Initial checkin of gRPC to third_party/

third_party/grpc/src/core/transport/transport.h

Index: third_party/grpc/src/core/transport/transport.h
diff --git a/third_party/grpc/src/core/transport/transport.h b/third_party/grpc/src/core/transport/transport.h
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+/*
+ *
+ * Copyright 2015-2016, Google Inc.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are
+ * met:
+ *
+ *     * Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#ifndef GRPC_INTERNAL_CORE_TRANSPORT_TRANSPORT_H
+#define GRPC_INTERNAL_CORE_TRANSPORT_TRANSPORT_H
+
+#include <stddef.h>
+
+#include "src/core/iomgr/pollset.h"
+#include "src/core/iomgr/pollset_set.h"
+#include "src/core/transport/metadata_batch.h"
+#include "src/core/transport/byte_stream.h"
+#include "src/core/channel/context.h"
+
+/* forward declarations */
+typedef struct grpc_transport grpc_transport;
+
+/* grpc_stream doesn't actually exist. It's used as a typesafe
+   opaque pointer for whatever data the transport wants to track
+   for a stream. */
+typedef struct grpc_stream grpc_stream;
+
+/*#define GRPC_STREAM_REFCOUNT_DEBUG*/
+
+typedef struct grpc_stream_refcount {
+  gpr_refcount refs;
+  grpc_closure destroy;
+#ifdef GRPC_STREAM_REFCOUNT_DEBUG
+  const char *object_type;
+#endif
+} grpc_stream_refcount;
+
+#ifdef GRPC_STREAM_REFCOUNT_DEBUG
+void grpc_stream_ref_init(grpc_stream_refcount *refcount, int initial_refs,
+                          grpc_iomgr_cb_func cb, void *cb_arg,
+                          const char *object_type);
+void grpc_stream_ref(grpc_stream_refcount *refcount, const char *reason);
+void grpc_stream_unref(grpc_exec_ctx *exec_ctx, grpc_stream_refcount *refcount,
+                       const char *reason);
+#define GRPC_STREAM_REF_INIT(rc, ir, cb, cb_arg, objtype) \
+  grpc_stream_ref_init(rc, ir, cb, cb_arg, objtype)
+#else
+void grpc_stream_ref_init(grpc_stream_refcount *refcount, int initial_refs,
+                          grpc_iomgr_cb_func cb, void *cb_arg);
+void grpc_stream_ref(grpc_stream_refcount *refcount);
+void grpc_stream_unref(grpc_exec_ctx *exec_ctx, grpc_stream_refcount *refcount);
+#define GRPC_STREAM_REF_INIT(rc, ir, cb, cb_arg, objtype) \
+  grpc_stream_ref_init(rc, ir, cb, cb_arg)
+#endif
+
+/* Transport stream op: a set of operations to perform on a transport
+   against a single stream */
+typedef struct grpc_transport_stream_op {
+  /** Send initial metadata to the peer, from the provided metadata batch. */
+  grpc_metadata_batch *send_initial_metadata;
+
+  /** Send trailing metadata to the peer, from the provided metadata batch. */
+  grpc_metadata_batch *send_trailing_metadata;
+
+  /** Send message data to the peer, from the provided byte stream. */
+  grpc_byte_stream *send_message;
+
+  /** Receive initial metadata from the stream, into provided metadata batch. */
+  grpc_metadata_batch *recv_initial_metadata;
+  /** Should be enqueued when initial metadata is ready to be processed. */
+  grpc_closure *recv_initial_metadata_ready;
+
+  /** Receive message data from the stream, into provided byte stream. */
+  grpc_byte_stream **recv_message;
+  /** Should be enqueued when one message is ready to be processed. */
+  grpc_closure *recv_message_ready;
+
+  /** Receive trailing metadata from the stream, into provided metadata batch.
+   */
+  grpc_metadata_batch *recv_trailing_metadata;
+
+  /** Should be enqueued when all requested operations (excluding recv_message
+      and recv_initial_metadata which have their own closures) in a given batch
+      have been completed. */
+  grpc_closure *on_complete;
+
+  /** If != GRPC_STATUS_OK, cancel this stream */
+  grpc_status_code cancel_with_status;
+
+  /** If != GRPC_STATUS_OK, send grpc-status, grpc-message, and close this
+      stream for both reading and writing */
+  grpc_status_code close_with_status;
+  gpr_slice *optional_close_message;
+
+  /* Indexes correspond to grpc_context_index enum values */
+  grpc_call_context_element *context;
+} grpc_transport_stream_op;
+
+/** Transport op: a set of operations to perform on a transport as a whole */
+typedef struct grpc_transport_op {
+  /** Called when processing of this op is done. */
+  grpc_closure *on_consumed;
+  /** connectivity monitoring - set connectivity_state to NULL to unsubscribe */
+  grpc_closure *on_connectivity_state_change;
+  grpc_connectivity_state *connectivity_state;
+  /** should the transport be disconnected */
+  int disconnect;
+  /** should we send a goaway?
+      after a goaway is sent, once there are no more active calls on
+      the transport, the transport should disconnect */
+  int send_goaway;
+  /** what should the goaway contain? */
+  grpc_status_code goaway_status;
+  gpr_slice *goaway_message;
+  /** set the callback for accepting new streams;
+      this is a permanent callback, unlike the other one-shot closures.
+      If true, the callback is set to set_accept_stream_fn, with its
+      user_data argument set to set_accept_stream_user_data */
+  bool set_accept_stream;
+  void (*set_accept_stream_fn)(grpc_exec_ctx *exec_ctx, void *user_data,
+                               grpc_transport *transport,
+                               const void *server_data);
+  void *set_accept_stream_user_data;
+  /** add this transport to a pollset */
+  grpc_pollset *bind_pollset;
+  /** add this transport to a pollset_set */
+  grpc_pollset_set *bind_pollset_set;
+  /** send a ping, call this back if not NULL */
+  grpc_closure *send_ping;
+} grpc_transport_op;
+
+/* Returns the amount of memory required to store a grpc_stream for this
+   transport */
+size_t grpc_transport_stream_size(grpc_transport *transport);
+
+/* Initialize transport data for a stream.
+
+   Returns 0 on success, any other (transport-defined) value for failure.
+
+   Arguments:
+     transport   - the transport on which to create this stream
+     stream      - a pointer to uninitialized memory to initialize
+     server_data - either NULL for a client initiated stream, or a pointer
+                   supplied from the accept_stream callback function */
+int grpc_transport_init_stream(grpc_exec_ctx *exec_ctx,
+                               grpc_transport *transport, grpc_stream *stream,
+                               grpc_stream_refcount *refcount,
+                               const void *server_data);
+
+void grpc_transport_set_pollset(grpc_exec_ctx *exec_ctx,
+                                grpc_transport *transport, grpc_stream *stream,
+                                grpc_pollset *pollset);
+
+/* Destroy transport data for a stream.
+
+   Requires: a recv_batch with final_state == GRPC_STREAM_CLOSED has been
+   received by the up-layer. Must not be called in the same call stack as
+   recv_frame.
+
+   Arguments:
+     transport - the transport on which to create this stream
+     stream    - the grpc_stream to destroy (memory is still owned by the
+                 caller, but any child memory must be cleaned up) */
+void grpc_transport_destroy_stream(grpc_exec_ctx *exec_ctx,
+                                   grpc_transport *transport,
+                                   grpc_stream *stream);
+
+void grpc_transport_stream_op_finish_with_failure(grpc_exec_ctx *exec_ctx,
+                                                  grpc_transport_stream_op *op);
+
+void grpc_transport_stream_op_add_cancellation(grpc_transport_stream_op *op,
+                                               grpc_status_code status);
+
+void grpc_transport_stream_op_add_close(grpc_transport_stream_op *op,
+                                        grpc_status_code status,
+                                        gpr_slice *optional_message);
+
+char *grpc_transport_stream_op_string(grpc_transport_stream_op *op);
+
+/* Send a batch of operations on a transport
+
+   Takes ownership of any objects contained in ops.
+
+   Arguments:
+     transport - the transport on which to initiate the stream
+     stream    - the stream on which to send the operations. This must be
+                 non-NULL and previously initialized by the same transport.
+     op        - a grpc_transport_stream_op specifying the op to perform */
+void grpc_transport_perform_stream_op(grpc_exec_ctx *exec_ctx,
+                                      grpc_transport *transport,
+                                      grpc_stream *stream,
+                                      grpc_transport_stream_op *op);
+
+void grpc_transport_perform_op(grpc_exec_ctx *exec_ctx,
+                               grpc_transport *transport,
+                               grpc_transport_op *op);
+
+/* Send a ping on a transport
+
+   Calls cb with user data when a response is received. */
+void grpc_transport_ping(grpc_transport *transport, grpc_closure *cb);
+
+/* Advise peer of pending connection termination. */
+void grpc_transport_goaway(grpc_transport *transport, grpc_status_code status,
+                           gpr_slice debug_data);
+
+/* Close a transport. Aborts all open streams. */
+void grpc_transport_close(grpc_transport *transport);
+
+/* Destroy the transport */
+void grpc_transport_destroy(grpc_exec_ctx *exec_ctx, grpc_transport *transport);
+
+/* Get the transports peer */
+char *grpc_transport_get_peer(grpc_exec_ctx *exec_ctx,
+                              grpc_transport *transport);
+
+#endif /* GRPC_INTERNAL_CORE_TRANSPORT_TRANSPORT_H */