Make MaxMessagePayload an exported constant.

ok @davecgh

common.go

@@ -426,9 +426,9 @@ func readVarString(r io.Reader, pver uint32) (string, error) {
 	// Prevent variable length strings that are larger than the maximum
 	// message size.  It would be possible to cause memory exhaustion and
 	// panics without a sane upper bound on this count.
-	if count > maxMessagePayload {
+	if count > MaxMessagePayload {
 		str := fmt.Sprintf("variable length string is too long "+
-			"[count %d, max %d]", count, maxMessagePayload)
+			"[count %d, max %d]", count, MaxMessagePayload)
 		return "", messageError("readVarString", str)
 	}
 

internal_test.go

@@ -16,10 +16,6 @@ import (
 )
 
 const (
-	// MaxMessagePayload makes the internal maxMessagePayload constant
-	// available to the test package.
-	MaxMessagePayload uint32 = maxMessagePayload
-
 	// MaxTxPerBlock makes the internal maxTxPerBlock constant available to
 	// the test package.
 	MaxTxPerBlock = maxTxPerBlock

message.go

@@ -20,9 +20,9 @@ const MessageHeaderSize = 24
 // header.  Shorter commands must be zero padded.
 const commandSize = 12
 
-// maxMessagePayload is the maximum bytes a message can be regardless of other
+// MaxMessagePayload is the maximum bytes a message can be regardless of other
 // individual limits imposed by messages themselves.
-const maxMessagePayload = (1024 * 1024 * 32) // 32MB
+const MaxMessagePayload = (1024 * 1024 * 32) // 32MB
 
 // Commands used in bitcoin message headers which describe the type of message.
 const (
@@ -212,10 +212,10 @@ func WriteMessageN(w io.Writer, msg Message, pver uint32, btcnet BitcoinNet) (in
 	lenp := len(payload)
 
 	// Enforce maximum overall message payload.
-	if lenp > maxMessagePayload {
+	if lenp > MaxMessagePayload {
 		str := fmt.Sprintf("message payload is too large - encoded "+
 			"%d bytes, but maximum message payload is %d bytes",
-			lenp, maxMessagePayload)
+			lenp, MaxMessagePayload)
 		return totalBytes, messageError("WriteMessage", str)
 	}
 
@@ -285,10 +285,10 @@ func ReadMessageN(r io.Reader, pver uint32, btcnet BitcoinNet) (int, Message, []
 	totalBytes += n
 
 	// Enforce maximum message payload.
-	if hdr.length > maxMessagePayload {
+	if hdr.length > MaxMessagePayload {
 		str := fmt.Sprintf("message payload is too large - header "+
 			"indicates %d bytes, but max message payload is %d "+
-			"bytes.", hdr.length, maxMessagePayload)
+			"bytes.", hdr.length, MaxMessagePayload)
 		return totalBytes, nil, nil, messageError("ReadMessage", str)
 
 	}

message_test.go

@@ -197,7 +197,7 @@ func TestReadMessageWireErrors(t *testing.T) {
 
 	// Wire encoded bytes for a message that exceeds max overall message
 	// length.
-	mpl := btcwire.MaxMessagePayload
+	mpl := uint32(btcwire.MaxMessagePayload)
 	exceedMaxPayloadBytes := makeHeader(btcnet, "getaddr", mpl+1, 0)
 
 	// Wire encoded bytes for a command which is invalid utf-8.

msgalert.go

@@ -76,8 +76,8 @@ const maxSignatureSize = 72
 // maxAlertSize is the maximum size an alert.
 //
 // MessagePayload = VarInt(Alert) + Alert + VarInt(Signature) + Signature
-// maxMessagePayload = maxAlertSize + max(VarInt) + maxSignatureSize + 1
-const maxAlertSize = maxMessagePayload - maxSignatureSize - MaxVarIntPayload - 1
+// MaxMessagePayload = maxAlertSize + max(VarInt) + maxSignatureSize + 1
+const maxAlertSize = MaxMessagePayload - maxSignatureSize - MaxVarIntPayload - 1
 
 // maxCountSetCancel is the maximum number of cancel IDs that could possibly
 // fit into a maximum size alert.
@@ -343,7 +343,7 @@ type MsgAlert struct {
 func (msg *MsgAlert) BtcDecode(r io.Reader, pver uint32) error {
 	var err error
 
-	msg.SerializedPayload, err = readVarBytes(r, pver, maxMessagePayload,
+	msg.SerializedPayload, err = readVarBytes(r, pver, MaxMessagePayload,
 		"alert serialized payload")
 	if err != nil {
 		return err
@@ -354,7 +354,7 @@ func (msg *MsgAlert) BtcDecode(r io.Reader, pver uint32) error {
 		msg.Payload = nil
 	}
 
-	msg.Signature, err = readVarBytes(r, pver, maxMessagePayload,
+	msg.Signature, err = readVarBytes(r, pver, MaxMessagePayload,
 		"alert signature")
 	if err != nil {
 		return err
@@ -408,7 +408,7 @@ func (msg *MsgAlert) Command() string {
 func (msg *MsgAlert) MaxPayloadLength(pver uint32) uint32 {
 	// Since this can vary depending on the message, make it the max
 	// size allowed.
-	return maxMessagePayload
+	return MaxMessagePayload
 }
 
 // NewMsgAlert returns a new bitcoin alert message that conforms to the Message

msgreject.go

@@ -167,7 +167,7 @@ func (msg *MsgReject) MaxPayloadLength(pver uint32) uint32 {
 		// Unfortunately the bitcoin protocol does not enforce a sane
 		// limit on the length of the reason, so the max payload is the
 		// overall maximum message payload.
-		plen = maxMessagePayload
+		plen = MaxMessagePayload
 	}
 
 	return plen

msgreject_test.go

@@ -76,7 +76,7 @@ func TestRejectLatest(t *testing.T) {
 	}
 
 	// Ensure max payload is expected value for latest protocol version.
-	wantPayload := btcwire.MaxMessagePayload
+	wantPayload := uint32(btcwire.MaxMessagePayload)
 	maxPayload := msg.MaxPayloadLength(pver)
 	if maxPayload != wantPayload {
 		t.Errorf("MaxPayloadLength: wrong max payload length for "+

msgtx.go

@@ -39,7 +39,7 @@ const (
 
 	// maxTxInPerMessage is the maximum number of transactions inputs that
 	// a transaction which fits into a message could possibly have.
-	maxTxInPerMessage = (maxMessagePayload / minTxInPayload) + 1
+	maxTxInPerMessage = (MaxMessagePayload / minTxInPayload) + 1
 
 	// minTxOutPayload is the minimum payload size for a transaction output.
 	// Value 8 bytes + Varint for PkScript length 1 byte.
@@ -47,7 +47,7 @@ const (
 
 	// maxTxOutPerMessage is the maximum number of transactions outputs that
 	// a transaction which fits into a message could possibly have.
-	maxTxOutPerMessage = (maxMessagePayload / minTxOutPayload) + 1
+	maxTxOutPerMessage = (MaxMessagePayload / minTxOutPayload) + 1
 
 	// minTxPayload is the minimum payload size for a transaction.  Note
 	// that any realistically usable transaction must have at least one
@@ -470,7 +470,7 @@ func readTxIn(r io.Reader, pver uint32, version uint32, ti *TxIn) error {
 	}
 	ti.PreviousOutpoint = op
 
-	ti.SignatureScript, err = readVarBytes(r, pver, maxMessagePayload,
+	ti.SignatureScript, err = readVarBytes(r, pver, MaxMessagePayload,
 		"transaction input signature script")
 	if err != nil {
 		return err
@@ -519,7 +519,7 @@ func readTxOut(r io.Reader, pver uint32, version uint32, to *TxOut) error {
 	}
 	to.Value = int64(binary.LittleEndian.Uint64(buf[:]))
 
-	to.PkScript, err = readVarBytes(r, pver, maxMessagePayload,
+	to.PkScript, err = readVarBytes(r, pver, MaxMessagePayload,
 		"transaction output public key script")
 	if err != nil {
 		return err