rclone/fs/metadata.go

79 lines
1.8 KiB
Go

package fs
import "context"
// Metadata represents Object metadata in a standardised form
//
// See docs/content/metadata.md for the interpretation of the keys
type Metadata map[string]string
// MetadataHelp represents help for a bit of system metadata
type MetadataHelp struct {
Help string
Type string
Example string
ReadOnly bool
}
// MetadataInfo is help for the whole metadata for this backend.
type MetadataInfo struct {
System map[string]MetadataHelp
Help string
}
// Set k to v on m
//
// If m is nil, then it will get made
func (m *Metadata) Set(k, v string) {
if *m == nil {
*m = make(Metadata, 1)
}
(*m)[k] = v
}
// Merge other into m
//
// If m is nil, then it will get made
func (m *Metadata) Merge(other Metadata) {
for k, v := range other {
if *m == nil {
*m = make(Metadata, len(other))
}
(*m)[k] = v
}
}
// MergeOptions gets any Metadata from the options passed in and
// stores it in m (which may be nil).
//
// If there is no m then metadata will be nil
func (m *Metadata) MergeOptions(options []OpenOption) {
for _, opt := range options {
if metadataOption, ok := opt.(MetadataOption); ok {
m.Merge(Metadata(metadataOption))
}
}
}
// GetMetadata from an ObjectInfo
//
// If the object has no metadata then metadata will be nil
func GetMetadata(ctx context.Context, o ObjectInfo) (metadata Metadata, err error) {
do, ok := o.(Metadataer)
if !ok {
return nil, nil
}
return do.Metadata(ctx)
}
// GetMetadataOptions from an ObjectInfo and merge it with any in options
//
// If the object has no metadata then metadata will be nil
func GetMetadataOptions(ctx context.Context, o ObjectInfo, options []OpenOption) (metadata Metadata, err error) {
metadata, err = GetMetadata(ctx, o)
if err != nil {
return nil, err
}
metadata.MergeOptions(options)
return metadata, nil
}