txsort: Convert to package

This converts the txsort code into a separate package and renames
'TxSort' and 'IsTxSorted' to 'Sort' an `IsSorted`, respectively.

It also adds a 'doc.go' and 'README.md' so it is consistent with the
other packages.

txsort/README.md

@@ -0,0 +1,44 @@
+txsort
+======
+
+[![Build Status](http://img.shields.io/travis/btcsuite/btcutil.svg)]
+(https://travis-ci.org/btcsuite/btcutil) [![ISC License]
+(http://img.shields.io/badge/license-ISC-blue.svg)](http://copyfree.org)
+
+Package txsort provides the transaction sorting according to BIPLI01.
+
+BIPLI01 defines a standard lexicographical sort order of transaction inputs and
+outputs.  This is useful to standardize transactions for faster multi-party
+agreement as well as preventing information leaks in a single-party use case.
+
+The BIP goes into more detail, but for a quick and simplistic overview, the
+order for inputs is defined as first sorting on the previous output hash and
+then on the index as a tie breaker.  The order for outputs is defined as first
+sorting on the amount and then on the raw public key script bytes as a tie
+breaker.
+
+A comprehensive suite of tests is provided to ensure proper functionality.
+
+## Documentation
+
+[![GoDoc](https://img.shields.io/badge/godoc-reference-blue.svg)]
+(http://godoc.org/github.com/btcsuite/btcutil/txsort)
+
+Full `go doc` style documentation for the project can be viewed online without
+installing this package by using the GoDoc site here:
+http://godoc.org/github.com/btcsuite/btcutil/txsort
+
+You can also view the documentation locally once the package is installed with
+the `godoc` tool by running `godoc -http=":6060"` and pointing your browser to
+http://localhost:6060/pkg/github.com/btcsuite/btcutil/txsort
+
+## Installation and Updating
+
+```bash
+$ go get -u github.com/btcsuite/btcutil/txsort
+```
+
+## License
+
+Package txsort is licensed under the [copyfree](http://copyfree.org) ISC
+License.

txsort/doc.go

@@ -0,0 +1,20 @@
+// Copyright (c) 2015 The btcsuite developers
+// Use of this source code is governed by an ISC
+// license that can be found in the LICENSE file.
+
+/*
+Package txsort provides the transaction sorting according to BIPLI01.
+
+Overview
+
+BIPLI01 defines a standard lexicographical sort order of transaction inputs and
+outputs.  This is useful to standardize transactions for faster multi-party
+agreement as well as preventing information leaks in a single-party use case.
+
+The BIP goes into more detail, but for a quick and simplistic overview, the
+order for inputs is defined as first sorting on the previous output hash and
+then on the index as a tie breaker.  The order for outputs is defined as first
+sorting on the amount and then on the raw public key script bytes as a tie
+breaker.
+*/
+package txsort

txsort/txsort.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by an ISC
 // license that can be found in the LICENSE file.
 
-package btcutil
+package txsort
 
 import (
 	"bytes"
@@ -15,19 +15,19 @@ import (
 // Provides functions for sorting tx inputs and outputs according to BIP LI01
 // (https://github.com/kristovatlas/rfc/blob/master/bips/bip-li01.mediawiki)
 
-// TxSort sorts the inputs and outputs of a tx based on BIP LI01
+// Sort sorts the inputs and outputs of a tx based on BIP LI01
 // It does not modify the transaction given, but returns a new copy
 // which has been sorted and may have a different txid.
-func TxSort(tx *wire.MsgTx) *wire.MsgTx {
+func Sort(tx *wire.MsgTx) *wire.MsgTx {
 	txCopy := tx.Copy()
 	sort.Sort(sortableInputSlice(txCopy.TxIn))
 	sort.Sort(sortableOutputSlice(txCopy.TxOut))
 	return txCopy
 }
 
-// TxIsSorted checks whether tx has inputs and outputs sorted according
+// IsSorted checks whether tx has inputs and outputs sorted according
 // to BIP LI01.
-func TxIsSorted(tx *wire.MsgTx) bool {
+func IsSorted(tx *wire.MsgTx) bool {
 	if !sort.IsSorted(sortableInputSlice(tx.TxIn)) {
 		return false
 	}

txsort/txsort_test.go

@@ -2,7 +2,7 @@
 // Use of this source code is governed by an ISC
 // license that can be found in the LICENSE file.
 
-package btcutil_test
+package txsort_test
 
 import (
 	"bytes"
@@ -10,26 +10,11 @@ import (
 	"testing"
 
 	"github.com/btcsuite/btcd/wire"
-	"github.com/btcsuite/btcutil"
+	"github.com/btcsuite/btcutil/txsort"
 )
 
-// TestSortTx tests SortTx function
-func TestSortTx(t *testing.T) {
-	//	 Use block 100,000 transaction 1.  Already sorted.
-	testTx := Block100000.Transactions[1]
-	sortedTx := btcutil.TxSort(testTx)
-
-	testTxid := testTx.TxSha()
-	sortedTxid := sortedTx.TxSha()
-	if !testTxid.IsEqual(&sortedTxid) {
-		t.Errorf("Sorted TxSha mismatch - got %v, want %v",
-			testTxid.String(), sortedTxid.String())
-	}
-	if !btcutil.TxIsSorted(testTx) {
-		t.Errorf("testTx %v is sorted but reported as unsorted",
-			testTxid.String())
-	}
-
+// TestSort tests Sort function
+func TestSort(t *testing.T) {
 	// Example 1 0a6a357e2f7796444e02638749d9611c008b253fb55f5dc88b739b230ed0c4c3
 	// test transaction 0a6a357e... which is the first test case of BIPLI01
 	li01Tx1bytes, err := hex.DecodeString(LI01Hex1)
@@ -43,11 +28,11 @@ func TestSortTx(t *testing.T) {
 		t.Errorf("Failed to Deserialize li01Tx from byte slice")
 	}
 
-	if btcutil.TxIsSorted(&li01Tx1) {
+	if txsort.IsSorted(&li01Tx1) {
 		t.Errorf("LI01 Test Transaction 1 seen as sorted, but isn't")
 	}
 
-	li01Tx1Sorted := btcutil.TxSort(&li01Tx1)
+	li01Tx1Sorted := txsort.Sort(&li01Tx1)
 	// txid of 0a6a357e... becomes 839503c... when sorted
 	wantSha := newShaHashFromStr("839503cb611a3e3734bd521c608f881be2293ff77b7384057ab994c794fce623")
 
@@ -78,11 +63,11 @@ func TestSortTx(t *testing.T) {
 	if err != nil {
 		t.Errorf("Failed to Deserialize li01Tx from byte slice")
 	}
-	if !btcutil.TxIsSorted(&li01Tx2) {
+	if !txsort.IsSorted(&li01Tx2) {
 		t.Errorf("LI01 Test Transaction 2 seen as unsorted, but it is sorted")
 	}
 
-	li01Tx2Sorted := btcutil.TxSort(&li01Tx2)
+	li01Tx2Sorted := txsort.Sort(&li01Tx2)
 
 	// txid of 28204cad... stays the same when sorted
 	wantSha = newShaHashFromStr("28204cad1d7fc1d199e8ef4fa22f182de6258a3eaafe1bbe56ebdcacd3069a5f")
@@ -104,11 +89,11 @@ func TestSortTx(t *testing.T) {
 	if err != nil {
 		t.Errorf("Failed to Deserialize li01Tx3 from byte slice")
 	}
-	if btcutil.TxIsSorted(&li01Tx3) {
+	if txsort.IsSorted(&li01Tx3) {
 		t.Errorf("LI01 Test Transaction 3 seen as sorted, but isn't")
 	}
 
-	li01Tx3Sorted := btcutil.TxSort(&li01Tx3)
+	li01Tx3Sorted := txsort.Sort(&li01Tx3)
 
 	// txid of 8131ffb0... changes to 0a8c246... when sorted
 	wantSha = newShaHashFromStr("0a8c246c55f6b82f094d211f4f57167bf2ea4898741d218b09bdb2536fd8d13f")
@@ -130,11 +115,11 @@ func TestSortTx(t *testing.T) {
 	if err != nil {
 		t.Errorf("Failed to Deserialize li01Tx4 from byte slice")
 	}
-	if btcutil.TxIsSorted(&li01Tx4) {
+	if txsort.IsSorted(&li01Tx4) {
 		t.Errorf("LI01 Test Transaction 4 seen as sorted, but isn't")
 	}
 
-	li01Tx4Sorted := btcutil.TxSort(&li01Tx4)
+	li01Tx4Sorted := txsort.Sort(&li01Tx4)
 
 	// txid of 8131ffb0... changes to 0a8c246... when sorted
 	wantSha = newShaHashFromStr("a3196553b928b0b6154b002fa9a1ce875adabc486fedaaaf4c17430fd4486329")
@@ -156,11 +141,11 @@ func TestSortTx(t *testing.T) {
 	if err != nil {
 		t.Errorf("Failed to Deserialize li01Tx5 from byte slice")
 	}
-	if btcutil.TxIsSorted(&li01Tx5) {
+	if txsort.IsSorted(&li01Tx5) {
 		t.Errorf("LI01 Test Transaction 5 seen as sorted, but isn't")
 	}
 
-	li01Tx5Sorted := btcutil.TxSort(&li01Tx5)
+	li01Tx5Sorted := txsort.Sort(&li01Tx5)
 
 	// txid of ff85e8f... changes to 9a6c247... when sorted
 	wantSha = newShaHashFromStr("9a6c24746de024f77cac9b2138694f11101d1c66289261224ca52a25155a7c94")