GRB_msgdef.h File Reference

The public part of the messaging between the client and server. More...

#include <PBI/Endianness.h>
#include <PBI/BSWP.ih>

Classes
struct	_GRB_msgHdr
	The message header. More...
Typedefs
typedef struct _GRB_msgHdr	GRB_msgHdr
	Typedef for struct _GRB_msgHdr.
Functions
static __inline void	GRB__msgCompose (GRB_msgHdr *hdr, unsigned char len32, unsigned long long key)
	Composes the message header, filling in the length and message sorting key.
static __inline unsigned int	GRB__msgLength (const GRB_msgHdr *hdr)
	Accessor to return the length of the message in 32-bit units.
static __inline unsigned long long int	GRB__msgKey (const GRB_msgHdr *hdr)
	Accessor to return the message sorting key.
static __inline const GRB_msgHdr *	GRB__msgNext (const GRB_msgHdr *hdr)
	Returns a pointer to the message header following the specified message header hdr.
static __inline const GRB_msgHdr *	GRB__msgAdvance (const GRB_msgHdr *hdr, int len32)
	Returns a pointer to the location of hdr + len32.

---

Detailed Description

The public part of the messaging between the client and server.

Author:

JJRussell - russell@slac.stanford.edu

   CVS $Id: GRB_msgdef.h,v 1.7 2011/03/25 23:20:51 apw Exp $

This defines the interface to the GRB message header. As a word of warning, do not access the structure's directly in user code. There are accessor functions that avoid endianness issues. Compliance with using the specified interface routines will at least keep the user code compile time compatiable to changes in this package.

---

Typedef Documentation

GRB_msgHdr

Typedef for struct _GRB_msgHdr.

This structure is the public part of the message, allowing one to iterate and sort the messages without knowledge of the actual message contents.

Note:

This structure should not be accessed directly, use the accessor functions GRB__msgLength and GRB__msgKey. This will provide compile time protection in case the format changes.

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Function Documentation

static __inline const GRB_msgHdr * GRB__msgAdvance	(	const GRB_msgHdr *	hdr,
		int	len32
	)			[static]

Returns a pointer to the location of hdr + len32.

Returns:

A pointer to the location of hdr + len32.

Parameters:

	hdr	The target message header
	len32	The amount, in 32-bit units to advance hdr by.

Note:

This routine can be used instead of GRB__msgNext when the length of message has already been extracted or when advancing by multiple messages. Otherwise, GRB__msgNext should be used.

Warning:

This routine only advances the pointer to the address following the target message header. There is no guarantee that a message header actually occupies that memory. That question can only be answered by some higher level protocol

static __inline void GRB__msgCompose	(	GRB_msgHdr *	hdr,
		unsigned char	len32,
		unsigned long long	key
	)			[static]

Composes the message header, filling in the length and message sorting key.

Parameters:

	hdr	The message header to compose
	len32	The length of the message, in 32-bit units
	key	The sorting key. This is meant to a unique, increasing unsigned 48 bit number. Here unique means unique within a run and amongst the data taking CPUs.

Warning:

Do not fill these locations in by hand. One should use this routine to avoid big/little endian issues.

References _GRB_msgHdr::keylo.

static __inline unsigned long long int GRB__msgKey

(

const GRB_msgHdr *

hdr

)

[static]

Accessor to return the message sorting key.

Returns:

The message sorting key

Parameters:

hdr

The target message header

References _GRB_msgHdr::keylo.

static __inline unsigned int GRB__msgLength

(

const GRB_msgHdr *

hdr

)

[static]

Accessor to return the length of the message in 32-bit units.

Returns:

The length of the message in 32-bit units

Parameters:

hdr

The target message header

Referenced by GRB__msgNext().

static __inline const GRB_msgHdr * GRB__msgNext

(

const GRB_msgHdr *

hdr

)

[static]

Returns a pointer to the message header following the specified message header hdr.

Returns:

A pointer to the message header following the specified message header hdr.

Parameters:

hdr

The target message header

Warning:

This routine only advances the pointer to the address following the target message header. There is no guarantee that a message header actually occupies that memory. That question can only be answered by some higher level protocol

References GRB__msgLength().