102 lines
3.1 KiB
Go
102 lines
3.1 KiB
Go
|
// Copyright 2017 Google Inc. All Rights Reserved.
|
||
|
|
//
|
||
|
|
// Licensed 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.
|
||
|
|
|
||
|
|
// This file supports generating unique IDs so that multiple test executions
|
||
|
|
// don't interfere with each other, and cleaning up old entities that may
|
||
|
|
// remain if tests exit early.
|
||
|
|
|
||
|
|
package testutil
|
||
|
|
|
||
|
|
import (
|
||
|
|
"fmt"
|
||
|
|
"regexp"
|
||
|
|
"strconv"
|
||
|
|
"sync"
|
||
|
|
"time"
|
||
|
|
)
|
||
|
|
|
||
|
|
var startTime = time.Now().UTC()
|
||
|
|
|
||
|
|
// A UIDSpace manages a set of unique IDs distinguished by a prefix.
|
||
|
|
type UIDSpace struct {
|
||
|
|
Prefix string
|
||
|
|
Sep rune
|
||
|
|
re *regexp.Regexp
|
||
|
|
mu sync.Mutex
|
||
|
|
count int
|
||
|
|
}
|
||
|
|
|
||
|
|
func NewUIDSpace(prefix string) *UIDSpace {
|
||
|
|
return NewUIDSpaceSep(prefix, '-')
|
||
|
|
}
|
||
|
|
|
||
|
|
func NewUIDSpaceSep(prefix string, sep rune) *UIDSpace {
|
||
|
|
re := fmt.Sprintf(`^%s%[2]c(\d{4})(\d{2})(\d{2})%[2]c(\d+)%[2]c\d+$`,
|
||
|
|
regexp.QuoteMeta(prefix), sep)
|
||
|
|
return &UIDSpace{
|
||
|
|
Prefix: prefix,
|
||
|
|
Sep: sep,
|
||
|
|
re: regexp.MustCompile(re),
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// New generates a new unique ID . The ID consists of the UIDSpace's prefix, a
|
||
|
|
// timestamp, and a counter value. All unique IDs generated in the same test
|
||
|
|
// execution will have the same timestamp.
|
||
|
|
//
|
||
|
|
// Aside from the characters in the prefix, IDs contain only letters, numbers
|
||
|
|
// and sep.
|
||
|
|
func (s *UIDSpace) New() string { return s.newID(startTime) }
|
||
|
|
|
||
|
|
func (s *UIDSpace) newID(t time.Time) string {
|
||
|
|
s.mu.Lock()
|
||
|
|
c := s.count
|
||
|
|
s.count++
|
||
|
|
s.mu.Unlock()
|
||
|
|
// Write the time as a date followed by nanoseconds from midnight of that date.
|
||
|
|
// That makes it easier to see the approximate time of the ID when it is displayed.
|
||
|
|
y, m, d := t.Date()
|
||
|
|
ns := t.Sub(time.Date(y, m, d, 0, 0, 0, 0, time.UTC))
|
||
|
|
// Zero-pad the counter for lexical sort order for IDs with the same timestamp.
|
||
|
|
return fmt.Sprintf("%s%c%04d%02d%02d%c%d%c%04d",
|
||
|
|
s.Prefix, s.Sep, y, m, d, s.Sep, ns, s.Sep, c)
|
||
|
|
}
|
||
|
|
|
||
|
|
// Timestamp extracts the timestamp of uid, which must have been generated by
|
||
|
|
// s. The second return value is true on success, false if there was a problem.
|
||
|
|
func (s *UIDSpace) Timestamp(uid string) (time.Time, bool) {
|
||
|
|
subs := s.re.FindStringSubmatch(uid)
|
||
|
|
if subs == nil {
|
||
|
|
return time.Time{}, false
|
||
|
|
}
|
||
|
|
y, err1 := strconv.Atoi(subs[1])
|
||
|
|
m, err2 := strconv.Atoi(subs[2])
|
||
|
|
d, err3 := strconv.Atoi(subs[3])
|
||
|
|
ns, err4 := strconv.Atoi(subs[4])
|
||
|
|
if err1 != nil || err2 != nil || err3 != nil || err4 != nil {
|
||
|
|
return time.Time{}, false
|
||
|
|
}
|
||
|
|
return time.Date(y, time.Month(m), d, 0, 0, 0, ns, time.UTC), true
|
||
|
|
}
|
||
|
|
|
||
|
|
// Older reports whether uid was created by m and has a timestamp older than
|
||
|
|
// the current time by at least d.
|
||
|
|
func (s *UIDSpace) Older(uid string, d time.Duration) bool {
|
||
|
|
ts, ok := s.Timestamp(uid)
|
||
|
|
if !ok {
|
||
|
|
return false
|
||
|
|
}
|
||
|
|
return time.Since(ts) > d
|
||
|
|
}
|