Remove hardcoded min and max limit for erasure coding (#4157)

cmd/endpoint.go

@@ -182,12 +182,12 @@ func (endpoints EndpointList) SetHTTP() {
 func NewEndpointList(args ...string) (endpoints EndpointList, err error) {
 	// isValidDistribution - checks whether given count is a valid distribution for erasure coding.
 	isValidDistribution := func(count int) bool {
-		return (count >= 4 && count <= 16 && count%2 == 0)
+		return (count >= minErasureBlocks && count <= maxErasureBlocks && count%2 == 0)
 	}
 
 	// Check whether no. of args are valid for XL distribution.
 	if !isValidDistribution(len(args)) {
-		return nil, fmt.Errorf("total endpoints %d found. For XL/Distribute, it should be 4, 6, 8, 10, 12, 14 or 16", len(args))
+		return nil, fmt.Errorf("A total of %d endpoints were found. For erasure mode it should be an even number between %d and %d", len(args), minErasureBlocks, maxErasureBlocks)
 	}
 
 	var endpointType EndpointType

cmd/endpoint_test.go

@@ -123,7 +123,7 @@ func TestNewEndpointList(t *testing.T) {
 		{[]string{"d1", "d2", "d3", "d1"}, fmt.Errorf("duplicate endpoints found")},
 		{[]string{"d1", "d2", "d3", "./d1"}, fmt.Errorf("duplicate endpoints found")},
 		{[]string{"http://localhost/d1", "http://localhost/d2", "http://localhost/d1", "http://localhost/d4"}, fmt.Errorf("duplicate endpoints found")},
-		{[]string{"d1", "d2", "d3", "d4", "d5"}, fmt.Errorf("total endpoints 5 found. For XL/Distribute, it should be 4, 6, 8, 10, 12, 14 or 16")},
+		{[]string{"d1", "d2", "d3", "d4", "d5"}, fmt.Errorf("A total of 5 endpoints were found. For erasure mode it should be an even number between 4 and 16")},
 		{[]string{"ftp://server/d1", "http://server/d2", "http://server/d3", "http://server/d4"}, fmt.Errorf("'ftp://server/d1': invalid URL endpoint format")},
 		{[]string{"d1", "http://localhost/d2", "d3", "d4"}, fmt.Errorf("mixed style endpoints are not supported")},
 		{[]string{"http://example.org/d1", "https://example.com/d1", "http://example.net/d1", "https://example.edut/d1"}, fmt.Errorf("mixed scheme is not supported")},