lbcd/blockheader_test.go
Dave Collins 144822d4bf Remove BlockHeader.TxnCount field.
This commit removes the TxnCount field from the BlockHeader type and
updates the tests accordingly.  Note that this change does not affect the
actual wire protocol encoding in any way.

The reason the field has been removed is it really doesn't belong there
even though the wire protocol wiki entry on the official bitcoin wiki
implies it does.  The implication is an artifact from the way the
reference implementation serializes headers (MsgHeaders) messages.  It
includes the transaction count, which is naturally always 0 for headers,
along with every header.  However, in reality, a block header does not
include the transaction count.  This can be evidenced by looking at how a
block hash is calculated.  It is only up to and including the Nonce field
(a total of 80 bytes).

From an API standpoint, having the field as part of the BlockHeader type
results in several odd cases.

For example, the transaction count for MsgBlocks (the only place that
actually has a real transaction count since MsgHeaders does not) is
available by taking the len of the Transactions slice.  As such, having
the extra field in the BlockHeader is really a useless field that could
potentially get out of sync and cause the encode to fail.

Another example is related to deserializing a block header from the
database in order to serve it in response to a getheaders (MsgGetheaders)
request.  If a block header is assumed to have the transaction count as a
part of it, then derserializing a block header not only consumes more than
the 80 bytes that actually comprise the header as stated above, but you
then need to change the transaction count to 0 before sending the headers
(MsgHeaders) message.  So, not only are you reading and deserializing more
bytes than needed, but worse, you generally have to make a copy of it so
you can change the transaction count without busting cached headers.

This is part 1 of #13.
2014-01-18 20:53:20 -06:00

158 lines
4.2 KiB
Go

// Copyright (c) 2013-2014 Conformal Systems LLC.
// Use of this source code is governed by an ISC
// license that can be found in the LICENSE file.
package btcwire_test
import (
"bytes"
"github.com/conformal/btcwire"
"github.com/davecgh/go-spew/spew"
"reflect"
"testing"
"time"
)
// TestBlockHeader tests the BlockHeader API.
func TestBlockHeader(t *testing.T) {
nonce64, err := btcwire.RandomUint64()
if err != nil {
t.Errorf("RandomUint64: Error generating nonce: %v", err)
}
nonce := uint32(nonce64)
hash := btcwire.GenesisHash
merkleHash := btcwire.GenesisMerkleRoot
bits := uint32(0x1d00ffff)
bh := btcwire.NewBlockHeader(&hash, &merkleHash, bits, nonce)
// Ensure we get the same data back out.
if !bh.PrevBlock.IsEqual(&hash) {
t.Errorf("NewBlockHeader: wrong prev hash - got %v, want %v",
spew.Sprint(bh.PrevBlock), spew.Sprint(hash))
}
if !bh.MerkleRoot.IsEqual(&merkleHash) {
t.Errorf("NewBlockHeader: wrong merkle root - got %v, want %v",
spew.Sprint(bh.MerkleRoot), spew.Sprint(merkleHash))
}
if bh.Bits != bits {
t.Errorf("NewBlockHeader: wrong bits - got %v, want %v",
bh.Bits, bits)
}
if bh.Nonce != nonce {
t.Errorf("NewBlockHeader: wrong nonce - got %v, want %v",
bh.Nonce, nonce)
}
}
// TestBlockHeaderWire tests the BlockHeader wire encode and decode for various
// protocol versions.
func TestBlockHeaderWire(t *testing.T) {
nonce := uint32(123123) // 0x1e0f3
// baseBlockHdr is used in the various tests as a baseline BlockHeader.
hash := btcwire.GenesisHash
merkleHash := btcwire.GenesisMerkleRoot
bits := uint32(0x1d00ffff)
baseBlockHdr := &btcwire.BlockHeader{
Version: 1,
PrevBlock: hash,
MerkleRoot: merkleHash,
Timestamp: time.Unix(0x495fab29, 0), // 2009-01-03 12:15:05 -0600 CST
Bits: bits,
Nonce: nonce,
}
// baseBlockHdrEncoded is the wire encoded bytes of baseBlockHdr.
baseBlockHdrEncoded := []byte{
0x01, 0x00, 0x00, 0x00, // Version 1
0x6f, 0xe2, 0x8c, 0x0a, 0xb6, 0xf1, 0xb3, 0x72,
0xc1, 0xa6, 0xa2, 0x46, 0xae, 0x63, 0xf7, 0x4f,
0x93, 0x1e, 0x83, 0x65, 0xe1, 0x5a, 0x08, 0x9c,
0x68, 0xd6, 0x19, 0x00, 0x00, 0x00, 0x00, 0x00, // PrevBlock
0x3b, 0xa3, 0xed, 0xfd, 0x7a, 0x7b, 0x12, 0xb2,
0x7a, 0xc7, 0x2c, 0x3e, 0x67, 0x76, 0x8f, 0x61,
0x7f, 0xc8, 0x1b, 0xc3, 0x88, 0x8a, 0x51, 0x32,
0x3a, 0x9f, 0xb8, 0xaa, 0x4b, 0x1e, 0x5e, 0x4a, // MerkleRoot
0x29, 0xab, 0x5f, 0x49, // Timestamp
0xff, 0xff, 0x00, 0x1d, // Bits
0xf3, 0xe0, 0x01, 0x00, // Nonce
}
tests := []struct {
in *btcwire.BlockHeader // Data to encode
out *btcwire.BlockHeader // Expected decoded data
buf []byte // Wire encoding
pver uint32 // Protocol version for wire encoding
}{
// Latest protocol version.
{
baseBlockHdr,
baseBlockHdr,
baseBlockHdrEncoded,
btcwire.ProtocolVersion,
},
// Protocol version BIP0035Version.
{
baseBlockHdr,
baseBlockHdr,
baseBlockHdrEncoded,
btcwire.BIP0035Version,
},
// Protocol version BIP0031Version.
{
baseBlockHdr,
baseBlockHdr,
baseBlockHdrEncoded,
btcwire.BIP0031Version,
},
// Protocol version NetAddressTimeVersion.
{
baseBlockHdr,
baseBlockHdr,
baseBlockHdrEncoded,
btcwire.NetAddressTimeVersion,
},
// Protocol version MultipleAddressVersion.
{
baseBlockHdr,
baseBlockHdr,
baseBlockHdrEncoded,
btcwire.MultipleAddressVersion,
},
}
t.Logf("Running %d tests", len(tests))
for i, test := range tests {
// Encode to wire format.
var buf bytes.Buffer
err := btcwire.TstWriteBlockHeader(&buf, test.pver, test.in)
if err != nil {
t.Errorf("writeBlockHeader #%d error %v", i, err)
continue
}
if !bytes.Equal(buf.Bytes(), test.buf) {
t.Errorf("writeBlockHeader #%d\n got: %s want: %s", i,
spew.Sdump(buf.Bytes()), spew.Sdump(test.buf))
continue
}
// Decode the block header from wire format.
var bh btcwire.BlockHeader
rbuf := bytes.NewBuffer(test.buf)
err = btcwire.TstReadBlockHeader(rbuf, test.pver, &bh)
if err != nil {
t.Errorf("readBlockHeader #%d error %v", i, err)
continue
}
if !reflect.DeepEqual(&bh, test.out) {
t.Errorf("readBlockHeader #%d\n got: %s want: %s", i,
spew.Sdump(&bh), spew.Sdump(test.out))
continue
}
}
}