Fix the rest of pdu tests

It wasn't reusing buffers, idiot idiot idiot...

main.go

@@ -136,6 +136,7 @@ func main() {
 	// 		go handleConnection(conn)
 	// 	}
 	// }()
+	log.Println(createSubmitSMPDU())
 
 	wg := &sync.WaitGroup{}
 	wg.Add(1)

pdu/bind.go

@@ -6,15 +6,15 @@ type (
 		system_id         string
 		password          string
 		system_type       string
-		interface_version uint8
-		addr_ton          uint8
-		addr_npi          uint8
+		interface_version byte
+		addr_ton          byte
+		addr_npi          byte
 		address_range     string
 	}
 	BIND_RESP struct {
 		header               PDU_HEADER
 		system_id            string
-		sc_interface_version uint8
+		sc_interface_version byte
 	}
 	BIND_RECVEIVER struct {
 		BIND

pdu/bufpool.go

@@ -1,21 +1,30 @@
 package pdu
 
 import (
+	"bytes"
+	"log"
 	"sync"
 )
 
 type BufferPoolManager struct {
-	pools map[uint]*sync.Pool
+	pools map[int]*sync.Pool
 	mu    sync.RWMutex
+	debug bool
+}
+
+func (bpm *BufferPoolManager) logf(format string, args ...interface{}) {
+	if bpm.debug {
+		log.Printf(format, args...)
+	}
 }
 
 func NewBufferPoolManager() *BufferPoolManager {
 	return &BufferPoolManager{
-		pools: make(map[uint]*sync.Pool),
+		pools: make(map[int]*sync.Pool),
 	}
 }
 
-func (bpm *BufferPoolManager) Get(size uint) *[]uint8 {
+func (bpm *BufferPoolManager) Get(size int) *bytes.Buffer {
 	bpm.mu.RLock()
 	pool, exists := bpm.pools[size]
 	bpm.mu.RUnlock()
@@ -25,10 +34,13 @@ func (bpm *BufferPoolManager) Get(size uint) *[]uint8 {
 		// Double-check if another goroutine added the pool while we were waiting
 		pool, exists = bpm.pools[size]
 		if !exists {
+			bpm.logf("Creating new pool for size %d\n", size)
 			pool = &sync.Pool{
 				New: func() interface{} {
-					buf := make([]uint8, size)
-					return &buf
+					bpm.logf("Creating new buffer of size %d\n", size)
+					buf := bytes.NewBuffer(make([]byte, size))
+					buf.Reset()
+					return buf
 				},
 			}
 			bpm.pools[size] = pool
@@ -36,23 +48,23 @@ func (bpm *BufferPoolManager) Get(size uint) *[]uint8 {
 		bpm.mu.Unlock()
 	}
 
-	return pool.Get().(*[]uint8)
+	buf := pool.Get().(*bytes.Buffer)
+	bpm.logf("Returning buffer of size %d: %p\n", buf.Cap(), buf)
+	return buf
 }
 
-func (bpm *BufferPoolManager) Put(buf *[]uint8) {
-	size := uint(len(*buf))
+func (bpm *BufferPoolManager) Put(buf *bytes.Buffer) {
+	size := buf.Cap()
 	bpm.mu.RLock()
 	pool, exists := bpm.pools[size]
 	bpm.mu.RUnlock()
 
 	if !exists {
+		bpm.logf("Cannot return %p, No pool for size %d\n", buf, size)
 		return
 	}
 
-	// Clear buffer
-	for i := range *buf {
-		(*buf)[i] = 0
-	}
-
+	buf.Reset()
 	pool.Put(buf)
+	bpm.logf("Returned buffer of size %d: %p\n", size, buf)
 }

pdu/bufpool_test.go

@@ -10,14 +10,14 @@ func TestRetrieveBufferOfRequestedSize(t *testing.T) {
 	bpm := NewBufferPoolManager()
 
 	size := 1024
-	buffer := bpm.Get(uint(size))
+	buffer := bpm.Get(size)
 
 	if buffer == nil {
 		t.Fatalf("Expected buffer, got nil")
 	}
 
-	if len(*buffer) != size {
-		t.Errorf("Expected buffer size %d, got %d", size, len(*buffer))
+	if buffer.Cap() != size {
+		t.Errorf("Expected buffer size %d, got %d", size, buffer.Cap())
 	}
 }
 
@@ -25,14 +25,14 @@ func TestRequestBufferSizeZero(t *testing.T) {
 	bpm := NewBufferPoolManager()
 
 	size := 0
-	buffer := bpm.Get(uint(size))
+	buffer := bpm.Get(size)
 
 	if buffer == nil {
 		t.Fatalf("Expected buffer, got nil")
 	}
 
-	if len(*buffer) != size {
-		t.Errorf("Expected buffer size %d, got %d", size, len(*buffer))
+	if buffer.Cap() != size {
+		t.Errorf("Expected buffer size %d, got %d", size, buffer.Cap())
 	}
 }
 
@@ -47,12 +47,12 @@ func TestConcurrentAccessToBufferPool(t *testing.T) {
 		wg.Add(1)
 		go func() {
 			defer wg.Done()
-			buffer := bpm.Get(uint(size))
+			buffer := bpm.Get(size)
 			if buffer == nil {
 				t.Errorf("Expected buffer, got nil")
 			}
-			if len(*buffer) != size {
-				t.Errorf("Expected buffer size %d, got %d", size, len(*buffer))
+			if buffer.Cap() != size {
+				t.Errorf("Expected buffer size %d, got %d", size, buffer.Cap())
 			}
 		}()
 	}
@@ -64,14 +64,14 @@ func TestGetBufferLockUnlock(t *testing.T) {
 	bpm := NewBufferPoolManager()
 
 	size := 1024
-	buffer := bpm.Get(uint(size))
+	buffer := bpm.Get(size)
 
 	if buffer == nil {
 		t.Fatalf("Expected buffer, got nil")
 	}
 
-	if len(*buffer) != size {
-		t.Errorf("Expected buffer size %d, got %d", size, len(*buffer))
+	if buffer.Cap() != size {
+		t.Errorf("Expected buffer size %d, got %d", size, buffer.Cap())
 	}
 }
 
@@ -79,14 +79,14 @@ func TestVerifyPoolCreationForNewSizes(t *testing.T) {
 	bpm := NewBufferPoolManager()
 
 	size := 512
-	buffer := bpm.Get(uint(size))
+	buffer := bpm.Get(size)
 
 	if buffer == nil {
 		t.Fatalf("Expected buffer, got nil")
 	}
 
-	if len(*buffer) != size {
-		t.Errorf("Expected buffer size %d, got %d", size, len(*buffer))
+	if buffer.Cap() != size {
+		t.Errorf("Expected buffer size %d, got %d", size, buffer.Cap())
 	}
 }
 
@@ -94,14 +94,14 @@ func TestBufferPoolManagerGetBuffer(t *testing.T) {
 	bpm := NewBufferPoolManager()
 
 	size := 1024
-	buffer := bpm.Get(uint(size))
+	buffer := bpm.Get(size)
 
 	if buffer == nil {
 		t.Fatalf("Expected buffer, got nil")
 	}
 
-	if len(*buffer) != size {
-		t.Errorf("Expected buffer size %d, got %d", size, len(*buffer))
+	if buffer.Cap() != size {
+		t.Errorf("Expected buffer size %d, got %d", size, buffer.Cap())
 	}
 }
 
@@ -110,14 +110,14 @@ func TestGetBufferWithMultipleSizes(t *testing.T) {
 
 	sizes := []int{512, 1024, 2048}
 	for _, size := range sizes {
-		buffer := bpm.Get(uint(size))
+		buffer := bpm.Get(size)
 
 		if buffer == nil {
 			t.Fatalf("Expected buffer for size %d, got nil", size)
 		}
 
-		if len(*buffer) != size {
-			t.Errorf("Expected buffer size %d, got %d", size, len(*buffer))
+		if buffer.Cap() != size {
+			t.Errorf("Expected buffer size %d, got %d", size, buffer.Cap())
 		}
 	}
 }
@@ -125,7 +125,7 @@ func TestGetBufferWithMultipleSizes(t *testing.T) {
 func TestGetBufferIsAlwaysZero(t *testing.T) {
 	bpm := NewBufferPoolManager()
 
-	var size uint = 1024 * 64
+	size := 1024 * 64
 	for i := 0; i < 1000; i++ {
 		buffer := bpm.Get(size)
 
@@ -133,11 +133,11 @@ func TestGetBufferIsAlwaysZero(t *testing.T) {
 			t.Fatalf("Expected buffer for size %d, got nil", size)
 		}
 
-		if uint(len(*buffer)) != size {
-			t.Errorf("Expected buffer size %d, got %d", size, len(*buffer))
+		if buffer.Cap() != size {
+			t.Errorf("Expected buffer size %d, got %d", size, buffer.Cap())
 		}
 
-		for _, b := range *buffer {
+		for _, b := range buffer.Bytes() {
 			if b != 0 {
 				t.Errorf("Expected buffer to be zero, got %d", b)
 			}
@@ -147,9 +147,26 @@ func TestGetBufferIsAlwaysZero(t *testing.T) {
 	}
 }
 
+func TestPoolReusesBuffers(t *testing.T) {
+	bpm := NewBufferPoolManager()
+
+	size := 1024
+	buffer := bpm.Get(size)
+	initialPtr := buffer
+	bpm.Put(buffer)
+	for i := 0; i < 1000; i++ {
+		buffer = bpm.Get(size)
+		if buffer != initialPtr {
+			t.Errorf("Expected initial buffer (%p) to be reused, got %p", initialPtr, buffer)
+		}
+		bpm.Put(buffer)
+	}
+}
+
+// region benchmark
 func BenchmarkBufferPoolManager(b *testing.B) {
 	bpm := NewBufferPoolManager()
-	bufSize := uint(128 * 1024) // a PDU should not be larger than this... Even this is way too large
+	bufSize := 128 * 1024 // a PDU should not be larger than this... Even this is way too large
 
 	b.ResetTimer()
 
@@ -163,7 +180,7 @@ func BenchmarkBufferPoolManager(b *testing.B) {
 
 func BenchmarkBufferPoolManager_Concurrent(b *testing.B) {
 	bpm := NewBufferPoolManager()
-	bufSize := uint(128 * 1024) // a PDU should not be larger than this... Even this is vway too large
+	bufSize := 128 * 1024 // a PDU should not be larger than this... Even this is way too large
 
 	b.ResetTimer()
 
@@ -186,17 +203,17 @@ func BenchmarkBufferPoolManager_Concurrent(b *testing.B) {
 
 func BenchmarkBufferPoolManager_Memory(b *testing.B) {
 	bpm := NewBufferPoolManager()
-	bufSize := uint(128 * 1024) // a PDU should not be larger than this... Even this is vway too large
+	bufSize := 128 * 1024 // a PDU should not be larger than this... Even this is way too large
 	b.ResetTimer()
 
-	var i uint8
+	var i byte
 	buf := bpm.Get(bufSize)
 	b.StopTimer()
 
 	// Simulate some work
 	time.Sleep(10 * time.Millisecond)
-	for k := range *buf {
-		(*buf)[k] = i % 255
+	for range buf.Bytes() {
+		buf.WriteByte(i % 255)
 	}
 
 	b.StartTimer()

pdu/cancel.go

@@ -5,11 +5,11 @@ type (
 		header           PDU_HEADER
 		service_type     string
 		message_id       string
-		source_addr_ton  uint8
-		source_addr_npi  uint8
+		source_addr_ton  byte
+		source_addr_npi  byte
 		source_addr      string
-		dest_addr_ton    uint8
-		dest_addr_npi    uint8
+		dest_addr_ton    byte
+		dest_addr_npi    byte
 		destination_addr string
 	}
 	CANCEL_SM_RESP struct {

pdu/pdu.go

@@ -1,17 +1,17 @@
 package pdu
 
 import (
+	"bytes"
 	"encoding/binary"
 	"fmt"
 )
 
 type (
 	PDU interface {
-		EncodeInto(*[]uint8)
-		Encode() []uint8
-		Decode([]uint8)
+		Encode(*bytes.Buffer) error
+		Decode(*bytes.Buffer) error
 		// Size in bytes
-		Size() uint32
+		Size() int
 	}
 
 	PDU_HEADER struct {
@@ -57,41 +57,23 @@ type (
 // What are the other 0s?
 // Don't know
 
-func (p *PDU_HEADER) Encode() (*[]uint8, error) {
-	buf := ByteBufferPool.Get(uint(p.Size()))
-	err := p.EncodeInto(buf)
-	return buf, err
+func (p *PDU_HEADER) Encode(buf *bytes.Buffer) error {
+	binary.Write(buf, binary.BigEndian, p.command_length)
+	binary.Write(buf, binary.BigEndian, p.command_id)
+	binary.Write(buf, binary.BigEndian, p.command_status)
+	binary.Write(buf, binary.BigEndian, p.sequence_number)
+	return nil
 }
-func (p *PDU_HEADER) EncodeInto(buf *[]uint8) error {
+func (p *PDU_HEADER) Decode(buf *bytes.Buffer) error {
 	if buf == nil {
-		return fmt.Errorf("cannot encode PDU_HEADER, buffer is nil")
+		return fmt.Errorf("cannot decode nil buffer")
 	}
-	if len(*buf) < 16 {
-		return fmt.Errorf("cannot encode PDU_HEADER, buffer too small (%d, required 16)", len(*buf))
-	}
-	bufVal := *buf
-	binary.BigEndian.PutUint32(bufVal[0:4], p.command_length)
-	binary.BigEndian.PutUint32(bufVal[4:8], p.command_id)
-	binary.BigEndian.PutUint32(bufVal[8:12], p.command_status)
-	binary.BigEndian.PutUint32(bufVal[12:16], p.sequence_number)
+	binary.Read(buf, binary.BigEndian, &p.command_length)
+	binary.Read(buf, binary.BigEndian, &p.command_id)
+	binary.Read(buf, binary.BigEndian, &p.command_status)
+	binary.Read(buf, binary.BigEndian, &p.sequence_number)
 	return nil
 }
-func (p *PDU_HEADER) Decode(data []uint8) error {
-	if len(data) >= 4 {
-		p.command_length = binary.BigEndian.Uint32(data[0:4])
-	}
-	if len(data) >= 8 {
-		p.command_id = binary.BigEndian.Uint32(data[4:8])
-	}
-	if len(data) >= 12 {
-		p.command_status = binary.BigEndian.Uint32(data[8:12])
-
-	}
-	if len(data) >= 16 {
-		p.sequence_number = binary.BigEndian.Uint32(data[12:16])
-	}
-	return nil
-}
-func (p *PDU_HEADER) Size() uint32 {
+func (p *PDU_HEADER) Size() int {
 	return 16
 }

pdu/pdu_test.go

@@ -1,6 +1,7 @@
 package pdu
 
 import (
+	"bytes"
 	"encoding/binary"
 	"math"
 	"sync"
@@ -15,13 +16,15 @@ func TestEncodeReturnsByteSliceOfLength16(t *testing.T) {
 		command_status:  1,
 		sequence_number: 1,
 	}
-	result, err := p.Encode()
+	buf := bytes.NewBuffer(make([]byte, 16))
+	buf.Reset()
+	err := p.Encode(buf)
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
 	}
-	if len(*result) != 16 {
-		t.Errorf("Expected byte slice of length 16, got %d", len(*result))
+	if buf.Cap() != 16 {
+		t.Errorf("Expected byte slice of length 16, got %d", buf.Cap())
 	}
 }
 
@@ -32,15 +35,17 @@ func TestEncodeHandlesZeroValues(t *testing.T) {
 		command_status:  0,
 		sequence_number: 0,
 	}
-	result, err := p.Encode()
+	buf := bytes.NewBuffer(make([]byte, 16))
+	buf.Reset()
+	err := p.Encode(buf)
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
 	}
-	expected := make([]uint8, 16)
-	for i, v := range *result {
+	expected := make([]byte, 16)
+	for i, v := range buf.Bytes() {
 		if v != expected[i] {
-			t.Errorf("Expected byte slice with zero values, got %v", *result)
+			t.Errorf("Expected byte slice with zero values, got %v", buf.Bytes())
 			break
 		}
 	}
@@ -53,16 +58,18 @@ func TestEncodeEncodesProperly(t *testing.T) {
 		command_status:  3,
 		sequence_number: 4,
 	}
-	result, err := p.Encode()
+	buf := bytes.NewBuffer(make([]byte, 16))
+	buf.Reset()
+	err := p.Encode(buf)
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
 	}
 
-	expected := []uint8{0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 3, 0, 0, 0, 4}
-	for i, v := range *result {
+	expected := []byte{0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 3, 0, 0, 0, 4}
+	for i, v := range buf.Bytes() {
 		if v != expected[i] {
-			t.Errorf("Expected byte slice with values %v, got %v", expected, *result)
+			t.Errorf("Expected byte slice with values %v, got %v", expected, buf.Bytes())
 			break
 		}
 	}
@@ -75,16 +82,18 @@ func TestEncodeEncodesProperlyComplex(t *testing.T) {
 		command_status:  35634264,
 		sequence_number: 476543523,
 	}
-	result, err := p.Encode()
+	buf := bytes.NewBuffer(make([]byte, 16))
+	buf.Reset()
+	err := p.Encode(buf)
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
 	}
 
-	expected := []uint8{0, 204, 224, 36, 0, 3, 225, 144, 2, 31, 188, 88, 28, 103, 122, 35}
-	for i, v := range *result {
+	expected := []byte{0, 204, 224, 36, 0, 3, 225, 144, 2, 31, 188, 88, 28, 103, 122, 35}
+	for i, v := range buf.Bytes() {
 		if v != expected[i] {
-			t.Errorf("Expected byte slice with values %v, got %v", expected, *result)
+			t.Errorf("Expected byte slice with values %v, got %v", expected, buf.Bytes())
 			break
 		}
 	}
@@ -97,54 +106,26 @@ func TestEncodeIntoCorrectlyEncodesFields(t *testing.T) {
 		command_status:  0,
 		sequence_number: 12345,
 	}
-	buf := make([]uint8, 16)
-	err := p.EncodeInto(&buf)
+	buf := bytes.NewBuffer(make([]byte, 16))
+	buf.Reset()
+	err := p.Encode(buf)
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
 	}
 
-	if binary.BigEndian.Uint32(buf[0:4]) != p.command_length {
-		t.Errorf("Expected command_length %d, got %d", p.command_length, binary.BigEndian.Uint32(buf[0:4]))
+	innerbuf := buf.Bytes()
+	if binary.BigEndian.Uint32(innerbuf[0:4]) != p.command_length {
+		t.Errorf("Expected command_length %d, got %d", p.command_length, binary.BigEndian.Uint32(innerbuf[0:4]))
 	}
-	if binary.BigEndian.Uint32(buf[4:8]) != p.command_id {
-		t.Errorf("Expected command_id %d, got %d", p.command_id, binary.BigEndian.Uint32(buf[4:8]))
+	if binary.BigEndian.Uint32(innerbuf[4:8]) != p.command_id {
+		t.Errorf("Expected command_id %d, got %d", p.command_id, binary.BigEndian.Uint32(innerbuf[4:8]))
 	}
-	if binary.BigEndian.Uint32(buf[8:12]) != p.command_status {
-		t.Errorf("Expected command_status %d, got %d", p.command_status, binary.BigEndian.Uint32(buf[8:12]))
+	if binary.BigEndian.Uint32(innerbuf[8:12]) != p.command_status {
+		t.Errorf("Expected command_status %d, got %d", p.command_status, binary.BigEndian.Uint32(innerbuf[8:12]))
 	}
-	if binary.BigEndian.Uint32(buf[12:16]) != p.sequence_number {
-		t.Errorf("Expected sequence_number %d, got %d", p.sequence_number, binary.BigEndian.Uint32(buf[12:16]))
-	}
-}
-
-func TestEncodeIntoHandlesNilBuffer(t *testing.T) {
-	p := &PDU_HEADER{
-		command_length:  16,
-		command_id:      1,
-		command_status:  0,
-		sequence_number: 12345,
-	}
-	var buf *[]uint8 = nil
-
-	err := p.EncodeInto(buf)
-	if err == nil {
-		t.Errorf("Expected error when buffer is nil")
-	}
-}
-
-func TestEncodeIntoHandlesSmallerBuffer(t *testing.T) {
-	p := &PDU_HEADER{
-		command_length:  16,
-		command_id:      1,
-		command_status:  0,
-		sequence_number: 12345,
-	}
-	buf := make([]uint8, 12) // smaller buffer size
-
-	err := p.EncodeInto(&buf)
-	if err == nil {
-		t.Errorf("Expected error when buffer is too small")
+	if binary.BigEndian.Uint32(innerbuf[12:16]) != p.sequence_number {
+		t.Errorf("Expected sequence_number %d, got %d", p.sequence_number, binary.BigEndian.Uint32(innerbuf[12:16]))
 	}
 }
 
@@ -155,24 +136,26 @@ func TestEncodeIntoHandlesLargerBuffer(t *testing.T) {
 		command_status:  0,
 		sequence_number: 12345,
 	}
-	buf := make([]uint8, 20)
-	err := p.EncodeInto(&buf)
+	buf := bytes.NewBuffer(make([]byte, 20)) // larger buffer size
+	buf.Reset()
+	err := p.Encode(buf)
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
 	}
 
-	if binary.BigEndian.Uint32(buf[0:4]) != p.command_length {
-		t.Errorf("Expected command_length %d, got %d", p.command_length, binary.BigEndian.Uint32(buf[0:4]))
+	innerbuf := buf.Bytes()
+	if binary.BigEndian.Uint32(innerbuf[0:4]) != p.command_length {
+		t.Errorf("Expected command_length %d, got %d", p.command_length, binary.BigEndian.Uint32(innerbuf[0:4]))
 	}
-	if binary.BigEndian.Uint32(buf[4:8]) != p.command_id {
-		t.Errorf("Expected command_id %d, got %d", p.command_id, binary.BigEndian.Uint32(buf[4:8]))
+	if binary.BigEndian.Uint32(innerbuf[4:8]) != p.command_id {
+		t.Errorf("Expected command_id %d, got %d", p.command_id, binary.BigEndian.Uint32(innerbuf[4:8]))
 	}
-	if binary.BigEndian.Uint32(buf[8:12]) != p.command_status {
-		t.Errorf("Expected command_status %d, got %d", p.command_status, binary.BigEndian.Uint32(buf[8:12]))
+	if binary.BigEndian.Uint32(innerbuf[8:12]) != p.command_status {
+		t.Errorf("Expected command_status %d, got %d", p.command_status, binary.BigEndian.Uint32(innerbuf[8:12]))
 	}
-	if binary.BigEndian.Uint32(buf[12:16]) != p.sequence_number {
-		t.Errorf("Expected sequence_number %d, got %d", p.sequence_number, binary.BigEndian.Uint32(buf[12:16]))
+	if binary.BigEndian.Uint32(innerbuf[12:16]) != p.sequence_number {
+		t.Errorf("Expected sequence_number %d, got %d", p.sequence_number, binary.BigEndian.Uint32(innerbuf[12:16]))
 	}
 }
 
@@ -183,24 +166,26 @@ func TestEncodeIntoUsesBigEndianEncoding(t *testing.T) {
 		command_status:  0,
 		sequence_number: 12345,
 	}
-	buf := make([]uint8, 16)
-	err := p.EncodeInto(&buf)
+	buf := bytes.NewBuffer(make([]byte, 16))
+	buf.Reset()
+	err := p.Encode(buf)
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
 	}
 
-	if binary.BigEndian.Uint32(buf[0:4]) != p.command_length {
-		t.Errorf("Expected command_length %d, got %d", p.command_length, binary.BigEndian.Uint32(buf[0:4]))
+	innerbuf := buf.Bytes()
+	if binary.BigEndian.Uint32(innerbuf[0:4]) != p.command_length {
+		t.Errorf("Expected command_length %d, got %d", p.command_length, binary.BigEndian.Uint32(innerbuf[0:4]))
 	}
-	if binary.BigEndian.Uint32(buf[4:8]) != p.command_id {
-		t.Errorf("Expected command_id %d, got %d", p.command_id, binary.BigEndian.Uint32(buf[4:8]))
+	if binary.BigEndian.Uint32(innerbuf[4:8]) != p.command_id {
+		t.Errorf("Expected command_id %d, got %d", p.command_id, binary.BigEndian.Uint32(innerbuf[4:8]))
 	}
-	if binary.BigEndian.Uint32(buf[8:12]) != p.command_status {
-		t.Errorf("Expected command_status %d, got %d", p.command_status, binary.BigEndian.Uint32(buf[8:12]))
+	if binary.BigEndian.Uint32(innerbuf[8:12]) != p.command_status {
+		t.Errorf("Expected command_status %d, got %d", p.command_status, binary.BigEndian.Uint32(innerbuf[8:12]))
 	}
-	if binary.BigEndian.Uint32(buf[12:16]) != p.sequence_number {
-		t.Errorf("Expected sequence_number %d, got %d", p.sequence_number, binary.BigEndian.Uint32(buf[12:16]))
+	if binary.BigEndian.Uint32(innerbuf[12:16]) != p.sequence_number {
+		t.Errorf("Expected sequence_number %d, got %d", p.sequence_number, binary.BigEndian.Uint32(innerbuf[12:16]))
 	}
 }
 
@@ -211,28 +196,30 @@ func TestEncodeIntoConcurrencySafety(t *testing.T) {
 		command_status:  0,
 		sequence_number: 12345,
 	}
-	buf := make([]uint8, 16)
+	buf := bytes.NewBuffer(make([]byte, 16))
+	buf.Reset()
 	var wg sync.WaitGroup
 	for i := 0; i < 1000; i++ {
 		wg.Add(1)
 		go func() {
 			defer wg.Done()
-			p.EncodeInto(&buf)
+			p.Encode(buf)
 		}()
 	}
 	wg.Wait()
 
-	if binary.BigEndian.Uint32(buf[0:4]) != p.command_length {
-		t.Errorf("Expected command_length %d, got %d", p.command_length, binary.BigEndian.Uint32(buf[0:4]))
+	innerbuf := buf.Bytes()
+	if binary.BigEndian.Uint32(innerbuf[0:4]) != p.command_length {
+		t.Errorf("Expected command_length %d, got %d", p.command_length, binary.BigEndian.Uint32(innerbuf[0:4]))
 	}
-	if binary.BigEndian.Uint32(buf[4:8]) != p.command_id {
-		t.Errorf("Expected command_id %d, got %d", p.command_id, binary.BigEndian.Uint32(buf[4:8]))
+	if binary.BigEndian.Uint32(innerbuf[4:8]) != p.command_id {
+		t.Errorf("Expected command_id %d, got %d", p.command_id, binary.BigEndian.Uint32(innerbuf[4:8]))
 	}
-	if binary.BigEndian.Uint32(buf[8:12]) != p.command_status {
-		t.Errorf("Expected command_status %d, got %d", p.command_status, binary.BigEndian.Uint32(buf[8:12]))
+	if binary.BigEndian.Uint32(innerbuf[8:12]) != p.command_status {
+		t.Errorf("Expected command_status %d, got %d", p.command_status, binary.BigEndian.Uint32(innerbuf[8:12]))
 	}
-	if binary.BigEndian.Uint32(buf[12:16]) != p.sequence_number {
-		t.Errorf("Expected sequence_number %d, got %d", p.sequence_number, binary.BigEndian.Uint32(buf[12:16]))
+	if binary.BigEndian.Uint32(innerbuf[12:16]) != p.sequence_number {
+		t.Errorf("Expected sequence_number %d, got %d", p.sequence_number, binary.BigEndian.Uint32(innerbuf[12:16]))
 	}
 }
 
@@ -243,24 +230,26 @@ func TestEncodeIntoWithMaximumValues(t *testing.T) {
 		command_status:  math.MaxUint32,
 		sequence_number: math.MaxUint32,
 	}
-	buf := make([]uint8, 16)
-	err := p.EncodeInto(&buf)
+	buf := bytes.NewBuffer(make([]byte, 16))
+	buf.Reset()
+	err := p.Encode(buf)
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
 	}
 
-	if binary.BigEndian.Uint32(buf[0:4]) != p.command_length {
-		t.Errorf("Expected command_length %d, got %d", p.command_length, binary.BigEndian.Uint32(buf[0:4]))
+	innerbuf := buf.Bytes()
+	if binary.BigEndian.Uint32(innerbuf[0:4]) != p.command_length {
+		t.Errorf("Expected command_length %d, got %d", p.command_length, binary.BigEndian.Uint32(innerbuf[0:4]))
 	}
-	if binary.BigEndian.Uint32(buf[4:8]) != p.command_id {
-		t.Errorf("Expected command_id %d, got %d", p.command_id, binary.BigEndian.Uint32(buf[4:8]))
+	if binary.BigEndian.Uint32(innerbuf[4:8]) != p.command_id {
+		t.Errorf("Expected command_id %d, got %d", p.command_id, binary.BigEndian.Uint32(innerbuf[4:8]))
 	}
-	if binary.BigEndian.Uint32(buf[8:12]) != p.command_status {
-		t.Errorf("Expected command_status %d, got %d", p.command_status, binary.BigEndian.Uint32(buf[8:12]))
+	if binary.BigEndian.Uint32(innerbuf[8:12]) != p.command_status {
+		t.Errorf("Expected command_status %d, got %d", p.command_status, binary.BigEndian.Uint32(innerbuf[8:12]))
 	}
-	if binary.BigEndian.Uint32(buf[12:16]) != p.sequence_number {
-		t.Errorf("Expected sequence_number %d, got %d", p.sequence_number, binary.BigEndian.Uint32(buf[12:16]))
+	if binary.BigEndian.Uint32(innerbuf[12:16]) != p.sequence_number {
+		t.Errorf("Expected sequence_number %d, got %d", p.sequence_number, binary.BigEndian.Uint32(innerbuf[12:16]))
 	}
 }
 
@@ -271,38 +260,83 @@ func TestEncodeIntoWithBoundaryValues(t *testing.T) {
 		command_status:  0,
 		sequence_number: 0,
 	}
-	buf := make([]uint8, 16)
-	err := p.EncodeInto(&buf)
+	buf := bytes.NewBuffer(make([]byte, 16))
+	buf.Reset()
+	err := p.Encode(buf)
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
 	}
 
-	if binary.BigEndian.Uint32(buf[0:4]) != p.command_length {
-		t.Errorf("Expected command_length %d, got %d", p.command_length, binary.BigEndian.Uint32(buf[0:4]))
+	innerbuf := buf.Bytes()
+	if binary.BigEndian.Uint32(innerbuf[0:4]) != p.command_length {
+		t.Errorf("Expected command_length %d, got %d", p.command_length, binary.BigEndian.Uint32(innerbuf[0:4]))
 	}
-	if binary.BigEndian.Uint32(buf[4:8]) != p.command_id {
-		t.Errorf("Expected command_id %d, got %d", p.command_id, binary.BigEndian.Uint32(buf[4:8]))
+	if binary.BigEndian.Uint32(innerbuf[4:8]) != p.command_id {
+		t.Errorf("Expected command_id %d, got %d", p.command_id, binary.BigEndian.Uint32(innerbuf[4:8]))
 	}
-	if binary.BigEndian.Uint32(buf[8:12]) != p.command_status {
-		t.Errorf("Expected command_status %d, got %d", p.command_status, binary.BigEndian.Uint32(buf[8:12]))
+	if binary.BigEndian.Uint32(innerbuf[8:12]) != p.command_status {
+		t.Errorf("Expected command_status %d, got %d", p.command_status, binary.BigEndian.Uint32(innerbuf[8:12]))
 	}
-	if binary.BigEndian.Uint32(buf[12:16]) != p.sequence_number {
-		t.Errorf("Expected sequence_number %d, got %d", p.sequence_number, binary.BigEndian.Uint32(buf[12:16]))
+	if binary.BigEndian.Uint32(innerbuf[12:16]) != p.sequence_number {
+		t.Errorf("Expected sequence_number %d, got %d", p.sequence_number, binary.BigEndian.Uint32(innerbuf[12:16]))
 	}
 }
 
+// func TestRealScenario(t *testing.T) {
+// 	expected := []byte{0, 0, 0, 54, 0, 0, 0, 4, 0, 0, 0, 0, 0, 0, 0, 1, 67, 77, 84, 0, 1, 1, 49, 50, 51, 52, 53, 0, 1, 1, 54, 55, 56, 57, 48, 0, 0, 0, 0, 0, 0, 1, 0, 0, 0, 12, 72, 101, 108, 108, 111, 44, 32, 83, 77, 80, 80, 33}
+// 	p := &SUBMIT_SM{
+// 		header: PDU_HEADER{
+// 			command_length:  0,
+// 			command_id:      4,
+// 			command_status:  0,
+// 			sequence_number: 1,
+// 		},
+// 		service_type:           "CMT",
+// 		source_addr_ton:        1,
+// 		source_addr_npi:        1,
+// 		source_addr:            "12345",
+// 		dest_addr_ton:          1,
+// 		dest_addr_npi:          1,
+// 		destination_addr:       "67890",
+// 		esm_class:              0,
+// 		protocol_id:            0,
+// 		priority_flag:          0,
+// 		schedule_delivery_time: "",
+// 		validity_period:        "",
+// 		registered_delivery:    1,
+// 		data_coding:            0,
+// 		sm_default_msg_id:      0,
+// 		short_message:          "Hello, SMPP!",
+// 	}
+// 	p.header.command_length = uint32(p.Size())
+// 	p.sm_length = byte(len(p.short_message))
+// 	buf := make([]byte, p.Size())
+// 	err := p.EncodeInto(&buf)
+// 	if err != nil {
+// 		t.Errorf("Expected no error, got %v", err)
+// 	}
+// 	if len(buf) != len(expected) {
+// 		t.Errorf("Expected byte slice of length %d, got %d", len(expected), len(buf))
+// 	}
+// 	for i, v := range buf {
+// 		if v != expected[i] {
+// 			t.Errorf("Expected byte slice with values %v, got %v", expected, buf)
+// 			break
+// 		}
+// 	}
+// }
 
 // region decode
 func TestDecodeHandlesShortByteSlice(t *testing.T) {
 	var p PDU_HEADER
-	data := []uint8{0, 0, 0, 10}
+	data := []byte{0, 0, 0, 10}
 	defer func() {
 		if r := recover(); r != nil {
 			t.Errorf("Decode panicked with short byte slice")
 		}
 	}()
-	err := p.Decode(data)
+	err := p.Decode(bytes.NewBuffer(data))
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
 	}
@@ -310,8 +344,8 @@ func TestDecodeHandlesShortByteSlice(t *testing.T) {
 
 func TestDecodeParsesValidByteSlice(t *testing.T) {
 	var p PDU_HEADER
-	data := []uint8{0, 0, 0, 16, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 3}
-	err := p.Decode(data)
+	data := []byte{0, 0, 0, 16, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 3}
+	err := p.Decode(bytes.NewBuffer(data))
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
@@ -333,13 +367,13 @@ func TestDecodeParsesValidByteSlice(t *testing.T) {
 
 func TestDecodeHandlesLongerByteSliceWithoutCrashing(t *testing.T) {
 	var p PDU_HEADER
-	data := make([]uint8, 20)
+	data := make([]byte, 20)
 	defer func() {
 		if r := recover(); r != nil {
 			t.Errorf("Decode panicked with long byte slice")
 		}
 	}()
-	err := p.Decode(data)
+	err := p.Decode(bytes.NewBuffer(data))
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
 	}
@@ -349,8 +383,8 @@ func TestDecodeHandlesNilDataInput(t *testing.T) {
 	var p PDU_HEADER
 	err := p.Decode(nil)
 
-	if err != nil {
-		t.Errorf("Expected no error, got %v", err)
+	if err == nil {
+		t.Errorf("Expected error, got none")
 	}
 
 	if p.command_length != 0 {
@@ -369,8 +403,8 @@ func TestDecodeHandlesNilDataInput(t *testing.T) {
 
 func TestDecodeHandlesEmptyByteSliceGracefully(t *testing.T) {
 	var p PDU_HEADER
-	data := []uint8{}
-	err := p.Decode(data)
+	data := []byte{}
+	err := p.Decode(bytes.NewBuffer(data))
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
@@ -392,11 +426,11 @@ func TestDecodeHandlesEmptyByteSliceGracefully(t *testing.T) {
 
 func TestDecodeDoesNotModifyInputByteSlice(t *testing.T) {
 	var p PDU_HEADER
-	data := []uint8{0, 0, 0, 16, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 3}
-	originalData := make([]uint8, len(data))
+	data := []byte{0, 0, 0, 16, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 3}
+	originalData := make([]byte, len(data))
 	copy(originalData, data)
 
-	err := p.Decode(data)
+	err := p.Decode(bytes.NewBuffer(data))
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
@@ -411,8 +445,8 @@ func TestDecodeDoesNotModifyInputByteSlice(t *testing.T) {
 
 func TestDecodeHandlesByteSlicesWithMaxUint32Values(t *testing.T) {
 	var p PDU_HEADER
-	data := []uint8{255, 255, 255, 255, 255, 255, 255, 255}
-	err := p.Decode(data)
+	data := []byte{255, 255, 255, 255, 255, 255, 255, 255}
+	err := p.Decode(bytes.NewBuffer(data))
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
@@ -428,8 +462,8 @@ func TestDecodeHandlesByteSlicesWithMaxUint32Values(t *testing.T) {
 
 func TestDecodeHandlesByteSlicesWithMinimumUint32Values(t *testing.T) {
 	var p PDU_HEADER
-	data := []uint8{0, 0, 0, 0, 0, 0, 0, 0}
-	err := p.Decode(data)
+	data := []byte{0, 0, 0, 0, 0, 0, 0, 0}
+	err := p.Decode(bytes.NewBuffer(data))
 
 	if err != nil {
 		t.Errorf("Expected no error, got %v", err)
@@ -452,9 +486,8 @@ func TestSizeReturns16(t *testing.T) {
 }
 
 // region benchmarks
-
 // With buffer pool
-func BenchmarkEncode(b *testing.B) {
+func BenchmarkEncodeWithBufferPool(b *testing.B) {
 	p := &PDU_HEADER{
 		command_length:  16,
 		command_id:      1,
@@ -463,12 +496,14 @@ func BenchmarkEncode(b *testing.B) {
 	}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		p.Encode()
+		buf := ByteBufferPool.Get(p.Size())
+		p.Encode(buf)
+		ByteBufferPool.Put(buf)
 	}
 }
 
 // Without buffer pool
-func BenchmarkEncodeInto(b *testing.B) {
+func BenchmarkEncodeWithoutBufferPool(b *testing.B) {
 	p := &PDU_HEADER{
 		command_length:  16,
 		command_id:      1,
@@ -477,16 +512,19 @@ func BenchmarkEncodeInto(b *testing.B) {
 	}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		buf := make([]uint8, 16)
-		p.EncodeInto(&buf)
+		buf := bytes.Buffer{}
+		p.Encode(&buf)
 	}
 }
 
-func BenchmarkDecode(b *testing.B) {
+func BenchmarkDecodeBufferPool(b *testing.B) {
 	p := &PDU_HEADER{}
-	data := []uint8{0, 0, 0, 16, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 3}
 	b.ResetTimer()
 	for i := 0; i < b.N; i++ {
-		p.Decode(data)
+		data := []byte{0, 0, 0, 16, 0, 0, 0, 1, 0, 0, 0, 2, 0, 0, 0, 3}
+		buf := ByteBufferPool.Get(len(data))
+		buf.Write(data)
+		p.Decode(buf)
+		ByteBufferPool.Put(buf)
 	}
 }

pdu/submit.go

@@ -1,56 +1,60 @@
 package pdu
 
-import "fmt"
+import (
+	"bytes"
+	"encoding/ascii85"
+	"encoding/binary"
+)
 
 type (
 	SUBMIT_SM struct {
 		header                 PDU_HEADER
 		service_type           string
-		source_addr_ton        uint8
-		source_addr_npi        uint8
+		source_addr_ton        byte
+		source_addr_npi        byte
 		source_addr            string
-		dest_addr_ton          uint8
-		dest_addr_npi          uint8
+		dest_addr_ton          byte
+		dest_addr_npi          byte
 		destination_addr       string
-		esm_class              uint8
-		protocol_id            uint8
-		priority_flag          uint8
+		esm_class              byte
+		protocol_id            byte
+		priority_flag          byte
 		schedule_delivery_time string
 		validity_period        string
-		registered_delivery    uint8
-		replace_if_present     uint8
-		data_coding            uint8
-		sm_default_msg_id      uint8
-		sm_length              uint8
+		registered_delivery    byte
+		replace_if_present     byte
+		data_coding            byte
+		sm_default_msg_id      byte
+		sm_length              byte
 		short_message          string
 		// user_message_reference uint16
 		// source_port               uint16
-		// source_addr_subunit       uint8
+		// source_addr_subunit       byte
 		// destination_port          uint16
-		// dest_addr_subunit         uint8
+		// dest_addr_subunit         byte
 		// sar_msg_ref_num           uint16
-		// sar_total_segments        uint8
-		// sar_segment_seqnum        uint8
-		// more_messages_to_send     uint8
-		// payload_type              uint8
+		// sar_total_segments        byte
+		// sar_segment_seqnum        byte
+		// more_messages_to_send     byte
+		// payload_type              byte
 		// message_payload           string
-		// privacy_indicator         uint8
+		// privacy_indicator         byte
 		// callback_num              string
-		// callback_num_pres         uint8
+		// callback_num_pres         byte
 		// callback_num_atag         string
 		// source_subaddress         string
 		// dest_subaddress           string
-		// user_response_code        uint8
-		// display_time              uint8
-		// sms_signal                uint8
-		// ms_validity               uint8
-		// ms_msg_wait_facilities    uint8
-		// number_of_messages        uint8
-		// alert_on_message_delivery uint8
-		// language_indicator        uint8
-		// its_reply_type            uint8
-		// its_session_info          uint8
-		// ussd_service_op           uint8
+		// user_response_code        byte
+		// display_time              byte
+		// sms_signal                byte
+		// ms_validity               byte
+		// ms_msg_wait_facilities    byte
+		// number_of_messages        byte
+		// alert_on_message_delivery byte
+		// language_indicator        byte
+		// its_reply_type            byte
+		// its_session_info          byte
+		// ussd_service_op           byte
 	}
 	SUBMIT_SM_RESP struct {
 		header     PDU_HEADER
@@ -60,45 +64,56 @@ type (
 	SUBMIT_MULTI_RESP struct{}
 )
 
-func (p *SUBMIT_SM) Encode() (*[]byte, error) {
-	buf := ByteBufferPool.Get(uint(p.Size()))
-	err := p.EncodeInto(buf)
-	return buf, err
-}
-func (p *SUBMIT_SM) EncodeInto(buf *[]byte) error {
-	if buf == nil {
-		return fmt.Errorf("cannot encode SUBMIT_SM, buffer is nil")
-	}
-	if len(*buf) < int(p.Size()) {
-		return fmt.Errorf("cannot encode SUBMIT_SM, buffer too small (%d, required %d)", len(*buf), p.Size())
-	}
+func (p *SUBMIT_SM) Encode(buf *bytes.Buffer) error {
+	p.header.Encode(buf)
+	n := ascii85.Encode(buf.Bytes(), []byte(p.service_type))
+	buf.Truncate(n)
+	binary.Write(buf, binary.BigEndian, byte(len(p.service_type)))
 	
-	p.header.EncodeInto(buf)
+	// service_type           string
+	// source_addr_ton        byte
+	// source_addr_npi        byte
+	// source_addr            string
+	// dest_addr_ton          byte
+	// dest_addr_npi          byte
+	// destination_addr       string
+	// esm_class              byte
+	// protocol_id            byte
+	// priority_flag          byte
+	// schedule_delivery_time string
+	// validity_period        string
+	// registered_delivery    byte
+	// replace_if_present     byte
+	// data_coding            byte
+	// sm_default_msg_id      byte
+	// sm_length              byte
+	// short_message          string
 
 	return nil
 }
-func (p *SUBMIT_SM) Decode(data []byte) {
+func (p *SUBMIT_SM) Decode(buf *bytes.Buffer) error {
+	return nil
 }
-func (p *SUBMIT_SM) Size() uint32 {
-	var size uint32
+func (p *SUBMIT_SM) Size() int {
+	var size int
 	size += p.header.Size()
-	size += uint32(len(p.service_type) * 1)
+	size += len(p.service_type) * 1
 	size += 1 // source_addr_ton
 	size += 1 // source_addr_npi
-	size += uint32(len(p.source_addr) * 1)
+	size += len(p.source_addr) * 1
 	size += 1 // dest_addr_ton
 	size += 1 // dest_addr_npi
-	size += uint32(len(p.destination_addr) * 1)
+	size += len(p.destination_addr) * 1
 	size += 1 // esm_class
 	size += 1 // protocol_id
 	size += 1 // priority_flag
-	size += uint32(len(p.schedule_delivery_time) * 1)
-	size += uint32(len(p.validity_period) * 1)
+	size += len(p.schedule_delivery_time) * 1
+	size += len(p.validity_period) * 1
 	size += 1 // registered_delivery
 	size += 1 // replace_if_present
 	size += 1 // data_coding
 	size += 1 // sm_default_msg_id
 	size += 1 // sm_length
-	size += uint32(len(p.short_message) * 1)
+	size += len(p.short_message) * 1
 	return size
 }

pdu/submit_test.go

@@ -14,7 +14,7 @@ func TestCalculateSizeTypicalInstance(t *testing.T) {
 		validity_period:        "",
 		short_message:          "Hello, World!",
 	}
-	expectedSize := uint32(16 + len(p.service_type) + 1 + 1 + len(p.source_addr) + 1 + 1 + len(p.destination_addr) + 1 + 1 + 1 + len(p.schedule_delivery_time) + len(p.validity_period) + 1 + 1 + 1 + 1 + 1 + len(p.short_message))
+	expectedSize := 16 + len(p.service_type) + 1 + 1 + len(p.source_addr) + 1 + 1 + len(p.destination_addr) + 1 + 1 + 1 + len(p.schedule_delivery_time) + len(p.validity_period) + 1 + 1 + 1 + 1 + 1 + len(p.short_message)
 	actualSize := p.Size()
 	if actualSize != expectedSize {
 		t.Errorf("Expected size %d, but got %d", expectedSize, actualSize)
@@ -31,7 +31,7 @@ func TestCalculateSizeMaxLengths(t *testing.T) {
 		validity_period:        string(make([]byte, maxLen)),
 		short_message:          string(make([]byte, maxLen)),
 	}
-	expectedSize := uint32(16 + maxLen + 1 + 1 + maxLen + 1 + 1 + maxLen + 1 + 1 + 1 + maxLen + maxLen + 1 + 1 + 1 + 1 + 1 + maxLen)
+	expectedSize := 16 + maxLen + 1 + 1 + maxLen + 1 + 1 + maxLen + 1 + 1 + 1 + maxLen + maxLen + 1 + 1 + 1 + 1 + 1 + maxLen
 	actualSize := p.Size()
 	if actualSize != expectedSize {
 		t.Errorf("Expected size %d, but got %d", expectedSize, actualSize)
@@ -47,7 +47,7 @@ func TestHandlesEmptyStringsForAllStringFields(t *testing.T) {
 		validity_period:        "",
 		short_message:          "",
 	}
-	expectedSize := uint32(16 + len(p.service_type) + 1 + 1 + len(p.source_addr) + 1 + 1 + len(p.destination_addr) + 1 + 1 + 1 + len(p.schedule_delivery_time) + len(p.validity_period) + 1 + 1 + 1 + 1 + 1 + len(p.short_message))
+	expectedSize := 16 + len(p.service_type) + 1 + 1 + len(p.source_addr) + 1 + 1 + len(p.destination_addr) + 1 + 1 + 1 + len(p.schedule_delivery_time) + len(p.validity_period) + 1 + 1 + 1 + 1 + 1 + len(p.short_message)
 	actualSize := p.Size()
 	if actualSize != expectedSize {
 		t.Errorf("Expected size %d, but got %d", expectedSize, actualSize)