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Diffstat (limited to 'src/arrow/go/arrow/internal/flatbuf/Timestamp.go')
| -rw-r--r-- | src/arrow/go/arrow/internal/flatbuf/Timestamp.go | 201 |
1 files changed, 201 insertions, 0 deletions
diff --git a/src/arrow/go/arrow/internal/flatbuf/Timestamp.go b/src/arrow/go/arrow/internal/flatbuf/Timestamp.go new file mode 100644 index 000000000..f53211455 --- /dev/null +++ b/src/arrow/go/arrow/internal/flatbuf/Timestamp.go @@ -0,0 +1,201 @@ +// Licensed to the Apache Software Foundation (ASF) under one +// or more contributor license agreements. See the NOTICE file +// distributed with this work for additional information +// regarding copyright ownership. The ASF licenses this file +// to you under the Apache License, Version 2.0 (the +// "License"); you may not use this file except in compliance +// with the License. You may obtain a copy of the License at +// +// http://www.apache.org/licenses/LICENSE-2.0 +// +// Unless required by applicable law or agreed to in writing, software +// distributed under the License is distributed on an "AS IS" BASIS, +// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. +// See the License for the specific language governing permissions and +// limitations under the License. + +// Code generated by the FlatBuffers compiler. DO NOT EDIT. + +package flatbuf + +import ( + flatbuffers "github.com/google/flatbuffers/go" +) + +/// 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. +type Timestamp struct { + _tab flatbuffers.Table +} + +func GetRootAsTimestamp(buf []byte, offset flatbuffers.UOffsetT) *Timestamp { + n := flatbuffers.GetUOffsetT(buf[offset:]) + x := &Timestamp{} + x.Init(buf, n+offset) + return x +} + +func (rcv *Timestamp) Init(buf []byte, i flatbuffers.UOffsetT) { + rcv._tab.Bytes = buf + rcv._tab.Pos = i +} + +func (rcv *Timestamp) Table() flatbuffers.Table { + return rcv._tab +} + +func (rcv *Timestamp) Unit() TimeUnit { + o := flatbuffers.UOffsetT(rcv._tab.Offset(4)) + if o != 0 { + return TimeUnit(rcv._tab.GetInt16(o + rcv._tab.Pos)) + } + return 0 +} + +func (rcv *Timestamp) MutateUnit(n TimeUnit) bool { + return rcv._tab.MutateInt16Slot(4, int16(n)) +} + +/// 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). +func (rcv *Timestamp) Timezone() []byte { + o := flatbuffers.UOffsetT(rcv._tab.Offset(6)) + if o != 0 { + return rcv._tab.ByteVector(o + rcv._tab.Pos) + } + return nil +} + +/// 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). +func TimestampStart(builder *flatbuffers.Builder) { + builder.StartObject(2) +} +func TimestampAddUnit(builder *flatbuffers.Builder, unit TimeUnit) { + builder.PrependInt16Slot(0, int16(unit), 0) +} +func TimestampAddTimezone(builder *flatbuffers.Builder, timezone flatbuffers.UOffsetT) { + builder.PrependUOffsetTSlot(1, flatbuffers.UOffsetT(timezone), 0) +} +func TimestampEnd(builder *flatbuffers.Builder) flatbuffers.UOffsetT { + return builder.EndObject() +} |