fs/xl: Combine input checks into re-usable functions. (#3383)

Repeated code around both object layers are moved
and combined into simple re-usable functions.

cmd/object-api-input-checks.go

@@ -0,0 +1,161 @@
+/*
+ * Minio Cloud Storage, (C) 2016 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package cmd
+
+import (
+	"strings"
+
+	"github.com/skyrings/skyring-common/tools/uuid"
+)
+
+// Checks on GetObject arguments, bucket and object.
+func checkGetObjArgs(bucket, object string) error {
+	return checkBucketAndObjectNames(bucket, object)
+}
+
+// Checks on DeleteObject arguments, bucket and object.
+func checkDelObjArgs(bucket, object string) error {
+	return checkBucketAndObjectNames(bucket, object)
+}
+
+// Checks bucket and object name validity, returns nil if both are valid.
+func checkBucketAndObjectNames(bucket, object string) error {
+	// Verify if bucket is valid.
+	if !IsValidBucketName(bucket) {
+		return traceError(BucketNameInvalid{Bucket: bucket})
+	}
+	// Verify if object is valid.
+	if !IsValidObjectName(object) {
+		return traceError(ObjectNameInvalid{Bucket: bucket, Object: object})
+	}
+	return nil
+}
+
+// Checks for all ListObjects arguments validity.
+func checkListObjsArgs(bucket, prefix, marker, delimiter string, obj ObjectLayer) error {
+	// Verify if bucket exists before validating object name.
+	// This is done on purpose since the order of errors is
+	// important here bucket does not exist error should
+	// happen before we return an error for invalid object name.
+	// FIXME: should be moved to handler layer.
+	if err := checkBucketExist(bucket, obj); err != nil {
+		return traceError(err)
+	}
+	// Validates object prefix validity after bucket exists.
+	if !IsValidObjectPrefix(prefix) {
+		return traceError(ObjectNameInvalid{
+			Bucket: bucket,
+			Object: prefix,
+		})
+	}
+	// Verify if delimiter is anything other than '/', which we do not support.
+	if delimiter != "" && delimiter != slashSeparator {
+		return traceError(UnsupportedDelimiter{
+			Delimiter: delimiter,
+		})
+	}
+	// Verify if marker has prefix.
+	if marker != "" && !strings.HasPrefix(marker, prefix) {
+		return traceError(InvalidMarkerPrefixCombination{
+			Marker: marker,
+			Prefix: prefix,
+		})
+	}
+	return nil
+}
+
+// Checks for all ListMultipartUploads arguments validity.
+func checkListMultipartArgs(bucket, prefix, keyMarker, uploadIDMarker, delimiter string, obj ObjectLayer) error {
+	if err := checkListObjsArgs(bucket, prefix, keyMarker, delimiter, obj); err != nil {
+		return err
+	}
+	if uploadIDMarker != "" {
+		if strings.HasSuffix(keyMarker, slashSeparator) {
+			return traceError(InvalidUploadIDKeyCombination{
+				UploadIDMarker: uploadIDMarker,
+				KeyMarker:      keyMarker,
+			})
+		}
+		id, err := uuid.Parse(uploadIDMarker)
+		if err != nil {
+			return traceError(err)
+		}
+		if id.IsZero() {
+			return traceError(MalformedUploadID{
+				UploadID: uploadIDMarker,
+			})
+		}
+	}
+	return nil
+}
+
+// Checks for NewMultipartUpload arguments validity, also validates if bucket exists.
+func checkNewMultipartArgs(bucket, object string, obj ObjectLayer) error {
+	return checkPutObjectArgs(bucket, object, obj)
+}
+
+// Checks for PutObjectPart arguments validity, also validates if bucket exists.
+func checkPutObjectPartArgs(bucket, object string, obj ObjectLayer) error {
+	return checkPutObjectArgs(bucket, object, obj)
+}
+
+// Checks for ListParts arguments validity, also validates if bucket exists.
+func checkListPartsArgs(bucket, object string, obj ObjectLayer) error {
+	return checkPutObjectArgs(bucket, object, obj)
+}
+
+// Checks for CompleteMultipartUpload arguments validity, also validates if bucket exists.
+func checkCompleteMultipartArgs(bucket, object string, obj ObjectLayer) error {
+	return checkPutObjectArgs(bucket, object, obj)
+}
+
+// Checks for AbortMultipartUpload arguments validity, also validates if bucket exists.
+func checkAbortMultipartArgs(bucket, object string, obj ObjectLayer) error {
+	return checkPutObjectArgs(bucket, object, obj)
+}
+
+// Checks for PutObject arguments validity, also validates if bucket exists.
+func checkPutObjectArgs(bucket, object string, obj ObjectLayer) error {
+	// Verify if bucket exists before validating object name.
+	// This is done on purpose since the order of errors is
+	// important here bucket does not exist error should
+	// happen before we return an error for invalid object name.
+	// FIXME: should be moved to handler layer.
+	if err := checkBucketExist(bucket, obj); err != nil {
+		return traceError(err)
+	}
+	// Validates object name validity after bucket exists.
+	if !IsValidObjectName(object) {
+		return traceError(ObjectNameInvalid{
+			Bucket: bucket,
+			Object: object,
+		})
+	}
+	return nil
+}
+
+// Checks whether bucket exists and returns appropriate error if not.
+func checkBucketExist(bucket string, obj ObjectLayer) error {
+	if !IsValidBucketName(bucket) {
+		return BucketNameInvalid{Bucket: bucket}
+	}
+	_, err := obj.GetBucketInfo(bucket)
+	if err != nil {
+		return BucketNotFound{Bucket: bucket}
+	}
+	return nil
+}