From b478482f210f33351c037105ad2e73d46f3a399a Mon Sep 17 00:00:00 2001
From: 4566704 <4566704@qq.com>
Date: Sun, 20 Sep 2026 12:25:35 +0800
Subject: [PATCH] =?UTF-8?q?feat(proto):=20=E8=87=AA=20go-hua=20=E8=BF=81?=
 =?UTF-8?q?=E5=85=A5=E9=95=BF=E5=BA=A6=E5=89=8D=E7=BC=80=E5=B0=81=E5=8C=85?=
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- 8 字节头(4 字节 ID/校验 + 4 字节长度, 小端序) + CRC32 校验版本
- 附测试、examples/proto 例程与包 README(含 Decode reader 复用告诫)
---
 examples/proto/main.go |  49 ++++++++++
 proto/README.md        |  40 ++++++++
 proto/proto.go         | 213 +++++++++++++++++++++++++++++++++++++++++
 proto/proto_test.go    |  90 +++++++++++++++++
 4 files changed, 392 insertions(+)
 create mode 100644 examples/proto/main.go
 create mode 100644 proto/README.md
 create mode 100644 proto/proto.go
 create mode 100644 proto/proto_test.go

diff --git a/examples/proto/main.go b/examples/proto/main.go
new file mode 100644
index 0000000..3de002b
--- /dev/null
+++ b/examples/proto/main.go
@@ -0,0 +1,49 @@
+// proto 包示例：通用封包协议（消息头 8 字节 = ID 4 字节 + 长度 4 字节，小端序），支持 CRC32 校验版本
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"net"
+
+	"git.zeroonesoft.cn/golib/zogo/proto"
+)
+
+func main() {
+	client, server := net.Pipe()
+	defer client.Close()
+	defer server.Close()
+
+	// ===== 普通封包：Encode / Decode =====
+	go func() {
+		data, err := proto.Encode([]byte("hello proto"))
+		if err != nil {
+			fmt.Println("Encode:", err)
+			return
+		}
+		client.Write(data)
+	}()
+
+	buf, err := proto.Decode(bufio.NewReader(server))
+	fmt.Println("Decode:", string(buf), "错误:", err)
+
+	// ===== CRC32 校验封包：EncodeCrc32 / DecodeCrc32 =====
+	go func() {
+		data, err := proto.EncodeCrc32([]byte("hello crc32"))
+		if err != nil {
+			fmt.Println("EncodeCrc32:", err)
+			return
+		}
+		client.Write(data)
+	}()
+
+	buf, err = proto.DecodeCrc32(bufio.NewReader(server))
+	fmt.Println("DecodeCrc32:", string(buf), "错误:", err)
+
+	// 实际 TCP 服务中的用法：
+	//   reader := bufio.NewReader(conn)
+	//   for {
+	//       data, err := proto.Decode(reader)  // 阻塞读到完整一帧
+	//       handle(data)
+	//   }
+}
diff --git a/proto/README.md b/proto/README.md
new file mode 100644
index 0000000..81cb6ad
--- /dev/null
+++ b/proto/README.md
@@ -0,0 +1,40 @@
+# proto
+
+长度前缀封包协议的编解码：8 字节头（4 字节 ID/校验 + 4 字节长度，小端序），
+支持 CRC32 校验版本，配合 `bufio.Reader` 使用。
+
+> 迁移自 go-hua/proto，代码保持原样。
+
+## 帧格式
+
+```
+普通版：  + id/流ID (4) + length (4) + data (length) +       小端序
+CRC32 版：+ id (4) + length (4) + crc32 (4) + data (length) + 小端序
+```
+
+## 用法
+
+```go
+import (
+    "bufio"
+    "net"
+
+    "git.zeroonesoft.cn/golib/zogo/proto"
+)
+
+// 发送端
+wire, _ := proto.Encode([]byte("payload"))   // 另有 EncodeCrc32
+conn.Write(wire)
+
+// 接收端（reader 需为 *bufio.Reader，可跨帧复用）
+r := bufio.NewReader(conn)
+data, err := proto.Decode(r)                 // 另有 DecodeCrc32（校验失败返回错误）
+```
+
+完整可运行例程：[examples/proto/main.go](../examples/proto/main.go)
+
+## 注意
+
+- `Decode` 会阻塞直到读满一帧；reader 请与连接同生命周期复用，勿每帧新建
+  （缓冲中多读的字节会丢失——与本仓库 `frame` 包迁移前问题同理）。
+- CRC32 版本与非校验版本的头部布局不同，两端必须约定同一种。
diff --git a/proto/proto.go b/proto/proto.go
new file mode 100644
index 0000000..6155dcc
--- /dev/null
+++ b/proto/proto.go
@@ -0,0 +1,213 @@
+// Package proto 提供长度前缀封包协议的编解码（8 字节头：4 字节 ID/校验 + 4 字节长度，小端序），支持 CRC32 校验版本。
+package proto
+
+import (
+	"bufio"
+	"bytes"
+	"encoding/binary"
+	"errors"
+	"hash/crc32"
+)
+
+// PakHeadLen 消息头长度：普通版为 ID 4 字节 + 长度 4 字节；CRC32 版为校验值 4 字节 + 长度 4 字节
+const (
+	PakHeadLen int32 = 8
+)
+
+// Encode 编码
+func Encode(buf []byte) ([]byte, error) {
+	// 读取消息的长度，转换成int32类型（占4个字节）
+	var id int32 = 5
+	var length = int32(len(buf))
+	var pkg = new(bytes.Buffer)
+	// 写入消息头
+	err := binary.Write(pkg, binary.LittleEndian, id)
+	if err != nil {
+		return nil, err
+	}
+	err = binary.Write(pkg, binary.LittleEndian, length)
+	if err != nil {
+		return nil, err
+	}
+	// 写入消息实体
+	err = binary.Write(pkg, binary.LittleEndian, []byte(buf))
+	if err != nil {
+		return nil, err
+	}
+	return pkg.Bytes(), nil
+}
+
+// Decode 解码
+func Decode(reader *bufio.Reader) ([]byte, error) {
+	// 读取头部
+	lengthByte, err := reader.Peek(int(PakHeadLen)) // 读取前4个字节的数据
+	if err != nil {
+		return nil, err
+	}
+	lengthBuff := bytes.NewBuffer(lengthByte)
+	var id int32 = 0
+	var length int32 = 0
+
+	err = binary.Read(lengthBuff, binary.LittleEndian, &id)
+	if err != nil {
+		return nil, err
+	}
+	err = binary.Read(lengthBuff, binary.LittleEndian, &length)
+	if err != nil {
+		return nil, err
+	}
+
+	if length <= 0 {
+		return nil, errors.New("decode length cannot be less than 0")
+	}
+
+	if length > 0x1000000 {
+		return nil, errors.New("decode length cannot be greater than 0x1000000")
+	}
+
+	var data []byte
+
+	// 剩余读长长度
+	unread := int(PakHeadLen + length)
+	readLen := 0
+	for {
+		if unread > 0x10000 {
+			readLen = 0x10000
+		} else {
+			readLen = unread
+		}
+
+		_, err = reader.Peek(readLen) // 先窥探数据
+		if err != nil {
+			return nil, err
+		}
+
+		// Buffered返回缓冲中现有的可读取的字节数。
+		if reader.Buffered() < readLen {
+			return nil, err
+		}
+
+		// 读取
+		buf := make([]byte, readLen)
+		_, err = reader.Read(buf)
+		if err != nil {
+			return nil, err
+		}
+		data = append(data, buf...)
+
+		unread -= readLen
+		//fmt.Println("readLen", readLen)
+		if unread <= 0 {
+			break
+		}
+
+	}
+
+	if len(data) < int(PakHeadLen) {
+		return nil, nil
+	}
+
+	return data[PakHeadLen:], nil
+}
+
+// EncodeCrc32 编码 Crc32校验
+func EncodeCrc32(buf []byte) ([]byte, error) {
+	// 读取消息的长度，转换成int32类型（占4个字节）
+	ieee := crc32.NewIEEE()
+	ieee.Write(buf)
+	var crc = ieee.Sum32()
+	var length = int32(len(buf))
+	var pkg = new(bytes.Buffer)
+	// 写入消息头
+	err := binary.Write(pkg, binary.LittleEndian, crc)
+	if err != nil {
+		return nil, err
+	}
+	err = binary.Write(pkg, binary.LittleEndian, length)
+	if err != nil {
+		return nil, err
+	}
+	// 写入消息实体
+	err = binary.Write(pkg, binary.LittleEndian, []byte(buf))
+	if err != nil {
+		return nil, err
+	}
+	return pkg.Bytes(), nil
+}
+
+// DecodeCrc32 解码 Crc32校验
+func DecodeCrc32(reader *bufio.Reader) ([]byte, error) {
+	// 读取头部
+	lengthByte, err := reader.Peek(int(PakHeadLen)) // 读取前4个字节的数据
+	if err != nil {
+		return nil, err
+	}
+	lengthBuff := bytes.NewBuffer(lengthByte)
+	var crc uint32 = 0
+	var length int32 = 0
+
+	err = binary.Read(lengthBuff, binary.LittleEndian, &crc)
+	if err != nil {
+		return nil, err
+	}
+	err = binary.Read(lengthBuff, binary.LittleEndian, &length)
+	if err != nil {
+		return nil, err
+	}
+
+	if length <= 0 {
+		return nil, errors.New("decode length cannot be less than 0")
+	}
+
+	if length > 0x1000000 {
+		return nil, errors.New("decode length cannot be greater than 0x1000000")
+	}
+
+	var data []byte
+
+	// 剩余读长长度
+	unread := int(PakHeadLen + length)
+	readLen := 0
+	for {
+		if unread > 0x1000 {
+			readLen = 0x1000
+		} else {
+			readLen = unread
+		}
+
+		_, err = reader.Peek(readLen) // 先窥探数据
+		if err != nil {
+			return nil, err
+		}
+
+		// Buffered返回缓冲中现有的可读取的字节数。
+		if reader.Buffered() < readLen {
+			return nil, err
+		}
+
+		// 读取
+		buf := make([]byte, readLen)
+		_, err = reader.Read(buf)
+		if err != nil {
+			return nil, err
+		}
+		data = append(data, buf...)
+
+		unread -= readLen
+		//fmt.Println("readLen", readLen)
+		if unread <= 0 {
+			break
+		}
+
+	}
+
+	if len(data) < int(PakHeadLen) {
+		return nil, nil
+	}
+	ieee := crc32.NewIEEE()
+	ieee.Write(data[PakHeadLen:])
+	if crc != ieee.Sum32() {
+		return nil, errors.New("crc check error")
+	}
+	return data[PakHeadLen:], nil
+}
diff --git a/proto/proto_test.go b/proto/proto_test.go
new file mode 100644
index 0000000..8998e55
--- /dev/null
+++ b/proto/proto_test.go
@@ -0,0 +1,90 @@
+package proto
+
+import (
+	"bufio"
+	"bytes"
+	"net"
+	"testing"
+)
+
+func TestEncodeDecode(t *testing.T) {
+	client, server := net.Pipe()
+	defer client.Close()
+	defer server.Close()
+
+	want := []byte("hello proto")
+	go func() {
+		data, err := Encode(want)
+		if err != nil {
+			t.Errorf("Encode: %v", err)
+			server.Close()
+			return
+		}
+		server.Write(data)
+	}()
+
+	got, err := Decode(bufio.NewReader(client))
+	if err != nil {
+		t.Fatalf("Decode: %v", err)
+	}
+	if !bytes.Equal(got, want) {
+		t.Errorf("Decode = %q, want %q", got, want)
+	}
+}
+
+func TestEncodeDecodeCrc32(t *testing.T) {
+	client, server := net.Pipe()
+	defer client.Close()
+	defer server.Close()
+
+	want := []byte("hello crc32")
+	go func() {
+		data, err := EncodeCrc32(want)
+		if err != nil {
+			t.Errorf("EncodeCrc32: %v", err)
+			server.Close()
+			return
+		}
+		server.Write(data)
+	}()
+
+	got, err := DecodeCrc32(bufio.NewReader(client))
+	if err != nil {
+		t.Fatalf("DecodeCrc32: %v", err)
+	}
+	if !bytes.Equal(got, want) {
+		t.Errorf("DecodeCrc32 = %q, want %q", got, want)
+	}
+}
+
+func TestDecodeCrc32Corrupted(t *testing.T) {
+	client, server := net.Pipe()
+	defer client.Close()
+	defer server.Close()
+
+	go func() {
+		data, _ := EncodeCrc32([]byte("payload"))
+		data[len(data)-1] ^= 0xFF // 篡改数据
+		server.Write(data)
+	}()
+
+	_, err := DecodeCrc32(bufio.NewReader(client))
+	if err == nil {
+		t.Error("篡改数据后 DecodeCrc32 应返回错误")
+	}
+}
+
+func TestEncodeHeaderFormat(t *testing.T) {
+	// 头 8 字节：[0:4] 为 CRC/ID，[4:8] 为小端长度
+	data, err := EncodeCrc32([]byte("abcd"))
+	if err != nil {
+		t.Fatalf("EncodeCrc32: %v", err)
+	}
+	length := int(data[4]) | int(data[5])<<8 | int(data[6])<<16 | int(data[7])<<24
+	if length != 4 {
+		t.Errorf("长度字段 = %d, want 4", length)
+	}
+	if len(data) != int(PakHeadLen)+4 {
+		t.Errorf("报文总长 = %d, want %d", len(data), PakHeadLen+4)
+	}
+}