github.com/GeniusesGroup/libgo@v0.0.0-20220929090155-5ff932cb408e/user/user.go (about)

     1  /* For license and copyright information please see LEGAL file in repository */
     2  
     3  package user
     4  
     5  import (
     6  	"crypto/rand"
     7  
     8  	"../binary"
     9  	"../protocol"
    10  	"../time/unix"
    11  )
    12  
    13  func NewID(userType protocol.UserType) (id UUID) {
    14  	var now = unix.Now()
    15  	id.setSecondElapsed(now.SecondElapsed())
    16  	id.setNanoSecondElapsed(now.NanoSecondElapsed())
    17  	id[12] = byte(userType)
    18  	// TODO::: moved to heap: id, Is it any way to prevent heap alloc??
    19  	rand.Read(id[13:])
    20  	return
    21  }
    22  
    23  // 0...7 >> second elapsed
    24  // 8...11 >> nano second elapsed
    25  // 12...12 >> type
    26  // 13...15 >> random id
    27  type UUID [16]byte
    28  
    29  func (id UUID) UUID() [16]byte          { return id }
    30  func (id UUID) Type() protocol.UserType { return protocol.UserType(id[8]) }
    31  func (id UUID) ID() [3]byte             { return id.id() }
    32  func (id UUID) ExistenceTime() protocol.Time {
    33  	var time unix.Time
    34  	time.ChangeTo(unix.SecElapsed(id.secondElapsed()), id.nanoSecondElapsed())
    35  	return &time
    36  }
    37  
    38  func (id UUID) id() (rid [3]byte)               { copy(rid[:], id[13:]); return }
    39  func (id UUID) secondElapsed() int64            { return int64(binary.LittleEndian.Uint64(id[0:])) }
    40  func (id UUID) nanoSecondElapsed() int32        { return int32(binary.LittleEndian.Uint32(id[8:])) }
    41  func (id UUID) setSecondElapsed(sec int64)      { binary.LittleEndian.PutUint64(id[0:], uint64(sec)) }
    42  func (id UUID) setNanoSecondElapsed(nsec int32) { binary.LittleEndian.PutUint32(id[8:], uint32(nsec)) }