73 lines
1.7 KiB
Go
73 lines
1.7 KiB
Go
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// 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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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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}
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// PieceRanger PieceRanger returns a RangeCloser from a PieceID.
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func PieceRanger(ctx context.Context, c *Client, id PieceID) (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}, 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, id PieceID, size int64) ranger.RangeCloser {
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return &pieceRanger{c: c, id: id, size: size}
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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.CloseConn()
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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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stream, err := r.c.route.Retrieve(ctx, &pb.PieceRetrieval{Id: r.id.String(), Size: length, Offset: offset})
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if err != nil {
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return nil, err
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}
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return NewStreamReader(stream), nil
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}
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