date_t.h

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#pragma once
 
#include "interval_t.h"
 
namespace kuzu {
namespace common {
 
struct timestamp_t;
 
// System representation of dates as the number of days since 1970-01-01.
struct KUZU_API date_t {
 int32_t days;
 
 date_t();
 explicit date_t(int32_t days_p);
 
 // Comparison operators with date_t.
 bool operator==(const date_t& rhs) const;
 bool operator!=(const date_t& rhs) const;
 bool operator<=(const date_t& rhs) const;
 bool operator<(const date_t& rhs) const;
 bool operator>(const date_t& rhs) const;
 bool operator>=(const date_t& rhs) const;
 
 // Comparison operators with timestamp_t.
 bool operator==(const timestamp_t& rhs) const;
 bool operator!=(const timestamp_t& rhs) const;
 bool operator<(const timestamp_t& rhs) const;
 bool operator<=(const timestamp_t& rhs) const;
 bool operator>(const timestamp_t& rhs) const;
 bool operator>=(const timestamp_t& rhs) const;
 
 // arithmetic operators
 date_t operator+(const int32_t& day) const;
 date_t operator-(const int32_t& day) const;
 
 date_t operator+(const interval_t& interval) const;
 date_t operator-(const interval_t& interval) const;
 
 int64_t operator-(const date_t& rhs) const;
};
 
inline date_t operator+(int64_t i, const date_t date) {
 return date + i;
}
 
// Note: Aside from some minor changes, this implementation is copied from DuckDB's source code:
// https://github.com/duckdb/duckdb/blob/master/src/include/duckdb/common/types/date.hpp.
// https://github.com/duckdb/duckdb/blob/master/src/common/types/date.cpp.
// For example, instead of using their idx_t type to refer to indices, we directly use uint64_t,
// which is the actual type of idx_t (so we say uint64_t len instead of idx_t len). When more
// functionality is needed, we should first consult these DuckDB links.
class Date {
public:
 KUZU_API static const int32_t NORMAL_DAYS[13];
 KUZU_API static const int32_t CUMULATIVE_DAYS[13];
 KUZU_API static const int32_t LEAP_DAYS[13];
 KUZU_API static const int32_t CUMULATIVE_LEAP_DAYS[13];
 KUZU_API static const int32_t CUMULATIVE_YEAR_DAYS[401];
 KUZU_API static const int8_t MONTH_PER_DAY_OF_YEAR[365];
 KUZU_API static const int8_t LEAP_MONTH_PER_DAY_OF_YEAR[366];
 
 KUZU_API constexpr static const int32_t MIN_YEAR = -290307;
 KUZU_API constexpr static const int32_t MAX_YEAR = 294247;
 KUZU_API constexpr static const int32_t EPOCH_YEAR = 1970;
 
 KUZU_API constexpr static const int32_t YEAR_INTERVAL = 400;
 KUZU_API constexpr static const int32_t DAYS_PER_YEAR_INTERVAL = 146097;
 constexpr static const char* BC_SUFFIX = " (BC)";
 
 // Convert a string in the format "YYYY-MM-DD" to a date object
 KUZU_API static date_t fromCString(const char* str, uint64_t len);
 // Convert a date object to a string in the format "YYYY-MM-DD"
 KUZU_API static std::string toString(date_t date);
 // Try to convert text in a buffer to a date; returns true if parsing was successful
 KUZU_API static bool tryConvertDate(const char* buf, uint64_t len, uint64_t& pos,
 date_t& result);
 
 // private:
 // Returns true if (year) is a leap year, and false otherwise
 KUZU_API static bool isLeapYear(int32_t year);
 // Returns true if the specified (year, month, day) combination is a valid
 // date
 KUZU_API static bool isValid(int32_t year, int32_t month, int32_t day);
 // Extract the year, month and day from a given date object
 KUZU_API static void convert(date_t date, int32_t& out_year, int32_t& out_month,
 int32_t& out_day);
 // Create a Date object from a specified (year, month, day) combination
 KUZU_API static date_t fromDate(int32_t year, int32_t month, int32_t day);
 
 // Helper function to parse two digits from a string (e.g. "30" -> 30, "03" -> 3, "3" -> 3)
 KUZU_API static bool parseDoubleDigit(const char* buf, uint64_t len, uint64_t& pos,
 int32_t& result);
 
 KUZU_API static int32_t monthDays(int32_t year, int32_t month);
 
 KUZU_API static std::string getDayName(date_t& date);
 
 KUZU_API static std::string getMonthName(date_t& date);
 
 KUZU_API static date_t getLastDay(date_t& date);
 
 KUZU_API static int32_t getDatePart(DatePartSpecifier specifier, date_t& date);
 
 KUZU_API static date_t trunc(DatePartSpecifier specifier, date_t& date);
 
 KUZU_API static int64_t getEpochNanoSeconds(const date_t& date);
 
private:
 static void extractYearOffset(int32_t& n, int32_t& year, int32_t& year_offset);
};
 
} // namespace common
} // namespace kuzu