tusd/datastore.go

72 lines
3.2 KiB
Go

package tusd
import (
"io"
)
type MetaData map[string]string
type FileInfo struct {
ID string
// Total file size in bytes specified in the NewUpload call
Size int64
// Offset in bytes (zero-based)
Offset int64
MetaData MetaData
// Indicates that this is a partial upload which will later be used to form
// a final upload by concatenation. Partial uploads should not be processed
// when they are finished since they are only incomplete chunks of files.
IsPartial bool
// Indicates that this is a final upload
IsFinal bool
// If the upload is a final one (see IsFinal) this will be a non-empty
// ordered slice containing the ids of the uploads of which the final upload
// will consist after concatenation.
PartialUploads []string
// Indicates that a write operation is currently pending for this file.
// This field is not needed to implement the tus specification.
// Implementations of tusd.DataStore may use this to prevent write
// collisions or race conditions.
Locked bool
}
type DataStore interface {
// Create a new upload using the size as the file's length. The method must
// return an unique id which is used to identify the upload. If no backend
// (e.g. Riak) specifes the id you may want to use the uid package to
// generate one. The properties Size and MetaData will be filled.
NewUpload(info FileInfo) (id string, err error)
// Write the chunk read from src into the file specified by the id at the
// given offset. The handler will take care of validating the offset and
// limiting the size of the src to not overflow the file's size. It may
// return an os.ErrNotExist which will be interpretet as a 404 Not Found.
// It will also lock resources while they are written to ensure only one
// write happens per time.
// The function call must return the number of bytes written.
WriteChunk(id string, offset int64, src io.Reader) (int64, error)
// Read the fileinformation used to validate the offset and respond to HEAD
// requests. It may return an os.ErrNotExist which will be interpretet as a
// 404 Not Found.
GetInfo(id string) (FileInfo, error)
// Get an io.Reader to allow downloading the file. This feature is not
// part of the official tus specification. If this additional function
// should not be enabled any call to GetReader should return
// tusd.ErrNotImplemented. The length of the resource is determined by
// retrieving the offset using GetInfo.
// If the returned reader also implements the io.Closer interface, the
// Close() method will be invoked once everything has been read.
GetReader(id string) (io.Reader, error)
// Terminate an upload so any further requests to the resource, both reading
// and writing, must return os.ErrNotExist or similar.
Terminate(id string) error
// Lock the upload file for writing. This feature is not part of the
// official TUS specification. Handlers should call this prior to writing
// chunks or terminating files. Returns true if the file lock has been
// acquired.
LockFile(id string) (bool, error)
// Unlock the upload file for writing. This feature is not part of the
// official TUS specification. Handlers should defer calls to this after
// acquiring a lock.
UnlockFile(id string) error
}