github.com/clubpay/ronykit/kit@v0.14.4-0.20240515065620-d0dace45cbc7/bridge_north.go (about)

     1  package kit
     2  
     3  import (
     4  	"context"
     5  	"sync"
     6  
     7  	"github.com/clubpay/ronykit/kit/errors"
     8  )
     9  
    10  type WriteFunc func(conn Conn, e *Envelope) error
    11  
    12  type GatewayStartConfig struct {
    13  	ReusePort bool
    14  }
    15  
    16  // Gateway is the main component of the EdgeServer. Without Gateway, the EdgeServer is not functional. You can use
    17  // some standard bundles in std/bundle path. However, if you need special handling of communication
    18  // between your server and clients, you are free to implement your own Gateway.
    19  // If you are a bundle developer need to work with interface otherwise, you don't need to know
    20  // much about this interface.
    21  type Gateway interface {
    22  	// Start starts the gateway to accept connections.
    23  	Start(ctx context.Context, cfg GatewayStartConfig) error
    24  	// Shutdown shuts down the gateway gracefully.
    25  	Shutdown(ctx context.Context) error
    26  	// Register registers the route in the Bundle. This is how Bundle gets information
    27  	// about the services and their contracts.
    28  	Register(
    29  		serviceName, contractID string, enc Encoding, sel RouteSelector, input Message,
    30  	)
    31  	// Subscribe will be called by the EdgeServer. These delegate functions
    32  	// must be called by the Gateway implementation. In other words, Gateway communicates
    33  	// with EdgeServer through the GatewayDelegate methods.
    34  	//
    35  	// NOTE: This func will be called only once and before calling Start function.
    36  	Subscribe(d GatewayDelegate)
    37  	// Dispatch receives the messages from external clients and runs the execFunc with appropriate
    38  	// arguments. The user of the Gateway does not need to implement this. If you are using some
    39  	// standard bundles like std/gateway/fasthttp or std/gateway/fastws, then all the implementation
    40  	// is taken care of.
    41  	Dispatch(ctx *Context, in []byte) (ExecuteArg, error)
    42  }
    43  
    44  // GatewayDelegate is the delegate that connects the Gateway to the rest of the system.
    45  type GatewayDelegate interface {
    46  	ConnDelegate
    47  	// OnMessage must be called whenever a new message arrives.
    48  	OnMessage(c Conn, msg []byte)
    49  }
    50  
    51  type ConnDelegate interface {
    52  	// OnOpen must be called whenever a new connection is established.
    53  	OnOpen(c Conn)
    54  	// OnClose must be called whenever the connection is gone.
    55  	OnClose(connID uint64)
    56  }
    57  
    58  // northBridge is a container component that connects EdgeServer with a Gateway type Bundle.
    59  type northBridge struct {
    60  	ctxPool
    61  	wg *sync.WaitGroup
    62  	eh ErrHandlerFunc
    63  	c  map[string]Contract
    64  	gw Gateway
    65  	sb *southBridge
    66  	cd ConnDelegate
    67  }
    68  
    69  var _ GatewayDelegate = (*northBridge)(nil)
    70  
    71  func (n *northBridge) OnOpen(c Conn) {
    72  	if n.cd == nil {
    73  		return
    74  	}
    75  
    76  	n.cd.OnOpen(c)
    77  }
    78  
    79  func (n *northBridge) OnClose(connID uint64) {
    80  	if n.cd == nil {
    81  		return
    82  	}
    83  
    84  	n.cd.OnClose(connID)
    85  }
    86  
    87  func (n *northBridge) OnMessage(conn Conn, msg []byte) {
    88  	n.wg.Add(1)
    89  	ctx := n.acquireCtx(conn)
    90  	ctx.sb = n.sb
    91  	ctx.rawData = msg
    92  
    93  	arg, err := n.gw.Dispatch(ctx, msg)
    94  	switch {
    95  	default:
    96  		n.eh(ctx, errors.Wrap(ErrDispatchFailed, err))
    97  	case errors.Is(err, ErrPreflight):
    98  		// If this is a Preflight request, we ignore executing it.
    99  		// This is a workaround for CORS Preflight requests.
   100  	case err == nil:
   101  		ctx.execute(arg, n.c[arg.ContractID])
   102  	}
   103  
   104  	n.releaseCtx(ctx)
   105  	n.wg.Done()
   106  }
   107  
   108  var (
   109  	ErrNoHandler                     = errors.New("handler is not set for request")
   110  	ErrWriteToClosedConn             = errors.New("write to closed connection")
   111  	ErrDecodeIncomingMessageFailed   = errors.New("decoding the incoming message failed")
   112  	ErrEncodeOutgoingMessageFailed   = errors.New("encoding the outgoing message failed")
   113  	ErrDecodeIncomingContainerFailed = errors.New("decoding the incoming container failed")
   114  	ErrDispatchFailed                = errors.New("dispatch failed")
   115  	ErrPreflight                     = errors.New("preflight request")
   116  )
   117  
   118  // These are just to silence the linter.
   119  var (
   120  	_ = ErrNoHandler
   121  	_ = ErrWriteToClosedConn
   122  	_ = ErrDecodeIncomingMessageFailed
   123  	_ = ErrEncodeOutgoingMessageFailed
   124  	_ = ErrDecodeIncomingContainerFailed
   125  )