| /* |
| * |
| * Copyright 2015, 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_TRANSPORT_TRANSPORT_H__ |
| #define __GRPC_INTERNAL_TRANSPORT_TRANSPORT_H__ |
| |
| #include <stddef.h> |
| |
| #include "src/core/iomgr/pollset.h" |
| #include "src/core/transport/stream_op.h" |
| |
| /* forward declarations */ |
| typedef struct grpc_transport grpc_transport; |
| typedef struct grpc_transport_callbacks grpc_transport_callbacks; |
| |
| /* 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; |
| |
| /* Represents the send/recv closed state of a stream. */ |
| typedef enum grpc_stream_state { |
| /* the stream is open for sends and receives */ |
| GRPC_STREAM_OPEN, |
| /* the stream is closed for sends, but may still receive data */ |
| GRPC_STREAM_SEND_CLOSED, |
| /* the stream is closed for receives, but may still send data */ |
| GRPC_STREAM_RECV_CLOSED, |
| /* the stream is closed for both sends and receives */ |
| GRPC_STREAM_CLOSED |
| } grpc_stream_state; |
| |
| /* Callbacks made from the transport to the upper layers of grpc. */ |
| struct grpc_transport_callbacks { |
| /* Allocate a buffer to receive data into. |
| It's safe to call grpc_slice_new() to do this, but performance minded |
| proxies may want to carefully place data into optimal locations for |
| transports. |
| This function must return a valid, non-empty slice. |
| |
| Arguments: |
| user_data - the transport user data set at transport creation time |
| transport - the grpc_transport instance making this call |
| stream - the grpc_stream instance the buffer will be used for, or |
| NULL if this is not known |
| size_hint - how big of a buffer would the transport optimally like? |
| the actual returned buffer can be smaller or larger than |
| size_hint as the implementation finds convenient */ |
| struct gpr_slice (*alloc_recv_buffer)(void *user_data, |
| grpc_transport *transport, |
| grpc_stream *stream, size_t size_hint); |
| |
| /* Initialize a new stream on behalf of the transport. |
| Must result in a call to |
| grpc_transport_init_stream(transport, ..., request) in the same call |
| stack. |
| Must not result in any other calls to the transport. |
| |
| Arguments: |
| user_data - the transport user data set at transport creation time |
| transport - the grpc_transport instance making this call |
| request - request parameters for this stream (owned by the caller) |
| server_data - opaque transport dependent argument that should be passed |
| to grpc_transport_init_stream |
| */ |
| void (*accept_stream)(void *user_data, grpc_transport *transport, |
| const void *server_data); |
| |
| /* Process a set of stream ops that have been received by the transport. |
| Called by network threads, so must be careful not to block on network |
| activity. |
| |
| If final_state == GRPC_STREAM_CLOSED, the upper layers should arrange to |
| call grpc_transport_destroy_stream. |
| |
| Ownership of any objects contained in ops is transferred to the callee. |
| |
| Arguments: |
| user_data - the transport user data set at transport creation time |
| transport - the grpc_transport instance making this call |
| stream - the stream this data was received for |
| ops - stream operations that are part of this batch |
| ops_count - the number of stream operations in this batch |
| final_state - the state of the stream as of the final operation in this |
| batch */ |
| void (*recv_batch)(void *user_data, grpc_transport *transport, |
| grpc_stream *stream, grpc_stream_op *ops, size_t ops_count, |
| grpc_stream_state final_state); |
| |
| /* The transport received a goaway */ |
| void (*goaway)(void *user_data, grpc_transport *transport, |
| grpc_status_code status, gpr_slice debug); |
| |
| /* The transport has been closed */ |
| void (*closed)(void *user_data, grpc_transport *transport); |
| }; |
| |
| /* 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_transport *transport, grpc_stream *stream, |
| const void *server_data); |
| |
| /* 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_transport *transport, |
| grpc_stream *stream); |
| |
| /* Enable/disable incoming data for a stream. |
| |
| This effectively disables new window becoming available for a given stream, |
| but does not prevent existing window from being consumed by a sender: the |
| caller must still be prepared to receive some additional data after this |
| call. |
| |
| 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) |
| allow - is it allowed that new window be opened up? */ |
| void grpc_transport_set_allow_window_updates(grpc_transport *transport, |
| grpc_stream *stream, int allow); |
| |
| /* 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. |
| ops - an array of operations to apply to the stream - can be NULL |
| if ops_count == 0. |
| ops_count - the number of elements in ops |
| is_last - is this the last batch of operations to be sent out */ |
| void grpc_transport_send_batch(grpc_transport *transport, grpc_stream *stream, |
| grpc_stream_op *ops, size_t ops_count, |
| int is_last); |
| |
| /* Send a ping on a transport |
| |
| Calls cb with user data when a response is received. |
| cb *MAY* be called with arbitrary transport level locks held. It is not safe |
| to call into the transport during cb. */ |
| void grpc_transport_ping(grpc_transport *transport, void (*cb)(void *user_data), |
| void *user_data); |
| |
| /* Abort a stream |
| |
| Terminate reading and writing for a stream. A final recv_batch with no |
| operations and final_state == GRPC_STREAM_CLOSED will be received locally, |
| and no more data will be presented to the up-layer. |
| |
| TODO(ctiller): consider adding a HTTP/2 reason to this function. */ |
| void grpc_transport_abort_stream(grpc_transport *transport, grpc_stream *stream, |
| grpc_status_code status); |
| |
| void grpc_transport_add_to_pollset(grpc_transport *transport, |
| grpc_pollset *pollset); |
| |
| /* 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_transport *transport); |
| |
| /* Return type for grpc_transport_setup_callback */ |
| typedef struct grpc_transport_setup_result { |
| void *user_data; |
| const grpc_transport_callbacks *callbacks; |
| } grpc_transport_setup_result; |
| |
| /* Given a transport, return callbacks for that transport. Used to finalize |
| setup as a transport is being created */ |
| typedef grpc_transport_setup_result (*grpc_transport_setup_callback)( |
| void *setup_arg, grpc_transport *transport, grpc_mdctx *mdctx); |
| |
| typedef struct grpc_transport_setup grpc_transport_setup; |
| typedef struct grpc_transport_setup_vtable grpc_transport_setup_vtable; |
| |
| struct grpc_transport_setup_vtable { |
| void (*initiate)(grpc_transport_setup *setup); |
| void (*cancel)(grpc_transport_setup *setup); |
| }; |
| |
| /* Transport setup is an asynchronous utility interface for client channels to |
| establish connections. It's transport agnostic. */ |
| struct grpc_transport_setup { |
| const grpc_transport_setup_vtable *vtable; |
| }; |
| |
| /* Initiate transport setup: e.g. for TCP+DNS trigger a resolve of the name |
| given at transport construction time, create the tcp connection, perform |
| handshakes, and call some grpc_transport_setup_result function provided at |
| setup construction time. |
| This *may* be implemented as a no-op if the setup process monitors something |
| continuously. */ |
| void grpc_transport_setup_initiate(grpc_transport_setup *setup); |
| /* Cancel transport setup. After this returns, no new transports should be |
| created, and all pending transport setup callbacks should be completed. |
| After this call completes, setup should be considered invalid (this can be |
| used as a destruction call by setup). */ |
| void grpc_transport_setup_cancel(grpc_transport_setup *setup); |
| |
| #endif /* __GRPC_INTERNAL_TRANSPORT_TRANSPORT_H__ */ |