kubo/routing/routing.go
Jeromy 05b197df2d update deps for libp2p 3.4.0
License: MIT
Signed-off-by: Jeromy <why@ipfs.io>
2016-08-25 19:02:55 -07:00

106 lines
3.5 KiB
Go

// package routing defines the interface for a routing system used by ipfs.
package routing
import (
"errors"
key "github.com/ipfs/go-ipfs/blocks/key"
pstore "gx/ipfs/QmSZi9ygLohBUGyHMqE5N6eToPwqcg7bZQTULeVLFu7Q6d/go-libp2p-peerstore"
ci "gx/ipfs/QmVoi5es8D5fNHZDqoW6DgDAEPEV5hQp8GBz161vZXiwpQ/go-libp2p-crypto"
peer "gx/ipfs/QmWtbQU15LaB5B1JC2F7TV9P4K88vD3PpA4AJrwfCjhML8/go-libp2p-peer"
context "gx/ipfs/QmZy2y8t9zQH2a1b8q2ZSLKp17ATuJoCNxxyMFG5qFExpt/go-net/context"
)
// ErrNotFound is returned when a search fails to find anything
var ErrNotFound = errors.New("routing: not found")
// ContentRouting is a value provider layer of indirection. It is used to find
// information about who has what content.
type ContentRouting interface {
// Announce that this node can provide value for given key
Provide(context.Context, key.Key) error
// Search for peers who are able to provide a given key
FindProvidersAsync(context.Context, key.Key, int) <-chan pstore.PeerInfo
}
// PeerRouting is a way to find information about certain peers.
// This can be implemented by a simple lookup table, a tracking server,
// or even a DHT.
type PeerRouting interface {
// Find specific Peer
// FindPeer searches for a peer with given ID, returns a pstore.PeerInfo
// with relevant addresses.
FindPeer(context.Context, peer.ID) (pstore.PeerInfo, error)
}
type ValueStore interface {
// Basic Put/Get
// PutValue adds value corresponding to given Key.
PutValue(context.Context, key.Key, []byte) error
// GetValue searches for the value corresponding to given Key.
GetValue(context.Context, key.Key) ([]byte, error)
// GetValues searches for values corresponding to given Key.
//
// Passing a value of '0' for the count argument will cause the
// routing interface to return values only from cached or local storage
// and return an error if no cached value is found.
//
// Passing a value of '1' will return a local value if found, and query
// the network for the first value it finds otherwise.
// As a result, a value of '1' is mostly useful for cases where the record
// in question has only one valid value (such as public keys)
GetValues(c context.Context, k key.Key, count int) ([]RecvdVal, error)
}
// IpfsRouting is the combination of different routing types that ipfs
// uses. It can be satisfied by a single item (such as a DHT) or multiple
// different pieces that are more optimized to each task.
type IpfsRouting interface {
ContentRouting
PeerRouting
ValueStore
// Bootstrap allows callers to hint to the routing system to get into a
// Boostrapped state
Bootstrap(context.Context) error
// TODO expose io.Closer or plain-old Close error
}
// RecvdVal represents a dht value record that has been received from a given peer
// it is used to track peers with expired records in order to correct them.
type RecvdVal struct {
From peer.ID
Val []byte
}
type PubKeyFetcher interface {
GetPublicKey(context.Context, peer.ID) (ci.PubKey, error)
}
// KeyForPublicKey returns the key used to retrieve public keys
// from the dht.
func KeyForPublicKey(id peer.ID) key.Key {
return key.Key("/pk/" + string(id))
}
func GetPublicKey(r ValueStore, ctx context.Context, pkhash []byte) (ci.PubKey, error) {
if dht, ok := r.(PubKeyFetcher); ok {
// If we have a DHT as our routing system, use optimized fetcher
return dht.GetPublicKey(ctx, peer.ID(pkhash))
} else {
key := key.Key("/pk/" + string(pkhash))
pkval, err := r.GetValue(ctx, key)
if err != nil {
return nil, err
}
// get PublicKey from node.Data
return ci.UnmarshalPublicKey(pkval)
}
}