GOCBC-483: Update transcoder API

Motivation
----------
We should use composition for building the default transcoder with
a serializer. We also shouldn't expose the serializer from the
transcoder.

Changes
-------
Update the signature of NewDefaultTranscoder to take serializer
as a parameter. Update subdoc and services options to
take a serializer directly. Add a serializer to cluster and
options.

Change-Id: I518b41fc9b0c9be1709d95d39be276702a633507
Reviewed-on: http://review.couchbase.org/110355
Reviewed-by: Mike Goldsmith <goldsmith.mike@gmail.com>
Reviewed-by: Brett Lawson <brett19@gmail.com>
Tested-by: Charles Dixon <chvckd@gmail.com>

analyticsquery_options.go

@@ -24,8 +24,9 @@ type AnalyticsQueryOptions struct {
 	// Experimental: This API is subject to change at any time.
 	Deferred bool
 
-	// Serializer is used to deserialize each row in the result. This should be a JSON deserializer as results are JSON.
-	Serializer Serializer
+	// JSONSerializer is used to deserialize each row in the result. This should be a JSON deserializer as results are JSON.
+	// NOTE: if not set then query will always default to DefaultJSONSerializer.
+	Serializer JSONSerializer
 }
 
 func (opts *AnalyticsQueryOptions) toMap(statement string) (map[string]interface{}, error) {

bucket.go

@@ -29,6 +29,7 @@ func newBucket(sb *stateBlock, bucketName string, opts BucketOptions) *Bucket {
 			client: sb.client,
 
 			Transcoder: sb.Transcoder,
+			Serializer: sb.Serializer,
 		},
 	}
 }

cluster.go

@@ -38,7 +38,11 @@ type ClusterOptions struct {
 	SearchTimeout     time.Duration
 	ManagementTimeout time.Duration
 	EnableTracing     bool
-	Transcoder        Transcoder
+	// Transcoder is used for trancoding data used in KV operations.
+	Transcoder Transcoder
+	// Serializer is used for deserialization of data used in query, analytics, view and search operations. This
+	// will default to DefaultJSONSerializer. NOTE: This is entirely independent of Transcoder.
+	Serializer JSONSerializer
 }
 
 // ClusterCloseOptions is the set of options available when disconnecting from a Cluster.
@@ -104,7 +108,10 @@ func Connect(connStr string, opts ClusterOptions) (*Cluster, error) {
 		searchTimeout = opts.SearchTimeout
 	}
 	if opts.Transcoder == nil {
-		opts.Transcoder = NewDefaultTranscoder()
+		opts.Transcoder = NewDefaultTranscoder(&DefaultJSONSerializer{})
+	}
+	if opts.Serializer == nil {
+		opts.Serializer = &DefaultJSONSerializer{}
 	}
 
 	cluster := &Cluster{
@@ -124,6 +131,7 @@ func Connect(connStr string, opts ClusterOptions) (*Cluster, error) {
 			DuraTimeout:            40000 * time.Millisecond,
 			DuraPollTimeout:        100 * time.Millisecond,
 			Transcoder:             opts.Transcoder,
+			Serializer:             opts.Serializer,
 		},
 
 		queryCache: make(map[string]*n1qlCache),

cluster_analyticsquery.go

@@ -77,7 +77,7 @@ type AnalyticsResults struct {
 	httpProvider httpProvider
 	ctx          context.Context
 
-	serializer Serializer
+	serializer JSONSerializer
 }
 
 // Next assigns the next result from the results into the value pointer, returning whether the read was successful.
@@ -367,7 +367,7 @@ func (c *Cluster) analyticsQuery(ctx context.Context, statement string, opts *An
 	// TODO: clientcontextid?
 
 	if opts.Serializer == nil {
-		opts.Serializer = c.sb.Transcoder.Serializer()
+		opts.Serializer = c.sb.Serializer
 	}
 
 	var retries uint
@@ -398,8 +398,7 @@ func (c *Cluster) analyticsQuery(ctx context.Context, statement string, opts *An
 }
 
 func (c *Cluster) executeAnalyticsQuery(ctx context.Context, opts map[string]interface{},
-	provider httpProvider, cancel context.CancelFunc, serializer Serializer) (*AnalyticsResults, error) {
-
+	provider httpProvider, cancel context.CancelFunc, serializer JSONSerializer) (*AnalyticsResults, error) {
 	// priority is sent as a header not in the body
 	priority, priorityCastOK := opts["priority"].(int)
 	if priorityCastOK {

cluster_analyticsquery_test.go

@@ -374,7 +374,7 @@ func TestBasicAnalyticsQuerySerializer(t *testing.T) {
 
 	queryOptions := &AnalyticsQueryOptions{
 		PositionalParameters: []interface{}{"brewery"},
-		Serializer:           &DefaultSerializer{},
+		Serializer:           &DefaultJSONSerializer{},
 	}
 
 	statement := "select `beer-sample`.* from `beer-sample` WHERE `type` = ? ORDER BY brewery_id, name"

cluster_query.go

@@ -75,7 +75,7 @@ type QueryResults struct {
 	ctx                context.Context
 	enhancedStatements bool
 
-	serializer Serializer
+	serializer JSONSerializer
 }
 
 // Next assigns the next result from the results into the value pointer, returning whether the read was successful.
@@ -356,7 +356,7 @@ func (c *Cluster) query(ctx context.Context, statement string, opts *QueryOption
 	}
 
 	if opts.Serializer == nil {
-		opts.Serializer = c.sb.Transcoder.Serializer()
+		opts.Serializer = c.sb.Serializer
 	}
 
 	var res *QueryResults
@@ -378,7 +378,7 @@ func (c *Cluster) query(ctx context.Context, statement string, opts *QueryOption
 }
 
 func (c *Cluster) doPreparedN1qlQuery(ctx context.Context, queryOpts map[string]interface{},
-	provider httpProvider, cancel context.CancelFunc, serializer Serializer) (*QueryResults, error) {
+	provider httpProvider, cancel context.CancelFunc, serializer JSONSerializer) (*QueryResults, error) {
 
 	if capabilitySupporter, ok := provider.(clusterCapabilityProvider); ok {
 		if !c.supportsEnhancedPreparedStatements() &&
@@ -449,7 +449,7 @@ func (c *Cluster) prepareN1qlQuery(ctx context.Context, opts map[string]interfac
 
 	// There's no need to pass cancel here, if there's an error then we'll cancel further up the stack
 	// and if there isn't then we run another query later where we will cancel
-	prepRes, err := c.doRetryableQuery(ctx, prepOpts, provider, nil, &DefaultSerializer{})
+	prepRes, err := c.doRetryableQuery(ctx, prepOpts, provider, nil, &DefaultJSONSerializer{})
 	if err != nil {
 		return nil, err
 	}
@@ -467,7 +467,7 @@ func (c *Cluster) prepareN1qlQuery(ctx context.Context, opts map[string]interfac
 }
 
 func (c *Cluster) doRetryableQuery(ctx context.Context, queryOpts map[string]interface{},
-	provider httpProvider, cancel context.CancelFunc, serializer Serializer) (*QueryResults, error) {
+	provider httpProvider, cancel context.CancelFunc, serializer JSONSerializer) (*QueryResults, error) {
 	var res *QueryResults
 	var err error
 	var retries uint
@@ -507,8 +507,7 @@ type n1qlPrepData struct {
 // settings. This function will inject any additional connection or request-level
 // settings into the `opts` map.
 func (c *Cluster) executeN1qlQuery(ctx context.Context, opts map[string]interface{},
-	provider httpProvider, cancel context.CancelFunc, endpoint string, serializer Serializer) (*QueryResults, error) {
-
+	provider httpProvider, cancel context.CancelFunc, endpoint string, serializer JSONSerializer) (*QueryResults, error) {
 	reqJSON, err := json.Marshal(opts)
 	if err != nil {
 		return nil, errors.Wrap(err, "failed to marshal query request body")

cluster_query_test.go

@@ -1377,7 +1377,8 @@ func testGetClusterForHTTP(provider *mockHTTPProvider, n1qlTimeout, analyticsTim
 	c.sb.AnalyticsTimeout = analyticsTimeout
 	c.sb.SearchTimeout = searchTimeout
 
-	c.sb.Transcoder = NewDefaultTranscoder()
+	c.sb.Transcoder = NewDefaultTranscoder(&DefaultJSONSerializer{})
+	c.sb.Serializer = &DefaultJSONSerializer{}
 
 	return c
 }

collection_subdoc.go

@@ -22,7 +22,7 @@ type LookupInOptions struct {
 	Context    context.Context
 	Timeout    time.Duration
 	WithExpiry bool
-	Transcoder Transcoder
+	Serializer JSONSerializer
 }
 
 // LookupInSpecGetOptions are the options available to LookupIn subdoc Get operations.
@@ -171,9 +171,9 @@ func (c *Collection) lookupIn(ctx context.Context, key string, ops []LookupInOp,
 		return nil, errors.New("too many lookupIn ops specified, maximum 16")
 	}
 
-	transcoder := opts.Transcoder
-	if transcoder == nil {
-		transcoder = c.sb.Transcoder
+	serializer := opts.Serializer
+	if serializer == nil {
+		serializer = &DefaultJSONSerializer{}
 	}
 
 	ctrl := c.newOpManager(ctx)
@@ -191,7 +191,7 @@ func (c *Collection) lookupIn(ctx context.Context, key string, ops []LookupInOp,
 
 		if res != nil {
 			resSet := &LookupInResult{}
-			resSet.serializer = transcoder.Serializer()
+			resSet.serializer = serializer
 			resSet.cas = Cas(res.Cas)
 			resSet.contents = make([]lookupInPartial, len(subdocs))
 
@@ -255,12 +255,12 @@ type MutateInOptions struct {
 	DurabilityLevel DurabilityLevel
 	InsertDocument  bool
 	UpsertDocument  bool
-	Transcoder      Transcoder
+	Serializer      JSONSerializer
 	// Internal: This should never be used and is not supported.
 	AccessDeleted bool
 }
 
-func (c *Collection) encodeMultiArray(in interface{}, serializer Serializer) ([]byte, error) {
+func (c *Collection) encodeMultiArray(in interface{}, serializer JSONSerializer) ([]byte, error) {
 	out, err := serializer.Serialize(in)
 	if err != nil {
 		return nil, err
@@ -710,9 +710,9 @@ func (c *Collection) mutate(ctx context.Context, key string, ops []MutateInOp, o
 		flags |= SubdocDocFlagAccessDeleted
 	}
 
-	transcoder := opts.Transcoder
-	if transcoder == nil {
-		transcoder = c.sb.Transcoder
+	serializer := opts.Serializer
+	if serializer == nil {
+		serializer = &DefaultJSONSerializer{}
 	}
 
 	var subdocs []gocbcore.SubDocOp
@@ -730,9 +730,9 @@ func (c *Collection) mutate(ctx context.Context, key string, ops []MutateInOp, o
 		var marshaled []byte
 		var err error
 		if op.op.MultiValue {
-			marshaled, err = c.encodeMultiArray(op.op.Value, transcoder.Serializer())
+			marshaled, err = c.encodeMultiArray(op.op.Value, serializer)
 		} else {
-			marshaled, err = transcoder.Serializer().Serialize(op.op.Value)
+			marshaled, err = serializer.Serialize(op.op.Value)
 		}
 		if err != nil {
 			return nil, err

queryoptions.go

@@ -52,8 +52,9 @@ type QueryOptions struct {
 	// Custom allows specifying custom query options.
 	Custom map[string]interface{}
 
-	// Serializer is used to deserialize each row in the result. This should be a JSON deserializer as results are JSON.
-	Serializer Serializer
+	// JSONSerializer is used to deserialize each row in the result. This should be a JSON deserializer as results are JSON.
+	// NOTE: if not set then query will always default to DefaultJSONSerializer.
+	Serializer JSONSerializer
 }
 
 func (opts *QueryOptions) toMap(statement string) (map[string]interface{}, error) {

results.go

@@ -191,7 +191,7 @@ func (d *GetResult) set(paths []subdocPath, content interface{}, value interface
 // LookupInResult is the return type for LookupIn.
 type LookupInResult struct {
 	Result
-	serializer Serializer
+	serializer JSONSerializer
 	contents   []lookupInPartial
 	pathMap    map[string]int
 }
@@ -201,7 +201,7 @@ type lookupInPartial struct {
 	err  error
 }
 
-func (pr *lookupInPartial) as(valuePtr interface{}, serializer Serializer) error {
+func (pr *lookupInPartial) as(valuePtr interface{}, serializer JSONSerializer) error {
 	if pr.err != nil {
 		return pr.err
 	}

results_test.go

@@ -61,7 +61,7 @@ func TestGetResultContent(t *testing.T) {
 
 	res := GetResult{
 		contents:   dataset,
-		transcoder: NewDefaultTranscoder(),
+		transcoder: NewDefaultTranscoder(&DefaultJSONSerializer{}),
 	}
 
 	var doc testBeerDocument
@@ -90,7 +90,7 @@ func TestGetResultFromSubDoc(t *testing.T) {
 
 	results := &LookupInResult{
 		contents:   make([]lookupInPartial, 3),
-		serializer: NewDefaultTranscoder().Serializer(),
+		serializer: &DefaultJSONSerializer{},
 	}
 
 	var err error
@@ -119,7 +119,7 @@ func TestGetResultFromSubDoc(t *testing.T) {
 		Address address `json:"address"`
 	}
 	var doc person
-	getResult := GetResult{transcoder: NewDefaultTranscoder()}
+	getResult := GetResult{transcoder: NewDefaultTranscoder(&DefaultJSONSerializer{})}
 	err = getResult.fromSubDoc([]LookupInOp{
 		{op: ops[0]},
 		{op: ops[1]},
@@ -229,7 +229,7 @@ func TestLookupInResultContentAt(t *testing.T) {
 				err: errors.New("error"),
 			},
 		},
-		serializer: NewDefaultTranscoder().Serializer(),
+		serializer: &DefaultJSONSerializer{},
 	}
 
 	var name string

stateblock.go

@@ -45,6 +45,7 @@ type stateBlock struct {
 	client func(*clientStateBlock) client
 
 	Transcoder Transcoder
+	Serializer JSONSerializer
 }
 
 func (sb *stateBlock) getCachedClient() client {

transcoding.go

@@ -14,16 +14,10 @@ type Transcoder interface {
 
 	// Encodes a Go type into bytes for storage.
 	Encode(interface{}) ([]byte, uint32, error)
-
-	// SetSerializer sets the Serializer to be used by the Transcoder.
-	SetSerializer(serializer Serializer)
-
-	// Serializer returns the Serializer being used by the Transcoder.
-	Serializer() Serializer
 }
 
-// Serializer is used a Transcoder for serialization/deserialization of JSON datatype values.
-type Serializer interface {
+// JSONSerializer is used a Transcoder for serialization/deserialization of JSON datatype values.
+type JSONSerializer interface {
 	// Serialize serializes an interface into bytes.
 	Serialize(value interface{}) ([]byte, error)
 
@@ -34,13 +28,13 @@ type Serializer interface {
 // DefaultTranscoder implements the default transcoding behaviour of
 // all Couchbase SDKs.
 type DefaultTranscoder struct {
-	serializer Serializer
+	serializer JSONSerializer
 }
 
-// NewDefaultTranscoder returns a new DefaultTranscoder initialized to use DefaultSerializer.
-func NewDefaultTranscoder() *DefaultTranscoder {
+// NewDefaultTranscoder returns a new DefaultTranscoder initialized to use DefaultSerializer.∂
+func NewDefaultTranscoder(serializer JSONSerializer) *DefaultTranscoder {
 	return &DefaultTranscoder{
-		serializer: &DefaultSerializer{},
+		serializer: &DefaultJSONSerializer{},
 	}
 }
 
@@ -121,22 +115,12 @@ func (t *DefaultTranscoder) Encode(value interface{}) ([]byte, uint32, error) {
 	return bytes, flags, nil
 }
 
-// Serializer returns the current serializer being used by the Transcoder.
-func (t *DefaultTranscoder) Serializer() Serializer {
-	return t.serializer
-}
-
-// SetSerializer set the current serializer to be used by the Transcoder.
-func (t *DefaultTranscoder) SetSerializer(serializer Serializer) {
-	t.serializer = serializer
-}
-
-// DefaultSerializer implements the Serializer interface using json.Marshal/Unmarshal.
-type DefaultSerializer struct {
+// DefaultJSONSerializer implements the JSONSerializer interface using json.Marshal/Unmarshal.
+type DefaultJSONSerializer struct {
 }
 
 // Serialize applies the json.Marshal behaviour to serialize a Go type
-func (s *DefaultSerializer) Serialize(value interface{}) ([]byte, error) {
+func (s *DefaultJSONSerializer) Serialize(value interface{}) ([]byte, error) {
 	bytes, err := json.Marshal(value)
 	if err != nil {
 		return nil, err
@@ -146,7 +130,7 @@ func (s *DefaultSerializer) Serialize(value interface{}) ([]byte, error) {
 }
 
 // Deserialize applies the json.Unmarshal behaviour to deserialize into a Go type
-func (s *DefaultSerializer) Deserialize(bytes []byte, out interface{}) error {
+func (s *DefaultJSONSerializer) Deserialize(bytes []byte, out interface{}) error {
 	err := json.Unmarshal(bytes, &out)
 	if err != nil {
 		return err