github.com/vugu/vugu@v0.3.5/comp-key.go (about)

     1  package vugu
     2  
     3  import (
     4  	"math/rand"
     5  	"time"
     6  
     7  	"github.com/vugu/xxhash"
     8  )
     9  
    10  // MakeCompKeyID forms a value for CompKey.ID from the given time the uint32 you provide for the lower 32 bits.
    11  func MakeCompKeyID(t time.Time, data uint32) uint64 {
    12  	var ret = uint64(t.Unix()) << 32
    13  	ret |= uint64(data)
    14  	return ret
    15  }
    16  
    17  // MakeCompKeyIDTimeHash forms a value for CompKey.ID from the given time and a hash of the bytes you provide.
    18  func MakeCompKeyIDTimeHash(t time.Time, b []byte) uint64 {
    19  	h := xxhash.New()
    20  	h.Write(b)
    21  	return MakeCompKeyID(t, uint32(h.Sum64()))
    22  }
    23  
    24  var compKeyRand *rand.Rand
    25  
    26  // MakeCompKeyIDNowRand generates a value for CompKey.ID based on the current unix timestamp in seconds for the top 32 bits and
    27  // the bottom 32 bits populated from a random source
    28  func MakeCompKeyIDNowRand() uint64 {
    29  	if compKeyRand == nil {
    30  		compKeyRand = rand.New(rand.NewSource(time.Now().UnixNano()))
    31  	}
    32  	var ret = uint64(time.Now().Unix()) << 32
    33  	ret |= uint64(compKeyRand.Int63() & 0xFFFFFFFF)
    34  	return ret
    35  }