gridfs

Documentation

Index

• Constants
• Variables
• type Bucket
  • func NewBucket(db *mongo.Database, opts ...*options.BucketOptions) (*Bucket, error)
  • func (b *Bucket) Delete(fileID primitive.ObjectID) error
  • func (b *Bucket) DownloadToStream(fileID primitive.ObjectID, stream io.Writer) (int64, error)
  • func (b *Bucket) DownloadToStreamByName(filename string, stream io.Writer, opts ...*options.NameOptions) (int64, error)
  • func (b *Bucket) Drop() error
  • func (b *Bucket) Find(filter interface{}, opts ...*options.GridFSFindOptions) (*mongo.Cursor, error)
  • func (b *Bucket) OpenDownloadStream(fileID primitive.ObjectID) (*DownloadStream, error)
  • func (b *Bucket) OpenDownloadStreamByName(filename string, opts ...*options.NameOptions) (*DownloadStream, error)
  • func (b *Bucket) OpenUploadStream(filename string, opts ...*options.UploadOptions) (*UploadStream, error)
  • func (b *Bucket) OpenUploadStreamWithID(fileID primitive.ObjectID, filename string, opts ...*options.UploadOptions) (*UploadStream, error)
  • func (b *Bucket) Rename(fileID primitive.ObjectID, newFilename string) error
  • func (b *Bucket) SetReadDeadline(t time.Time) error
  • func (b *Bucket) SetWriteDeadline(t time.Time) error
  • func (b *Bucket) UploadFromStream(filename string, source io.Reader, opts ...*options.UploadOptions) (primitive.ObjectID, error)
  • func (b *Bucket) UploadFromStreamWithID(fileID primitive.ObjectID, filename string, source io.Reader, ...) error
• type DownloadStream
  • func (ds *DownloadStream) Close() error
  • func (ds *DownloadStream) Read(p []byte) (int, error)
  • func (ds *DownloadStream) SetReadDeadline(t time.Time) error
  • func (ds *DownloadStream) Skip(skip int64) (int64, error)
• type Upload
• type UploadStream
  • func (us *UploadStream) Abort() error
  • func (us *UploadStream) Close() error
  • func (us *UploadStream) SetWriteDeadline(t time.Time) error
  • func (us *UploadStream) Write(p []byte) (int, error)

Constants

const DefaultChunkSize int32 = 255 * 1000 // 255 KB

DefaultChunkSize is the default size of each file chunk.

const UploadBufferSize = 16 * 1000000 // 16 MB

UploadBufferSize is the size in bytes of one stream batch. Chunks will be written to the db after the sum of chunk lengths is equal to the batch size.

Variables

var ErrFileNotFound = errors.New("file with given parameters not found")

ErrFileNotFound occurs if a user asks to download a file with a file ID that isn't found in the files collection.

var ErrStreamClosed = errors.New("stream is closed or aborted")

ErrStreamClosed is an error returned if an operation is attempted on a closed/aborted stream.

var ErrWrongIndex = errors.New("chunk index does not match expected index")

ErrWrongIndex is used when the chunk retrieved from the server does not have the expected index.

var ErrWrongSize = errors.New("chunk size does not match expected size")

ErrWrongSize is used when the chunk retrieved from the server does not have the expected size.

Types

type Bucket

type Bucket struct {
	// contains filtered or unexported fields
}

Bucket represents a GridFS bucket.

func NewBucket

func NewBucket(db *mongo.Database, opts ...*options.BucketOptions) (*Bucket, error)

NewBucket creates a GridFS bucket.

func (*Bucket) Delete

func (b *Bucket) Delete(fileID primitive.ObjectID) error

Delete deletes all chunks and metadata associated with the file with the given file ID.

func (*Bucket) DownloadToStream

func (b *Bucket) DownloadToStream(fileID primitive.ObjectID, stream io.Writer) (int64, error)

DownloadToStream downloads the file with the specified fileID and writes it to the provided io.Writer. Returns the number of bytes written to the steam and an error, or nil if there was no error.

func (*Bucket) DownloadToStreamByName

func (b *Bucket) DownloadToStreamByName(filename string, stream io.Writer, opts ...*options.NameOptions) (int64, error)

DownloadToStreamByName downloads the file with the given name to the given io.Writer.

func (*Bucket) Drop

func (b *Bucket) Drop() error

Drop drops the files and chunks collections associated with this bucket.

func (*Bucket) Find

func (b *Bucket) Find(filter interface{}, opts ...*options.GridFSFindOptions) (*mongo.Cursor, error)

Find returns the files collection documents that match the given filter.

func (*Bucket) OpenDownloadStream

func (b *Bucket) OpenDownloadStream(fileID primitive.ObjectID) (*DownloadStream, error)

OpenDownloadStream creates a stream from which the contents of the file can be read.

func (*Bucket) OpenDownloadStreamByName

func (b *Bucket) OpenDownloadStreamByName(filename string, opts ...*options.NameOptions) (*DownloadStream, error)

OpenDownloadStreamByName opens a download stream for the file with the given filename.

func (*Bucket) OpenUploadStream

func (b *Bucket) OpenUploadStream(filename string, opts ...*options.UploadOptions) (*UploadStream, error)

OpenUploadStream creates a file ID new upload stream for a file given the filename.

func (*Bucket) OpenUploadStreamWithID

func (b *Bucket) OpenUploadStreamWithID(fileID primitive.ObjectID, filename string, opts ...*options.UploadOptions) (*UploadStream, error)

OpenUploadStreamWithID creates a new upload stream for a file given the file ID and filename.

func (*Bucket) Rename

func (b *Bucket) Rename(fileID primitive.ObjectID, newFilename string) error

Rename renames the stored file with the specified file ID.

func (*Bucket) SetReadDeadline

func (b *Bucket) SetReadDeadline(t time.Time) error

SetReadDeadline sets the read deadline for this bucket

func (*Bucket) SetWriteDeadline

func (b *Bucket) SetWriteDeadline(t time.Time) error

SetWriteDeadline sets the write deadline for this bucket.

func (*Bucket) UploadFromStream

func (b *Bucket) UploadFromStream(filename string, source io.Reader, opts ...*options.UploadOptions) (primitive.ObjectID, error)

UploadFromStream creates a fileID and uploads a file given a source stream.

func (*Bucket) UploadFromStreamWithID

func (b *Bucket) UploadFromStreamWithID(fileID primitive.ObjectID, filename string, source io.Reader, opts ...*options.UploadOptions) error

UploadFromStreamWithID uploads a file given a source stream.

type DownloadStream

type DownloadStream struct {
	// contains filtered or unexported fields
}

DownloadStream is a io.Reader that can be used to download a file from a GridFS bucket.

func (*DownloadStream) Close

func (ds *DownloadStream) Close() error

Close closes this download stream.

func (*DownloadStream) Read

func (ds *DownloadStream) Read(p []byte) (int, error)

Read reads the file from the server and writes it to a destination byte slice.

func (*DownloadStream) SetReadDeadline

func (ds *DownloadStream) SetReadDeadline(t time.Time) error

SetReadDeadline sets the read deadline for this download stream.

func (*DownloadStream) Skip

func (ds *DownloadStream) Skip(skip int64) (int64, error)

Skip skips a given number of bytes in the file.

type Upload

type Upload struct {
	// contains filtered or unexported fields
}

Upload contains options to upload a file to a bucket.

type UploadStream

type UploadStream struct {
	*Upload // chunk size and metadata
	FileID  primitive.ObjectID
	// contains filtered or unexported fields
}

UploadStream is used to upload files in chunks.

func (*UploadStream) Abort

func (us *UploadStream) Abort() error

Abort closes the stream and deletes all file chunks that have already been written.

func (*UploadStream) Close

func (us *UploadStream) Close() error

Close closes this upload stream.

func (*UploadStream) SetWriteDeadline

func (us *UploadStream) SetWriteDeadline(t time.Time) error

SetWriteDeadline sets the write deadline for this stream.

func (*UploadStream) Write

func (us *UploadStream) Write(p []byte) (int, error)

Write transfers the contents of a byte slice into this upload stream. If the stream's underlying buffer fills up, the buffer will be uploaded as chunks to the server. Implements the io.Writer interface.