X-Git-Url: https://git.r.bdr.sh/rbdr/mobius/blobdiff_plain/d4c152a4dba0eec7c8ecd13732900909f51b1c97..af0e8409bd0eb3bbd97ce8d2a249344ac4d2894d:/hotline/transaction.go

diff --git a/hotline/transaction.go b/hotline/transaction.go
index 9eb8794..8d7d9ed 100644
--- a/hotline/transaction.go
+++ b/hotline/transaction.go
@@ -1,6 +1,7 @@
 package hotline
 
 import (
+	"bytes"
 	"encoding/binary"
 	"errors"
 	"fmt"
@@ -31,6 +32,7 @@ const (
 	tranNotifyChatSubject    = 119
 	tranSetChatSubject       = 120
 	tranAgreed               = 121
+	tranServerBanner         = 122
 	tranGetFileNameList      = 200
 	tranDownloadFile         = 202
 	tranUploadFile           = 203
@@ -39,10 +41,10 @@ const (
 	tranGetFileInfo          = 206
 	tranSetFileInfo          = 207
 	tranMoveFile             = 208
-	tranMakeFileAlias        = 209 // TODO: implement file alias command
+	tranMakeFileAlias        = 209
 	tranDownloadFldr         = 210
 	// tranDownloadInfo         = 211 TODO: implement file transfer queue
-	// tranDownloadBanner     = 212 TODO: figure out what this is used for
+	tranDownloadBanner     = 212
 	tranUploadFldr         = 213
 	tranGetUserNameList    = 300
 	tranNotifyChangeUser   = 301
@@ -100,53 +102,53 @@ func NewTransaction(t int, clientID *[]byte, fields ...Field) *Transaction {
 	}
 }
 
-// ReadTransaction parses a byte slice into a struct.  The input slice may be shorter or longer
-// that the transaction size depending on what was read from the network connection.
-func ReadTransaction(buf []byte) (*Transaction, int, error) {
-	totalSize := binary.BigEndian.Uint32(buf[12:16])
+// Write implements io.Writer interface for Transaction
+func (t *Transaction) Write(p []byte) (n int, err error) {
+	totalSize := binary.BigEndian.Uint32(p[12:16])
 
 	// the buf may include extra bytes that are not part of the transaction
 	// tranLen represents the length of bytes that are part of the transaction
 	tranLen := int(20 + totalSize)
 
-	if tranLen > len(buf) {
-		return nil, 0, errors.New("buflen too small for tranLen")
+	if tranLen > len(p) {
+		return n, errors.New("buflen too small for tranLen")
 	}
-	fields, err := ReadFields(buf[20:22], buf[22:tranLen])
+	fields, err := ReadFields(p[20:22], p[22:tranLen])
 	if err != nil {
-		return nil, 0, err
+		return n, err
 	}
 
-	return &Transaction{
-		Flags:      buf[0],
-		IsReply:    buf[1],
-		Type:       buf[2:4],
-		ID:         buf[4:8],
-		ErrorCode:  buf[8:12],
-		TotalSize:  buf[12:16],
-		DataSize:   buf[16:20],
-		ParamCount: buf[20:22],
-		Fields:     fields,
-	}, tranLen, nil
+	t.Flags = p[0]
+	t.IsReply = p[1]
+	t.Type = p[2:4]
+	t.ID = p[4:8]
+	t.ErrorCode = p[8:12]
+	t.TotalSize = p[12:16]
+	t.DataSize = p[16:20]
+	t.ParamCount = p[20:22]
+	t.Fields = fields
+
+	return len(p), err
 }
 
-func readTransactions(buf []byte) ([]Transaction, int, error) {
-	var transactions []Transaction
+const tranHeaderLen = 20 // fixed length of transaction fields before the variable length fields
 
-	bufLen := len(buf)
+// transactionScanner implements bufio.SplitFunc for parsing incoming byte slices into complete tokens
+func transactionScanner(data []byte, _ bool) (advance int, token []byte, err error) {
+	// The bytes that contain the size of a transaction are from 12:16, so we need at least 16 bytes
+	if len(data) < 16 {
+		return 0, nil, nil
+	}
 
-	var bytesRead = 0
-	for bytesRead < bufLen {
-		t, tReadLen, err := ReadTransaction(buf[bytesRead:])
-		if err != nil {
-			return transactions, bytesRead, err
-		}
-		bytesRead += tReadLen
+	totalSize := binary.BigEndian.Uint32(data[12:16])
 
-		transactions = append(transactions, *t)
+	// tranLen represents the length of bytes that are part of the transaction
+	tranLen := int(tranHeaderLen + totalSize)
+	if tranLen > len(data) {
+		return 0, nil, nil
 	}
 
-	return transactions, bytesRead, nil
+	return tranLen, data[0:tranLen], nil
 }
 
 const minFieldLen = 4
@@ -236,3 +238,7 @@ func (t *Transaction) GetField(id int) Field {
 
 	return Field{}
 }
+
+func (t *Transaction) IsError() bool {
+	return bytes.Equal(t.ErrorCode, []byte{0, 0, 0, 1})
+}