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// automatically generated by the FlatBuffers compiler, do not modify | |
import * as flatbuffers from 'flatbuffers'; | |
import { TimeUnit } from './time-unit.js'; | |
/** | |
* Timestamp is a 64-bit signed integer representing an elapsed time since a | |
* fixed epoch, stored in either of four units: seconds, milliseconds, | |
* microseconds or nanoseconds, and is optionally annotated with a timezone. | |
* | |
* Timestamp values do not include any leap seconds (in other words, all | |
* days are considered 86400 seconds long). | |
* | |
* Timestamps with a non-empty timezone | |
* ------------------------------------ | |
* | |
* If a Timestamp column has a non-empty timezone value, its epoch is | |
* 1970-01-01 00:00:00 (January 1st 1970, midnight) in the *UTC* timezone | |
* (the Unix epoch), regardless of the Timestamp's own timezone. | |
* | |
* Therefore, timestamp values with a non-empty timezone correspond to | |
* physical points in time together with some additional information about | |
* how the data was obtained and/or how to display it (the timezone). | |
* | |
* For example, the timestamp value 0 with the timezone string "Europe/Paris" | |
* corresponds to "January 1st 1970, 00h00" in the UTC timezone, but the | |
* application may prefer to display it as "January 1st 1970, 01h00" in | |
* the Europe/Paris timezone (which is the same physical point in time). | |
* | |
* One consequence is that timestamp values with a non-empty timezone | |
* can be compared and ordered directly, since they all share the same | |
* well-known point of reference (the Unix epoch). | |
* | |
* Timestamps with an unset / empty timezone | |
* ----------------------------------------- | |
* | |
* If a Timestamp column has no timezone value, its epoch is | |
* 1970-01-01 00:00:00 (January 1st 1970, midnight) in an *unknown* timezone. | |
* | |
* Therefore, timestamp values without a timezone cannot be meaningfully | |
* interpreted as physical points in time, but only as calendar / clock | |
* indications ("wall clock time") in an unspecified timezone. | |
* | |
* For example, the timestamp value 0 with an empty timezone string | |
* corresponds to "January 1st 1970, 00h00" in an unknown timezone: there | |
* is not enough information to interpret it as a well-defined physical | |
* point in time. | |
* | |
* One consequence is that timestamp values without a timezone cannot | |
* be reliably compared or ordered, since they may have different points of | |
* reference. In particular, it is *not* possible to interpret an unset | |
* or empty timezone as the same as "UTC". | |
* | |
* Conversion between timezones | |
* ---------------------------- | |
* | |
* If a Timestamp column has a non-empty timezone, changing the timezone | |
* to a different non-empty value is a metadata-only operation: | |
* the timestamp values need not change as their point of reference remains | |
* the same (the Unix epoch). | |
* | |
* However, if a Timestamp column has no timezone value, changing it to a | |
* non-empty value requires to think about the desired semantics. | |
* One possibility is to assume that the original timestamp values are | |
* relative to the epoch of the timezone being set; timestamp values should | |
* then adjusted to the Unix epoch (for example, changing the timezone from | |
* empty to "Europe/Paris" would require converting the timestamp values | |
* from "Europe/Paris" to "UTC", which seems counter-intuitive but is | |
* nevertheless correct). | |
* | |
* Guidelines for encoding data from external libraries | |
* ---------------------------------------------------- | |
* | |
* Date & time libraries often have multiple different data types for temporal | |
* data. In order to ease interoperability between different implementations the | |
* Arrow project has some recommendations for encoding these types into a Timestamp | |
* column. | |
* | |
* An "instant" represents a physical point in time that has no relevant timezone | |
* (for example, astronomical data). To encode an instant, use a Timestamp with | |
* the timezone string set to "UTC", and make sure the Timestamp values | |
* are relative to the UTC epoch (January 1st 1970, midnight). | |
* | |
* A "zoned date-time" represents a physical point in time annotated with an | |
* informative timezone (for example, the timezone in which the data was | |
* recorded). To encode a zoned date-time, use a Timestamp with the timezone | |
* string set to the name of the timezone, and make sure the Timestamp values | |
* are relative to the UTC epoch (January 1st 1970, midnight). | |
* | |
* (There is some ambiguity between an instant and a zoned date-time with the | |
* UTC timezone. Both of these are stored the same in Arrow. Typically, | |
* this distinction does not matter. If it does, then an application should | |
* use custom metadata or an extension type to distinguish between the two cases.) | |
* | |
* An "offset date-time" represents a physical point in time combined with an | |
* explicit offset from UTC. To encode an offset date-time, use a Timestamp | |
* with the timezone string set to the numeric timezone offset string | |
* (e.g. "+03:00"), and make sure the Timestamp values are relative to | |
* the UTC epoch (January 1st 1970, midnight). | |
* | |
* A "naive date-time" (also called "local date-time" in some libraries) | |
* represents a wall clock time combined with a calendar date, but with | |
* no indication of how to map this information to a physical point in time. | |
* Naive date-times must be handled with care because of this missing | |
* information, and also because daylight saving time (DST) may make | |
* some values ambiguous or non-existent. A naive date-time may be | |
* stored as a struct with Date and Time fields. However, it may also be | |
* encoded into a Timestamp column with an empty timezone. The timestamp | |
* values should be computed "as if" the timezone of the date-time values | |
* was UTC; for example, the naive date-time "January 1st 1970, 00h00" would | |
* be encoded as timestamp value 0. | |
*/ | |
export class Timestamp { | |
bb: flatbuffers.ByteBuffer|null = null; | |
bb_pos = 0; | |
__init(i:number, bb:flatbuffers.ByteBuffer):Timestamp { | |
this.bb_pos = i; | |
this.bb = bb; | |
return this; | |
} | |
static getRootAsTimestamp(bb:flatbuffers.ByteBuffer, obj?:Timestamp):Timestamp { | |
return (obj || new Timestamp()).__init(bb.readInt32(bb.position()) + bb.position(), bb); | |
} | |
static getSizePrefixedRootAsTimestamp(bb:flatbuffers.ByteBuffer, obj?:Timestamp):Timestamp { | |
bb.setPosition(bb.position() + flatbuffers.SIZE_PREFIX_LENGTH); | |
return (obj || new Timestamp()).__init(bb.readInt32(bb.position()) + bb.position(), bb); | |
} | |
unit():TimeUnit { | |
const offset = this.bb!.__offset(this.bb_pos, 4); | |
return offset ? this.bb!.readInt16(this.bb_pos + offset) : TimeUnit.SECOND; | |
} | |
/** | |
* The timezone is an optional string indicating the name of a timezone, | |
* one of: | |
* | |
* * As used in the Olson timezone database (the "tz database" or | |
* "tzdata"), such as "America/New_York". | |
* * An absolute timezone offset of the form "+XX:XX" or "-XX:XX", | |
* such as "+07:30". | |
* | |
* Whether a timezone string is present indicates different semantics about | |
* the data (see above). | |
*/ | |
timezone():string|null | |
timezone(optionalEncoding:flatbuffers.Encoding):string|Uint8Array|null | |
timezone(optionalEncoding?:any):string|Uint8Array|null { | |
const offset = this.bb!.__offset(this.bb_pos, 6); | |
return offset ? this.bb!.__string(this.bb_pos + offset, optionalEncoding) : null; | |
} | |
static startTimestamp(builder:flatbuffers.Builder) { | |
builder.startObject(2); | |
} | |
static addUnit(builder:flatbuffers.Builder, unit:TimeUnit) { | |
builder.addFieldInt16(0, unit, TimeUnit.SECOND); | |
} | |
static addTimezone(builder:flatbuffers.Builder, timezoneOffset:flatbuffers.Offset) { | |
builder.addFieldOffset(1, timezoneOffset, 0); | |
} | |
static endTimestamp(builder:flatbuffers.Builder):flatbuffers.Offset { | |
const offset = builder.endObject(); | |
return offset; | |
} | |
static createTimestamp(builder:flatbuffers.Builder, unit:TimeUnit, timezoneOffset:flatbuffers.Offset):flatbuffers.Offset { | |
Timestamp.startTimestamp(builder); | |
Timestamp.addUnit(builder, unit); | |
Timestamp.addTimezone(builder, timezoneOffset); | |
return Timestamp.endTimestamp(builder); | |
} | |
} | |