rclone/fs/options.go
Nick Craig-Wood 11da2a6c9b Break the fs package up into smaller parts.
The purpose of this is to make it easier to maintain and eventually to
allow the rclone backends to be re-used in other projects without
having to use the rclone configuration system.

The new code layout is documented in CONTRIBUTING.
2018-01-15 17:51:14 +00:00

160 lines
3.9 KiB
Go

// Define the options for Open
package fs
import (
"fmt"
"net/http"
"strconv"
"github.com/ncw/rclone/fs/hash"
)
// OpenOption is an interface describing options for Open
type OpenOption interface {
fmt.Stringer
// Header returns the option as an HTTP header
Header() (key string, value string)
// Mandatory returns whether this option can be ignored or not
Mandatory() bool
}
// RangeOption defines an HTTP Range option with start and end. If
// either start or end are < 0 then they will be omitted.
type RangeOption struct {
Start int64
End int64
}
// Header formats the option as an http header
func (o *RangeOption) Header() (key string, value string) {
key = "Range"
value = "bytes="
if o.Start >= 0 {
value += strconv.FormatInt(o.Start, 10)
}
value += "-"
if o.End >= 0 {
value += strconv.FormatInt(o.End, 10)
}
return key, value
}
// String formats the option into human readable form
func (o *RangeOption) String() string {
return fmt.Sprintf("RangeOption(%d,%d)", o.Start, o.End)
}
// Mandatory returns whether the option must be parsed or can be ignored
func (o *RangeOption) Mandatory() bool {
return false
}
// SeekOption defines an HTTP Range option with start only.
type SeekOption struct {
Offset int64
}
// Header formats the option as an http header
func (o *SeekOption) Header() (key string, value string) {
key = "Range"
value = fmt.Sprintf("bytes=%d-", o.Offset)
return key, value
}
// String formats the option into human readable form
func (o *SeekOption) String() string {
return fmt.Sprintf("SeekOption(%d)", o.Offset)
}
// Mandatory returns whether the option must be parsed or can be ignored
func (o *SeekOption) Mandatory() bool {
return true
}
// HTTPOption defines a general purpose HTTP option
type HTTPOption struct {
Key string
Value string
}
// Header formats the option as an http header
func (o *HTTPOption) Header() (key string, value string) {
return o.Key, o.Value
}
// String formats the option into human readable form
func (o *HTTPOption) String() string {
return fmt.Sprintf("HTTPOption(%q,%q)", o.Key, o.Value)
}
// Mandatory returns whether the option must be parsed or can be ignored
func (o *HTTPOption) Mandatory() bool {
return false
}
// HashesOption defines an option used to tell the local fs to limit
// the number of hashes it calculates.
type HashesOption struct {
Hashes hash.Set
}
// Header formats the option as an http header
func (o *HashesOption) Header() (key string, value string) {
return "", ""
}
// String formats the option into human readable form
func (o *HashesOption) String() string {
return fmt.Sprintf("HashesOption(%v)", o.Hashes)
}
// Mandatory returns whether the option must be parsed or can be ignored
func (o *HashesOption) Mandatory() bool {
return false
}
// OpenOptionAddHeaders adds each header found in options to the
// headers map provided the key was non empty.
func OpenOptionAddHeaders(options []OpenOption, headers map[string]string) {
for _, option := range options {
key, value := option.Header()
if key != "" && value != "" {
headers[key] = value
}
}
}
// OpenOptionHeaders adds each header found in options to the
// headers map provided the key was non empty.
//
// It returns a nil map if options was empty
func OpenOptionHeaders(options []OpenOption) (headers map[string]string) {
if len(options) == 0 {
return nil
}
headers = make(map[string]string, len(options))
OpenOptionAddHeaders(options, headers)
return headers
}
// OpenOptionAddHTTPHeaders Sets each header found in options to the
// http.Header map provided the key was non empty.
func OpenOptionAddHTTPHeaders(headers http.Header, options []OpenOption) {
for _, option := range options {
key, value := option.Header()
if key != "" && value != "" {
headers.Set(key, value)
}
}
}
// check interface
var (
_ OpenOption = (*RangeOption)(nil)
_ OpenOption = (*SeekOption)(nil)
_ OpenOption = (*HTTPOption)(nil)
)