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authorLibravatar tobi <31960611+tsmethurst@users.noreply.github.com>2022-11-11 12:18:38 +0100
committerLibravatar GitHub <noreply@github.com>2022-11-11 12:18:38 +0100
commitedcee14d07bae129e2d1a06d99c30fc6f659ff5e (patch)
tree5b9d605654347fe104c55bf4b0e7fb1e1533e2a0 /vendor/codeberg.org/gruf/go-maps/lru.go
parent[feature] S3: add config flag to proxy S3 media (#1014) (diff)
downloadgotosocial-edcee14d07bae129e2d1a06d99c30fc6f659ff5e.tar.xz
[feature] Read + Write tombstones for deleted Actors (#1005)
* [feature] Read + Write tombstones for deleted Actors * copyTombstone * update to use resultcache instead of old ttl cache Signed-off-by: kim <grufwub@gmail.com> * update go-cache library to fix result cache capacity / ordering bugs Signed-off-by: kim <grufwub@gmail.com> * bump go-cache/v3 to v3.1.6 to fix bugs Signed-off-by: kim <grufwub@gmail.com> * switch on status code * better explain ErrGone reasoning Signed-off-by: kim <grufwub@gmail.com> Co-authored-by: kim <grufwub@gmail.com>
Diffstat (limited to 'vendor/codeberg.org/gruf/go-maps/lru.go')
-rw-r--r--vendor/codeberg.org/gruf/go-maps/lru.go153
1 files changed, 153 insertions, 0 deletions
diff --git a/vendor/codeberg.org/gruf/go-maps/lru.go b/vendor/codeberg.org/gruf/go-maps/lru.go
new file mode 100644
index 000000000..06ea2ab10
--- /dev/null
+++ b/vendor/codeberg.org/gruf/go-maps/lru.go
@@ -0,0 +1,153 @@
+package maps
+
+import (
+ "fmt"
+ "reflect"
+)
+
+// LRU provides an ordered hashmap implementation that keeps elements ordered according to last recently used (hence, LRU).
+type LRUMap[K comparable, V any] struct {
+ ordered[K, V]
+ size int
+}
+
+// NewLRU returns a new instance of LRUMap with given initializing length and maximum capacity.
+func NewLRU[K comparable, V any](len, cap int) *LRUMap[K, V] {
+ m := new(LRUMap[K, V])
+ m.Init(len, cap)
+ return m
+}
+
+// Init will initialize this map with initial length and maximum capacity.
+func (m *LRUMap[K, V]) Init(len, cap int) {
+ if cap <= 0 {
+ panic("lru cap must be greater than zero")
+ } else if m.pool != nil {
+ panic("lru map already initialized")
+ }
+ m.ordered.hmap = make(map[K]*elem[K, V], len)
+ m.ordered.pool = allocElems[K, V](len)
+ m.size = cap
+}
+
+// Get will fetch value for given key from map, in the process pushing it to the front of the map. Returns false if not found.
+func (m *LRUMap[K, V]) Get(key K) (V, bool) {
+ if elem, ok := m.hmap[key]; ok {
+ // Ensure safe
+ m.write_check()
+
+ // Unlink elem from list
+ m.list.Unlink(elem)
+
+ // Push to front of list
+ m.list.PushFront(elem)
+
+ return elem.V, true
+ }
+ var z V // zero value
+ return z, false
+}
+
+// Add will add the given key-value pair to the map, pushing them to the front of the map. Returns false if already exists. Evicts old at maximum capacity.
+func (m *LRUMap[K, V]) Add(key K, value V) bool {
+ return m.AddWithHook(key, value, nil)
+}
+
+// AddWithHook performs .Add() but passing any evicted entry to given hook function.
+func (m *LRUMap[K, V]) AddWithHook(key K, value V, evict func(K, V)) bool {
+ // Ensure safe
+ m.write_check()
+
+ // Look for existing elem
+ elem, ok := m.hmap[key]
+ if ok {
+ return false
+ }
+
+ if m.list.len >= m.size {
+ // We're at capacity, sir!
+ // Pop current tail elem
+ elem = m.list.PopTail()
+
+ if evict != nil {
+ // Pass to evict hook
+ evict(elem.K, elem.V)
+ }
+
+ // Delete key from map
+ delete(m.hmap, elem.K)
+ } else {
+ // Allocate elem
+ elem = m.alloc()
+ }
+
+ // Set elem
+ elem.K = key
+ elem.V = value
+
+ // Add element map entry
+ m.hmap[key] = elem
+
+ // Push to front of list
+ m.list.PushFront(elem)
+ return true
+}
+
+// Set will ensure that given key-value pair exists in the map, by either adding new or updating existing, pushing them to the front of the map. Evicts old at maximum capacity.
+func (m *LRUMap[K, V]) Set(key K, value V) {
+ m.SetWithHook(key, value, nil)
+}
+
+// SetWithHook performs .Set() but passing any evicted entry to given hook function.
+func (m *LRUMap[K, V]) SetWithHook(key K, value V, evict func(K, V)) {
+ // Ensure safe
+ m.write_check()
+
+ // Look for existing elem
+ elem, ok := m.hmap[key]
+
+ if ok {
+ // Unlink elem from list
+ m.list.Unlink(elem)
+
+ // Update existing
+ elem.V = value
+ } else {
+ if m.list.len >= m.size {
+ // We're at capacity, sir!
+ // Pop current tail elem
+ elem = m.list.PopTail()
+
+ if evict != nil {
+ // Pass to evict hook
+ evict(elem.K, elem.V)
+ }
+
+ // Delete key from map
+ delete(m.hmap, elem.K)
+ } else {
+ // Allocate elem
+ elem = m.alloc()
+ }
+
+ // Set elem
+ elem.K = key
+ elem.V = value
+
+ // Add element map entry
+ m.hmap[key] = elem
+ }
+
+ // Push to front of list
+ m.list.PushFront(elem)
+}
+
+// Cap returns the maximum capacity of this LRU map.
+func (m *LRUMap[K, V]) Cap() int {
+ return m.size
+}
+
+// Format implements fmt.Formatter, allowing performant string formatting of map.
+func (m *LRUMap[K, V]) Format(state fmt.State, verb rune) {
+ m.format(reflect.TypeOf(m), state, verb)
+}