Fix the Content Header-related issue with CBOR.

Signed-off-by: Akram Ahmad <sftwr2020@gmail.com>

internal/autoevent/executor.go

@@ -11,11 +11,12 @@ import (
 	"sync"
 	"time"
 
-	"github.com/OneOfOne/xxhash"
 	"github.com/edgexfoundry/device-sdk-go/internal/common"
 	"github.com/edgexfoundry/device-sdk-go/internal/handler"
 	dsModels "github.com/edgexfoundry/device-sdk-go/pkg/models"
 	contract "github.com/edgexfoundry/go-mod-core-contracts/models"
+
+	"github.com/OneOfOne/xxhash"
 )
 
 type Executor interface {
@@ -75,7 +76,7 @@ func readResource(e *executor) (*dsModels.Event, common.AppError) {
 	vars[common.NameVar] = e.deviceName
 	vars[common.CommandVar] = e.autoEvent.Resource
 
-	evt, appErr := handler.CommandHandler(vars, "", common.GetCmdMethod, "")
+	evt, appErr := handler.CommandHandler(vars, "", nil)
 	return evt, appErr
 }
 

internal/common/types.go

@@ -17,7 +17,8 @@ import (
 // WritableInfo is a struct which contains configuration settings that can be changed in the Registry .
 type WritableInfo struct {
 	// Level is the logging level of writing log message
-	LogLevel string
+	LogLevel     string
+	ChecksumAlgo string
 }
 
 // ServiceInfo is a struct which contains service related configuration

internal/common/utils.go

@@ -10,7 +10,12 @@ package common
 import (
 	"bytes"
 	"context"
+	"crypto/md5"
+	"encoding/json"
 	"fmt"
+	"io"
+	"io/ioutil"
+	"net/http"
 	"net/url"
 	"reflect"
 	"strings"
@@ -21,6 +26,14 @@ import (
 	"github.com/edgexfoundry/go-mod-core-contracts/clients"
 	contract "github.com/edgexfoundry/go-mod-core-contracts/models"
 	"github.com/google/uuid"
+
+	"github.com/OneOfOne/xxhash"
+	"github.com/ugorji/go/codec"
+)
+
+const (
+	ChecksumAlgoxxHash = "xxHash"
+	checksumContextKey = "payload-checksum"
 )
 
 var (
@@ -286,3 +299,80 @@ func FilterQueryParams(queryParams string) url.Values {
 
 	return m
 }
+
+// Read reads and converts the request's JSON event data into an Event struct
+func (jsonReader) Read(reader io.Reader, ctx *context.Context) (dsModels.Event, error) {
+	c := context.WithValue(*ctx, clients.ContentType, clients.ContentTypeJSON)
+	*ctx = c
+
+	event := dsModels.Event{}
+	err := json.NewDecoder(reader).Decode(&event)
+	if err != nil {
+		return event, err
+	}
+
+	return event, nil
+}
+
+// Read reads and converts the request's CBOR event data into an Event struct
+func (cr cborReader) Read(reader io.Reader, ctx *context.Context) (dsModels.Event, error) {
+	c := context.WithValue(*ctx, clients.ContentType, clients.ContentTypeCBOR)
+	event := dsModels.Event{}
+	bytes, err := ioutil.ReadAll(reader)
+	if err != nil {
+		return event, err
+	}
+
+	x := codec.CborHandle{}
+	err = codec.NewDecoderBytes(bytes, &x).Decode(&event)
+	if err != nil {
+		return event, err
+	}
+
+	switch cr.configuration.Writable.ChecksumAlgo {
+	case ChecksumAlgoxxHash:
+		event.Checksum = fmt.Sprintf("%x", xxhash.Checksum64(bytes))
+	default:
+		event.Checksum = fmt.Sprintf("%x", md5.Sum(bytes))
+	}
+	c = context.WithValue(c, checksumContextKey, event.Checksum)
+	*ctx = c
+	event.EncodedEvent = bytes
+
+	return event, nil
+}
+
+// jsonReader handles unmarshaling of a JSON request body payload
+type jsonReader struct{}
+
+// NewJsonReader creates a new instance of jsonReader.
+func NewJsonReader() jsonReader {
+	return jsonReader{}
+}
+
+// cborReader handles unmarshaling of a CBOR request body payload
+type cborReader struct {
+	configuration *Config
+}
+
+// NewCborReader creates a new instance of cborReader.
+func NewCborReader(configuration *Config) cborReader {
+	return cborReader{configuration: configuration}
+}
+
+// EventReader unmarshals a request body into an Event type
+type EventReader interface {
+	Read(reader io.Reader, ctx *context.Context) (dsModels.Event, error)
+}
+
+// NewRequestReader returns a BodyReader capable of processing the request body
+func NewRequestReader(request *http.Request, configuration *Config) EventReader {
+	contentType := request.Header.Get(clients.ContentType)
+
+	switch strings.ToLower(contentType) {
+	case clients.ContentTypeCBOR:
+		return NewCborReader(configuration)
+	default:
+		return NewJsonReader()
+	}
+}

internal/controller/restfuncs.go

@@ -20,6 +20,7 @@ import (
 	"github.com/edgexfoundry/device-sdk-go/internal/handler/callback"
 	"github.com/edgexfoundry/go-mod-core-contracts/clients"
 	contract "github.com/edgexfoundry/go-mod-core-contracts/models"
+
 	"github.com/gorilla/mux"
 )
 
@@ -105,7 +106,7 @@ func commandFunc(w http.ResponseWriter, req *http.Request) {
 		return
 	}
 
-	event, appErr := handler.CommandHandler(vars, body, req.Method, req.URL.RawQuery)
+	event, appErr := handler.CommandHandler(vars, body, req)
 
 	if appErr != nil {
 		http.Error(w, fmt.Sprintf("%s %s", appErr.Message(), req.URL.Path), appErr.Code())
@@ -149,7 +150,7 @@ func commandAllFunc(w http.ResponseWriter, req *http.Request) {
 		return
 	}
 
-	events, appErr := handler.CommandAllHandler(vars[common.CommandVar], body, req.Method, req.URL.RawQuery)
+	events, appErr := handler.CommandAllHandler(vars[common.CommandVar], body, req)
 	if appErr != nil {
 		http.Error(w, appErr.Message(), appErr.Code())
 	} else if len(events) > 0 {