62 lines
1.5 KiB
Go
62 lines
1.5 KiB
Go
// Copyright (C) 2018 Storj Labs, Inc.
|
|
// See LICENSE for copying information.
|
|
|
|
package ranger
|
|
|
|
import (
|
|
"bytes"
|
|
"context"
|
|
"io"
|
|
"io/ioutil"
|
|
|
|
"storj.io/storj/pkg/piecestore/rpc/client"
|
|
)
|
|
|
|
type grpcRanger struct {
|
|
c *client.Client
|
|
id string
|
|
size int64
|
|
}
|
|
|
|
// GRPCRanger turns a gRPC connection to piece store into a Ranger
|
|
func GRPCRanger(ctx context.Context, c *client.Client, id string) (Ranger, error) {
|
|
piece, err := c.PieceMetaRequest(ctx, id)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return &grpcRanger{c: c, id: id, size: piece.Size}, nil
|
|
}
|
|
|
|
// GRPCRangerSize creates a GRPCRanger 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 GRPCRangerSize(c *client.Client, id string, size int64) Ranger {
|
|
return &grpcRanger{c: c, id: id, size: size}
|
|
}
|
|
|
|
// Size implements Ranger.Size
|
|
func (r *grpcRanger) Size() int64 {
|
|
return r.size
|
|
}
|
|
|
|
// Range implements Ranger.Range
|
|
func (r *grpcRanger) 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
|
|
}
|
|
reader, err := r.c.RetrievePieceRequest(ctx, r.id, offset, length)
|
|
if err != nil {
|
|
return nil, Error.Wrap(err)
|
|
}
|
|
return reader, nil
|
|
}
|