Extend SimpleCache to allow for unbounded growth (#38)

* Allow SimpleCache to be of unbounded size

* Only panic if incorrect size for LRU/LFU/ARC caches

* Change unbounded flag value to c.size = 0

* Fix typo in evictedFunc test case

* Add test case for simple unbounded cache

arc_test.go

@@ -31,7 +31,7 @@ func buildLoadingARCacheWithExpiration(size int, ep time.Duration) Cache {
 }
 
 func evictedFuncForARC(key, value interface{}) {
- fmt.Printf("[ARC] Key:%v Value:%v will evicted.\n", key, value)
+ fmt.Printf("[ARC] Key:%v Value:%v will be evicted.\n", key, value)
 }
 
 func TestARCGet(t *testing.T) {

cache.go

@@ -70,9 +70,6 @@ type CacheBuilder struct {
 }
 
 func New(size int) *CacheBuilder {
- if size <= 0 {
- panic("gcache: size <= 0")
- }
  return &CacheBuilder{
  clock: NewRealClock(),
  tp: TYPE_SIMPLE,
@@ -155,6 +152,10 @@ func (cb *CacheBuilder) Expiration(expiration time.Duration) *CacheBuilder {
 }
 
 func (cb *CacheBuilder) Build() Cache {
+ if cb.size <= 0 && cb.tp != TYPE_SIMPLE {
+ panic("gcache: Cache size <= 0")
+ }
+
  return cb.build()
 }
 

lfu_test.go

@@ -7,7 +7,7 @@ import (
 )
 
 func evictedFuncForLFU(key, value interface{}) {
- fmt.Printf("[LFU] Key:%v Value:%v will evicted.\n", key, value)
+ fmt.Printf("[LFU] Key:%v Value:%v will be evicted.\n", key, value)
 }
 
 func buildLFUCache(size int) Cache {

lru_test.go

@@ -7,7 +7,7 @@ import (
 )
 
 func evictedFuncForLRU(key, value interface{}) {
- fmt.Printf("[LRU] Key:%v Value:%v will evicted.\n", key, value)
+ fmt.Printf("[LRU] Key:%v Value:%v will be evicted.\n", key, value)
 }
 
 func buildLRUCache(size int) Cache {

simple.go

@@ -18,7 +18,11 @@ func newSimpleCache(cb *CacheBuilder) *SimpleCache {
 }
 
 func (c *SimpleCache) init() {
- c.items = make(map[interface{}]*simpleItem, c.size)
+ if c.size <= 0 {
+ c.items = make(map[interface{}]*simpleItem)
+ } else {
+ c.items = make(map[interface{}]*simpleItem, c.size)
+ }
 }
 
 // Set a new key-value pair
@@ -58,7 +62,7 @@ func (c *SimpleCache) set(key, value interface{}) (interface{}, error) {
  item.value = value
  } else {
  // Verify size not exceeded
- if len(c.items) >= c.size {
+ if (len(c.items) >= c.size) && c.size > 0 {
  c.evict(1)
  }
  item = &simpleItem{

simple_test.go

@@ -21,7 +21,7 @@ func buildLoadingSimpleCache(size int, loader LoaderFunc) Cache {
 }
 
 func evictedFuncForSimple(key, value interface{}) {
- fmt.Printf("[Simple] Key:%v Value:%v will evicted.\n", key, value)
+ fmt.Printf("[Simple] Key:%v Value:%v will be evicted.\n", key, value)
 }
 
 func TestSimpleGet(t *testing.T) {
@@ -61,6 +61,26 @@ func TestSimpleEvictItem(t *testing.T) {
  }
 }
 
+func TestSimpleUnboundedNoEviction(t *testing.T) {
+ numbers := 1000
+ size_tracker := 0
+ gcu := buildLoadingSimpleCache(0, loader)
+
+ for i := 0; i < numbers; i++ {
+ current_size := gcu.Len()
+ if current_size != size_tracker {
+ t.Errorf("Excepted cache size is %v not %v", current_size, size_tracker)
+ }
+
+ _, err := gcu.Get(fmt.Sprintf("Key-%d", i))
+ if err != nil {
+ t.Errorf("Unexpected error: %v", err)
+ }
+
+ size_tracker++
+ }
+}
+
 func TestSimpleGetIFPresent(t *testing.T) {
  testGetIFPresent(t, TYPE_SIMPLE)
 }