rclone/vendor/github.com/ncw/go-acd/changes.go
2018-01-16 13:20:59 +00:00

86 lines
2.4 KiB
Go

package acd
import (
"encoding/json"
"io"
"net/http"
)
// ChangesService provides access to incemental changes in the Amazon Cloud Drive API.
//
// See: https://developer.amazon.com/public/apis/experience/cloud-drive/content/changes
type ChangesService struct {
client *Client
}
// A ChangeSet is collection of node changes as received from the Changes API
type ChangeSet struct {
Checkpoint string `json:"checkpoint"`
Nodes []*Node `json:"nodes"`
Reset bool `json:"reset"`
StatusCode int `json:"statusCode"`
End bool `json:"end"`
}
// ChangesOptions contains all possible arguments for the Changes API
type ChangesOptions struct {
Checkpoint string `json:"checkpoint,omitempty"`
ChunkSize int `json:"chunkSize,omitempty"`
MaxNodes int `json:"maxNodes,omitempty"`
IncludePurged bool `json:"includePurged,omitempty,string"`
}
// GetChanges returns all the changes since opts.Checkpoint
func (s *ChangesService) GetChanges(opts *ChangesOptions) ([]*ChangeSet, *http.Response, error) {
var changeSets []*ChangeSet
resp, err := s.GetChangesFunc(opts, func(cs *ChangeSet, err error) error {
if err != nil {
return err
}
changeSets = append(changeSets, cs)
return nil
})
return changeSets, resp, err
}
// GetChangesChan gets all the changes since opts.Checkpoint sending each ChangeSet to the channel.
// The provided channel is closed before returning
func (s *ChangesService) GetChangesChan(opts *ChangesOptions, ch chan<- *ChangeSet) (*http.Response, error) {
defer close(ch)
return s.GetChangesFunc(opts, func(cs *ChangeSet, err error) error {
if err != nil {
return err
}
ch <- cs
return nil
})
}
// GetChangesFunc gets all the changes since opts.Checkpoint and calls f with the ChangeSet or the error received.
// If f returns a non nil value, GetChangesFunc exits and returns the given error.
func (s *ChangesService) GetChangesFunc(opts *ChangesOptions, f func(*ChangeSet, error) error) (*http.Response, error) {
req, err := s.client.NewMetadataRequest("POST", "changes", opts)
if err != nil {
return nil, err
}
resp, err := s.client.Do(req, nil)
if err != nil {
return resp, err
}
defer resp.Body.Close()
decoder := json.NewDecoder(resp.Body)
for {
changeSet := &ChangeSet{}
err := decoder.Decode(&changeSet)
if err == io.EOF {
return resp, nil
}
err = f(changeSet, err)
if err != nil {
return resp, err
}
}
}