SatCat5
satcat5::io::PacketBufferTee Class Referencefinal

Detailed Description

PacketBuffer with optional wiretap(s).

Reads and writes go to the buffer. If additional ports are added, then each gets a carbon-copy of all written data.

Definition at line 136 of file posix_utils.h.

#include <posix_utils.h>

Inheritance diagram for satcat5::io::PacketBufferTee:
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Collaboration diagram for satcat5::io::PacketBufferTee:
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Public Member Functions

 PacketBufferTee (unsigned nbytes=4096)
 
void clear ()
 
void set_callback (satcat5::io::EventListener *callback) override
 Update registered callback for data_rcvd() events. More...
 
unsigned get_read_ready () const override
 How many bytes can be read without blocking? More...
 
bool read_bytes (unsigned nbytes, void *dst) override
 Read 0 or more bytes into a buffer. More...
 
bool read_consume (unsigned nbytes) override
 Read and discard 0 or more bytes. More...
 
void read_finalize () override
 Consume any remaining bytes in this frame, if applicable. More...
 
u8 read_u8 ()
 One of many functions for reading integer/floating point values, see details. More...
 
unsigned read_str (unsigned dst_size, char *dst)
 Safely read a null-terminated input string. More...
 
template<class T >
bool read_obj (T &t)
 Templated wrapper for any object with the following method: bool read_from(satcat5::io::Readable* rd);
 
unsigned copy_to (satcat5::io::Writeable *dst)
 Copy data to a Writeable object, without finalizing. More...
 
bool copy_and_finalize (satcat5::io::Writeable *dst, satcat5::io::CopyMode mode=CopyMode::PACKET)
 Copy data to a Writeable object, then finalize. More...
 
void request_poll ()
 Call this method to request polling at a later time. More...
 
void request_cancel ()
 Call this method to cancel a previous request_poll().
 
void add (satcat5::io::Writeable *dst)
 Update the list of destination objects.
 
void remove (satcat5::io::Writeable *dst)
 
bool write_finalize () override
 Override end-of-packet handling.
 
unsigned get_write_space () const override
 How many bytes can be written without blocking? More...
 
void write_abort () override
 If possible, abort the current partially-written packet. More...
 
void write_overflow () override
 Optional error handling for write overflow. More...
 
const u8 * buffer () const
 Read-only access to the working buffer.
 
unsigned written_len () const
 Report total length after write_finalize() is called.
 
void write_u8 (u8 data)
 One of many functions for writing integer/floating point values, see details. More...
 
virtual void write_bytes (unsigned nbytes, const void *src)
 Write 0 or more bytes from a buffer. More...
 
void write_str (const char *str)
 Write the contents of a null-terminated string. More...
 
template<class T >
void write_obj (const T &obj)
 Templated wrapper for any object with the following method: void write_to(satcat5::io::Writeable* wr) const;
 

Static Public Member Functions

static unsigned count_ondemand ()
 Count queued objects of this type (i.e., non-idle).
 

Protected Member Functions

u8 read_next () override
 Read the next byte from the underlying buffer or device. More...
 
void read_underflow () override
 Optional error handling for read underflow. More...
 
void read_src (satcat5::io::Readable *src)
 Children may reset the source object as needed.
 
void read_notify ()
 Attempt notification by calling m_callback->data_rcvd(). More...
 

Protected Attributes

satcat5::io::PacketBufferHeap m_buff
 
std::list< satcat5::io::Writeable * > m_list
 
u8 *const m_buffptr
 Pointer to the underlying buffer.
 
friend LimitedWrite
 
friend WriteableBroadcast
 
friend WriteableRedirect
 

Private Member Functions

void poll_demand ()
 Event handler for on-demand polling.
 
void write_next (u8 data) override
 Write the next byte to the underlying buffer or device. More...
 

Private Attributes

satcat5::io::Readablem_src
 
satcat5::io::EventListenerm_callback
 Pointer to the callback object, or NULL. More...
 
satcat5::poll::OnDemandm_next
 
bool m_idle
 
u8 *const m_dst
 
const unsigned m_len
 
bool m_ovr
 
unsigned m_wridx
 
unsigned m_wrlen
 

Member Function Documentation

◆ copy_and_finalize()

bool Readable::copy_and_finalize ( satcat5::io::Writeable dst,
satcat5::io::CopyMode  mode = CopyMode::PACKET 
)
inherited

Copy data to a Writeable object, then finalize.

As copy_to(), but also calls read_finalize() and/or write_finalize() depending on the input/output mode.

In packet mode (the default), call both read_finalize() and write_finalize() if the operation copies all available data. Use this mode whenever the input is packetized.

In byte-stream mode, call write_finalize() if the operation copies any data, but never call read_finalize(). Use this mode for inputs that do not delimit packet boundaries.

Parameters
dstThe destination object.
modeSelect packet mode or stream mode.
Returns
True if the output was finalized successfully.

Definition at line 234 of file io_readable.cc.

◆ copy_to()

unsigned Readable::copy_to ( satcat5::io::Writeable dst)
inherited

Copy data to a Writeable object, without finalizing.

Copy the contents of this Readable to a Writeable object, stopping at end-of-input, end-of-frame, or the capacity of the destination buffer (whichever comes first). This method does not call read_finalize or write_finalize(). To automatically make finalize calls,

See also
copy_and_finalize.
Returns
The number of bytes copied.

Definition at line 214 of file io_readable.cc.

◆ get_read_ready()

unsigned ReadableRedirect::get_read_ready ( ) const
overridevirtualinherited

How many bytes can be read without blocking?

Child objects of io::Readable MUST override this method.

Implements satcat5::io::Readable.

Definition at line 336 of file io_readable.cc.

◆ get_write_space()

unsigned ArrayWrite::get_write_space ( ) const
overridevirtualinherited

How many bytes can be written without blocking?

Child objects of io::Writeable MUST override this method.

Implements satcat5::io::Writeable.

Definition at line 189 of file io_writeable.cc.

◆ read_bytes()

bool ReadableRedirect::read_bytes ( unsigned  nbytes,
void *  dst 
)
overridevirtualinherited

Read 0 or more bytes into a buffer.

Child objects of io::Readable MAY override this method for improved performance.

Reimplemented from satcat5::io::Readable.

Definition at line 339 of file io_readable.cc.

◆ read_consume()

bool ReadableRedirect::read_consume ( unsigned  nbytes)
overridevirtualinherited

Read and discard 0 or more bytes.

Child objects of io::Readable MAY override this method for improved performance.

Reimplemented from satcat5::io::Readable.

Definition at line 342 of file io_readable.cc.

◆ read_finalize()

void ReadableRedirect::read_finalize ( )
overridevirtualinherited

Consume any remaining bytes in this frame, if applicable.

Child objects of io::Readable SHOULD override this method if they support framing.

Reimplemented from satcat5::io::Readable.

Definition at line 345 of file io_readable.cc.

◆ read_next()

u8 ReadableRedirect::read_next ( )
overrideprotectedvirtualinherited

Read the next byte from the underlying buffer or device.

Child objects of io::Readable MUST override this method.

Implements satcat5::io::Readable.

Definition at line 348 of file io_readable.cc.

◆ read_notify()

void Readable::read_notify ( )
protectedinherited

Attempt notification by calling m_callback->data_rcvd().

Child objects of io::Readable MAY call this to override default notifications.

Definition at line 254 of file io_readable.cc.

◆ read_str()

unsigned Readable::read_str ( unsigned  dst_size,
char *  dst 
)
inherited

Safely read a null-terminated input string.

The input is always consumed up to the end-of-input or the first zero byte, whichever comes first.

Returns
The length of the output string, which may be truncated as needed to fit in the provided buffer.

Definition at line 179 of file io_readable.cc.

◆ read_u8()

u8 Readable::read_u8 ( )
inherited

One of many functions for reading integer/floating point values, see details.

Several functions are provided for reading and writing scalar types to/from io::Readable and io::Writeable instances. Since there are many of these that are frequently inherited, they are hidden from documentation. These functions follow a shared template:

  • read_ or write_ prefix.
  • u for unsigned, s for signed, f for floating-point.
  • Data-type width in bits.
    • Available widths for ints: 8/16/24/32/48/64.
    • Available widths for floats: 32/64.
  • l suffix if little-endian, no suffix if big-endian.

Example: write_s48l is "Write 48 bits (6 bytes) to this io::Writeable as a signed value in little-endian order".

Definition at line 44 of file io_readable.cc.

◆ read_underflow()

void ReadableRedirect::read_underflow ( )
overrideprotectedvirtualinherited

Optional error handling for read underflow.

Child objects of io::Readable MAY override this method.

Reimplemented from satcat5::io::Readable.

Definition at line 351 of file io_readable.cc.

◆ request_poll()

void satcat5::poll::OnDemand::request_poll ( )
inherited

Call this method to request polling at a later time.

Safe to stack requests, but only one call to poll().

Definition at line 208 of file polling.cc.

◆ set_callback()

void ReadableRedirect::set_callback ( satcat5::io::EventListener callback)
overridevirtualinherited

Update registered callback for data_rcvd() events.

Child objects of io::Readable SHOULD usually leave this method as-is.

Reimplemented from satcat5::io::Readable.

Definition at line 331 of file io_readable.cc.

◆ write_abort()

void ArrayWrite::write_abort ( )
overridevirtualinherited

If possible, abort the current partially-written packet.

Child objects of io::Writeable SHOULD override this method if it is practical to prevent in-progress data from being relayed downstream.

Reimplemented from satcat5::io::Writeable.

Definition at line 193 of file io_writeable.cc.

◆ write_bytes()

void Writeable::write_bytes ( unsigned  nbytes,
const void *  src 
)
virtualinherited

◆ write_next()

void ArrayWrite::write_next ( u8  data)
overrideprivatevirtualinherited

Write the next byte to the underlying buffer or device.

Child objects of io::Writeable MUST override this method.

Implements satcat5::io::Writeable.

Definition at line 211 of file io_writeable.cc.

◆ write_overflow()

void ArrayWrite::write_overflow ( )
overridevirtualinherited

Optional error handling for write overflow.

Child objects of io::Writeable MAY override this method for error handling.

Reimplemented from satcat5::io::Writeable.

Definition at line 207 of file io_writeable.cc.

◆ write_str()

void Writeable::write_str ( const char *  str)
inherited

Write the contents of a null-terminated string.

Note: Null-termination is not copied to the output.

Definition at line 180 of file io_writeable.cc.

◆ write_u8()

void Writeable::write_u8 ( u8  data)
inherited

One of many functions for writing integer/floating point values, see details.

Several functions are provided for reading and writing scalar types to/from io::Readable and io::Writeable instances. Since there are many of these that are frequently inherited, they are hidden from documentation. These functions follow a shared template:

  • read_ or write_ prefix.
  • u for unsigned, s for signed, f for floating-point.
  • Data-type width in bits.
    • Available widths for ints: 8/16/24/32/48/64.
    • Available widths for floats: 32/64.
  • l suffix if little-endian, no suffix if big-endian.

Example: write_s48l is "Write 48 bits (6 bytes) to this io::Writeable as a signed value in little-endian order".

Definition at line 20 of file io_writeable.cc.

Member Data Documentation

◆ m_callback

satcat5::io::EventListener* satcat5::io::Readable::m_callback
privateinherited

Pointer to the callback object, or NULL.

This can only be modified through the set_callback(...) method.

Definition at line 199 of file io_readable.h.


The documentation for this class was generated from the following files: