func (self *ProductViewAPI) ServeHTTP(w http.ResponseWriter, req *http.Request) {
var cp *cassandra.ColumnParent
var pred *cassandra.SlicePredicate
var res []*cassandra.ColumnOrSuperColumn
var csc *cassandra.ColumnOrSuperColumn
var ire *cassandra.InvalidRequestException
var ue *cassandra.UnavailableException
var te *cassandra.TimedOutException
var prod Product
var err error
var uuidstr string = req.FormValue("id")
var ts int64 = 0
var uuid UUID
var rawdata []byte
numRequests.Add(1)
numAPIRequests.Add(1)
// Check the user is in the reqeuested scope.
if !self.authenticator.IsAuthenticatedScope(req, self.scope) {
numDisallowedScope.Add(1)
http.Error(w,
"You are not in the right group to access this resource",
http.StatusForbidden)
return
}
if len(uuidstr) <= 0 {
http.Error(w, "Requested UUID empty", http.StatusNotAcceptable)
return
}
uuid, err = ParseUUID(uuidstr)
if err != nil {
http.Error(w, "Requested UUID invalid", http.StatusNotAcceptable)
return
}
cp = cassandra.NewColumnParent()
cp.ColumnFamily = "products"
pred = cassandra.NewSlicePredicate()
pred.ColumnNames = [][]byte{
[]byte("name"), []byte("price"), []byte("vendor"),
[]byte("barcodes"), []byte("stock"),
}
res, ire, ue, te, err = self.client.GetSlice([]byte(uuid), cp, pred,
cassandra.ConsistencyLevel_ONE)
if ire != nil {
log.Print("Invalid request: ", ire.Why)
productViewErrors.Add(ire.Why, 1)
return
}
if ue != nil {
log.Print("Unavailable")
productViewErrors.Add("unavailable", 1)
return
}
if te != nil {
log.Print("Request to database backend timed out")
productViewErrors.Add("timeout", 1)
return
}
if err != nil {
log.Print("Generic error: ", err)
productViewErrors.Add(err.Error(), 1)
return
}
for _, csc = range res {
var col = csc.Column
var cname string
if !csc.IsSetColumn() {
continue
}
cname = string(col.Name)
if col.IsSetTimestamp() && col.Timestamp > ts {
ts = col.Timestamp
}
if cname == "name" {
prod.Name = string(col.Value)
} else if cname == "price" {
var buf *bytes.Buffer = bytes.NewBuffer(col.Value)
err = binary.Read(buf, binary.BigEndian, &prod.Price)
if err != nil {
log.Print("Row ", uuid.String(), " price is invalid")
productViewErrors.Add("corrupted-price", 1)
}
} else if cname == "vendor" {
prod.VendorId = UUID(col.Value).String()
} else if cname == "barcodes" {
var bc Barcodes
err = proto.Unmarshal(col.Value, &bc)
if err != nil {
log.Print("Row ", uuid.String(), " barcode is invalid")
productViewErrors.Add("corrupted-barcode", 1)
return
}
for _, code := range bc.Barcode {
prod.Barcodes = append(prod.Barcodes, code)
}
} else if cname == "stock" {
var buf *bytes.Buffer = bytes.NewBuffer(col.Value)
err = binary.Read(buf, binary.BigEndian, &prod.Stock)
if err != nil {
log.Print("Row ", uuid.String(), " stock is invalid")
productViewErrors.Add("corrupted-stock", 1)
}
}
}
rawdata, err = json.Marshal(prod)
if err != nil {
log.Print("Error marshalling JSON: ", err)
numJSONMarshalErrors.Add(1)
http.Error(w, err.Error(), http.StatusInternalServerError)
return
}
w.Header().Add("Content-type", "application/json")
w.WriteHeader(http.StatusOK)
_, err = w.Write(rawdata)
if err != nil {
log.Print("Error writing JSON response: ", err)
numHTTPWriteErrors.Add(err.Error(), 1)
}
}
