Added datastore handling

Started on basic data layer stuff

datastore/key.go

@@ -0,0 +1,85 @@
+// Copyright 2016 Tim Shannon. All rights reserved.
+// Use of this source code is governed by the MIT license
+// that can be found in the LICENSE file.
+
+package datastore
+
+import (
+	"crypto/rand"
+	"encoding/hex"
+	"fmt"
+	"io"
+	"time"
+)
+
+// TimeKey is a unique time ordered key for use in the datastore
+// A TimeKey is 32 bits random data + 96 bit UNIX timestamp (64bits seconds + 32 bit nanoseconds)
+type TimeKey [16]byte
+
+// NewTimeKey returns a newly generated TimeKey based on the current time
+func NewTimeKey() TimeKey {
+	rBits := make([]byte, 32/8)
+	_, err := io.ReadFull(rand.Reader, rBits)
+	if err != nil {
+		panic(fmt.Sprintf("Error generating random values for New TimeKey: %v", err))
+	}
+
+	t := time.Now()
+	sec := t.Unix()
+	nsec := t.Nanosecond()
+
+	return TimeKey{
+		rBits[0], //random
+		rBits[1],
+		rBits[2],
+		rBits[3],
+		byte(sec >> 56), // seconds
+		byte(sec >> 48),
+		byte(sec >> 40),
+		byte(sec >> 32),
+		byte(sec >> 24),
+		byte(sec >> 16),
+		byte(sec >> 8),
+		byte(sec),
+		byte(nsec >> 24), // nanoseconds
+		byte(nsec >> 16),
+		byte(nsec >> 8),
+		byte(nsec),
+	}
+}
+
+// Time returns the time portion of a timekey
+func (k TimeKey) Time() time.Time {
+	buf := k[4:]
+
+	sec := int64(buf[7]) | int64(buf[6])<<8 | int64(buf[5])<<16 | int64(buf[4])<<24 |
+		int64(buf[3])<<32 | int64(buf[2])<<40 | int64(buf[1])<<48 | int64(buf[0])<<56
+
+	buf = buf[8:]
+	nsec := int32(buf[3]) | int32(buf[2])<<8 | int32(buf[1])<<16 | int32(buf[0])<<24
+
+	return time.Unix(sec, int64(nsec))
+}
+
+// UUID returns the string representation of a TimeKey in Hex format separated by dashes
+// similar to a UUID xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx
+func (k TimeKey) UUID() string {
+	buf := make([]byte, 36)
+
+	hex.Encode(buf[0:8], k[0:4])
+	buf[8] = '-'
+	hex.Encode(buf[9:13], k[4:6])
+	buf[13] = '-'
+	hex.Encode(buf[14:18], k[6:8])
+	buf[18] = '-'
+	hex.Encode(buf[19:23], k[8:10])
+	buf[23] = '-'
+	hex.Encode(buf[24:], k[10:])
+
+	return string(buf)
+}
+
+// Bytes returns the a slice of the underlying bytes of a TimeKey
+func (k TimeKey) Bytes() []byte {
+	return []byte(k[:])
+}