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/*
* This file is part of libdyn.a, the C Dynamic Object library. It
* contains the source code for the functions DynGet() and DynAdd().
*
* There are no restrictions on this code; however, if you make any
* changes, I request that you document them so that I do not get
* credit or blame for your modifications.
*
* Written by Barr3y Jaspan, Student Information Processing Board (SIPB)
* and MIT-Project Athena, 1989.
*/
#include "dynP.h"
static int DynPut __P((DynObject obj, DynPtr el, int index));
DynPtr
DynGet(DynObject obj,
int num)
{
if (num < 0) {
if (obj->debug)
fprintf(stderr, "dyn: get: bad index %d\n", num);
return NULL;
}
if (num >= obj->num_el) {
if (obj->debug)
fprintf(stderr, "dyn: get: highest element is %d.\n",
obj->num_el);
return NULL;
}
if (obj->debug)
fprintf(stderr, "dyn: get: Returning address %p + %d.\n",
obj->array, obj->el_size*num);
return (DynPtr) obj->array + obj->el_size*num;
}
int
DynAdd(DynObject obj,
DynPtr el)
{
int ret;
ret = DynPut(obj, el, obj->num_el);
if (ret != DYN_OK)
return ret;
++obj->num_el;
return ret;
}
/*
* WARNING! There is a reason this function is not documented in the
* man page. If DynPut used to mutate already existing elements,
* everything will go fine. If it is used to add new elements
* directly, however, the state within the object (such as
* obj->num_el) will not be updated properly and many other functions
* in the library will lose. Have a nice day.
*/
static int
DynPut(DynObject obj,
DynPtr el,
int index)
{
int ret;
if (obj->debug)
fprintf(stderr, "dyn: put: Writing %d bytes from %p to %p + %d\n",
obj->el_size, el, obj->array, index*obj->el_size);
if ((ret = _DynResize(obj, index)) != DYN_OK)
return ret;
(void) memmove(obj->array + index*obj->el_size, el, obj->el_size);
if (obj->debug)
fprintf(stderr, "dyn: put: done.\n");
return DYN_OK;
}
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