datetime: add datetime type in msgpack

This patch provides datetime support for all space operations and as
function return result. Datetime type was introduced in Tarantool 2.10.
See more in issue [1].

Note that timezone's index and offset and intervals are not implemented
in Tarantool, see [2] and [3].

This Lua snippet was quite useful for debugging encoding and decoding
datetime in MessagePack:

local msgpack = require('msgpack')
local datetime = require('datetime')

local dt = datetime.parse('2012-01-31T23:59:59.000000010Z')
local mp_dt = msgpack.encode(dt):gsub('.',
    function (c)
        return string.format('%02x', string.byte(c))
    end)

print(mp_dt)  -- d8047f80284f000000000a00000000000000

1. tarantool/tarantool#5946
2. #163
3. #165

Closes #118

CHANGELOG.md

@@ -14,6 +14,7 @@ Versioning](http://semver.org/spec/v2.0.0.html) except to the first release.
 - IPROTO_PUSH messages support (#67)
 - Public API with request object types (#126)
 - Support decimal type in msgpack (#96)
+- Support datetime type in msgpack (#118)
 
 ### Changed
 

Makefile

@@ -46,6 +46,12 @@ test-connection-pool:
 	go clean -testcache
 	go test -tags "$(TAGS)" ./connection_pool/ -v -p 1
 
+.PHONY: test-datetime
+test-datetime:
+	@echo "Running tests in datetime package"
+	go clean -testcache
+	go test -tags "$(TAGS)" ./datetime/ -v -p 1
+
 .PHONY: test-decimal
 test-decimal:
 	@echo "Running tests in decimal package"

datetime/config.lua

@@ -0,0 +1,69 @@
+local has_datetime, datetime = pcall(require, 'datetime')
+
+if not has_datetime then
+    error('Datetime unsupported, use Tarantool 2.10 or newer')
+end
+
+-- Do not set listen for now so connector won't be
+-- able to send requests until everything is configured.
+box.cfg{
+    work_dir = os.getenv("TEST_TNT_WORK_DIR"),
+}
+
+box.schema.user.create('test', { password = 'test' , if_not_exists = true })
+box.schema.user.grant('test', 'execute', 'universe', nil, { if_not_exists = true })
+
+box.once("init", function()
+    local s_1 = box.schema.space.create('testDatetime_1', {
+        id = 524,
+        if_not_exists = true,
+    })
+    s_1:create_index('primary', {
+        type = 'TREE',
+        parts = {
+            { field = 1, type = 'datetime' },
+        },
+        if_not_exists = true
+    })
+    s_1:truncate()
+
+    local s_3 = box.schema.space.create('testDatetime_2', {
+        id = 526,
+        if_not_exists = true,
+    })
+    s_3:create_index('primary', {
+        type = 'tree',
+        parts = {
+            {1, 'uint'},
+        },
+        if_not_exists = true
+    })
+    s_3:truncate()
+
+    box.schema.func.create('call_datetime_testdata')
+    box.schema.user.grant('test', 'read,write', 'space', 'testDatetime_1', { if_not_exists = true })
+    box.schema.user.grant('test', 'read,write', 'space', 'testDatetime_2', { if_not_exists = true })
+end)
+
+local function call_datetime_testdata()
+    local dt1 = datetime.new({ year = 1934 })
+    local dt2 = datetime.new({ year = 1961 })
+    local dt3 = datetime.new({ year = 1968 })
+    return {
+        {
+            5, "Go!", {
+                {"Klushino", dt1},
+                {"Baikonur", dt2},
+                {"Novoselovo", dt3},
+            },
+        }
+    }
+end
+rawset(_G, 'call_datetime_testdata', call_datetime_testdata)
+
+-- Set listen only when every other thing is configured.
+box.cfg{
+    listen = os.getenv("TEST_TNT_LISTEN"),
+}
+
+require('console').start()

datetime/datetime.go

@@ -0,0 +1,140 @@
+// Package with support of Tarantool's datetime data type.
+//
+// Datetime data type supported in Tarantool since 2.10.
+//
+// Since: 1.7.0
+//
+// See also:
+//
+// * Datetime Internals https://github.com/tarantool/tarantool/wiki/Datetime-Internals
+package datetime
+
+import (
+	"encoding/binary"
+	"fmt"
+	"time"
+
+	"gopkg.in/vmihailenco/msgpack.v2"
+)
+
+// Datetime MessagePack serialization schema is an MP_EXT extension, which
+// creates container of 8 or 16 bytes long payload.
+//
+//   +---------+--------+===============+-------------------------------+
+//   |0xd7/0xd8|type (4)| seconds (8b)  | nsec; tzoffset; tzindex; (8b) |
+//   +---------+--------+===============+-------------------------------+
+//
+// MessagePack data encoded using fixext8 (0xd7) or fixext16 (0xd8), and may
+// contain:
+//
+// * [required] seconds parts as full, unencoded, signed 64-bit integer,
+// stored in little-endian order;
+//
+// * [optional] all the other fields (nsec, tzoffset, tzindex) if any of them
+// were having not 0 value. They are packed naturally in little-endian order;
+
+// Datetime external type. Supported since Tarantool 2.10. See more details in
+// issue https://github.com/tarantool/tarantool/issues/5946.
+const datetime_extId = 4
+
+// datetime structure keeps a number of seconds and nanoseconds since Unix Epoch.
+// Time is normalized by UTC, so time-zone offset is informative only.
+type datetime struct {
+	// Seconds since Epoch, where the epoch is the point where the time
+	// starts, and is platform dependent. For Unix, the epoch is January 1,
+	// 1970, 00:00:00 (UTC). Tarantool uses a double type, see a structure
+	// definition in src/lib/core/datetime.h and reasons in
+	// https://github.com/tarantool/tarantool/wiki/Datetime-internals#intervals-in-c
+	seconds int64
+	// Nanoseconds, fractional part of seconds. Tarantool uses int32_t, see
+	// a definition in src/lib/core/datetime.h.
+	nsec int32
+	// Timezone offset in minutes from UTC (not implemented in Tarantool,
+	// see gh-163). Tarantool uses a int16_t type, see a structure
+	// definition in src/lib/core/datetime.h.
+	tzOffset int16
+	// Olson timezone id (not implemented in Tarantool, see gh-163).
+	// Tarantool uses a int16_t type, see a structure definition in
+	// src/lib/core/datetime.h.
+	tzIndex int16
+}
+
+// Size of datetime fields in a MessagePack value.
+const (
+	secondsSize  = 8
+	nsecSize     = 4
+	tzIndexSize  = 2
+	tzOffsetSize = 2
+)
+
+const maxSize = secondsSize + nsecSize + tzIndexSize + tzOffsetSize
+
+type Datetime struct {
+	time time.Time
+}
+
+// NewDatetime returns a pointer to a new datetime.Datetime that contains a
+// specified time.Time.
+func NewDatetime(t time.Time) *Datetime {
+	dt := new(Datetime)
+	dt.time = t
+	return dt
+}
+
+// ToTime returns a time.Time that Datetime contains.
+func (dtime *Datetime) ToTime() time.Time {
+	return dtime.time
+}
+
+var _ msgpack.Marshaler = (*Datetime)(nil)
+var _ msgpack.Unmarshaler = (*Datetime)(nil)
+
+func (dtime *Datetime) MarshalMsgpack() ([]byte, error) {
+	tm := dtime.ToTime()
+
+	var dt datetime
+	dt.seconds = tm.Unix()
+	dt.nsec = int32(tm.Nanosecond())
+	dt.tzIndex = 0  // It is not implemented, see gh-163.
+	dt.tzOffset = 0 // It is not implemented, see gh-163.
+
+	var bytesSize = secondsSize
+	if dt.nsec != 0 || dt.tzOffset != 0 || dt.tzIndex != 0 {
+		bytesSize += nsecSize + tzIndexSize + tzOffsetSize
+	}
+
+	buf := make([]byte, bytesSize)
+	binary.LittleEndian.PutUint64(buf, uint64(dt.seconds))
+	if bytesSize == maxSize {
+		binary.LittleEndian.PutUint32(buf[secondsSize:], uint32(dt.nsec))
+		binary.LittleEndian.PutUint16(buf[secondsSize+nsecSize:], uint16(dt.tzOffset))
+		binary.LittleEndian.PutUint16(buf[secondsSize+nsecSize+tzOffsetSize:], uint16(dt.tzIndex))
+	}
+
+	return buf, nil
+}
+
+func (tm *Datetime) UnmarshalMsgpack(b []byte) error {
+	l := len(b)
+	if l != maxSize && l != secondsSize {
+		return fmt.Errorf("invalid data length: got %d, wanted %d or %d", len(b), secondsSize, maxSize)
+	}
+
+	var dt datetime
+	sec := binary.LittleEndian.Uint64(b)
+	dt.seconds = int64(sec)
+	dt.nsec = 0
+	if l == maxSize {
+		dt.nsec = int32(binary.LittleEndian.Uint32(b[secondsSize:]))
+		dt.tzOffset = int16(binary.LittleEndian.Uint16(b[secondsSize+nsecSize:]))
+		dt.tzIndex = int16(binary.LittleEndian.Uint16(b[secondsSize+nsecSize+tzOffsetSize:]))
+	}
+	tt := time.Unix(dt.seconds, int64(dt.nsec)).UTC()
+	*tm = *NewDatetime(tt)
+
+	return nil
+}
+
+func init() {
+	msgpack.RegisterExt(datetime_extId, &Datetime{})
+}