109 };
110
111 /**
112 * Represents the parsed POSIX timezone rule strings that are used to
113 * describe the future transitions, because they can go arbitrarily far into
114 * the future.
115 */
116 class FutureRule {
117 public:
118 virtual ~FutureRule();
119 virtual bool isDefined() const = 0;
120 virtual const TimezoneVariant& getVariant(int64_t clk) const = 0;
121 virtual void print(std::ostream& out) const = 0;
122 };
123
124 /**
125 * Parse the POSIX TZ string.
126 */
127 std::shared_ptr<FutureRule> parseFutureRule(const std::string& ruleString);
128}
129
130#endif
131