Abstract Sequential Streams

Collaboration diagram for Abstract Sequential Streams:

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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.

Data Structures
struct	BaseSequentialStreamVMT
	BaseSequentialStream virtual methods table. More...
struct	BaseSequentialStream
	Base stream class. More...
Macro Functions (BaseSequentialStream)
#define	chSequentialStreamWrite(ip, bp, n)   ((ip)->vmt->write(ip, bp, n))
	Sequential Stream write.
#define	chSequentialStreamRead(ip, bp, n)   ((ip)->vmt->read(ip, bp, n))
	Sequential Stream read.
#define	chSequentialStreamPut(ip, b)   ((ip)->vmt->put(ip, b))
	Sequential Stream blocking byte write.
#define	chSequentialStreamGet(ip)   ((ip)->vmt->get(ip))
	Sequential Stream blocking byte read.
Defines
#define	_base_sequential_stream_methods
	BaseSequentialStream specific methods.
#define	_base_sequential_stream_data
	BaseSequentialStream specific data.

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Define Documentation

#define _base_sequential_stream_methods

Value:

/* 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 45 of file chstreams.h.

#define _base_sequential_stream_data

BaseSequentialStream specific data.

Note:

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

Definition at line 60 of file chstreams.h.

#define chSequentialStreamWrite	(		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 97 of file chstreams.h.

Referenced by test_println().

#define chSequentialStreamRead	(		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 112 of file chstreams.h.

Referenced by shellGetLine().

#define chSequentialStreamPut	(		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:

Q_OK	if the operation succeeded.
Q_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 128 of file chstreams.h.

Referenced by chprintf(), shellGetLine(), test_print(), and test_printn().

#define chSequentialStreamGet

(

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:

Q_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 142 of file chstreams.h.