kraken

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// Copyright (c) 2016-2019 Uber Technologies, Inc.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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//     http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package storage
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import (
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	"errors"
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	"io"
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	"github.com/uber/kraken/core"
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	"github.com/willf/bitset"
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)
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// ErrNotFound occurs when TorrentArchive cannot found a torrent.
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var ErrNotFound = errors.New("torrent not found")
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// ErrPieceComplete occurs when Torrent cannot write a piece because it is already
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// complete.
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var ErrPieceComplete = errors.New("piece is already complete")
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// PieceReader defines operations for lazy piece reading.
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type PieceReader interface {
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	io.ReadCloser
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	Length() int
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}
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// Torrent represents a read/write interface for a torrent
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type Torrent interface {
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	Digest() core.Digest
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	Stat() *TorrentInfo
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	NumPieces() int
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	Length() int64
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	PieceLength(piece int) int64
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	MaxPieceLength() int64
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	InfoHash() core.InfoHash
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	Complete() bool
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	BytesDownloaded() int64
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	Bitfield() *bitset.BitSet
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	String() string
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	HasPiece(piece int) bool
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	MissingPieces() []int
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	WritePiece(src PieceReader, piece int) error
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	GetPieceReader(piece int) (PieceReader, error)
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}
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// TorrentArchive creates and open torrent file
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type TorrentArchive interface {
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	Stat(namespace string, d core.Digest) (*TorrentInfo, error)
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	CreateTorrent(namespace string, d core.Digest) (Torrent, error)
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	GetTorrent(namespace string, d core.Digest) (Torrent, error)
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	DeleteTorrent(d core.Digest) error
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}
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