Merge pull request #336 from go-playground/correct-var-lock

Correct Var tagCache locking

Author: Dean Karn

README.md

@@ -1,7 +1,7 @@
 Package validator
 ================
 <img align="right" src="https://raw.githubusercontent.com/go-playground/validator/v9/logo.png">[![Join the chat at https://gitter.im/go-playground/validator](https://badges.gitter.im/Join%20Chat.svg)](https://gitter.im/go-playground/validator?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
-![Project status](https://img.shields.io/badge/version-9.9.2-green.svg)
+![Project status](https://img.shields.io/badge/version-9.9.3-green.svg)
 [![Build Status](https://semaphoreci.com/api/v1/joeybloggs/validator/branches/v9/badge.svg)](https://semaphoreci.com/joeybloggs/validator)
 [![Coverage Status](https://coveralls.io/repos/go-playground/validator/badge.svg?branch=v9&service=github)](https://coveralls.io/github/go-playground/validator?branch=v9)
 [![Go Report Card](https://goreportcard.com/badge/github.com/go-playground/validator)](https://goreportcard.com/report/github.com/go-playground/validator)

cache.go

@@ -315,6 +315,23 @@ func (v *Validate) parseFieldTagsRecursive(tag string, fieldName string, alias s
 			current.isBlockEnd = true
 		}
 	}
-
 	return
 }
+
+func (v *Validate) fetchCacheTag(tag string) *cTag {
+	// find cached tag
+	ctag, found := v.tagCache.Get(tag)
+	if !found {
+		v.tagCache.lock.Lock()
+		defer v.tagCache.lock.Unlock()
+
+		// could have been multiple trying to access, but once first is done this ensures tag
+		// isn't parsed again.
+		ctag, found = v.tagCache.Get(tag)
+		if !found {
+			ctag, _ = v.parseFieldTagsRecursive(tag, "", "", false)
+			v.tagCache.Set(tag, ctag)
+		}
+	}
+	return ctag
+}

validator.go

@@ -473,9 +473,7 @@ OUTER:
 				)
 
 				return
-
 			}
-
 			ct = ct.next
 		}
 	}

validator_instance.go

@@ -520,36 +520,18 @@ func (v *Validate) VarCtx(ctx context.Context, field interface{}, tag string) (e
 		return nil
 	}
 
-	// find cached tag
-	ctag, ok := v.tagCache.Get(tag)
-	if !ok {
-		v.tagCache.lock.Lock()
-		defer v.tagCache.lock.Unlock()
-
-		// could have been multiple trying to access, but once first is done this ensures tag
-		// isn't parsed again.
-		ctag, ok = v.tagCache.Get(tag)
-		if !ok {
-			ctag, _ = v.parseFieldTagsRecursive(tag, "", "", false)
-			v.tagCache.Set(tag, ctag)
-		}
-	}
-
+	ctag := v.fetchCacheTag(tag)
 	val := reflect.ValueOf(field)
-
 	vd := v.pool.Get().(*validate)
 	vd.top = val
 	vd.isPartial = false
-
 	vd.traverseField(ctx, val, val, vd.ns[0:0], vd.actualNs[0:0], defaultCField, ctag)
 
 	if len(vd.errs) > 0 {
 		err = vd.errs
 		vd.errs = nil
 	}
-
 	v.pool.Put(vd)
-
 	return
 }
 
@@ -590,36 +572,17 @@ func (v *Validate) VarWithValueCtx(ctx context.Context, field interface{}, other
 	if len(tag) == 0 || tag == skipValidationTag {
 		return nil
 	}
-
-	// find cached tag
-	ctag, ok := v.tagCache.Get(tag)
-	if !ok {
-		v.tagCache.lock.Lock()
-		defer v.tagCache.lock.Unlock()
-
-		// could have been multiple trying to access, but once first is done this ensures tag
-		// isn't parsed again.
-		ctag, ok = v.tagCache.Get(tag)
-		if !ok {
-			ctag, _ = v.parseFieldTagsRecursive(tag, "", "", false)
-			v.tagCache.Set(tag, ctag)
-		}
-	}
-
+	ctag := v.fetchCacheTag(tag)
 	otherVal := reflect.ValueOf(other)
-
 	vd := v.pool.Get().(*validate)
 	vd.top = otherVal
 	vd.isPartial = false
-
 	vd.traverseField(ctx, otherVal, reflect.ValueOf(field), vd.ns[0:0], vd.actualNs[0:0], defaultCField, ctag)
 
 	if len(vd.errs) > 0 {
 		err = vd.errs
 		vd.errs = nil
 	}
-
 	v.pool.Put(vd)
-
 	return
 }