| /* |
| * |
| * Copyright 2015 gRPC authors. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| * |
| */ |
| |
| #ifndef GRPC_CORE_LIB_TRANSPORT_BYTE_STREAM_H |
| #define GRPC_CORE_LIB_TRANSPORT_BYTE_STREAM_H |
| |
| #include <grpc/slice_buffer.h> |
| #include "src/core/lib/iomgr/exec_ctx.h" |
| |
| /** Internal bit flag for grpc_begin_message's \a flags signaling the use of |
| * compression for the message */ |
| #define GRPC_WRITE_INTERNAL_COMPRESS (0x80000000u) |
| /** Mask of all valid internal flags. */ |
| #define GRPC_WRITE_INTERNAL_USED_MASK (GRPC_WRITE_INTERNAL_COMPRESS) |
| |
| #ifdef __cplusplus |
| extern "C" { |
| #endif |
| |
| typedef struct grpc_byte_stream grpc_byte_stream; |
| |
| typedef struct { |
| bool (*next)(grpc_exec_ctx *exec_ctx, grpc_byte_stream *byte_stream, |
| size_t max_size_hint, grpc_closure *on_complete); |
| grpc_error *(*pull)(grpc_exec_ctx *exec_ctx, grpc_byte_stream *byte_stream, |
| grpc_slice *slice); |
| void (*shutdown)(grpc_exec_ctx *exec_ctx, grpc_byte_stream *byte_stream, |
| grpc_error *error); |
| void (*destroy)(grpc_exec_ctx *exec_ctx, grpc_byte_stream *byte_stream); |
| } grpc_byte_stream_vtable; |
| |
| struct grpc_byte_stream { |
| uint32_t length; |
| uint32_t flags; |
| const grpc_byte_stream_vtable *vtable; |
| }; |
| |
| // Returns true if the bytes are available immediately (in which case |
| // on_complete will not be called), false if the bytes will be available |
| // asynchronously. |
| // |
| // max_size_hint can be set as a hint as to the maximum number |
| // of bytes that would be acceptable to read. |
| bool grpc_byte_stream_next(grpc_exec_ctx *exec_ctx, |
| grpc_byte_stream *byte_stream, size_t max_size_hint, |
| grpc_closure *on_complete); |
| |
| // Returns the next slice in the byte stream when it is ready (indicated by |
| // either grpc_byte_stream_next returning true or on_complete passed to |
| // grpc_byte_stream_next is called). |
| // |
| // Once a slice is returned into *slice, it is owned by the caller. |
| grpc_error *grpc_byte_stream_pull(grpc_exec_ctx *exec_ctx, |
| grpc_byte_stream *byte_stream, |
| grpc_slice *slice); |
| |
| // Shuts down the byte stream. |
| // |
| // If there is a pending call to on_complete from grpc_byte_stream_next(), |
| // it will be invoked with the error passed to grpc_byte_stream_shutdown(). |
| // |
| // The next call to grpc_byte_stream_pull() (if any) will return the error |
| // passed to grpc_byte_stream_shutdown(). |
| void grpc_byte_stream_shutdown(grpc_exec_ctx *exec_ctx, |
| grpc_byte_stream *byte_stream, |
| grpc_error *error); |
| |
| void grpc_byte_stream_destroy(grpc_exec_ctx *exec_ctx, |
| grpc_byte_stream *byte_stream); |
| |
| // grpc_slice_buffer_stream |
| // |
| // A grpc_byte_stream that wraps a slice buffer. The stream takes |
| // ownership of the slices in the buffer, and on destruction will |
| // reset the contents of the buffer. |
| |
| typedef struct grpc_slice_buffer_stream { |
| grpc_byte_stream base; |
| grpc_slice_buffer *backing_buffer; |
| size_t cursor; |
| grpc_error *shutdown_error; |
| } grpc_slice_buffer_stream; |
| |
| void grpc_slice_buffer_stream_init(grpc_slice_buffer_stream *stream, |
| grpc_slice_buffer *slice_buffer, |
| uint32_t flags); |
| |
| // grpc_caching_byte_stream |
| // |
| // A grpc_byte_stream that that wraps an underlying byte stream but caches |
| // the resulting slices in a slice buffer. If an initial attempt fails |
| // without fully draining the underlying stream, a new caching stream |
| // can be created from the same underlying cache, in which case it will |
| // return whatever is in the backing buffer before continuing to read the |
| // underlying stream. |
| // |
| // NOTE: No synchronization is done, so it is not safe to have multiple |
| // grpc_caching_byte_streams simultaneously drawing from the same underlying |
| // grpc_byte_stream_cache at the same time. |
| |
| typedef struct { |
| grpc_byte_stream *underlying_stream; |
| grpc_slice_buffer cache_buffer; |
| } grpc_byte_stream_cache; |
| |
| // Takes ownership of underlying_stream. |
| void grpc_byte_stream_cache_init(grpc_byte_stream_cache *cache, |
| grpc_byte_stream *underlying_stream); |
| |
| // Must not be called while still in use by a grpc_caching_byte_stream. |
| void grpc_byte_stream_cache_destroy(grpc_exec_ctx *exec_ctx, |
| grpc_byte_stream_cache *cache); |
| |
| typedef struct { |
| grpc_byte_stream base; |
| grpc_byte_stream_cache *cache; |
| size_t cursor; |
| grpc_error *shutdown_error; |
| } grpc_caching_byte_stream; |
| |
| void grpc_caching_byte_stream_init(grpc_caching_byte_stream *stream, |
| grpc_byte_stream_cache *cache); |
| |
| // Resets the byte stream to the start of the underlying stream. |
| void grpc_caching_byte_stream_reset(grpc_caching_byte_stream *stream); |
| |
| #ifdef __cplusplus |
| } |
| #endif |
| |
| #endif /* GRPC_CORE_LIB_TRANSPORT_BYTE_STREAM_H */ |