ot_iovec.c

   1 /* This software was written by Dirk Engling <erdgeist@erdgeist.org>
   2    It is considered beerware. Prost. Skol. Cheers or whatever.
   3
   4    $id$ */
   5
   6 /* System */
   7 #include <stdlib.h>
   8 #include <sys/types.h>
   9 #include <sys/uio.h>
  10 #include <unistd.h>
  11
  12 /* Libowfat */
  13
  14 /* Opentracker */
  15 #include "ot_iovec.h"
  16
  17 void *iovec_increase(int *iovec_entries, struct iovec **iovector, size_t new_alloc) {
  18   void         *new_data;
  19   int           new_entries = 1 + *iovec_entries;
  20   struct iovec *new_vec     = realloc(*iovector, new_entries * sizeof(struct iovec));
  21
  22   if (!new_vec)
  23     return NULL;
  24
  25   /* Only allocate after we have a place to store the pointer */
  26   new_data = malloc(new_alloc);
  27   if (!new_data)
  28     return NULL;
  29
  30   new_vec[new_entries - 1].iov_base = new_data;
  31   new_vec[new_entries - 1].iov_len  = new_alloc;
  32
  33   *iovector                         = new_vec;
  34   ++*iovec_entries;
  35   return new_data;
  36 }
  37
  38 void *iovec_append(int *iovec_entries, struct iovec **iovector, struct iovec *append_iovector) {
  39   int           new_entries = *iovec_entries + 1;
  40   struct iovec *new_vec     = realloc(*iovector, new_entries * sizeof(struct iovec));
  41   if (!new_vec)
  42     return NULL;
  43
  44   /* Take over data from appended iovec */
  45   new_vec[*iovec_entries].iov_base = append_iovector->iov_base;
  46   new_vec[*iovec_entries].iov_len  = append_iovector->iov_len;
  47
  48   append_iovector->iov_base        = NULL;
  49   append_iovector->iov_len         = 0;
  50
  51   *iovector                        = new_vec;
  52   *iovec_entries                   = new_entries;
  53
  54   return new_vec;
  55 }
  56
  57 void iovec_free(int *iovec_entries, struct iovec **iovector) {
  58   int i;
  59   for (i = 0; i < *iovec_entries; ++i)
  60     free(((*iovector)[i]).iov_base);
  61   *iovector      = NULL;
  62   *iovec_entries = 0;
  63 }
  64
  65 void iovec_fixlast(int *iovec_entries, struct iovec **iovector, void *last_ptr) {
  66   if (*iovec_entries) {
  67     char  *base      = (char *)((*iovector)[*iovec_entries - 1]).iov_base;
  68     size_t new_alloc = ((char *)last_ptr) - base;
  69
  70     ((*iovector)[*iovec_entries - 1]).iov_base = realloc(base, new_alloc);
  71     ((*iovector)[*iovec_entries - 1]).iov_len  = new_alloc;
  72   }
  73 }
  74
  75 void *iovec_fix_increase_or_free(int *iovec_entries, struct iovec **iovector, void *last_ptr, size_t new_alloc) {
  76   void *new_data;
  77
  78   iovec_fixlast(iovec_entries, iovector, last_ptr);
  79
  80   if (!(new_data = iovec_increase(iovec_entries, iovector, new_alloc)))
  81     iovec_free(iovec_entries, iovector);
  82
  83   return new_data;
  84 }
  85
  86 size_t iovec_length(const int *iovec_entries, const struct iovec **iovector) {
  87   size_t length = 0;
  88   int    i;
  89   for (i = 0; i < *iovec_entries; ++i)
  90     length += ((*iovector)[i]).iov_len;
  91   return length;
  92 }