Merge pull request #127 from adomaskizogian/master

make isHolCache access thread-safe

v2/cal.go

@@ -2,7 +2,10 @@
 
 package cal
 
-import "time"
+import (
+ "sync"
+ "time"
+)
 
 // DefaultLoc is the default time.Location to use in functions that do not
 // require a full time.Time value.
@@ -23,6 +26,9 @@ type Calendar struct {
  Cacheable bool // indicates that holiday calcs can be cached (don't change holiday defs while enabled)
 
  isHolCache map[holCacheKey]*holCacheEntry // cached results for IsHoliday
+
+ isHolCacheInitOnce sync.Once
+ isHolCacheMutex sync.RWMutex
 }
 
 type holCacheKey struct {
@@ -76,12 +82,16 @@ func (c *Calendar) IsHoliday(date time.Time) (actual, observed bool, h *Holiday)
  year, month, day := date.Date()
 
  if c.Cacheable {
- if c.isHolCache == nil {
+ c.isHolCacheInitOnce.Do(func() {
  c.isHolCache = make(map[holCacheKey]*holCacheEntry)
- }
+ })
+
+ c.isHolCacheMutex.RLock()
  if v, ok := c.isHolCache[holCacheKey{year: year, month: month, day: day}]; ok {
+ c.isHolCacheMutex.RUnlock()
  return v.act, v.obs, v.hol
  }
+ c.isHolCacheMutex.RUnlock()
  }
 
  for _, hol := range c.Holidays {
@@ -99,9 +109,11 @@ func (c *Calendar) IsHoliday(date time.Time) (actual, observed bool, h *Holiday)
  }
  if actMatch || obsMatch {
  if c.Cacheable {
+ c.isHolCacheMutex.Lock()
  c.evict()
  c.isHolCache[holCacheKey{year: year, month: month, day: day}] =
  &holCacheEntry{act: actMatch, obs: obsMatch, hol: hol}
+ c.isHolCacheMutex.Unlock()
  }
  return actMatch, obsMatch, hol
  }
@@ -122,9 +134,11 @@ func (c *Calendar) IsHoliday(date time.Time) (actual, observed bool, h *Holiday)
  }
  if obsMatch {
  if c.Cacheable {
+ c.isHolCacheMutex.Lock()
  c.evict()
  c.isHolCache[holCacheKey{year: year, month: month, day: day}] =
  &holCacheEntry{act: false, obs: obsMatch, hol: hol}
+ c.isHolCacheMutex.Unlock()
  }
  return false, obsMatch, hol
  }
@@ -137,9 +151,11 @@ func (c *Calendar) IsHoliday(date time.Time) (actual, observed bool, h *Holiday)
  }
  if obsMatch {
  if c.Cacheable {
+ c.isHolCacheMutex.Lock()
  c.evict()
  c.isHolCache[holCacheKey{year: year, month: month, day: day}] =
  &holCacheEntry{act: false, obs: obsMatch, hol: hol}
+ c.isHolCacheMutex.Unlock()
  }
  return false, obsMatch, hol
  }
@@ -148,8 +164,10 @@ func (c *Calendar) IsHoliday(date time.Time) (actual, observed bool, h *Holiday)
  }
 
  if c.Cacheable {
+ c.isHolCacheMutex.Lock()
  c.evict()
  c.isHolCache[holCacheKey{year: year, month: month, day: day}] = holFalseEntry
+ c.isHolCacheMutex.Unlock()
  }
  return false, false, nil
 }