snapshot.go

snapshot.go

package types

import "fmt"

const ManifestVersion int32 = 0

type SHA256Sum [32]byte	// check sum of chunk

func (hsum SHA256Sum) String() string {
	return fmt.Sprintf("%X", hsum)
}

type Manifest struct {
	Version int32 // snapshot Version

	Height         int64       // the height of this snapshot
	StateHashes    []SHA256Sum // hashes of state chunks
	AppStateHashes []SHA256Sum // hashes of app state chunks
	BlockHashes    []SHA256Sum // Block hashes
	NumKeys        []int64     // num of keys for each substore, this sacrifices clear boundary between cosmos and tendermint, saying tendermint knows applicaction db might organized by substores. But reduce network/disk pressure that each chunk must has a field indicates what's his store
}

func NewManifest(
	height int64,
	stateHashes []SHA256Sum,
	appStateHashes []SHA256Sum,
	blockHashes []SHA256Sum,
	numKeys []int64) Manifest {
	return Manifest {
		ManifestVersion,
		height,
		stateHashes,
		appStateHashes,
		blockHashes,
		numKeys,
	}
}

func (m *Manifest) Serialize() []byte {
	// encode to amino bytes
	// snappy compression
	return nil
}

type SnapshotChunk interface{}

type StateChunk struct {
	statepart []byte
}

type AppStateChunk struct {
	startIdx int64	// compare (startIdx and number of complete nodes) against (Manifest.NumKeys) we know each node's substore
	complete bool	// whether last node in `nodes` is complete, if not we concatenate bytes with following chunks first node
	nodes [][]byte // iavl tree serialized node, one big node (i.e. active orders and orderbook) might be split into different chunks (complete is flag to indicate that), ordering is ensured by list on manifest
}

type BlockChunk struct {
	blockpart []byte
}