forked from thirdweb-dev/go-sdk
/
sharded_merkle_tree.go
269 lines (225 loc) · 5.74 KB
/
sharded_merkle_tree.go
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package thirdweb
import (
"context"
"encoding/hex"
"encoding/json"
"fmt"
"reflect"
"strings"
"github.com/ethereum/go-ethereum/ethclient"
solsha3 "github.com/miguelmota/go-solidity-sha3"
"golang.org/x/crypto/sha3"
merkletree "github.com/qnfnypen/thirdweb-go-sdk/v2/merkle"
)
type ShardedMerkleTree struct {
storage storage
baseUri string
originalEntriesUri string
shardNybbles int
tokenDecimals int
shards map[string]ShardData
trees map[string]*merkletree.MerkleTree
}
func newShardedMerkleTree(
storage storage,
baseUri string,
originalEntriesUri string,
shardNybbles int,
tokenDecimals int,
) *ShardedMerkleTree {
return &ShardedMerkleTree{
storage,
baseUri,
originalEntriesUri,
shardNybbles,
tokenDecimals,
make(map[string]ShardData),
make(map[string]*merkletree.MerkleTree),
}
}
func shardedMerkleTreeFromInfo(metadata *ShardedMerkleTreeInfo, storage storage) *ShardedMerkleTree {
return newShardedMerkleTree(
storage,
metadata.BaseUri,
metadata.OriginalEntriesUri,
metadata.ShardNybbles,
metadata.TokenDecimals,
)
}
func (tree *ShardedMerkleTree) FetchAndCacheDecimals(
ctx context.Context,
cache map[string]int,
provider *ethclient.Client,
currencyAddress string,
) (int, error) {
decimals, exists := cache[currencyAddress]
if !exists {
currencyMetadata, err := fetchCurrencyMetadata(ctx, provider, currencyAddress)
if err != nil {
return 0, err
}
decimals = currencyMetadata.Decimals
cache[currencyAddress] = decimals
}
return decimals, nil
}
func (tree *ShardedMerkleTree) HashEntry(
entry *SnapshotEntry,
tokenDecimals int,
currencyDecimals int,
) (string, error) {
maxClaimable, err := convertQuantityToBigNumber(entry.MaxClaimable, tokenDecimals)
if err != nil {
return "", err
}
entryPrice := entry.Price
if entryPrice == "" {
entryPrice = "unlimited"
}
price, err := convertQuantityToBigNumber(entryPrice, currencyDecimals)
if err != nil {
return "", err
}
currencyAddress := entry.CurrencyAddress
if currencyAddress == "" {
currencyAddress = zeroAddress
}
hash := solsha3.SoliditySHA3(
[]string{"address", "uint256", "uint256", "address"},
[]interface{}{
entry.Address,
maxClaimable.String(),
price.String(),
currencyAddress,
},
)
return hex.EncodeToString(hash), nil
}
func (tree *ShardedMerkleTree) GetProof(
ctx context.Context,
address string,
provider *ethclient.Client,
) (*SnapshotEntryWithProof, error) {
shardId := strings.ToLower(address[2 : tree.shardNybbles+2])
shard, exists := tree.shards[shardId]
currencyDecimalMap := make(map[string]int)
if !exists {
var shardData ShardData
uri := tree.baseUri + `/` + shardId + `.json`
raw, err := tree.storage.Get(ctx, uri)
if err != nil {
fmt.Println("[warning] specified address is not in merkle tree")
return nil, nil
}
err = json.Unmarshal(raw, &shardData)
if err != nil {
return nil, err
}
tree.shards[shardId] = shardData
shard = tree.shards[shardId]
hashedEntries := []merkletree.DataBlock{}
for _, entry := range shard.Entries {
currencyDecimals, err := tree.FetchAndCacheDecimals(ctx, currencyDecimalMap, provider, entry.CurrencyAddress)
if err != nil {
return nil, err
}
hash, err := tree.HashEntry(&entry, tree.tokenDecimals, currencyDecimals)
if err != nil {
return nil, err
}
hashBytes, err := hex.DecodeString(hash)
if err != nil {
return nil, err
}
hashedEntries = append(hashedEntries, &MerkleNode{data: hashBytes})
}
// Define our own hash function so we can match merkletreejs
calculateHash := func(data []byte) ([]byte, error) {
// Avoid hashing the leaf nodes to match merkletreejs implementation
for _, node := range hashedEntries {
node, err := node.Serialize()
if err != nil {
return nil, err
}
if reflect.DeepEqual(node, data) {
return data, nil
}
}
h := sha3.NewLegacyKeccak256()
if _, err := h.Write(data); err != nil {
return nil, err
}
return h.Sum(nil), nil
}
if len(hashedEntries) > 1 {
config := &merkletree.Config{
Mode: merkletree.ModeProofGenAndTreeBuild,
HashFunc: calculateHash,
SortLeaves: true,
SortPairs: true,
}
merkleTree, err := merkletree.New(config, hashedEntries)
if err != nil {
return nil, err
}
tree.trees[shardId] = merkleTree
}
}
var entry *SnapshotEntry
for _, e := range shard.Entries {
if strings.ToLower(e.Address) == strings.ToLower(address) {
entry = &e
break
}
}
if entry == nil {
return nil, nil
}
currencyDecimals, err := tree.FetchAndCacheDecimals(ctx, currencyDecimalMap, provider, entry.CurrencyAddress)
if err != nil {
return nil, err
}
leaf, err := tree.HashEntry(entry, tree.tokenDecimals, currencyDecimals)
if err != nil {
return nil, err
}
leafBytes, err := hex.DecodeString(leaf)
if err != nil {
return nil, err
}
proof := [][32]byte{}
currentTree := tree.trees[shardId]
if currentTree != nil {
proofData, err := currentTree.GenerateProof(&MerkleNode{data: leafBytes})
if err != nil {
return nil, err
}
for _, p := range proofData.Siblings {
var proofItem [32]byte
copy(proofItem[:], p)
proof = append(proof, proofItem)
}
}
for _, p := range shard.Proofs {
var proofItem [32]byte
proofBytes, err := hex.DecodeString(p[2:])
if err != nil {
return nil, err
}
copy(proofItem[:], proofBytes)
proof = append(proof, proofItem)
}
return &SnapshotEntryWithProof{
Address: entry.Address,
MaxClaimable: entry.MaxClaimable,
Price: entry.Price,
CurrencyAddress: entry.CurrencyAddress,
Proof: proof,
}, nil
}
type MerkleNode struct {
data []byte
}
func (t *MerkleNode) Serialize() ([]byte, error) {
return t.data, nil
}