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Diffstat (limited to 'vendor/codeberg.org/gruf/go-mangler/v2/cache.go')
-rw-r--r--vendor/codeberg.org/gruf/go-mangler/v2/cache.go62
1 files changed, 62 insertions, 0 deletions
diff --git a/vendor/codeberg.org/gruf/go-mangler/v2/cache.go b/vendor/codeberg.org/gruf/go-mangler/v2/cache.go
new file mode 100644
index 000000000..0f6f71cd0
--- /dev/null
+++ b/vendor/codeberg.org/gruf/go-mangler/v2/cache.go
@@ -0,0 +1,62 @@
+package mangler
+
+import (
+ "sync/atomic"
+ "unsafe"
+
+ "codeberg.org/gruf/go-xunsafe"
+)
+
+var manglers cache
+
+// cache is a concurrency-safe map[xunsafe.TypeInfo]Mangler
+// cache, designed for heavy reads but with unfortunately expensive
+// writes. it is designed such that after some initial load period
+// in which functions are cached by types, all future ops are reads.
+type cache struct{ p unsafe.Pointer }
+
+// Get will check cache for mangler func under key.
+func (c *cache) Get(t xunsafe.TypeInfo) Mangler {
+ if p := c.load(); p != nil {
+ return (*p)[t]
+ }
+ return nil
+}
+
+// Put will place given mangler func in cache under key, if not already exists.
+func (c *cache) Put(t xunsafe.TypeInfo, fn Mangler) {
+ for {
+ p := c.load()
+
+ var cache map[xunsafe.TypeInfo]Mangler
+
+ if p != nil {
+ if _, ok := (*p)[t]; ok {
+ return
+ }
+
+ cache = make(map[xunsafe.TypeInfo]Mangler, len(*p)+1)
+ for key, value := range *p {
+ cache[key] = value
+ }
+ } else {
+ cache = make(map[xunsafe.TypeInfo]Mangler, 1)
+ }
+
+ cache[t] = fn
+
+ if c.cas(p, &cache) {
+ return
+ }
+ }
+}
+
+// load is a typed wrapper around atomic.LoadPointer().
+func (c *cache) load() *map[xunsafe.TypeInfo]Mangler {
+ return (*map[xunsafe.TypeInfo]Mangler)(atomic.LoadPointer(&c.p))
+}
+
+// cas is a typed wrapper around atomic.CompareAndSwapPointer().
+func (c *cache) cas(old, new *map[xunsafe.TypeInfo]Mangler) bool {
+ return atomic.CompareAndSwapPointer(&c.p, unsafe.Pointer(old), unsafe.Pointer(new))
+}