From 01842a547caf6a5d39d1db580f08923b840ea7fe Mon Sep 17 00:00:00 2001 From: Patrick Mylund Nielsen Date: Mon, 30 Nov 2015 14:47:22 -0500 Subject: [PATCH] Use timevals --- cache.go | 44 +++++++++++++++++++++++++++++++------------- cache_test.go | 5 +++-- 2 files changed, 34 insertions(+), 15 deletions(-) diff --git a/cache.go b/cache.go index cea90c5..b9bf974 100644 --- a/cache.go +++ b/cache.go @@ -7,22 +7,23 @@ import ( "os" "runtime" "sync" + "syscall" "time" ) -var emptyTime = time.Time{} - type Item struct { Object interface{} - Expiration int64 + Expiration syscall.Timeval } // Returns true if the item has expired. func (item Item) Expired() bool { - if item.Expiration == 0 { + if item.Expiration.Sec == 0 { return false } - return time.Now().UnixNano() > item.Expiration + var tv syscall.Timeval + syscall.Gettimeofday(&tv) + return tv.Sec > item.Expiration.Sec || (tv.Sec == item.Expiration.Sec && tv.Usec > item.Expiration.Usec) } const ( @@ -59,12 +60,12 @@ func (c *cache) Set(k string, x interface{}, d time.Duration) { } func (c *cache) set(k string, x interface{}, d time.Duration) { - var e int64 + var e syscall.Timeval if d == DefaultExpiration { d = c.defaultExpiration } if d > 0 { - e = time.Now().Add(d).UnixNano() + e = syscall.NsecToTimeval(time.Now().Add(d).UnixNano()) } c.items[k] = Item{ Object: x, @@ -106,20 +107,36 @@ func (c *cache) Get(k string) (interface{}, bool) { c.mu.RLock() // "Inlining" of get and expired item, found := c.items[k] - if !found || (item.Expiration > 0 && time.Now().UnixNano() > item.Expiration) { + if !found { c.mu.RUnlock() return nil, false } + if item.Expiration.Sec > 0 { + var tv syscall.Timeval + syscall.Gettimeofday(&tv) + if tv.Sec > item.Expiration.Sec || (tv.Sec == item.Expiration.Sec && tv.Usec > item.Expiration.Usec) { + c.mu.RUnlock() + return nil, false + } + } c.mu.RUnlock() - return item.Object, found + return item.Object, true } func (c *cache) get(k string) (interface{}, bool) { item, found := c.items[k] - // "Inlining" of expired - if !found || (item.Expiration > 0 && time.Now().UnixNano() > item.Expiration) { + if !found { return nil, false } + // "Inlining" of Expired + if item.Expiration.Sec > 0 { + var tv syscall.Timeval + syscall.Gettimeofday(&tv) + if tv.Sec > item.Expiration.Sec || (tv.Sec == item.Expiration.Sec && tv.Usec > item.Expiration.Usec) { + c.mu.RUnlock() + return nil, false + } + } return item.Object, true } @@ -874,11 +891,12 @@ type keyAndValue struct { // Delete all expired items from the cache. func (c *cache) DeleteExpired() { var evictedItems []keyAndValue - now := time.Now().UnixNano() + var now syscall.Timeval + syscall.Gettimeofday(&now) c.mu.Lock() for k, v := range c.items { // "Inlining" of expired - if v.Expiration > 0 && now > v.Expiration { + if v.Expiration.Sec > 0 && (now.Sec > v.Expiration.Sec || (now.Sec == v.Expiration.Sec && now.Usec > v.Expiration.Usec)) { ov, evicted := c.delete(k) if evicted { evictedItems = append(evictedItems, keyAndValue{k, ov}) diff --git a/cache_test.go b/cache_test.go index f604794..62b2854 100644 --- a/cache_test.go +++ b/cache_test.go @@ -6,6 +6,7 @@ import ( "runtime" "strconv" "sync" + "syscall" "testing" "time" ) @@ -110,11 +111,11 @@ func TestNewFrom(t *testing.T) { m := map[string]Item{ "a": Item{ Object: 1, - Expiration: 0, + Expiration: syscall.Timeval{}, }, "b": Item{ Object: 2, - Expiration: 0, + Expiration: syscall.Timeval{}, }, } tc := NewFrom(DefaultExpiration, 0, m)