xugu_go_driver/xugu/xugu_buffer.go

package xugu

import (
	"errors"
	"fmt"
	"net"
	"time"
)

var (
	ErrBusyBuffer = errors.New("busy buffer")
)

type buffer struct {
	buf     []byte // buf 是一个字节缓冲区，长度和容量相等。
	conn    net.Conn
	idx     int64
	length  int
	timeout time.Duration
}

// newBuffer 分配并返回一个新的缓冲区。
func newBuffer(nc net.Conn) buffer {
	return buffer{
		buf:  make([]byte, 2048),
		conn: nc,
	}
}

// store 存储 buf，这是一个更新的缓冲区，如果合适的话。
func (b *buffer) store(buf []byte) error {
	if len(buf) > cap(b.buf) {

		return ErrBusyBuffer
	}
	b.buf = buf[:cap(buf)]

	return nil
}

func (b *buffer) peekChar() byte {
	ret := b.buf[b.idx]
	//	fmt.Println("peekChar内部的: ", b.buf[b.idx:])
	return ret
}
func (b *buffer) reset() {
	b.idx = 0
	b.length = 0
	b.buf = make([]byte, 2048)
}

func (b *buffer) readNext(need int, reverse bool) ([]byte, error) {
	//长度不够返回

	if len(b.buf[b.idx:b.length]) < need {
		buffer := make([]byte, need+1)
		b.buf = append(b.buf[:b.length], buffer...)
		n, err := b.conn.Read(b.buf[b.length:])
		if err != nil {
			// if err == io.EOF {

			// }
			//	fmt.Println("Error reading from server:", err)
			return nil, err
		}

		b.length += n

		for b.length-int(b.idx) < need {

			n, err := b.conn.Read(b.buf[b.length:])
			if err != nil {
				// if err == io.EOF {
				// 	fmt.Println("End of data")

				// }
				fmt.Println("Error reading from server:", err)
				return nil, err
			}
			//nTmp += n
			b.length += n
		}

	}

	offset := b.idx
	b.idx += int64(need)

	if reverse {
		//	tmp2 := b.buf[offset:b.idx]
		//fmt.Println("readNext: 转换小端前", tmp2, " - ", string(tmp2))
		tmp := reverseBytes(b.buf[offset:b.idx])
		//	fmt.Println("readNext: 转换小端后", tmp, " - ", string(tmp))

		return tmp, nil
	} else {
		//	fmt.Println("readNext: 没有转换:", b.buf[offset:b.idx])
		//	fmt.Println("readNext: 没有转换:", string(b.buf[offset:b.idx]))

		return b.buf[offset:b.idx], nil
	}

}