Initial commit

client/client.go

@@ -0,0 +1,89 @@
+package client
+
+import (
+	"bytes"
+	"context"
+	"encoding/binary"
+	"errors"
+	"io"
+	"net"
+	"sync"
+	"sync/atomic"
+)
+
+type ClientID uint64
+
+var currentClientID uint64
+
+func getID() ClientID {
+	return ClientID(atomic.AddUint64(&currentClientID, 1))
+}
+
+type Client struct {
+	conn      net.Conn
+	id        ClientID
+	ctx       context.Context
+	cancel    context.CancelFunc
+	writeLock sync.Mutex
+	readLock  sync.Mutex
+}
+
+func NewClient(conn net.Conn, ctx context.Context) *Client {
+	ctx, cancel := context.WithCancel(ctx)
+	return &Client{
+		conn:   conn,
+		id:     getID(),
+		ctx:    ctx,
+		cancel: cancel,
+	}
+}
+
+func (c *Client) GetID() ClientID {
+	return c.id
+}
+
+func (c *Client) SendMsg(msg []byte) error {
+	c.writeLock.Lock()
+	defer c.writeLock.Unlock()
+
+	sizeBytes := make([]byte, 8)
+	binary.PutVarint(sizeBytes, int64(len(msg)))
+
+	_, err := io.Copy(c.conn, bytes.NewReader(append(sizeBytes, msg...)))
+	return err
+}
+
+func (c *Client) GetMsg() ([]byte, error) {
+	c.readLock.Lock()
+	defer c.readLock.Unlock()
+
+	sizeBytes := make([]byte, 8)
+	_, err := io.ReadFull(c.conn, sizeBytes)
+	if err != nil {
+		return nil, err
+	}
+
+	msgSize, errInt := binary.Varint(sizeBytes)
+	if errInt <= 0 || msgSize <= 0 {
+		return nil, errors.New("Failed to decode message size bytes")
+	}
+
+	output := bytes.NewBuffer(make([]byte, msgSize))
+	output.Reset()
+
+	_, err = io.CopyN(output, c.conn, msgSize)
+	if err != nil {
+		return nil, err
+	}
+
+	return output.Bytes(), nil
+}
+
+func (c *Client) Done() bool {
+	return c.ctx.Err() != nil
+}
+
+func (c *Client) Close() error {
+	c.cancel()
+	return c.conn.Close()
+}