storj/pkg/piecestore/rpc/client/pieceranger.go
Cameron 6463b87ebe
Errcheck (#133)
* add errcheck

* fixed linter errors

* fixes

* errcheck fixes in pkg/paths

* Fix errchecks in PieceID.Derive

* Fix ecclient tests

* Move closeConn a little bit above in the exectution flow

* fix new lint errors

* Fatalf -> Printf

* address eclipsed errors

* rename err to closeErr

* rename err to closeErr for differentiation
2018-07-16 15:22:34 -04:00

74 lines
1.7 KiB
Go

// Copyright (C) 2018 Storj Labs, Inc.
// See LICENSE for copying information.
package client
import (
"bytes"
"context"
"io"
"io/ioutil"
"github.com/zeebo/errs"
"storj.io/storj/pkg/ranger"
pb "storj.io/storj/protos/piecestore"
)
// Error is the error class for pieceRanger
var Error = errs.Class("pieceRanger error")
type pieceRanger struct {
c *Client
id PieceID
size int64
}
// PieceRanger PieceRanger returns a RangeCloser from a PieceID.
func PieceRanger(ctx context.Context, c *Client, id PieceID) (ranger.RangeCloser, error) {
piece, err := c.Meta(ctx, PieceID(id))
if err != nil {
return nil, err
}
return &pieceRanger{c: c, id: id, size: piece.Size}, nil
}
// PieceRangerSize creates a PieceRanger with known size.
// Use it if you know the piece size. This will safe the extra request for
// retrieving the piece size from the piece storage.
func PieceRangerSize(c *Client, id PieceID, size int64) ranger.RangeCloser {
return &pieceRanger{c: c, id: id, size: size}
}
// Size implements Ranger.Size
func (r *pieceRanger) Size() int64 {
return r.size
}
// Size implements Ranger.Size
func (r *pieceRanger) Close() error {
return r.c.CloseConn()
}
// Range implements Ranger.Range
func (r *pieceRanger) Range(ctx context.Context, offset, length int64) (io.ReadCloser, error) {
if offset < 0 {
return nil, Error.New("negative offset")
}
if length < 0 {
return nil, Error.New("negative length")
}
if offset+length > r.size {
return nil, Error.New("range beyond end")
}
if length == 0 {
return ioutil.NopCloser(bytes.NewReader([]byte{})), nil
}
stream, err := r.c.route.Retrieve(ctx, &pb.PieceRetrieval{Id: r.id.String(), Size: length, Offset: offset})
if err != nil {
return nil, err
}
return NewStreamReader(stream), nil
}