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