1 /****************************************************************************** 2 * 3 * Copyright (C) 2014 Google, Inc. 4 * 5 * Licensed under the Apache License, Version 2.0 (the "License"); 6 * you may not use this file except in compliance with the License. 7 * You may obtain a copy of the License at: 8 * 9 * http://www.apache.org/licenses/LICENSE-2.0 10 * 11 * Unless required by applicable law or agreed to in writing, software 12 * distributed under the License is distributed on an "AS IS" BASIS, 13 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 * See the License for the specific language governing permissions and 15 * limitations under the License. 16 * 17 ******************************************************************************/ 18 19 #pragma once 20 21 #include <stdbool.h> 22 #include <stddef.h> 23 #include <stdint.h> 24 25 #include "allocator.h" 26 27 typedef struct eager_reader_t eager_reader_t; 28 typedef struct reactor_t reactor_t; 29 30 typedef void (*eager_reader_cb)(eager_reader_t *reader, void *context); 31 32 // Creates a new eager reader object, which pulls data from |fd_to_read| into 33 // buffers of size |buffer_size| allocated using |allocator|, and has an 34 // internal read thread named |thread_name|. The returned object must be freed using 35 // |eager_reader_free|. |fd_to_read| must be valid, |buffer_size| and |max_buffer_count| 36 // must be greater than zero. |allocator| and |thread_name| may not be NULL. 37 eager_reader_t *eager_reader_new( 38 int fd_to_read, 39 const allocator_t *allocator, 40 size_t buffer_size, 41 size_t max_buffer_count, 42 const char *thread_name 43 ); 44 45 // Frees an eager reader object, and associated internal resources. 46 // |reader| may be NULL. 47 void eager_reader_free(eager_reader_t *reader); 48 49 // Registers |reader| with the |reactor|. When the reader has data 50 // |read_cb| will be called. The |context| parameter is passed, untouched, to |read_cb|. 51 // Neither |reader|, nor |reactor|, nor |read_cb| may be NULL. |context| may be NULL. 52 void eager_reader_register(eager_reader_t *reader, reactor_t *reactor, eager_reader_cb read_cb, void *context); 53 54 // Unregisters |reader| from whichever reactor it is registered with, if any. This 55 // function is idempotent. 56 void eager_reader_unregister(eager_reader_t *reader); 57 58 // Reads up to |max_size| bytes into |buffer|. If |block| is true, blocks until 59 // |max_size| bytes are read. Otherwise only reads from currently available bytes. 60 // NOT SAFE FOR READING FROM MULTIPLE THREADS 61 // but you should probably only be reading from one thread anyway, 62 // otherwise the byte stream probably doesn't make sense. 63 size_t eager_reader_read(eager_reader_t *reader, uint8_t *buffer, size_t max_size, bool block); 64