1 files changed, 341 insertions, 0 deletions
diff --git a/vendor/codeberg.org/gruf/go-cache/v3/result/cache.go b/vendor/codeberg.org/gruf/go-cache/v3/result/cache.go
new file mode 100644
index 000000000..69f5593e3
--- /dev/null
+++ b/vendor/codeberg.org/gruf/go-cache/v3/result/cache.go
@@ -0,0 +1,341 @@
+package result
+
+import (
+	"reflect"
+	"time"
+
+	"codeberg.org/gruf/go-cache/v3/ttl"
+)
+
+// Cache ...
+type Cache[Value any] struct {
+	cache   ttl.Cache[int64, result[Value]] // underlying result cache
+	lookups structKeys                      // pre-determined struct lookups
+	copy    func(Value) Value               // copies a Value type
+	next    int64                           // update key counter
+}
+
+// New returns a new initialized Cache, with given lookups and underlying value copy function.
+func New[Value any](lookups []string, copy func(Value) Value) *Cache[Value] {
+	return NewSized(lookups, copy, 64)
+}
+
+// NewSized returns a new initialized Cache, with given lookups, underlying value copy function and provided capacity.
+func NewSized[Value any](lookups []string, copy func(Value) Value, cap int) *Cache[Value] {
+	var z Value
+
+	// Determine generic type
+	t := reflect.TypeOf(z)
+
+	// Iteratively deref pointer type
+	for t.Kind() == reflect.Pointer {
+		t = t.Elem()
+	}
+
+	// Ensure that this is a struct type
+	if t.Kind() != reflect.Struct {
+		panic("generic parameter type must be struct (or ptr to)")
+	}
+
+	// Allocate new cache object
+	c := &Cache[Value]{copy: copy}
+	c.lookups = make([]keyFields, len(lookups))
+
+	for i, lookup := range lookups {
+		// Generate keyed field info for lookup
+		c.lookups[i].pkeys = make(map[string]int64, cap)
+		c.lookups[i].lookup = lookup
+		c.lookups[i].populate(t)
+	}
+
+	// Create and initialize underlying cache
+	c.cache.Init(0, cap, 0)
+	c.SetEvictionCallback(nil)
+	c.SetInvalidateCallback(nil)
+	return c
+}
+
+// Start will start the cache background eviction routine with given sweep frequency. If already
+// running or a freq <= 0 provided, this is a no-op. This will block until eviction routine started.
+func (c *Cache[Value]) Start(freq time.Duration) bool {
+	return c.cache.Start(freq)
+}
+
+// Stop will stop cache background eviction routine. If not running this
+// is a no-op. This will block until the eviction routine has stopped.
+func (c *Cache[Value]) Stop() bool {
+	return c.cache.Stop()
+}
+
+// SetTTL sets the cache item TTL. Update can be specified to force updates of existing items
+// in the cache, this will simply add the change in TTL to their current expiry time.
+func (c *Cache[Value]) SetTTL(ttl time.Duration, update bool) {
+	c.cache.SetTTL(ttl, update)
+}
+
+// SetEvictionCallback sets the eviction callback to the provided hook.
+func (c *Cache[Value]) SetEvictionCallback(hook func(Value)) {
+	if hook == nil {
+		// Ensure non-nil hook.
+		hook = func(Value) {}
+	}
+	c.cache.SetEvictionCallback(func(item *ttl.Entry[int64, result[Value]]) {
+		for _, key := range item.Value.Keys {
+			// Delete key->pkey lookup
+			pkeys := key.fields.pkeys
+			delete(pkeys, key.value)
+		}
+
+		if item.Value.Error != nil {
+			// Skip error hooks
+			return
+		}
+
+		// Call user hook.
+		hook(item.Value.Value)
+	})
+}
+
+// SetInvalidateCallback sets the invalidate callback to the provided hook.
+func (c *Cache[Value]) SetInvalidateCallback(hook func(Value)) {
+	if hook == nil {
+		// Ensure non-nil hook.
+		hook = func(Value) {}
+	}
+	c.cache.SetInvalidateCallback(func(item *ttl.Entry[int64, result[Value]]) {
+		for _, key := range item.Value.Keys {
+			if key.fields != nil {
+				// Delete key->pkey lookup
+				pkeys := key.fields.pkeys
+				delete(pkeys, key.value)
+			}
+		}
+
+		if item.Value.Error != nil {
+			// Skip error hooks
+			return
+		}
+
+		// Call user hook.
+		hook(item.Value.Value)
+	})
+}
+
+// Load ...
+func (c *Cache[Value]) Load(lookup string, load func() (Value, error), keyParts ...any) (Value, error) {
+	var (
+		zero Value
+		res  result[Value]
+	)
+
+	// Get lookup map by name.
+	kfields := c.getFields(lookup)
+	lmap := kfields.pkeys
+
+	// Generate cache key string.
+	ckey := genkey(keyParts...)
+
+	// Acquire cache lock
+	c.cache.Lock()
+
+	// Look for primary key
+	pkey, ok := lmap[ckey]
+
+	if ok {
+		// Fetch the result for primary key
+		entry, _ := c.cache.Cache.Get(pkey)
+		res = entry.Value
+	}
+
+	// Done with lock
+	c.cache.Unlock()
+
+	if !ok {
+		// Generate new result from fresh load.
+		res.Value, res.Error = load()
+
+		if res.Error != nil {
+			// This load returned an error, only
+			// store this item under provided key.
+			res.Keys = []cacheKey{{
+				value:  ckey,
+				fields: kfields,
+			}}
+		} else {
+			// This was a successful load, generate keys.
+			res.Keys = c.lookups.generate(res.Value)
+		}
+
+		// Acquire cache lock.
+		c.cache.Lock()
+		defer c.cache.Unlock()
+
+		// Attempt to cache this result.
+		if key, ok := c.storeResult(res); !ok {
+			return zero, ConflictError{key}
+		}
+	}
+
+	// Catch and return error
+	if res.Error != nil {
+		return zero, res.Error
+	}
+
+	// Return a copy of value from cache
+	return c.copy(res.Value), nil
+}
+
+// Store ...
+func (c *Cache[Value]) Store(value Value, store func() error) error {
+	// Attempt to store this value.
+	if err := store(); err != nil {
+		return err
+	}
+
+	// Prepare cached result.
+	result := result[Value]{
+		Keys:  c.lookups.generate(value),
+		Value: c.copy(value),
+		Error: nil,
+	}
+
+	// Acquire cache lock.
+	c.cache.Lock()
+	defer c.cache.Unlock()
+
+	// Attempt to cache result, only return conflict
+	// error if the appropriate flag has been set.
+	if key, ok := c.storeResult(result); !ok {
+		return ConflictError{key}
+	}
+
+	return nil
+}
+
+// Has ...
+func (c *Cache[Value]) Has(lookup string, keyParts ...any) bool {
+	var res result[Value]
+
+	// Get lookup map by name.
+	kfields := c.getFields(lookup)
+	lmap := kfields.pkeys
+
+	// Generate cache key string.
+	ckey := genkey(keyParts...)
+
+	// Acquire cache lock
+	c.cache.Lock()
+
+	// Look for primary key
+	pkey, ok := lmap[ckey]
+
+	if ok {
+		// Fetch the result for primary key
+		entry, _ := c.cache.Cache.Get(pkey)
+		res = entry.Value
+	}
+
+	// Done with lock
+	c.cache.Unlock()
+
+	// Check for non-error result.
+	return ok && (res.Error == nil)
+}
+
+// Invalidate ...
+func (c *Cache[Value]) Invalidate(lookup string, keyParts ...any) {
+	// Get lookup map by name.
+	kfields := c.getFields(lookup)
+	lmap := kfields.pkeys
+
+	// Generate cache key string.
+	ckey := genkey(keyParts...)
+
+	// Look for primary key
+	c.cache.Lock()
+	pkey, ok := lmap[ckey]
+	c.cache.Unlock()
+
+	if !ok {
+		return
+	}
+
+	// Invalid by primary key
+	c.cache.Invalidate(pkey)
+}
+
+// Clear empties the cache, calling the invalidate callback.
+func (c *Cache[Value]) Clear() {
+	c.cache.Clear()
+}
+
+// Len ...
+func (c *Cache[Value]) Len() int {
+	return c.cache.Cache.Len()
+}
+
+// Cap ...
+func (c *Cache[Value]) Cap() int {
+	return c.cache.Cache.Cap()
+}
+
+func (c *Cache[Value]) getFields(name string) *keyFields {
+	for _, k := range c.lookups {
+		// Find key fields with name
+		if k.lookup == name {
+			return &k
+		}
+	}
+	panic("invalid lookup: " + name)
+}
+
+func (c *Cache[Value]) storeResult(res result[Value]) (string, bool) {
+	for _, key := range res.Keys {
+		pkeys := key.fields.pkeys
+
+		// Look for cache primary key
+		pkey, ok := pkeys[key.value]
+
+		if ok {
+			// Look for overlap with non error keys,
+			// as an overlap for some but not all keys
+			// could produce inconsistent results.
+			entry, _ := c.cache.Cache.Get(pkey)
+			if entry.Value.Error == nil {
+				return key.value, false
+			}
+		}
+	}
+
+	// Get primary key
+	pkey := c.next
+	c.next++
+
+	// Store all primary key lookups
+	for _, key := range res.Keys {
+		pkeys := key.fields.pkeys
+		pkeys[key.value] = pkey
+	}
+
+	// Store main entry under primary key, using evict hook if needed
+	c.cache.Cache.SetWithHook(pkey, &ttl.Entry[int64, result[Value]]{
+		Expiry: time.Now().Add(c.cache.TTL),
+		Key:    pkey,
+		Value:  res,
+	}, func(_ int64, item *ttl.Entry[int64, result[Value]]) {
+		c.cache.Evict(item)
+	})
+
+	return "", true
+}
+
+type result[Value any] struct {
+	// keys accessible under
+	Keys []cacheKey
+
+	// cached value
+	Value Value
+
+	// cached error
+	Error error
+}