// error returned in IAM subsystem when groups doesn't exist.
var errNoSuchGroup = errors.New("Specified group does not exist")

// error returned in IAM subsystem when a policy attach/detach request has no
// net effect, i.e. it is already applied.
var errNoPolicyToAttachOrDetach = errors.New("Specified policy update has no net effect")

// error returned in IAM subsystem when a non-empty group needs to be

	var isGroup bool
	if r.User != "" {
		dn, err = sys.LDAPConfig.GetValidatedDNForUsername(r.User)
		if err != nil {
			iamLogIf(ctx, err)
			return
		}
		if dn == "" {
			// Still attempt to detach if provided user is a DN.
			if !isAttach && sys.LDAPConfig.IsLDAPUserDN(r.User) {
				dn = r.User
			} else {
				err = errNoSuchUser
				return
			}
		}
		isGroup = false
	} else {

			HandlerFunc(adminMiddleware(adminAPI.SetPolicyForUserOrGroup)).
			Queries("policyName", "{policyName:.*}", "userOrGroup", "{userOrGroup:.*}", "isGroup", "{isGroup:true|false}")

		// Attach/Detach policies to/from user or group
		adminRouter.Methods(http.MethodPost).Path(adminVersion + "/idp/builtin/policy/{operation}").HandlerFunc(adminMiddleware(adminAPI.AttachDetachPolicyBuiltin))

		// Remove user IAM

		return nil
	}

	gi := cache.iamGroupsMap[group]

	// Updating the group memberships cache happens in two steps:
	//
	// 1. Remove the group from each user's list of memberships.
	// 2. Add the group to each member's list of memberships.
	//
	// This ensures that regardless of members being added or
	// removed, the cache stays current.
	cache.removeGroupFromMembershipsMap(group)

	gzip "github.com/klauspost/pgzip"
	"github.com/pierrec/lz4"
)

// Max bzip2 concurrency across calls. 50% of GOMAXPROCS.
var bz2Limiter = pbzip2.CreateConcurrencyPool((runtime.GOMAXPROCS(0) + 1) / 2)

func detect(r *bufio.Reader) format {
	z, err := r.Peek(4)
	if err != nil {
		return formatUnknown
	}
	for _, f := range magicHeaders {
		if bytes.Equal(f.header, z[:len(f.header)]) {
			return f.f
		}
	}

		})
		if err != nil {
			c.Fatalf("export %d: Unable to attach policy: %v", caseNum, err)
		}
	}

	for groupDN, policies := range content.ldapGroupPolicyMappings {
		_, err := s.adm.AttachPolicyLDAP(ctx, madmin.PolicyAssociationReq{
			Policies: policies,
			Group:    groupDN,
		})
		if err != nil {
			c.Fatalf("export %d: Unable to attach group policy: %v", caseNum, err)
		}
	}

	return payloadLength
}

// continuationMessage - S3 periodically sends this message to keep the TCP connection open.
// These messages appear in responses at random. The client must detect the message type and process accordingly.
//
// Header specification:
// Continuation messages contain two headers, as follows:
// https://docs.aws.amazon.com/AmazonS3/latest/API/images/s3select-frame-diagram-cont.png
//

	return start, end - start + 1, nil
}

// S3Select - filters the contents on a simple structured query language (SQL) statement. It
// represents elements inside <SelectRequest/> in request XML specified in detail at
// https://docs.aws.amazon.com/AmazonS3/latest/API/RESTObjectSELECTContent.html.
type S3Select struct {
	XMLName        xml.Name            `xml:"SelectRequest"`
	Expression     string              `xml:"Expression"`

	xlVersionMajor = 1

	// Non breaking changes.
	// Bumping this is informational, but should be done
	// if any change is made to the data stored, bumping this
	// will allow to detect the exact version later.
	xlVersionMinor = 1
)

func init() {
	binary.LittleEndian.PutUint16(xlVersionCurrent[0:2], xlVersionMajor)
	binary.LittleEndian.PutUint16(xlVersionCurrent[2:4], xlVersionMinor)
}

	// assert the http response.
	c.Assert(response.StatusCode, http.StatusOK)

	// make HTTP request to fetch the object.
	request, err = newTestSignedRequest(http.MethodGet, getGetObjectURL(s.endPoint, bucketName, objectName),
		0, nil, s.accessKey, s.secretKey, s.signer)
	c.Assert(err, nil)

	// execute the http request to fetch object.
	response, err = s.client.Do(request)
	c.Assert(err, nil)
	// assert the http response status code.