pmsg.c File Reference

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Detailed Description

PDU Messages.

Author:

Raphael Manfredi

Date:

2002-2003

#include "common.h"
#include "pmsg.h"
#include "lib/zalloc.h"
#include "lib/walloc.h"
#include "lib/override.h"

Data Structures
struct	pmsg_ext
	An extended message block. More...
Defines
#define	implies(a, b)   (!(a) || (b))
#define	valid_ptr(a)   (((gulong) (a)) > 100L)
#define	EMBEDDED_OFFSET   G_STRUCT_OFFSET(pdata_t, d_embedded)
Typedefs
typedef pmsg_ext	pmsg_ext_t
	An extended message block.
Functions
void	pmsg_ext_check_consistency (const pmsg_ext_t *const emb)
ALWAYS_INLINE pmsg_ext_t *	cast_to_pmsg_ext (pmsg_t *mb)
ALWAYS_INLINE pmsg_t *	cast_to_pmsg (pmsg_ext_t *emb)
void	pmsg_init (void)
	Allocate internal variables.
void	pmsg_close (void)
	Free internal variables.
int	pmsg_size (const pmsg_t *mb)
	Compute message's size.
pmsg_t *	pmsg_fill (pmsg_t *mb, pdata_t *db, gint prio, gconstpointer buf, gint len)
	Fill newly created message block.
pmsg_t *	pmsg_new (gint prio, gconstpointer buf, gint len)
	Create new message from user provided data, which are copied into the allocated data block.
pmsg_t *	pmsg_new_extend (gint prio, gconstpointer buf, gint len, pmsg_free_t free_cb, gpointer arg)
	Like pmsg_new() but returns an extended form with a free routine callback.
pmsg_t *	pmsg_alloc (gint prio, pdata_t *db, gint roff, gint woff)
	Allocate new message using existing data block `db'.
pmsg_t *	pmsg_clone_extend (pmsg_t *mb, pmsg_free_t free_cb, gpointer arg)
	Extended cloning of message, adds a free routine callback.
pmsg_free_t	pmsg_replace_ext (pmsg_t *mb, pmsg_free_t nfree, gpointer narg, gpointer *oarg)
	Replace free routine from an extended message block.
gpointer	pmsg_get_metadata (pmsg_t *mb)
	Get the "meta data" from an extended message block (the argument passed to the embedded free routine).
pmsg_check_t	pmsg_set_check (pmsg_t *mb, pmsg_check_t check)
	Set the pre-send checking routine for the buffer.
pmsg_t *	pmsg_clone_ext (pmsg_ext_t *mb)
	Shallow cloning of extended message, result is referencing the same data.
pmsg_t *	pmsg_clone (pmsg_t *mb)
	Shallow cloning of message, result is referencing the same data.
void	pmsg_free (pmsg_t *mb)
	Free all message blocks, and decrease ref count on all data buffers.
gint	pmsg_writable_length (const pmsg_t *mb)
gint	pmsg_write (pmsg_t *mb, gconstpointer data, gint len)
	Write data at the end of the message.
gint	pmsg_read (pmsg_t *mb, gpointer data, gint len)
	Read data from the message, returning the amount of bytes transferred.
gint	pmsg_discard (pmsg_t *mb, gint len)
	Discard data from the message, returning the amount of bytes discarded.
gint	pmsg_discard_trailing (pmsg_t *mb, gint len)
	Discard trailing data from the message, returning the amount of bytes discarded.
pdata_t *	pdata_new (int len)
	Allocate a new data block of given size.
pdata_t *	pdata_allocb (void *buf, gint len, pdata_free_t freecb, gpointer freearg)
	Create an embedded data buffer out of existing arena.
pdata_t *	pdata_allocb_ext (void *buf, gint len, pdata_free_t freecb, gpointer freearg)
	Create an external (arena not embedded) data buffer out of existing arena.
void	pdata_free_nop (gpointer unused_p, gpointer unused_arg)
	This free routine can be used when there is nothing to be freed for the buffer, probably because it was made out of a static buffer.
void	pdata_free (pdata_t *db)
	Free data block when its reference count has reached 0.
void	pdata_unref (pdata_t *db)
	Decrease reference count on buffer, and free it when it reaches 0.
iovec *	pmsg_slist_to_iovec (slist_t *slist, gint *iovcnt_ptr, size_t *size_ptr)
	Creates an iovec from a singly-linked list of pmsg_t buffers.
void	pmsg_slist_discard (slist_t *slist, size_t n_bytes)
	Discard `n_bytes' from the pmsg_t buffer slist and free all completely discarded buffers.
void	pmsg_slist_append (slist_t *slist, const void *data, size_t n_bytes)
	Appends `n_bytes' to the pmsg_t buffer.
void	pmsg_slist_free (slist_t **ptr)
	Frees all pmsg_t buffers, the slist itself and nullifies the pointer.
Variables
zone_t *	mb_zone = NULL

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Define Documentation

#define EMBEDDED_OFFSET   G_STRUCT_OFFSET(pdata_t, d_embedded)

#define implies (  a, b   )     (!(a) || (b))

#define valid_ptr (  a   )     (((gulong) (a)) > 100L)

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Typedef Documentation

typedef struct pmsg_ext pmsg_ext_t

An extended message block. An extended message block can be identified by its `m_prio' field having the PMSG_PF_EXT flag set.

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Function Documentation

ALWAYS_INLINE pmsg_t* cast_to_pmsg (  pmsg_ext_t *  emb  )  [inline, static]

ALWAYS_INLINE pmsg_ext_t* cast_to_pmsg_ext (  pmsg_t *  mb  )  [inline, static]

pdata_t* pdata_allocb (  void *  buf, gint  len, pdata_free_t  freecb, gpointer  freearg )

Create an embedded data buffer out of existing arena. The optional `freecb' structure supplies the free routine callback to be used to free the arena, with freearg as additional argument.

pdata_t* pdata_allocb_ext (  void *  buf, gint  len, pdata_free_t  freecb, gpointer  freearg )

Create an external (arena not embedded) data buffer out of existing arena. The optional `freecb' structure supplies the free routine callback to be used to free the arena, with freearg as additional argument.

void pdata_free (  pdata_t *  db  )  [static]

Free data block when its reference count has reached 0.

void pdata_free_nop (  gpointer  unused_p, gpointer  unused_arg )

This free routine can be used when there is nothing to be freed for the buffer, probably because it was made out of a static buffer.

pdata_t* pdata_new (  int  len  )

Allocate a new data block of given size. The block header is at the start of the allocated block.

void pdata_unref (  pdata_t *  db  )

Decrease reference count on buffer, and free it when it reaches 0.

pmsg_t* pmsg_alloc (  gint  prio, pdata_t *  db, gint  roff, gint  woff )

Allocate new message using existing data block `db'. The `roff' and `woff' are used to delimit the start and the end (first unwritten byte) of the message within the data buffer. Returns: new message.

pmsg_t* pmsg_clone (  pmsg_t *  mb  )

Shallow cloning of message, result is referencing the same data.

pmsg_t* pmsg_clone_ext (  pmsg_ext_t *  mb  )  [static]

Shallow cloning of extended message, result is referencing the same data.

pmsg_t* pmsg_clone_extend (  pmsg_t *  mb, pmsg_free_t  free_cb, gpointer  arg )

Extended cloning of message, adds a free routine callback.

void pmsg_close (  void   )

Free internal variables.

gint pmsg_discard (  pmsg_t *  mb, gint  len )

Discard data from the message, returning the amount of bytes discarded.

gint pmsg_discard_trailing (  pmsg_t *  mb, gint  len )

Discard trailing data from the message, returning the amount of bytes discarded.

void pmsg_ext_check_consistency (  const pmsg_ext_t *const   emb  )  [inline, static]

pmsg_t* pmsg_fill (  pmsg_t *  mb, pdata_t *  db, gint  prio, gconstpointer  buf, gint  len )  [static]

Fill newly created message block. Returns: the message block given as argument.

void pmsg_free (  pmsg_t *  mb  )

Free all message blocks, and decrease ref count on all data buffers.

gpointer pmsg_get_metadata (  pmsg_t *  mb  )

Get the "meta data" from an extended message block (the argument passed to the embedded free routine).

void pmsg_init (  void   )

Allocate internal variables.

pmsg_t* pmsg_new (  gint  prio, gconstpointer  buf, gint  len )

Create new message from user provided data, which are copied into the allocated data block. If no user buffer is provided, an empty message is created and the length is used to size the data block. Returns: a message made of one message block referencing one new data block.

pmsg_t* pmsg_new_extend (  gint  prio, gconstpointer  buf, gint  len, pmsg_free_t  free_cb, gpointer  arg )

Like pmsg_new() but returns an extended form with a free routine callback.

gint pmsg_read (  pmsg_t *  mb, gpointer  data, gint  len )

Read data from the message, returning the amount of bytes transferred.

pmsg_free_t pmsg_replace_ext (  pmsg_t *  mb, pmsg_free_t  nfree, gpointer  narg, gpointer *  oarg )

Replace free routine from an extended message block. The original free routine and its argument are returned. This is used when wrapping an existing extended message and its metadata in another extension structure. Parameters: mb  the extended message block nfree  the new free routine (NULL to cancel) narg  the new argument to pass to the free routine oarg  where the old argument to the free routine is returned. Can be NULL if no return is expected. Returns: the old free routine.

pmsg_check_t pmsg_set_check (  pmsg_t *  mb, pmsg_check_t  check )

Set the pre-send checking routine for the buffer. This routine, if it exists (non-NULL) is called just before enqueueing the message for sending. If it returns FALSE, the message is immediately dropped. The callback routine must not modify the message, as the buffer can be shared among multiple messages, unless its refcount is 1. Returns: the previous pre-send checking routine.

int pmsg_size (  const pmsg_t *  mb  )

Compute message's size.

void pmsg_slist_append (  slist_t *  slist, const void *  data, size_t  n_bytes )

Appends `n_bytes' to the pmsg_t buffer. If the last pmsg_t is writable it is filled with as much data as space is still available. Otherwise or if this space is not sufficient another pmsg_t is created and append to the list.

void pmsg_slist_discard (  slist_t *  slist, size_t  n_bytes )

Discard `n_bytes' from the pmsg_t buffer slist and free all completely discarded buffers.

void pmsg_slist_free (  slist_t **  ptr  )

Frees all pmsg_t buffers, the slist itself and nullifies the pointer.

struct iovec* pmsg_slist_to_iovec (  slist_t *  slist, gint *  iovcnt_ptr, size_t *  size_ptr )

Creates an iovec from a singly-linked list of pmsg_t buffers. NOTE: The iovec will hold no more than MAX_IOV_COUNT items. That means the iovec might not cover the whole buffered data. This limited is applied because writev() could fail with EINVAL otherwise which would simply add more unnecessary complexity.

gint pmsg_writable_length (  const pmsg_t *  mb  )

Returns: amount of data that can be written at the end of the message.

gint pmsg_write (  pmsg_t *  mb, gconstpointer  data, gint  len )

Write data at the end of the message. The message must be the only reference to the underlying data. Returns: amount of written data.

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Variable Documentation

zone_t* mb_zone = NULL [static]

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