lbcutil/bloom/example_test.go
2021-09-10 16:37:45 -04:00

45 lines
1.3 KiB
Go

// Copyright (c) 2014-2016 The btcsuite developers
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.
package bloom_test
import (
"fmt"
"math/rand"
"time"
"github.com/lbryio/lbcd/chaincfg/chainhash"
"github.com/lbryio/lbcd/wire"
"github.com/lbryio/lbcutil/bloom"
)
// This example demonstrates how to create a new bloom filter, add a transaction
// hash to it, and check if the filter matches the transaction.
func ExampleNewFilter() {
rand.Seed(time.Now().UnixNano())
tweak := rand.Uint32()
// Create a new bloom filter intended to hold 10 elements with a 0.01%
// false positive rate and does not include any automatic update
// functionality when transactions are matched.
filter := bloom.NewFilter(10, tweak, 0.0001, wire.BloomUpdateNone)
// Create a transaction hash and add it to the filter. This particular
// trasaction is the first transaction in block 310,000 of the main
// bitcoin block chain.
txHashStr := "fd611c56ca0d378cdcd16244b45c2ba9588da3adac367c4ef43e808b280b8a45"
txHash, err := chainhash.NewHashFromStr(txHashStr)
if err != nil {
fmt.Println(err)
return
}
filter.AddHash(txHash)
// Show that the filter matches.
matches := filter.Matches(txHash[:])
fmt.Println("Filter Matches?:", matches)
// Output:
// Filter Matches?: true
}