1 files changed, 166 insertions, 0 deletions
diff --git a/vendor/go.mongodb.org/mongo-driver/bson/bsoncodec/codec_cache.go b/vendor/go.mongodb.org/mongo-driver/bson/bsoncodec/codec_cache.go
new file mode 100644
index 000000000..844b50299
--- /dev/null
+++ b/vendor/go.mongodb.org/mongo-driver/bson/bsoncodec/codec_cache.go
@@ -0,0 +1,166 @@
+// Copyright (C) MongoDB, Inc. 2017-present.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"); you may
+// not use this file except in compliance with the License. You may obtain
+// a copy of the License at http://www.apache.org/licenses/LICENSE-2.0
+
+package bsoncodec
+
+import (
+	"reflect"
+	"sync"
+	"sync/atomic"
+)
+
+// Runtime check that the kind encoder and decoder caches can store any valid
+// reflect.Kind constant.
+func init() {
+	if s := reflect.Kind(len(kindEncoderCache{}.entries)).String(); s != "kind27" {
+		panic("The capacity of kindEncoderCache is too small.\n" +
+			"This is due to a new type being added to reflect.Kind.")
+	}
+}
+
+// statically assert array size
+var _ = (kindEncoderCache{}).entries[reflect.UnsafePointer]
+var _ = (kindDecoderCache{}).entries[reflect.UnsafePointer]
+
+type typeEncoderCache struct {
+	cache sync.Map // map[reflect.Type]ValueEncoder
+}
+
+func (c *typeEncoderCache) Store(rt reflect.Type, enc ValueEncoder) {
+	c.cache.Store(rt, enc)
+}
+
+func (c *typeEncoderCache) Load(rt reflect.Type) (ValueEncoder, bool) {
+	if v, _ := c.cache.Load(rt); v != nil {
+		return v.(ValueEncoder), true
+	}
+	return nil, false
+}
+
+func (c *typeEncoderCache) LoadOrStore(rt reflect.Type, enc ValueEncoder) ValueEncoder {
+	if v, loaded := c.cache.LoadOrStore(rt, enc); loaded {
+		enc = v.(ValueEncoder)
+	}
+	return enc
+}
+
+func (c *typeEncoderCache) Clone() *typeEncoderCache {
+	cc := new(typeEncoderCache)
+	c.cache.Range(func(k, v interface{}) bool {
+		if k != nil && v != nil {
+			cc.cache.Store(k, v)
+		}
+		return true
+	})
+	return cc
+}
+
+type typeDecoderCache struct {
+	cache sync.Map // map[reflect.Type]ValueDecoder
+}
+
+func (c *typeDecoderCache) Store(rt reflect.Type, dec ValueDecoder) {
+	c.cache.Store(rt, dec)
+}
+
+func (c *typeDecoderCache) Load(rt reflect.Type) (ValueDecoder, bool) {
+	if v, _ := c.cache.Load(rt); v != nil {
+		return v.(ValueDecoder), true
+	}
+	return nil, false
+}
+
+func (c *typeDecoderCache) LoadOrStore(rt reflect.Type, dec ValueDecoder) ValueDecoder {
+	if v, loaded := c.cache.LoadOrStore(rt, dec); loaded {
+		dec = v.(ValueDecoder)
+	}
+	return dec
+}
+
+func (c *typeDecoderCache) Clone() *typeDecoderCache {
+	cc := new(typeDecoderCache)
+	c.cache.Range(func(k, v interface{}) bool {
+		if k != nil && v != nil {
+			cc.cache.Store(k, v)
+		}
+		return true
+	})
+	return cc
+}
+
+// atomic.Value requires that all calls to Store() have the same concrete type
+// so we wrap the ValueEncoder with a kindEncoderCacheEntry to ensure the type
+// is always the same (since different concrete types may implement the
+// ValueEncoder interface).
+type kindEncoderCacheEntry struct {
+	enc ValueEncoder
+}
+
+type kindEncoderCache struct {
+	entries [reflect.UnsafePointer + 1]atomic.Value // *kindEncoderCacheEntry
+}
+
+func (c *kindEncoderCache) Store(rt reflect.Kind, enc ValueEncoder) {
+	if enc != nil && rt < reflect.Kind(len(c.entries)) {
+		c.entries[rt].Store(&kindEncoderCacheEntry{enc: enc})
+	}
+}
+
+func (c *kindEncoderCache) Load(rt reflect.Kind) (ValueEncoder, bool) {
+	if rt < reflect.Kind(len(c.entries)) {
+		if ent, ok := c.entries[rt].Load().(*kindEncoderCacheEntry); ok {
+			return ent.enc, ent.enc != nil
+		}
+	}
+	return nil, false
+}
+
+func (c *kindEncoderCache) Clone() *kindEncoderCache {
+	cc := new(kindEncoderCache)
+	for i, v := range c.entries {
+		if val := v.Load(); val != nil {
+			cc.entries[i].Store(val)
+		}
+	}
+	return cc
+}
+
+// atomic.Value requires that all calls to Store() have the same concrete type
+// so we wrap the ValueDecoder with a kindDecoderCacheEntry to ensure the type
+// is always the same (since different concrete types may implement the
+// ValueDecoder interface).
+type kindDecoderCacheEntry struct {
+	dec ValueDecoder
+}
+
+type kindDecoderCache struct {
+	entries [reflect.UnsafePointer + 1]atomic.Value // *kindDecoderCacheEntry
+}
+
+func (c *kindDecoderCache) Store(rt reflect.Kind, dec ValueDecoder) {
+	if rt < reflect.Kind(len(c.entries)) {
+		c.entries[rt].Store(&kindDecoderCacheEntry{dec: dec})
+	}
+}
+
+func (c *kindDecoderCache) Load(rt reflect.Kind) (ValueDecoder, bool) {
+	if rt < reflect.Kind(len(c.entries)) {
+		if ent, ok := c.entries[rt].Load().(*kindDecoderCacheEntry); ok {
+			return ent.dec, ent.dec != nil
+		}
+	}
+	return nil, false
+}
+
+func (c *kindDecoderCache) Clone() *kindDecoderCache {
+	cc := new(kindDecoderCache)
+	for i, v := range c.entries {
+		if val := v.Load(); val != nil {
+			cc.entries[i].Store(val)
+		}
+	}
+	return cc
+}