Abstract Streams Interface

Collaboration diagram for Abstract Streams Interface:

Detailed Description

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.
The stream interface can be used as base class for high level object types such as files, sockets, serial ports, pipes etc.

Macros
#define	_base_sequential_stream_methods
	BaseSequentialStream specific methods. More...
#define	_base_sequential_stream_data   _base_object_data
	BaseSequentialStream specific data. More...

Streams return codes
#define	STM_OK   MSG_OK
#define	STM_TIMEOUT   MSG_TIMEOUT
#define	STM_RESET   MSG_RESET

Macro Functions (BaseSequentialStream)
#define	streamWrite(ip, bp, n)   ((ip)->vmt->write(ip, bp, n))
	Sequential Stream write. More...
#define	streamRead(ip, bp, n)   ((ip)->vmt->read(ip, bp, n))
	Sequential Stream read. More...
#define	streamPut(ip, b)   ((ip)->vmt->put(ip, b))
	Sequential Stream blocking byte write. More...
#define	streamGet(ip)   ((ip)->vmt->get(ip))
	Sequential Stream blocking byte read. More...

Data Structures
struct	BaseSequentialStreamVMT
	BaseSequentialStream virtual methods table. More...
struct	BaseSequentialStream
	Base stream class. More...

Macro Definition Documentation

#define _base_sequential_stream_methods

Value:

_base_object_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);                                             \

BaseSequentialStream specific methods.

Definition at line 50 of file hal_streams.h.

#define _base_sequential_stream_data   _base_object_data

BaseSequentialStream specific data.

Note

It is empty because BaseSequentialStream is only an interface without implementation.

Definition at line 66 of file hal_streams.h.

#define streamWrite	(		ip,
			bp,
			n
	)		((ip)->vmt->write(ip, bp, n))

Sequential Stream write.

The function writes data from a buffer to a stream.

Parameters

[in]	ip	pointer to a BaseSequentialStream or derived class
[in]	bp	pointer to the data buffer
[in]	n	the maximum amount of data to be transferred

Returns

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.

Function Class:Normal API, this function can be invoked by regular system threads but not from within a lock zone.

Definition at line 106 of file hal_streams.h.

#define streamRead	(		ip,
			bp,
			n
	)		((ip)->vmt->read(ip, bp, n))

Sequential Stream read.

The function reads data from a stream into a buffer.

Parameters

[in]	ip	pointer to a BaseSequentialStream or derived class
[out]	bp	pointer to the data buffer
[in]	n	the maximum amount of data to be transferred

Returns

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.

Function Class:Normal API, this function can be invoked by regular system threads but not from within a lock zone.

Definition at line 121 of file hal_streams.h.

#define streamPut	(		ip,
			b
	)		((ip)->vmt->put(ip, b))

Sequential Stream blocking byte write.

This function writes a byte value to a channel. If the channel is not ready to accept data then the calling thread is suspended.

Parameters

[in]	ip	pointer to a BaseChannel or derived class
[in]	b	the byte value to be written to the channel

Returns

The operation status.

Return values

STM_OK	if the operation succeeded.
STM_RESET	if an end-of-file condition has been met.

Function Class:Normal API, this function can be invoked by regular system threads but not from within a lock zone.

Definition at line 137 of file hal_streams.h.

Referenced by chvprintf().

#define streamGet

(

ip

)

((ip)->vmt->get(ip))

Sequential Stream blocking byte read.

This function reads a byte value from a channel. If the data is not available then the calling thread is suspended.

Parameters

[in]

ip

pointer to a BaseChannel or derived class

Returns

A byte value from the queue.

Return values

STM_RESET

if an end-of-file condition has been met.

Function Class:Normal API, this function can be invoked by regular system threads but not from within a lock zone.

Definition at line 151 of file hal_streams.h.