ClickHouse/src/Common/IntervalKind.h
2022-09-02 08:54:48 +00:00

87 lines
2.7 KiB
C++

#pragma once
#include <base/types.h>
#include <base/EnumReflection.h>
namespace DB
{
/// Kind of a temporal interval.
struct IntervalKind
{
enum Kind
{
Nanosecond,
Microsecond,
Millisecond,
Second,
Minute,
Hour,
Day,
Week,
Month,
Quarter,
Year,
};
Kind kind = Second;
IntervalKind(Kind kind_ = Second) : kind(kind_) {} /// NOLINT
operator Kind() const { return kind; } /// NOLINT
constexpr std::string_view toString() const { return magic_enum::enum_name(kind); }
/// Returns number of seconds in one interval.
/// For `Month`, `Quarter` and `Year` the function returns an average number of seconds.
Int32 toAvgSeconds() const;
/// Returns exact number of seconds in one interval.
/// For `Month`, `Quarter` and `Year` the function raises an error.
Float64 toSeconds() const;
/// Chooses an interval kind based on number of seconds.
/// For example, `IntervalKind::fromAvgSeconds(3600)` returns `IntervalKind::Hour`.
static IntervalKind fromAvgSeconds(Int64 num_seconds);
/// Returns whether IntervalKind has a fixed number of seconds (e.g. Day) or non-fixed(e.g. Month)
bool isFixedLength() const;
/// Returns an uppercased version of what `toString()` returns.
const char * toKeyword() const;
const char * toLowercasedKeyword() const;
/// Returns the string which can be passed to the `unit` parameter of the dateDiff() function.
/// For example, `IntervalKind{IntervalKind::Day}.getDateDiffParameter()` returns "day".
const char * toDateDiffUnit() const;
/// Returns the name of the function converting a number to the interval data type.
/// For example, `IntervalKind{IntervalKind::Day}.getToIntervalDataTypeFunctionName()`
/// returns "toIntervalDay".
const char * toNameOfFunctionToIntervalDataType() const;
/// Returns the name of the function extracting time part from a date or a time.
/// For example, `IntervalKind{IntervalKind::Day}.getExtractTimePartFunctionName()`
/// returns "toDayOfMonth".
const char * toNameOfFunctionExtractTimePart() const;
/// Converts the string representation of an interval kind to its IntervalKind equivalent.
/// Returns false if the conversion did not succeed.
/// For example, `IntervalKind::tryParseString('second', result)` returns `result` equals `IntervalKind::Kind::Second`.
static bool tryParseString(const std::string & kind, IntervalKind::Kind & result);
};
/// NOLINTNEXTLINE
#define FOR_EACH_INTERVAL_KIND(M) \
M(Nanosecond) \
M(Microsecond) \
M(Millisecond) \
M(Second) \
M(Minute) \
M(Hour) \
M(Day) \
M(Week) \
M(Month) \
M(Quarter) \
M(Year)
}