}

// Validates the preconditions. Returns true if GET/HEAD operation should not proceed.
// Preconditions supported are:
//
//	If-Modified-Since
//	If-Unmodified-Since
//	If-Match
//	If-None-Match
func checkPreconditions(ctx context.Context, w http.ResponseWriter, r *http.Request, objInfo ObjectInfo, opts ObjectOptions) bool {
	// Return false for methods other than GET and HEAD.

		if s.walkMu != nil {
			s.walkMu.Lock()
		}
		entries, err := s.ListDir(ctx, "", opts.Bucket, current, -1)
		if s.walkMu != nil {
			s.walkMu.Unlock()
		}
		if err != nil {
			// Folder could have gone away in-between
			if err != errVolumeNotFound && err != errFileNotFound {
				internalLogOnceIf(ctx, err, "metacache-walk-scan-dir")
			}
			if opts.ReportNotFound && err == errFileNotFound && current == opts.BaseDir {

		}

		if vnf == len(readers) {
			return errVolumeNotFound
		}

		// Break if all at EOF or error.
		if atEOF+hasErr == len(readers) {
			if hasErr > 0 && opts.finished != nil {
				opts.finished(errs)
			}
			break
		}

		if fnf == len(readers) {
			return errFileNotFound
		}

		if agree == len(readers) {
			// Everybody agreed

	if r == nil {
		return nil
	}

	if r.APIVersion != batchReplJobAPIVersion {
		return errInvalidArgument
	}

	if r.Source.Endpoint != "" && r.Target.Endpoint != "" {
		return errInvalidArgument
	}

	if r.Source.Creds.Empty() && r.Target.Creds.Empty() {
		return errInvalidArgument
	}

	if r.Source.Bucket == "" || r.Target.Bucket == "" {

	hip.objPrefix = vars[mgmtPrefix]

	if hip.bucket == "" {
		if hip.objPrefix != "" {
			// Bucket is required if object-prefix is given
			err = ErrHealMissingBucket
			return
		}
	} else if isReservedOrInvalidBucket(hip.bucket, false) {
		err = ErrInvalidBucketName
		return
	}

	// empty prefix is valid.
	if !IsValidObjectPrefix(hip.objPrefix) {
		err = ErrInvalidObjectName

		if objName <= startAfter || objName <= token {
			continue
		}
		if strings.HasPrefix(objName, prefix) {
			if count == maxKeys {
				isTruncated = true
				break
			}
			if delimiter != "" {
				i := strings.Index(objName[len(prefix):], delimiter)
				if i >= 0 {
					commonPrefix := objName[:len(prefix)+i+1]

	}

	// Guess content-type from the extension if possible.
	if userDefined["content-type"] == "" {
		userDefined["content-type"] = mimedb.TypeByExtension(path.Ext(object))
	}

	// if storageClass is standard no need to save it as part of metadata.
	if userDefined[xhttp.AmzStorageClass] == storageclass.STANDARD {
		delete(userDefined, xhttp.AmzStorageClass)
	}

	if opts.WantChecksum != nil && opts.WantChecksum.Type.IsSet() {

	opts = ObjectOptions{UserDefined: metadata}
	if copySource {
		if crypto.SSECopy.IsRequested(header) {
			clientKey, err = crypto.SSECopy.ParseHTTP(header)
			if err != nil {
				return
			}
			if sse, err = encrypt.NewSSEC(clientKey[:]); err != nil {
				return
			}
			opts.ServerSideEncryption = encrypt.SSECopy(sse)
			return
		}
		return
	}

	if crypto.SSEC.IsRequested(header) {

		e.ObjVersions[i] += v
	}

	if other.AllTierStats != nil && len(other.AllTierStats.Tiers) != 0 {
		if e.AllTierStats == nil {
			e.AllTierStats = newAllTierStats()
		}
		e.AllTierStats.merge(other.AllTierStats)
	}
}

// mod returns true if the hash mod cycles == cycle.
// If cycles is 0 false is always returned.
// If cycles is 1 true is always returned (as expected).

	if configFile == bucketLifecycleConfig {
		// Get bucket config from current site
		meta, e := globalBucketMetadataSys.GetConfigFromDisk(ctx, bucket)
		if e != nil && !errors.Is(e, errConfigNotFound) {
			return updatedAt, e
		}
		var expiryRuleRemoved bool
		if len(meta.LifecycleConfigXML) > 0 {
			var lcCfg lifecycle.Lifecycle