storage

package
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 Go to latest Published: Dec 14, 2016 License: GPL-3.0 Imports: 21 Imported by: 0

Documentation

Index

Constants

This section is empty.

Variables

View Source 
var ZeroKey = Key(common.Hash{}.Bytes())

Functions

func BytesToU64 

func BytesToU64(data []byte) uint64

func IsZeroKey 

func IsZeroKey(key Key) bool

func NewDpaChunkStore 

func NewDpaChunkStore(localStore, netStore ChunkStore) *dpaChunkStore

func U64ToBytes 

func U64ToBytes(val uint64) []byte

Types

type Chunk 

type Chunk struct {
	Key    Key            // always
	SData  []byte         // nil if request, to be supplied by dpa
	Size   int64          // size of the data covered by the subtree encoded in this chunk
	Source Peer           // peer
	C      chan bool      // to signal data delivery by the dpa
	Req    *RequestStatus // request Status needed by netStore
	// contains filtered or unexported fields
}

Chunk also serves as a request object passed to ChunkStores in case it is a retrieval request, Data is nil and Size is 0 Note that Size is not the size of the data chunk, which is Data.Size() but the size of the subtree encoded in the chunk 0 if request, to be supplied by the dpa

func NewChunk 

func NewChunk(key Key, rs *RequestStatus) *Chunk

func (*Chunk) String 

func (self *Chunk) String() string

String() for pretty printing

type ChunkStore 

type ChunkStore interface {
	Put(*Chunk) // effectively there is no error even if there is an error
	Get(Key) (*Chunk, error)
}

The ChunkStore interface is implemented by :

- MemStore: a memory cache - DbStore: local disk/db store - LocalStore: a combination (sequence of) memStore and dbStore - NetStore: cloud storage abstraction layer - DPA: local requests for swarm storage and retrieval

type Chunker 

type Chunker interface {
	Joiner
	Splitter
}

type ChunkerParams 

type ChunkerParams struct {
	Branches int64
	Hash     string
}

func NewChunkerParams 

func NewChunkerParams() *ChunkerParams

type CloudStore 

type CloudStore interface {
	Store(*Chunk)
	Deliver(*Chunk)
	Retrieve(*Chunk)
}

backend engine for cloud store It can be aggregate dispatching to several parallel implementations: bzz/network/forwarder. forwarder or IPFS or IPΞS

type DPA 

type DPA struct {
	ChunkStore

	Chunker Chunker
	// contains filtered or unexported fields
}

func NewDPA 

func NewDPA(store ChunkStore, params *ChunkerParams) *DPA

func NewLocalDPA 

func NewLocalDPA(datadir string) (*DPA, error)

for testing locally

func (*DPA) Retrieve 

func (self *DPA) Retrieve(key Key) LazySectionReader

Public API. Main entry point for document retrieval directly. Used by the FS-aware API and httpaccess Chunk retrieval blocks on netStore requests with a timeout so reader will report error if retrieval of chunks within requested range time out.

func (*DPA) Start 

func (self *DPA) Start()

func (*DPA) Stop 

func (self *DPA) Stop()

func (*DPA) Store 

func (self *DPA) Store(data io.Reader, size int64, swg *sync.WaitGroup, wwg *sync.WaitGroup) (key Key, err error)

Public API. Main entry point for document storage directly. Used by the FS-aware API and httpaccess

type DbStore 

type DbStore struct {
	// contains filtered or unexported fields
}

func NewDbStore 

func NewDbStore(path string, hash Hasher, capacity uint64, radius int) (s *DbStore, err error)

func (*DbStore) Counter 

func (s *DbStore) Counter() uint64

func (*DbStore) Get 

func (s *DbStore) Get(key Key) (chunk *Chunk, err error)

func (*DbStore) NewSyncIterator 

func (self *DbStore) NewSyncIterator(state DbSyncState) (si *dbSyncIterator, err error)

initialises a sync iterator from a syncToken (passed in with the handshake)

func (*DbStore) Put 

func (s *DbStore) Put(chunk *Chunk)

type DbSyncState 

type DbSyncState struct {
	Start, Stop Key
	First, Last uint64
}
describes a section of the DbStore representing the unsynced

domain relevant to a peer Start - Stop designate a continuous area Keys in an address space typically the addresses closer to us than to the peer but not closer another closer peer in between From - To designates a time interval typically from the last disconnect till the latest connection (real time traffic is relayed)

type Hasher 

type Hasher func() hash.Hash

func MakeHashFunc 

func MakeHashFunc(hash string) Hasher

type Joiner 

type Joiner interface {
	/*
	   Join reconstructs original content based on a root key.
	   When joining, the caller gets returned a Lazy SectionReader, which is
	   seekable and implements on-demand fetching of chunks as and where it is read.
	   New chunks to retrieve are coming to caller via the Chunk channel, which the caller provides.
	   If an error is encountered during joining, it appears as a reader error.
	   The SectionReader.
	   As a result, partial reads from a document are possible even if other parts
	   are corrupt or lost.
	   The chunks are not meant to be validated by the chunker when joining. This
	   is because it is left to the DPA to decide which sources are trusted.
	*/
	Join(key Key, chunkC chan *Chunk) LazySectionReader
}

type Key 

type Key []byte

func (Key) Hex 

func (key Key) Hex() string

func (Key) Log 

func (key Key) Log() string

func (Key) MarshalJSON 

func (key Key) MarshalJSON() (out []byte, err error)

func (Key) Size 

func (x Key) Size() uint

func (Key) String 

func (key Key) String() string

func (*Key) UnmarshalJSON 

func (key *Key) UnmarshalJSON(value []byte) error

type LDBDatabase 

type LDBDatabase struct {
	// contains filtered or unexported fields
}

func NewLDBDatabase 

func NewLDBDatabase(file string) (*LDBDatabase, error)

func (*LDBDatabase) Close 

func (self *LDBDatabase) Close()

func (*LDBDatabase) Delete 

func (self *LDBDatabase) Delete(key []byte) error

func (*LDBDatabase) Get 

func (self *LDBDatabase) Get(key []byte) ([]byte, error)

func (*LDBDatabase) LastKnownTD 

func (self *LDBDatabase) LastKnownTD() []byte

func (*LDBDatabase) NewIterator 

func (self *LDBDatabase) NewIterator() iterator.Iterator

func (*LDBDatabase) Put 

func (self *LDBDatabase) Put(key []byte, value []byte)

func (*LDBDatabase) Write 

func (self *LDBDatabase) Write(batch *leveldb.Batch) error

type LazyChunkReader 

type LazyChunkReader struct {
	// contains filtered or unexported fields
}

LazyChunkReader implements LazySectionReader

func (*LazyChunkReader) Read 

func (self *LazyChunkReader) Read(b []byte) (read int, err error)

Read keeps a cursor so cannot be called simulateously, see ReadAt

func (*LazyChunkReader) ReadAt 

func (self *LazyChunkReader) ReadAt(b []byte, off int64) (read int, err error)

read at can be called numerous times concurrent reads are allowed Size() needs to be called synchronously on the LazyChunkReader first

func (*LazyChunkReader) Seek 

func (s *LazyChunkReader) Seek(offset int64, whence int) (int64, error)

func (*LazyChunkReader) Size 

func (self *LazyChunkReader) Size(quitC chan bool) (n int64, err error)

Size is meant to be called on the LazySectionReader

type LazySectionReader 

type LazySectionReader interface {
	Size(chan bool) (int64, error)
	io.Seeker
	io.Reader
	io.ReaderAt
}

Size, Seek, Read, ReadAt

type LazyTestSectionReader 

type LazyTestSectionReader struct {
	*io.SectionReader
}

func (*LazyTestSectionReader) Size 

func (self *LazyTestSectionReader) Size(chan bool) (int64, error)

type LocalStore 

type LocalStore struct {
	DbStore ChunkStore
	// contains filtered or unexported fields
}

LocalStore is a combination of inmemory db over a disk persisted db implements a Get/Put with fallback (caching) logic using any 2 ChunkStores

func NewLocalStore 

func NewLocalStore(hash Hasher, params *StoreParams) (*LocalStore, error)

This constructor uses MemStore and DbStore as components

func (*LocalStore) Get 

func (self *LocalStore) Get(key Key) (chunk *Chunk, err error)

Get(chunk *Chunk) looks up a chunk in the local stores This method is blocking until the chunk is retrieved so additional timeout may be needed to wrap this call if ChunkStores are remote and can have long latency

func (*LocalStore) Put 

func (self *LocalStore) Put(chunk *Chunk)

LocalStore is itself a chunk store unsafe, in that the data is not integrity checked

type MemStore 

type MemStore struct {
	// contains filtered or unexported fields
}

func NewMemStore 

func NewMemStore(d *DbStore, capacity uint) (m *MemStore)

func (*MemStore) Get 

func (s *MemStore) Get(hash Key) (chunk *Chunk, err error)

func (*MemStore) Put 

func (s *MemStore) Put(entry *Chunk)

entry (not its copy) is going to be in MemStore

type NetStore 

type NetStore struct {
	// contains filtered or unexported fields
}

NetStore is a cloud storage access abstaction layer for swarm it contains the shared logic of network served chunk store/retrieval requests both local (coming from DPA api) and remote (coming from peers via bzz protocol) it implements the ChunkStore interface and embeds LocalStore

It is called by the bzz protocol instances via Depo (the store/retrieve request handler) a protocol instance is running on each peer, so this is heavily parallelised. NetStore falls back to a backend (CloudStorage interface) implemented by bzz/network/forwarder. forwarder or IPFS or IPΞS

func NewNetStore 

func NewNetStore(hash Hasher, lstore *LocalStore, cloud CloudStore, params *StoreParams) *NetStore

netstore contructor, takes path argument that is used to initialise dbStore, the persistent (disk) storage component of LocalStore the second argument is the hive, the connection/logistics manager for the node

func (*NetStore) Get 

func (self *NetStore) Get(key Key) (*Chunk, error)

retrieve logic common for local and network chunk retrieval requests

func (*NetStore) Put 

func (self *NetStore) Put(entry *Chunk)

store logic common to local and network chunk store requests ~ unsafe put in localdb no check if exists no extra copy no hash validation the chunk is forced to propagate (Cloud.Store) even if locally found! caller needs to make sure if that is wanted

type Node 

type Node struct {
	Pending  int64
	Size     uint64
	Children []common.Hash
	Last     bool
}

func (*Node) String 

func (self *Node) String() string

type Peer 

type Peer interface{}

Peer is the recorded as Source on the chunk should probably not be here? but network should wrap chunk object

type PyramidChunker 

type PyramidChunker struct {
	// contains filtered or unexported fields
}

func NewPyramidChunker 

func NewPyramidChunker(params *ChunkerParams) (self *PyramidChunker)

func (*PyramidChunker) Split 

func (self *PyramidChunker) Split(data io.Reader, size int64, chunkC chan *Chunk, swg, wwg *sync.WaitGroup) (Key, error)

type RequestStatus 

type RequestStatus struct {
	Key        Key
	Source     Peer
	C          chan bool
	Requesters map[uint64][]interface{}
}

each chunk when first requested opens a record associated with the request next time a request for the same chunk arrives, this record is updated this request status keeps track of the request ID-s as well as the requesting peers and has a channel that is closed when the chunk is retrieved. Multiple local callers can wait on this channel (or combined with a timeout, block with a select).

type Splitter 

type Splitter interface {
	/*
	   When splitting, data is given as a SectionReader, and the key is a hashSize long byte slice (Key), the root hash of the entire content will fill this once processing finishes.
	   New chunks to store are coming to caller via the chunk storage channel, which the caller provides.
	   wg is a Waitgroup (can be nil) that can be used to block until the local storage finishes
	   The caller gets returned an error channel, if an error is encountered during splitting, it is fed to errC error channel.
	   A closed error signals process completion at which point the key can be considered final if there were no errors.
	*/
	Split(io.Reader, int64, chan *Chunk, *sync.WaitGroup, *sync.WaitGroup) (Key, error)
}

Chunker is the interface to a component that is responsible for disassembling and assembling larger data and indended to be the dependency of a DPA storage system with fixed maximum chunksize.

It relies on the underlying chunking model.

When calling Split, the caller provides a channel (chan *Chunk) on which it receives chunks to store. The DPA delegates to storage layers (implementing ChunkStore interface).

Split returns an error channel, which the caller can monitor. After getting notified that all the data has been split (the error channel is closed), the caller can safely read or save the root key. Optionally it times out if not all chunks get stored or not the entire stream of data has been processed. By inspecting the errc channel the caller can check if any explicit errors (typically IO read/write failures) occured during splitting.

When calling Join with a root key, the caller gets returned a seekable lazy reader. The caller again provides a channel on which the caller receives placeholder chunks with missing data. The DPA is supposed to forward this to the chunk stores and notify the chunker if the data has been delivered (i.e. retrieved from memory cache, disk-persisted db or cloud based swarm delivery). As the seekable reader is used, the chunker then puts these together the relevant parts on demand.

type StoreParams 

type StoreParams struct {
	ChunkDbPath   string
	DbCapacity    uint64
	CacheCapacity uint
	Radius        int
}

func NewStoreParams 

func NewStoreParams(path string) (self *StoreParams)

type Task 

type Task struct {
	Index int64 // Index of the chunk being processed
	Size  uint64
	Data  []byte // Binary blob of the chunk
	Last  bool
}

type Tree 

type Tree struct {
	Chunks int64
	Levels []map[int64]*Node
	Lock   sync.RWMutex
}

type TreeChunker 

type TreeChunker struct {
	// contains filtered or unexported fields
}

func NewTreeChunker 

func NewTreeChunker(params *ChunkerParams) (self *TreeChunker)

func (*TreeChunker) Join 

func (self *TreeChunker) Join(key Key, chunkC chan *Chunk) LazySectionReader

implements the Joiner interface

func (*TreeChunker) Split 

func (self *TreeChunker) Split(data io.Reader, size int64, chunkC chan *Chunk, swg, wwg *sync.WaitGroup) (Key, error)

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