opentracker/ot_iovec.c

/* This software was written by Dirk Engling <erdgeist@erdgeist.org>
   It is considered beerware. Prost. Skol. Cheers or whatever.

   $id$ */

/* System */
#include <sys/types.h>
#include <sys/mman.h>
#include <stdlib.h>
#include <unistd.h>
#include <sys/uio.h>

/* Libowfat */

/* Opentracker */
#include "ot_iovec.h"

void *iovec_increase( int *iovec_entries, struct iovec **iovector, size_t new_alloc ) {
  void *new_data;
  int new_entries = 1 + *iovec_entries;
  struct iovec *new_vec = realloc( *iovector, new_entries * sizeof( struct iovec ) );

  if( !new_vec )
    return NULL;

  /* Only allocate after we have a place to store the pointer */
  new_data = malloc( new_alloc );
  if( !new_data )
    return NULL;

  new_vec[new_entries - 1].iov_base = new_data;
  new_vec[new_entries - 1].iov_len  = new_alloc;

  *iovector = new_vec;
  ++*iovec_entries;
  return new_data;
}

void iovec_free( int *iovec_entries, struct iovec **iovector ) {
  int i;
  for( i=0; i<*iovec_entries; ++i )
    free( ((*iovector)[i]).iov_base );
  *iovector = NULL;
  *iovec_entries = 0;
}

void iovec_fixlast( int *iovec_entries, struct iovec **iovector, void *last_ptr ) {
  if( *iovec_entries ) {
      char * base = (char*)((*iovector)[ *iovec_entries - 1 ]).iov_base;
      size_t new_alloc = ((char*)last_ptr) - base;

      ((*iovector)[*iovec_entries - 1 ]).iov_base = realloc( base, new_alloc );
      ((*iovector)[*iovec_entries - 1 ]).iov_len = new_alloc;
  }
}

void *iovec_fix_increase_or_free( int *iovec_entries, struct iovec **iovector, void *last_ptr, size_t new_alloc ) {
  void *new_data;

  iovec_fixlast( iovec_entries, iovector, last_ptr );

  if( !( new_data = iovec_increase( iovec_entries, iovector, new_alloc ) ) )
    iovec_free( iovec_entries, iovector );

  return new_data;
}


size_t iovec_length( const int *iovec_entries, const struct iovec **iovector ) {
  size_t length = 0;
  int i;
  for( i=0; i<*iovec_entries; ++i )
    length += ((*iovector)[i]).iov_len;
  return length;
}

const char *g_version_iovec_c = "$Source$: $Revision$\n";