Remove dependencies

I don't want to clone the whole input string

.gitignore

@@ -1 +1,3 @@
 jstester/node_modules
+encoding/tmp
+pdu/tmp

benchmark/results/2024-07-24_2453d639ff4deec5a900ac7524f34fc004da43ce.txt

@@ -1,12 +0,0 @@
-goos: linux
-goarch: amd64
-pkg: smpptester/pdu
-cpu: Intel(R) Core(TM) i5-8400 CPU @ 2.80GHz
-BenchmarkBufferPoolManager-6              	13663852	        90.76 ns/op
-BenchmarkBufferPoolManager_Concurrent-6   	 9525358	       130.7 ns/op
-BenchmarkBufferPoolManager_Memory-6       	16205492	        74.61 ns/op
-BenchmarkEncodeWithBufferPool-6           	 8466584	       143.2 ns/op
-BenchmarkEncodeWithoutBufferPool-6        	 6701893	       221.0 ns/op
-BenchmarkDecodeBufferPool-6               	 7069999	       162.3 ns/op
-PASS
-ok  	smpptester/pdu	8.413s

benchmark/results/2024-07-24_500cb11235b9a8c6bb3c33d24ec2164de9c145e5.txt

@@ -1,12 +0,0 @@
-goos: linux
-goarch: amd64
-pkg: smpptester/pdu
-cpu: Intel(R) Core(TM) i5-8400 CPU @ 2.80GHz
-BenchmarkBufferPoolManager-6              	16792826	        71.92 ns/op
-BenchmarkBufferPoolManager_Concurrent-6   	 9800792	       127.2 ns/op
-BenchmarkBufferPoolManager_Memory-6       	13066466	        79.52 ns/op
-BenchmarkEncodeWithBufferPool-6           	 8162733	       141.6 ns/op
-BenchmarkEncodeWithoutBufferPool-6        	 6148492	       272.3 ns/op
-BenchmarkDecodeBufferPool-6               	 7300572	       170.5 ns/op
-PASS
-ok  	smpptester/pdu	10.059s

benchmark/results/2024-07-24_7faa683237a04c069efef6642fc86caa4e33a710.txt

@@ -1,12 +0,0 @@
-goos: linux
-goarch: amd64
-pkg: smpptester/pdu
-cpu: Intel(R) Core(TM) i5-8400 CPU @ 2.80GHz
-BenchmarkBufferPoolManager-6              	  433611	      2688 ns/op
-BenchmarkBufferPoolManager_Concurrent-6   	 1467840	       683.2 ns/op
-BenchmarkBufferPoolManager_Memory-6       	  497097	      2389 ns/op
-BenchmarkEncode-6                         	 8964351	       148.5 ns/op
-BenchmarkEncodeInto-6                     	371218869	         2.987 ns/op
-BenchmarkDecode-6                         	1000000000	         0.2681 ns/op
-PASS
-ok  	smpptester/pdu	7.851s

benchmark/results/2024-07-24_bed69fbfd388402aed0f2845d1585a7e4f00e9ff.txt

@@ -1,13 +0,0 @@
-goos: linux
-goarch: amd64
-pkg: smpptester/pdu
-cpu: Intel(R) Core(TM) i5-8400 CPU @ 2.80GHz
-BenchmarkBufferPoolManager-6              	  457300	      2609 ns/op
-BenchmarkBufferPoolManager_Concurrent-6   	 2050396	       561.0 ns/op
-BenchmarkBufferPoolManager_Memory-6       	  504205	      2242 ns/op
-BenchmarkEncode-6                         	27733428	        44.06 ns/op
-BenchmarkEncodeWithBufferPool-6           	27795820	        42.97 ns/op
-BenchmarkEncodeInto-6                     	397897166	         3.004 ns/op
-BenchmarkDecode-6                         	1000000000	         0.2653 ns/op
-PASS
-ok  	smpptester/pdu	10.935s

benchmark/results/2024-07-31_38af7b146dd43175678c7246c1939b578ad0fe19.txt

@@ -1,27 +0,0 @@
-?   	smpptester	[no test files]
-?   	smpptester/benchmark	[no test files]
-?   	smpptester/client	[no test files]
-goos: linux
-goarch: amd64
-pkg: smpptester/encoding
-cpu: Intel(R) Core(TM) i5-8400 CPU @ 2.80GHz
-BenchmarkGSM7EncodeSimpleASCIIString-6              	19589385	        67.23 ns/op
-BenchmarkGSM7EncodeComplexASCIIString-6             	 3757233	       288.3 ns/op
-BenchmarkGSM7EncodeComplex8nASCIIString-6           	 2576941	       532.0 ns/op
-BenchmarkGSM7EncodeComplex8nASCIIStringPrealloc-6   	 2611428	       460.3 ns/op
-PASS
-ok  	smpptester/encoding	6.483s
-?   	smpptester/lua	[no test files]
-goos: linux
-goarch: amd64
-pkg: smpptester/pdu
-cpu: Intel(R) Core(TM) i5-8400 CPU @ 2.80GHz
-BenchmarkBufferPoolManager-6              	16908814	        71.62 ns/op
-BenchmarkBufferPoolManager_Concurrent-6   	 8895826	       125.1 ns/op
-BenchmarkBufferPoolManager_Memory-6       	13243089	        80.48 ns/op
-BenchmarkEncodeWithBufferPool-6           	 8433070	       139.2 ns/op
-BenchmarkEncodeWithoutBufferPool-6        	 7134577	       248.2 ns/op
-BenchmarkDecodeBufferPool-6               	 6587127	       166.0 ns/op
-PASS
-ok  	smpptester/pdu	8.296s
-?   	smpptester/server	[no test files]

benchmark/results/2024-07-31_4771ffa1546af62dcf03d03599094b3329f5c616.txt

@@ -1,27 +0,0 @@
-?   	smpptester	[no test files]
-?   	smpptester/benchmark	[no test files]
-?   	smpptester/client	[no test files]
-goos: linux
-goarch: amd64
-pkg: smpptester/encoding
-cpu: Intel(R) Core(TM) i5-8400 CPU @ 2.80GHz
-BenchmarkGSM7EncodeSimpleASCIIString-6              	14935776	        76.91 ns/op
-BenchmarkGSM7EncodeComplexASCIIString-6             	 3364554	       353.1 ns/op
-BenchmarkGSM7EncodeComplex8nASCIIString-6           	 1840044	       591.6 ns/op
-BenchmarkGSM7EncodeComplex8nASCIIStringPrealloc-6   	 2081725	       520.4 ns/op
-PASS
-ok  	smpptester/encoding	6.270s
-?   	smpptester/lua	[no test files]
-goos: linux
-goarch: amd64
-pkg: smpptester/pdu
-cpu: Intel(R) Core(TM) i5-8400 CPU @ 2.80GHz
-BenchmarkBufferPoolManager-6              	16804492	        75.91 ns/op
-BenchmarkBufferPoolManager_Concurrent-6   	11214482	       134.8 ns/op
-BenchmarkBufferPoolManager_Memory-6       	15180892	        71.99 ns/op
-BenchmarkEncodeWithBufferPool-6           	 8587657	       139.1 ns/op
-BenchmarkEncodeWithoutBufferPool-6        	 5282655	       223.4 ns/op
-BenchmarkDecodeBufferPool-6               	 6659464	       170.4 ns/op
-PASS
-ok  	smpptester/pdu	10.264s
-?   	smpptester/server	[no test files]

benchmark/results/2024-07-31_4d7e13a304f6f9e0cf735e1a0d9067d9fbb15495.txt

@@ -1,27 +0,0 @@
-?   	smpptester	[no test files]
-?   	smpptester/benchmark	[no test files]
-?   	smpptester/client	[no test files]
-goos: linux
-goarch: amd64
-pkg: smpptester/encoding
-cpu: Intel(R) Core(TM) i5-8400 CPU @ 2.80GHz
-BenchmarkGSM7EncodeSimpleASCIIString-6              	17371128	        63.88 ns/op
-BenchmarkGSM7EncodeComplexASCIIString-6             	 4210346	       332.9 ns/op
-BenchmarkGSM7EncodeComplex8nASCIIString-6           	 2748054	       517.4 ns/op
-BenchmarkGSM7EncodeComplex8nASCIIStringPrealloc-6   	 2576667	       469.9 ns/op
-PASS
-ok  	smpptester/encoding	6.462s
-?   	smpptester/lua	[no test files]
-goos: linux
-goarch: amd64
-pkg: smpptester/pdu
-cpu: Intel(R) Core(TM) i5-8400 CPU @ 2.80GHz
-BenchmarkBufferPoolManager-6              	16765892	        70.02 ns/op
-BenchmarkBufferPoolManager_Concurrent-6   	 9238833	       119.7 ns/op
-BenchmarkBufferPoolManager_Memory-6       	15343066	        75.22 ns/op
-BenchmarkEncodeWithBufferPool-6           	 8445075	       139.0 ns/op
-BenchmarkEncodeWithoutBufferPool-6        	 5464392	       274.3 ns/op
-BenchmarkDecodeBufferPool-6               	 6709528	       165.3 ns/op
-PASS
-ok  	smpptester/pdu	8.739s
-?   	smpptester/server	[no test files]

benchmark/results/2024-07-31_76bdc5214bb697407c2a6197dee26c2068be49fb.txt

@@ -1,27 +0,0 @@
-?   	smpptester	[no test files]
-?   	smpptester/benchmark	[no test files]
-?   	smpptester/client	[no test files]
-goos: linux
-goarch: amd64
-pkg: smpptester/encoding
-cpu: Intel(R) Core(TM) i5-8400 CPU @ 2.80GHz
-BenchmarkGSM7EncodeSimpleASCIIString-6              	18785672	        65.00 ns/op
-BenchmarkGSM7EncodeComplexASCIIString-6             	 4313766	       332.7 ns/op
-BenchmarkGSM7EncodeComplex8nASCIIString-6           	 2686035	       520.9 ns/op
-BenchmarkGSM7EncodeComplex8nASCIIStringPrealloc-6   	 2613550	       461.0 ns/op
-PASS
-ok  	smpptester/encoding	6.548s
-?   	smpptester/lua	[no test files]
-goos: linux
-goarch: amd64
-pkg: smpptester/pdu
-cpu: Intel(R) Core(TM) i5-8400 CPU @ 2.80GHz
-BenchmarkBufferPoolManager-6              	16675815	        69.97 ns/op
-BenchmarkBufferPoolManager_Concurrent-6   	 9622903	       120.8 ns/op
-BenchmarkBufferPoolManager_Memory-6       	15080410	        84.43 ns/op
-BenchmarkEncodeWithBufferPool-6           	 8589709	       138.9 ns/op
-BenchmarkEncodeWithoutBufferPool-6        	 6965332	       228.4 ns/op
-BenchmarkDecodeBufferPool-6               	 7003172	       165.4 ns/op
-PASS
-ok  	smpptester/pdu	8.384s
-?   	smpptester/server	[no test files]

benchmark/results/2024-07-31_85e674753e6e234b69324b46b911ba7cccd91ac8.txt

@@ -1,12 +0,0 @@
-goos: linux
-goarch: amd64
-pkg: smpptester/pdu
-cpu: Intel(R) Core(TM) i5-8400 CPU @ 2.80GHz
-BenchmarkBufferPoolManager-6              	15687109	        91.05 ns/op
-BenchmarkBufferPoolManager_Concurrent-6   	11083287	       128.9 ns/op
-BenchmarkBufferPoolManager_Memory-6       	16576201	        74.12 ns/op
-BenchmarkEncodeWithBufferPool-6           	 7868800	       138.1 ns/op
-BenchmarkEncodeWithoutBufferPool-6        	 6833810	       221.2 ns/op
-BenchmarkDecodeBufferPool-6               	 7195328	       166.0 ns/op
-PASS
-ok  	smpptester/pdu	8.763s

benchmark/results/2024-07-31_c56d441891915141cf35c38d8d7b4e06385377ab.txt

@@ -1,12 +0,0 @@
-goos: linux
-goarch: amd64
-pkg: smpptester/pdu
-cpu: Intel(R) Core(TM) i5-8400 CPU @ 2.80GHz
-BenchmarkBufferPoolManager-6              	14983336	        90.65 ns/op
-BenchmarkBufferPoolManager_Concurrent-6   	10671728	       124.4 ns/op
-BenchmarkBufferPoolManager_Memory-6       	16471220	        75.06 ns/op
-BenchmarkEncodeWithBufferPool-6           	 8545360	       139.1 ns/op
-BenchmarkEncodeWithoutBufferPool-6        	 6794032	       224.7 ns/op
-BenchmarkDecodeBufferPool-6               	 6737445	       165.3 ns/op
-PASS
-ok  	smpptester/pdu	8.681s

benchmark/results/2024-08-02_78fc53a9a41e241c74ce94cdab5952a0e123d1d4.txt

@@ -1,28 +0,0 @@
-?   	smpptester	[no test files]
-?   	smpptester/benchmark	[no test files]
-?   	smpptester/client	[no test files]
-goos: linux
-goarch: amd64
-pkg: smpptester/encoding
-cpu: Intel(R) Core(TM) i5-8400 CPU @ 2.80GHz
-BenchmarkGSM7EncodeSimpleASCIIString-6              	17190692	        63.88 ns/op
-BenchmarkGSM7EncodeComplexASCIIString-6             	 3987712	       302.8 ns/op
-BenchmarkGSM7EncodeComplex8nASCIIString-6           	 2563090	       523.2 ns/op
-BenchmarkGSM7EncodeComplex8nASCIIStringPrealloc-6   	 2615463	       462.5 ns/op
-PASS
-ok  	smpptester/encoding	6.235s
-?   	smpptester/lua	[no test files]
-goos: linux
-goarch: amd64
-pkg: smpptester/pdu
-cpu: Intel(R) Core(TM) i5-8400 CPU @ 2.80GHz
-BenchmarkBufferPoolManager-6              	16913668	        70.22 ns/op
-BenchmarkBufferPoolManager_Concurrent-6   	 9289608	       129.8 ns/op
-BenchmarkBufferPoolManager_Memory-6       	13000988	        83.78 ns/op
-BenchmarkEncodeWithBufferPool-6           	 7950153	       137.7 ns/op
-BenchmarkEncodeWithoutBufferPool-6        	 6290456	       172.9 ns/op
-BenchmarkDecodeBufferPool-6               	 7194349	       162.7 ns/op
-PASS
-ok  	smpptester/pdu	7.717s
-?   	smpptester/server	[no test files]
-?   	smpptester/utils	[no test files]

encoding/.air.toml

@@ -0,0 +1,51 @@
+root = "."
+testdata_dir = "testdata"
+tmp_dir = "tmp"
+
+[build]
+  args_bin = []
+  bin = "tmp\\main.exe"
+  cmd = "go test ."
+  delay = 1000
+  exclude_dir = ["assets", "tmp", "vendor", "testdata"]
+  exclude_file = []
+  exclude_regex = []
+  exclude_unchanged = false
+  follow_symlink = false
+  full_bin = ""
+  include_dir = []
+  include_ext = ["go", "tpl", "tmpl", "html"]
+  include_file = []
+  kill_delay = "0s"
+  log = "build-errors.log"
+  poll = false
+  poll_interval = 0
+  post_cmd = []
+  pre_cmd = []
+  rerun = false
+  rerun_delay = 100
+  send_interrupt = false
+  stop_on_error = false
+
+[color]
+  app = ""
+  build = "yellow"
+  main = "magenta"
+  runner = "green"
+  watcher = "cyan"
+
+[log]
+  main_only = false
+  time = false
+
+[misc]
+  clean_on_exit = true
+
+[proxy]
+  app_port = 0
+  enabled = false
+  proxy_port = 0
+
+[screen]
+  clear_on_rebuild = true
+  keep_scroll = true

encoding/ascii.go

@@ -0,0 +1,22 @@
+package encoding
+
+import "bytes"
+
+type ASCIICoder struct{}
+
+func (c *ASCIICoder) Encode(s *string, buf *bytes.Buffer) error {
+	// These should be ASCII but UTF8 is a superset of ASCII so hopefully this'll be fine
+	buf.WriteString(*s)
+	return nil
+}
+
+func (c *ASCIICoder) Decode(buf *bytes.Buffer) (string, error) {
+	return buf.String(), nil
+}
+
+func (c ASCIICoder) EncodesInto(s *string) int {
+	return len(*s)
+}
+func (c ASCIICoder) DecodesInto(buf *bytes.Buffer) int {
+	return buf.Len()
+}

encoding/ascii_test.go

@@ -0,0 +1,74 @@
+package encoding
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestASCIIEncodeSimpleASCIIString(t *testing.T) {
+	coder := &ASCIICoder{}
+	var buf bytes.Buffer
+	input := "Hello, World!"
+
+	expected := []byte{72, 101, 108, 108, 111, 44, 32, 87, 111, 114, 108, 100, 33}
+	err := coder.Encode(&input, &buf)
+
+	if err != nil {
+		t.Errorf("Expected no error, but got %v", err)
+	}
+
+	if !bytes.Equal(buf.Bytes(), expected) {
+		t.Errorf("Expected %v, but got %v", expected, buf.Bytes())
+	}
+}
+
+func TestASCIIDecodeSimpleASCIIString(t *testing.T) {
+	coder := &ASCIICoder{}
+	var buf bytes.Buffer
+	input := []byte{72, 101, 108, 108, 111, 44, 32, 87, 111, 114, 108, 100, 33}
+
+	expected := "Hello, World!"
+	buf.Write(input)
+	output, err := coder.Decode(&buf)
+
+	if err != nil {
+		t.Errorf("Expected no error, but got %v", err)
+	}
+
+	if output != expected {
+		t.Errorf("Expected %v, but got %v", expected, output)
+	}
+}
+
+func TestASCIIEncodeEmptyString(t *testing.T) {
+	coder := &ASCIICoder{}
+	var buf bytes.Buffer
+	input := ""
+
+	expected := []byte{}
+	err := coder.Encode(&input, &buf)
+
+	if err != nil {
+		t.Errorf("Expected no error, but got %v", err)
+	}
+
+	if !bytes.Equal(buf.Bytes(), expected) {
+		t.Errorf("Expected %v, but got %v", expected, buf.Bytes())
+	}
+}
+
+func TestASCIIDecodeEmptyString(t *testing.T) {
+	coder := &ASCIICoder{}
+	buf := bytes.NewBuffer([]byte{})
+
+	expected := ""
+	output, err := coder.Decode(buf)
+
+	if err != nil {
+		t.Errorf("Expected no error, but got %v", err)
+	}
+
+	if output != expected {
+		t.Errorf("Expected %v, but got %v", expected, output)
+	}
+}

encoding/charset.json

@@ -0,0 +1,5 @@
+{
+	"ucs2": {
+		"link": "http://www.columbia.edu/kermit/ucs2.html"
+	}
+}

encoding/coder.go

@@ -0,0 +1,10 @@
+package encoding
+
+import "bytes"
+
+type Coder interface {
+	Encode(s *string, buf *bytes.Buffer) error
+	Decode(buf *bytes.Buffer) (string, error)
+	EncodesInto(s *string) int
+	DecodesInto(buf *bytes.Buffer) int
+}

encoding/gsm7.go

@@ -0,0 +1,136 @@
+package encoding
+
+import (
+	"bytes"
+	"fmt"
+)
+
+type GSM7Coder struct{}
+
+// Make sure buffer can fit EncodesInto bytes
+// Otherwise Encode will allocate memory as it sees fit
+// Which is fine but not optimal
+// Preallocate the buffer with the size of EncodesInto bytes
+func (c *GSM7Coder) Encode(s *string, buf *bytes.Buffer) error {
+	// utf8 := *(*[]byte)(unsafe.Pointer(&s))
+	utf8 := []byte(*s)
+	var (
+		offset      int  = 1
+		bitshift    byte = 0
+		leap, shift bool
+	)
+	encodedSize := c.EncodesInto(s)
+	cap := buf.Cap()
+	if cap < encodedSize {
+		buf.Grow(encodedSize - cap)
+	}
+
+	for index, septet := range utf8 {
+		if septet > 0b01111111 {
+			return fmt.Errorf("invalid character at index %d", index)
+		}
+		if index == 0 {
+			continue
+		}
+		bitshift++
+		// log.Printf("Index:%-3d Offset:%-3d Bitshift:%-3d CurrentByte:%08b (%-3d) OffsetByte:%08b (%-3d) Leap:%5v", index, offset, bitshift, utf8[index], utf8[index], utf8[index-offset], utf8[index-offset], leap)
+		mask := byte(255 >> (8 - bitshift))
+		masked := (mask & septet) << (8 - bitshift)
+		// log.Printf("Index:%-3d Offset:%-3d Bitshift:%-3d Mask:%08b Masked:%08b", index, offset, bitshift, mask, masked)
+		if leap {
+			masked >>= 1
+		}
+		utf8[index-offset] |= masked
+		utf8[index] >>= bitshift
+
+		if !leap {
+			buf.WriteByte(utf8[index-offset])
+		}
+		if index == len(utf8)-1 && utf8[index] > 0 {
+			buf.WriteByte(utf8[index])
+		}
+		// log.Printf("Index:%-3d Offset:%-3d Bitshift:%-3d CurrentByte:%08b (%-3d) OffsetByte:%08b (%-3d) Leap:%5v", index, offset, bitshift, utf8[index], utf8[index], utf8[index-offset], utf8[index-offset], leap)
+		if bitshift >= 7 {
+			if leap {
+				// log.Printf("Shift at Index:%-3d Offset:%-3d Bitshift:%-3d", index, offset, bitshift)
+				leap = false
+				bitshift = 0
+				offset++
+				shift = true
+				continue
+			}
+			// log.Printf("Leap at Index:%-3d Offset:%-3d Bitshift:%-3d", index, offset, bitshift)
+			leap = true
+			bitshift = 6
+		}
+		if shift {
+			offset = 1
+		}
+	}
+	return nil
+}
+
+func (c *GSM7Coder) Decode(buf *bytes.Buffer) (string, error) {
+	gsm7 := buf.Bytes()
+	var (
+		offset   int
+		bitshift byte = 0
+		leap     bool
+	)
+	outLength := c.DecodesInto(buf)
+	lengthDiff := outLength - len(gsm7)
+	gsm7 = append(gsm7, make([]byte, lengthDiff)...)
+	start := len(gsm7) - 2
+
+	// We don't care about the last byte
+	// Unless it's the %8.......
+	// We'll deal with that later
+	for index := start; index >= 0; index-- {
+		octet := gsm7[index]
+		bitshift = byte((index % 7) + 1)
+		if bitshift == 7 {
+			leap = true
+		}
+		offset = 1
+		// log.Println(offset, index, index+offset)
+		// log.Printf("Index:%-3d Offset:%-3d Bitshift:%-3d CurrentByte:%08b (%-3d) OffsetByte(%-3d):%08b (%-3d) Leap:%5v", index, offset, bitshift, gsm7[index], gsm7[index], index+offset, gsm7[index+offset], gsm7[index+offset], leap)
+
+		mask := byte(255 << (8 - bitshift))
+		masked := (mask & octet) >> (8 - bitshift)
+		// log.Printf("Index:%-3d Offset:%-3d Bitshift:%-3d Mask:%08b Masked:%08b", index, offset, bitshift, mask, masked)
+		if leap {
+			InsertAt(&gsm7, index+offset, masked)
+		} else {
+			gsm7[index+offset] |= masked
+		}
+		// Remove last bitshift bits
+		gsm7[index] <<= bitshift
+		// Move the remaining bit once to the right to form septet instead of octet
+		gsm7[index] >>= 1
+
+		// log.Printf("Index:%-3d Offset:%-3d Bitshift:%-3d CurrentByte:%08b (%-3d) OffsetByte(%-3d):%08b (%-3d) Leap:%5v", index, offset, bitshift, gsm7[index], gsm7[index], index+offset, gsm7[index+offset], gsm7[index+offset], leap)
+		leap = false
+	}
+	return string(gsm7), nil
+}
+
+// Allocation free
+// Which means data MUST have space for value
+func InsertAt(data *[]byte, index int, value byte) {
+	copy((*data)[index+1:], (*data)[index:])
+	(*data)[index] = value
+}
+
+func (c GSM7Coder) EncodesInto(s *string) int {
+	slen := len(*s)
+	enclen := slen * 7 / 8
+	if slen%8 != 0 {
+		enclen++
+	}
+	return enclen
+}
+func (c GSM7Coder) DecodesInto(buf *bytes.Buffer) int {
+	blen := buf.Len()
+	declen := blen * 8 / 7
+	return declen
+}

encoding/gsm7_test.go

@@ -0,0 +1,369 @@
+package encoding
+
+import (
+	"bytes"
+	"testing"
+)
+
+var (
+	short8nString   = "Sunshine"
+	longNot8nString = "Golden rays play, Chasing night away."
+	long8nString    = "Ducks are fucking great, they quacks, O quackers, what the fuck."
+
+	short8nStringEncodedBytes   = []byte{0b11010011, 0b10111010, 0b01111011, 0b10001110, 0b01001110, 0b10111011, 0b11001011}
+	longNot8nStringEncodedBytes = []byte{0b11000111, 0b00110111, 0b10011011, 0b01011100, 0b01110110, 0b10000011, 0b11100100, 0b11100001, 0b11111100, 0b00011100, 0b00000100, 0b01100111, 0b10000111, 0b11110011, 0b00101100, 0b11010000, 0b00010000, 0b00011101, 0b10011110, 0b10100111, 0b11011101, 0b01100111, 0b10010000, 0b00111011, 0b01111101, 0b01000110, 0b11010011, 0b01000001, 0b11100001, 0b01111011, 0b00111000, 0b11101111, 0b00000010}
+	long8nStringEncodedBytes    = []byte{0b11000100, 0b11111010, 0b01111000, 0b00111101, 0b00000111, 0b10000101, 0b11100101, 0b01100101, 0b10010000, 0b10111001, 0b00111110, 0b01011110, 0b10100111, 0b11011101, 0b01100111, 0b11010000, 0b01011001, 0b01011110, 0b00001110, 0b11010011, 0b01011001, 0b00100000, 0b00111010, 0b10111010, 0b10011100, 0b00000111, 0b11000101, 0b11101011, 0b11100001, 0b11110001, 0b01111010, 0b11001110, 0b00000010, 0b00111101, 0b01000001, 0b11110001, 0b01111010, 0b01111000, 0b10111100, 0b00101110, 0b11001011, 0b11100111, 0b00101100, 0b11010000, 0b00011101, 0b00011101, 0b10100110, 0b10000011, 0b11101000, 0b11101000, 0b00110010, 0b11001000, 0b01011100, 0b00011111, 0b10101111, 0b01011101}
+)
+
+// region encode
+func TestGSM7EncodeSimpleASCIIString(t *testing.T) {
+	coder := &GSM7Coder{}
+	var buf bytes.Buffer
+	input := short8nString
+
+	expected := short8nStringEncodedBytes
+	err := coder.Encode(&input, &buf)
+
+	if err != nil {
+		t.Errorf("Expected no error, but got %v", err)
+	}
+
+	if !bytes.Equal(buf.Bytes(), expected) {
+		t.Errorf("Expected '%v', but got '%v'", expected, buf.Bytes())
+	}
+}
+
+func TestGSM7EncodeComplexASCIIString(t *testing.T) {
+	coder := &GSM7Coder{}
+	var buf bytes.Buffer
+	input := longNot8nString
+
+	expected := longNot8nStringEncodedBytes
+	err := coder.Encode(&input, &buf)
+
+	if err != nil {
+		t.Errorf("Expected no error, but got %v", err)
+	}
+
+	if !bytes.Equal(buf.Bytes(), expected) {
+		t.Errorf("Expected '%v', but got '%v'", expected, buf.Bytes())
+	}
+}
+
+func TestGSM7EncodeComplex8nASCIIString(t *testing.T) {
+	coder := &GSM7Coder{}
+	var buf bytes.Buffer
+	input := "Ducks are fucking great, they quacks, O quackers, what the fuck."
+
+	expected := long8nStringEncodedBytes
+	err := coder.Encode(&input, &buf)
+
+	if err != nil {
+		t.Errorf("Expected no error, but got %v", err)
+	}
+
+	if !bytes.Equal(buf.Bytes(), expected) {
+		t.Errorf("Expected '%v', but got '%v'", expected, buf.Bytes())
+	}
+}
+
+func TestGSM7EncodeDoesNotAllocateMoreThanNecessary(t *testing.T) {
+	coder := &GSM7Coder{}
+	input := "Ducks are fucking great, they quacks, O quackers, what the fuck."
+	buf := bytes.NewBuffer(make([]byte, coder.EncodesInto(&input)))
+	buf.Reset()
+
+	expected := buf.Cap()
+	err := coder.Encode(&input, buf)
+	actual := buf.Cap()
+
+	if err != nil {
+		t.Errorf("Expected no error, but got %v", err)
+	}
+
+	if actual != expected {
+		t.Errorf("Expected buffer of size %v, but got %v", expected, actual)
+	}
+}
+
+func TestGSM7EncodeDoesAllocateWhenNecessary(t *testing.T) {
+	coder := &GSM7Coder{}
+	input := "Ducks are fucking great, they quacks, O quackers, what the fuck."
+	var buf bytes.Buffer
+	buf.Reset()
+
+	original := buf.Cap()
+	err := coder.Encode(&input, &buf)
+	modified := buf.Cap()
+
+	if err != nil {
+		t.Errorf("Expected no error, but got %v", err)
+	}
+
+	if !(modified > original) {
+		t.Errorf("Expected buffer to grow but buffer changed from %v to %v", original, modified)
+	}
+}
+
+func TestGSM7EncodeEmptyString(t *testing.T) {
+	coder := &GSM7Coder{}
+	var buf bytes.Buffer
+	input := ""
+
+	expected := []byte{}
+	err := coder.Encode(&input, &buf)
+
+	if err != nil {
+		t.Errorf("Expected no error, but got %v", err)
+	}
+
+	if !bytes.Equal(buf.Bytes(), expected) {
+		t.Errorf("Expected '%v', but got '%v'", expected, buf.Bytes())
+	}
+}
+
+// region decode
+func TestGSM7DecodeSimpleASCIIString(t *testing.T) {
+	coder := &GSM7Coder{}
+	var buf bytes.Buffer
+	input := short8nStringEncodedBytes
+
+	expected := short8nString
+	buf.Write(input)
+	actual, err := coder.Decode(&buf)
+
+	if err != nil {
+		t.Errorf("Expected no error, but got %v", err)
+	}
+
+	if actual != expected {
+		t.Errorf("Expected '%v', but got '%v'", expected, actual)
+	}
+}
+
+func TestGSM7DecodeComplexASCIIString(t *testing.T) {
+	coder := &GSM7Coder{}
+	var buf bytes.Buffer
+	input := longNot8nStringEncodedBytes
+
+	expected := longNot8nString
+	buf.Write(input)
+	actual, err := coder.Decode(&buf)
+
+	if err != nil {
+		t.Errorf("Expected no error, but got %v", err)
+	}
+
+	if actual != expected {
+		t.Errorf("Expected '%v', but got '%v'", expected, actual)
+	}
+}
+
+func TestGSM7DecodeComplex8nASCIIString(t *testing.T) {
+	coder := &GSM7Coder{}
+	var buf bytes.Buffer
+	input := long8nStringEncodedBytes
+
+	expected := long8nString
+	buf.Write(input)
+	actual, err := coder.Decode(&buf)
+
+	if err != nil {
+		t.Errorf("Expected no error, but got %v", err)
+	}
+
+	if actual != expected {
+		t.Errorf("Expected '%v', but got '%v'", expected, actual)
+	}
+}
+
+func TestGSM7DecodeEmptyString(t *testing.T) {
+	coder := &GSM7Coder{}
+	buf := bytes.NewBuffer([]byte{})
+
+	expected := ""
+	actual, err := coder.Decode(buf)
+
+	if err != nil {
+		t.Errorf("Expected no error, but got %v", err)
+	}
+
+	if actual != expected {
+		t.Errorf("Expected '%v', but got '%v'", expected, actual)
+	}
+}
+
+// region insertat
+func TestInsertAtBeginning(t *testing.T) {
+	data := []byte{2, 3, 4, 0}
+	InsertAt(&data, 0, 1)
+	expected := []byte{1, 2, 3, 4}
+	if !bytes.Equal(data, expected) {
+		t.Errorf("expected %v, got %v", expected, data)
+	}
+}
+
+func TestInsertInMiddle(t *testing.T) {
+	data := []byte{2, 3, 4, 0}
+	InsertAt(&data, 1, 5)
+	expected := []byte{2, 5, 3, 4}
+	if !bytes.Equal(data, expected) {
+		t.Errorf("expected %v, got %v", expected, data)
+	}
+}
+
+func TestInsertAtEnd(t *testing.T) {
+	data := []byte{1, 2, 3, 0}
+	InsertAt(&data, 3, 4)
+	expected := []byte{1, 2, 3, 4}
+	if !bytes.Equal(data, expected) {
+		t.Errorf("expected %v, got %v", expected, data)
+	}
+}
+
+func TestIndexOutOfBounds(t *testing.T) {
+	data := []byte{2, 3, 4}
+	defer func() {
+		if r := recover(); r == nil {
+			t.Errorf("The code did not panic")
+		}
+	}()
+	InsertAt(&data, 4, 5)
+}
+
+func TestNegativeIndex(t *testing.T) {
+	data := []byte{2, 3, 4}
+	defer func() {
+		if r := recover(); r == nil {
+			t.Errorf("The code did not panic")
+		}
+	}()
+	InsertAt(&data, -1, 1)
+}
+
+func TestMaintainsOrderAfterInsertion(t *testing.T) {
+	data := []byte{2, 3, 4, 0}
+	InsertAt(&data, 1, 1)
+	expected := []byte{2, 1, 3, 4}
+	if !bytes.Equal(data, expected) {
+		t.Errorf("expected %v, got %v", expected, data)
+	}
+}
+
+func TestMaintainsLength(t *testing.T) {
+	data := []byte{2, 3, 4, 0}
+	InsertAt(&data, 1, 1)
+	if len(data) != 4 {
+		t.Errorf("expected length 4, got %d", len(data))
+	}
+}
+
+func TestDeletesLastValue(t *testing.T) {
+	data := []byte{2, 3, 4, 5}
+	InsertAt(&data, 0, 1)
+	expected := []byte{1, 2, 3, 4}
+	if !bytes.Equal(data, expected) {
+		t.Errorf("expected %v, got %v", expected, data)
+	}
+}
+
+// region misc tests
+func TestGSM7EncodesIntoSmallString(t *testing.T) {
+	input := short8nString
+	expected := 7
+	actual := GSM7Coder{}.EncodesInto(&input)
+	if actual != expected {
+		t.Errorf("Expected %d, but got %d", expected, actual)
+	}
+}
+
+func TestGSM7EncodesIntoLargerNot8nString(t *testing.T) {
+	input := longNot8nString
+	expected := 33
+	actual := GSM7Coder{}.EncodesInto(&input)
+	if actual != expected {
+		t.Errorf("Expected %d, but got %d", expected, actual)
+	}
+}
+
+func TestGSM7EncodesIntoLarger8nString(t *testing.T) {
+	input := long8nString
+	expected := 56
+	actual := GSM7Coder{}.EncodesInto(&input)
+	if actual != expected {
+		t.Errorf("Expected %d, but got %d", expected, actual)
+	}
+}
+
+func TestGSM7DecodesIntoSmallString(t *testing.T) {
+	input := short8nStringEncodedBytes
+	expected := 8
+	actual := GSM7Coder{}.DecodesInto(bytes.NewBuffer(input))
+	if actual != expected {
+		t.Errorf("Expected %d, but got %d", expected, actual)
+	}
+}
+
+func TestGSM7DecodesIntoLargerNot8nString(t *testing.T) {
+	input := longNot8nStringEncodedBytes
+	expected := 37
+	actual := GSM7Coder{}.DecodesInto(bytes.NewBuffer(input))
+	if actual != expected {
+		t.Errorf("Expected %d, but got %d", expected, actual)
+	}
+}
+
+func TestGSM7DecodesIntoLarger8nString(t *testing.T) {
+	input := long8nStringEncodedBytes
+	expected := 64
+	actual := GSM7Coder{}.DecodesInto(bytes.NewBuffer(input))
+	if actual != expected {
+		t.Errorf("Expected %d, but got %d", expected, actual)
+	}
+}
+
+// region benchmark
+func BenchmarkGSM7EncodeSimpleASCIIString(b *testing.B) {
+	coder := &GSM7Coder{}
+	var buf bytes.Buffer
+	input := short8nString
+	b.ResetTimer()
+
+	for i := 0; i < b.N; i++ {
+		coder.Encode(&input, &buf)
+	}
+}
+
+func BenchmarkGSM7EncodeComplexASCIIString(b *testing.B) {
+	coder := &GSM7Coder{}
+	var buf bytes.Buffer
+	input := longNot8nString
+	b.ResetTimer()
+
+	for i := 0; i < b.N; i++ {
+		coder.Encode(&input, &buf)
+	}
+}
+
+func BenchmarkGSM7EncodeComplex8nASCIIString(b *testing.B) {
+	coder := &GSM7Coder{}
+	var buf bytes.Buffer
+	input := long8nString
+	b.ResetTimer()
+
+	for i := 0; i < b.N; i++ {
+		coder.Encode(&input, &buf)
+	}
+}
+
+func BenchmarkGSM7EncodeComplex8nASCIIStringPrealloc(b *testing.B) {
+	coder := &GSM7Coder{}
+	input := long8nString
+	b.ResetTimer()
+
+	for i := 0; i < b.N; i++ {
+		buf := bytes.NewBuffer(make([]byte, coder.EncodesInto(&input)))
+		buf.Reset()
+		coder.Encode(&input, buf)
+	}
+}

encoding/ucs2.go

@@ -0,0 +1,19 @@
+package encoding
+
+import "bytes"
+
+type UCS2Coder struct{}
+
+func (c *UCS2Coder) Encode(s *string, buf *bytes.Buffer) error {
+	panic("UCS2 not implemented yet")
+}
+func (c *UCS2Coder) Decode(buf *bytes.Buffer) (string, error) {
+	panic("UCS2 not implemented yet")
+}
+
+func (c UCS2Coder) EncodesInto(s *string) int {
+	return len(*s) * 2
+}
+func (c UCS2Coder) DecodesInto(buf *bytes.Buffer) int {
+	return buf.Len() / 2
+}

main.go

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

pdu/.air.toml

@@ -0,0 +1,51 @@
+root = "."
+testdata_dir = "testdata"
+tmp_dir = "tmp"
+
+[build]
+  args_bin = []
+  bin = "tmp\\main.exe"
+  cmd = "go test ."
+  delay = 1000
+  exclude_dir = ["assets", "tmp", "vendor", "testdata"]
+  exclude_file = []
+  exclude_regex = []
+  exclude_unchanged = false
+  follow_symlink = false
+  full_bin = ""
+  include_dir = []
+  include_ext = ["go", "tpl", "tmpl", "html"]
+  include_file = []
+  kill_delay = "0s"
+  log = "build-errors.log"
+  poll = false
+  poll_interval = 0
+  post_cmd = []
+  pre_cmd = []
+  rerun = false
+  rerun_delay = 500
+  send_interrupt = false
+  stop_on_error = false
+
+[color]
+  app = ""
+  build = "yellow"
+  main = "magenta"
+  runner = "green"
+  watcher = "cyan"
+
+[log]
+  main_only = false
+  time = false
+
+[misc]
+  clean_on_exit = false
+
+[proxy]
+  app_port = 0
+  enabled = false
+  proxy_port = 0
+
+[screen]
+  clear_on_rebuild = false
+  keep_scroll = true

pdu/bind.go

@@ -2,19 +2,19 @@ package pdu
 
 type (
 	BIND struct {
-		header            PDU_HEADER
+		header            *PDU_HEADER
 		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
+		header               *PDU_HEADER
 		system_id            string
-		sc_interface_version uint8
+		sc_interface_version byte
 	}
 	BIND_RECVEIVER struct {
 		BIND
@@ -36,9 +36,9 @@ type (
 	}
 
 	UNBIND struct {
-		PDU_HEADER
+		header *PDU_HEADER
 	}
 	UNBIND_RESP struct {
-		PDU_HEADER
+		header *PDU_HEADER
 	}
 )

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

@@ -2,17 +2,17 @@ package pdu
 
 type (
 	CANCEL_SM struct {
-		header           PDU_HEADER
+		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 {
-		header PDU_HEADER
+		header *PDU_HEADER
 	}
 )

pdu/deliver.go

@@ -2,11 +2,11 @@ package pdu
 
 type (
 	DELIVER_SM struct {
-		header PDU_HEADER
+		header *PDU_HEADER
 		SUBMIT_SM
 	}
 	DELIVER_SM_RESP struct {
-		header PDU_HEADER
+		header *PDU_HEADER
 		SUBMIT_SM_RESP
 	}
 )

pdu/enquire.go

@@ -2,9 +2,9 @@ package pdu
 
 type (
 	ENQUIRE_LINK struct {
-		header PDU_HEADER
+		header *PDU_HEADER
 	}
 	ENQUIRE_LINK_RESP struct {
-		header PDU_HEADER
+		header *PDU_HEADER
 	}
 )

pdu/global.go

@@ -1,3 +1,5 @@
 package pdu
 
 var ByteBufferPool = NewBufferPoolManager()
+const NULL = byte(0x00)
+var NULL_ARR = []byte{NULL}

pdu/pdu.go

@@ -1,17 +1,18 @@
 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
+		UpdateSize()
 	}
 
 	PDU_HEADER struct {
@@ -22,7 +23,7 @@ type (
 	}
 
 	GENERIC_NACK struct {
-		header PDU_HEADER
+		header *PDU_HEADER
 	}
 )
 
@@ -57,41 +58,29 @@ 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) EncodeInto(buf *[]uint8) error {
+func (p *PDU_HEADER) Encode(buf *bytes.Buffer) error {
 	if buf == nil {
-		return fmt.Errorf("cannot encode PDU_HEADER, buffer is nil")
+		return fmt.Errorf("cannot encode into 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.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) 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])
+func (p *PDU_HEADER) Decode(buf *bytes.Buffer) error {
+	if buf == nil {
+		return fmt.Errorf("cannot decode nil buffer")
 	}
+	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) Size() uint32 {
+func (p *PDU_HEADER) Size() int {
 	return 16
 }
+func (p *PDU_HEADER) UpdateSize() {
+	p.command_length = uint32(p.Size())
+}

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 +260,39 @@ 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]))
 	}
 }
 
-
 // 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 +300,8 @@ 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 +323,13 @@ 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 +339,8 @@ 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 +359,8 @@ 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 +382,11 @@ 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 +401,8 @@ 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 +418,8 @@ 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 +442,8 @@ 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 +452,14 @@ 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 +468,19 @@ 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

@@ -1,104 +1,153 @@
 package pdu
 
-import "fmt"
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+
+	"smpptester/encoding"
+)
 
 type (
 	SUBMIT_SM struct {
-		header                 PDU_HEADER
+		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
+		header     *PDU_HEADER
 		message_id string
 	}
 	SUBMIT_MULTI      struct{}
 	SUBMIT_MULTI_RESP struct{}
 )
+// See https://www.codeproject.com/Tips/470755/Encoding-Decoding-7-bit-User-Data-for-SMS-PDU-PDU
+// Another great site: https://doubleblak.com/blogPost.php?k=7bitpdu
 
-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 {
+func (p *SUBMIT_SM) Encode(buf *bytes.Buffer) error {
 	if buf == nil {
-		return fmt.Errorf("cannot encode SUBMIT_SM, buffer is nil")
+		return fmt.Errorf("cannot encode into nil buffer")
 	}
-	if len(*buf) < int(p.Size()) {
-		return fmt.Errorf("cannot encode SUBMIT_SM, buffer too small (%d, required %d)", len(*buf), p.Size())
+	messageEncoder := p.GetEncoder()
+
+	p.header.Encode(buf)
+	// These should be ASCII but UTF8 is a superset of ASCII so hopefully this'll be fine
+	buf.WriteString(p.service_type)
+	buf.Write(NULL_ARR)
+	binary.Write(buf, binary.BigEndian, p.source_addr_ton)
+	binary.Write(buf, binary.BigEndian, p.source_addr_npi)
+	buf.WriteString(p.source_addr)
+	buf.Write(NULL_ARR)
+	binary.Write(buf, binary.BigEndian, p.dest_addr_ton)
+	binary.Write(buf, binary.BigEndian, p.dest_addr_npi)
+	buf.WriteString(p.destination_addr)
+	buf.Write(NULL_ARR)
+	binary.Write(buf, binary.BigEndian, p.esm_class)
+	binary.Write(buf, binary.BigEndian, p.protocol_id)
+	binary.Write(buf, binary.BigEndian, p.priority_flag)
+	buf.WriteString(p.schedule_delivery_time)
+	buf.Write(NULL_ARR)
+	buf.WriteString(p.validity_period)
+	buf.Write(NULL_ARR)
+	binary.Write(buf, binary.BigEndian, p.registered_delivery)
+	binary.Write(buf, binary.BigEndian, p.replace_if_present)
+	binary.Write(buf, binary.BigEndian, p.data_coding)
+	binary.Write(buf, binary.BigEndian, p.sm_default_msg_id)
+	binary.Write(buf, binary.BigEndian, p.sm_length)
+	err := messageEncoder.Encode(&p.short_message, buf)
+	if err != nil {
+		return err
 	}
-
-	p.header.EncodeInto(buf)
-
 	return nil
 }
-func (p *SUBMIT_SM) Decode(data []byte) {
+func (p *SUBMIT_SM) Decode(buf *bytes.Buffer) error {
+	if buf == nil {
+		return fmt.Errorf("cannot decode nil buffer")
+	}
+	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 += 1 + len(p.service_type)
 	size += 1 // source_addr_ton
 	size += 1 // source_addr_npi
-	size += uint32(len(p.source_addr) * 1)
+	size += 1 + len(p.source_addr)
 	size += 1 // dest_addr_ton
 	size += 1 // dest_addr_npi
-	size += uint32(len(p.destination_addr) * 1)
+	size += 1 + len(p.destination_addr)
 	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 += 1 + len(p.schedule_delivery_time)
+	size += 1 + len(p.validity_period)
 	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 += p.GetEncoder().EncodesInto(&p.short_message)
 	return size
 }
+func (p *SUBMIT_SM) UpdateSize() {
+	p.header.command_length = uint32(p.Size())
+	p.sm_length = byte(len(p.short_message))
+}
+func (p *SUBMIT_SM) GetEncoder() encoding.Coder {
+	switch p.data_coding {
+	case 0b00000000: // GSM7
+		return &encoding.GSM7Coder{}
+	case 0b00000001: // ASCII
+		return &encoding.ASCIICoder{}
+	// case 0b00000011: // LATIN1
+	// 	return &encoding.LATIN1Coder{}
+	case 0b00001000: // UCS2
+		return &encoding.UCS2Coder{}
+	default:
+		return &encoding.ASCIICoder{}
+	}
+}

pdu/submit_test.go

@@ -1,9 +1,72 @@
 package pdu
 
 import (
+	"bytes"
 	"testing"
 )
 
+// region encode
+// See examples: https://www.openmarket.com/docs/Content/apis/v4smpp/mt-examples.htm
+func TestEncodeFunctionCorrectlyEncodesAllFields(t *testing.T) {
+	p := &SUBMIT_SM{
+		header: &PDU_HEADER{
+			command_length:  0,
+			command_id:      4,
+			command_status:  0,
+			sequence_number: 378019,
+		},
+		service_type:           "OMV4",
+		source_addr_ton:        3,
+		source_addr_npi:        1,
+		source_addr:            "80362",
+		dest_addr_ton:          1,
+		dest_addr_npi:          1,
+		destination_addr:       "812345001000",
+		esm_class:              0,
+		protocol_id:            0,
+		priority_flag:          0,
+		schedule_delivery_time: "",
+		validity_period:        "180105120000004+",
+		registered_delivery:    1,
+		data_coding:            1, // The example uses 0 and claims to use GSM but the message is encoded as ASCII...
+		sm_default_msg_id:      0,
+		short_message:          "Reply Yes to opt in or No to opt out.",
+	}
+	p.UpdateSize()
+	buf := ByteBufferPool.Get(p.Size())
+	err := p.Encode(buf)
+	if err != nil {
+		t.Fatalf("expected no error, got %v", err)
+	}
+
+	expected := []byte{0, 0, 0, 107, 0, 0, 0, 4, 0, 0, 0, 0, 0, 5, 196, 163, 79, 77, 86, 52, 0, 3, 1, 56, 48, 51, 54, 50, 0, 1, 1, 56, 49, 50, 51, 52, 53, 48, 48, 49, 48, 48, 48, 0, 0, 0, 0, 0, 49, 56, 48, 49, 48, 53, 49, 50, 48, 48, 48, 48, 48, 48, 52, 43, 0, 1, 0, 1, 0, 37, 82, 101, 112, 108, 121, 32, 89, 101, 115, 32, 116, 111, 32, 111, 112, 116, 32, 105, 110, 32, 111, 114, 32, 78, 111, 32, 116, 111, 32, 111, 112, 116, 32, 111, 117, 116, 46}
+	if !bytes.Equal(buf.Bytes(), expected) {
+		t.Fatalf("expected %v, got %v", expected, buf.Bytes())
+	}
+}
+
+// func TestRealScenario(t *testing.T) {
+//
+// 	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
+
 // region size
 func TestCalculateSizeTypicalInstance(t *testing.T) {
 	p := &SUBMIT_SM{
@@ -14,7 +77,7 @@ 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 +94,7 @@ 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)
@@ -47,9 +110,11 @@ 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)
 	}
 }
+
+// region benchmark