1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
|
/*
ChibiOS/RT - Copyright (C) 2006,2007,2008,2009,2010,
2011,2012 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
ChibiOS/RT is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* @file chstreams.h
* @brief Data streams.
* @details This header defines abstract interfaces useful to access generic
* data streams in a standardized way.
*
* @addtogroup data_streams
* @details This module define an abstract interface for generic data streams.
* Note that no code is present, just abstract interfaces-like
* structures, you should look at the system as to a set of
* abstract C++ classes (even if written in C). This system
* has then advantage to make the access to data streams
* independent from the implementation logic.<br>
* The stream interface can be used as base class for high level
* object types such as files, sockets, serial ports, pipes etc.
* @{
*/
#ifndef _CHSTREAMS_H_
#define _CHSTREAMS_H_
/**
* @brief BaseSequentialStream specific methods.
*/
#define _base_sequential_stream_methods \
/* Stream write buffer method.*/ \
size_t (*write)(void *instance, const uint8_t *bp, size_t n); \
/* Stream read buffer method.*/ \
size_t (*read)(void *instance, uint8_t *bp, size_t n); \
/* Channel put method, blocking.*/ \
msg_t (*put)(void *instance, uint8_t b); \
/* Channel get method, blocking.*/ \
msg_t (*get)(void *instance); \
/**
* @brief @p BaseSequentialStream specific data.
* @note It is empty because @p BaseSequentialStream is only an interface
* without implementation.
*/
#define _base_sequential_stream_data
/**
* @brief @p BaseSequentialStream virtual methods table.
*/
struct BaseSequentialStreamVMT {
_base_sequential_stream_methods
};
/**
* @brief Base stream class.
* @details This class represents a generic blocking unbuffered sequential
* data stream.
*/
typedef struct {
/** @brief Virtual Methods Table.*/
const struct BaseSequentialStreamVMT *vmt;
_base_sequential_stream_data
} BaseSequentialStream;
/**
* @name Macro Functions (BaseSequentialStream)
* @{
*/
/**
* @brief Sequential Stream write.
* @details The function writes data from a buffer to a stream.
*
* @param[in] ip pointer to a @p BaseSequentialStream or derived class
* @param[in] bp pointer to the data buffer
* @param[in] n the maximum amount of data to be transferred
* @return The number of bytes transferred. The return value can
* be less than the specified number of bytes if an
* end-of-file condition has been met.
*
* @api
*/
#define chSequentialStreamWrite(ip, bp, n) ((ip)->vmt->write(ip, bp, n))
/**
* @brief Sequential Stream read.
* @details The function reads data from a stream into a buffer.
*
* @param[in] ip pointer to a @p BaseSequentialStream or derived class
* @param[out] bp pointer to the data buffer
* @param[in] n the maximum amount of data to be transferred
* @return The number of bytes transferred. The return value can
* be less than the specified number of bytes if an
* end-of-file condition has been met.
*
* @api
*/
#define chSequentialStreamRead(ip, bp, n) ((ip)->vmt->read(ip, bp, n))
/**
* @brief Sequential Stream blocking byte write.
* @details This function writes a byte value to a channel. If the channel
* is not ready to accept data then the calling thread is suspended.
*
* @param[in] ip pointer to a @p BaseChannel or derived class
* @param[in] b the byte value to be written to the channel
*
* @return The operation status.
* @retval Q_OK if the operation succeeded.
* @retval Q_RESET if an end-of-file condition has been met.
*
* @api
*/
#define chSequentialStreamPut(ip, b) ((ip)->vmt->put(ip, b))
/**
* @brief Sequential Stream blocking byte read.
* @details This function reads a byte value from a channel. If the data
* is not available then the calling thread is suspended.
*
* @param[in] ip pointer to a @p BaseChannel or derived class
*
* @return A byte value from the queue.
* @retval Q_RESET if an end-of-file condition has been met.
*
* @api
*/
#define chSequentialStreamGet(ip) ((ip)->vmt->get(ip))
/** @} */
#endif /* _CHSTREAMS_H_ */
/** @} */
|