#ifndef lint
static char *RCSid() { return RCSid("$Id: dynarray.c,v 1.12 2015/04/23 20:10:02 sfeam Exp $"); }
#endif
/*[
* Copyright 1999, 2004 Hans-Bernhard Broeker
*
* Permission to use, copy, and distribute this software and its
* documentation for any purpose with or without fee is hereby granted,
* provided that the above copyright notice appear in all copies and
* that both that copyright notice and this permission notice appear
* in supporting documentation.
*
* Permission to modify the software is granted, but not the right to
* distribute the complete modified source code. Modifications are to
* be distributed as patches to the released version. Permission to
* distribute binaries produced by compiling modified sources is granted,
* provided you
* 1. distribute the corresponding source modifications from the
* released version in the form of a patch file along with the binaries,
* 2. add special version identification to distinguish your version
* in addition to the base release version number,
* 3. provide your name and address as the primary contact for the
* support of your modified version, and
* 4. retain our contact information in regard to use of the base
* software.
* Permission to distribute the released version of the source code along
* with corresponding source modifications in the form of a patch file is
* granted with same provisions 2 through 4 for binary distributions.
*
* This software is provided "as is" without express or implied warranty
* to the extent permitted by applicable law.
]*/
/* This module implements a dynamically growing array of arbitrary
* elements parametrized by their sizeof(). There is no 'access
* function', i.e. you'll have to access the elements of the
* dynarray->v memory block by hand. It's implemented in OO-style,
* even though this is C, not C++. In particular, every function
* takes a pointer to a data structure type 'dynarray', which mimics
* the 'this' pointer of an object. */
#include "dynarray.h"
#include "alloc.h"
#include "util.h" /* for int_error() */
static char *init_failure_msg = "dynarray wasn't initialized";
/* The 'constructor' of a dynarray object: initializes all the
* variables to well-defined startup values */
void
init_dynarray(dynarray *this, size_t entry_size, long size, long increment)
{
this->v = 0; /* preset value, in case gp_alloc fails */
if (size)
this->v = gp_alloc(entry_size*size, "init dynarray");
this->size = size;
this->end = 0;
this->increment = increment;
this->entry_size = entry_size;
}
/* The 'destructor'; sets all crucial elements of the structure to
* well-defined values to avoid problems by use of bad pointers... */
void
free_dynarray(dynarray *this)
{
free(this->v); /* should work, even if gp_alloc failed */
this->v = 0;
this->end = this->size = 0;
}
/* Set the size of the dynamical array to a new, fixed value */
void
resize_dynarray(dynarray *this, long newsize)
{
if (!this->v)
int_error(NO_CARET, init_failure_msg);
if (newsize == 0)
free_dynarray(this);
else {
this->v = gp_realloc(this->v, this->entry_size * newsize, "extend dynarray");
this->size = newsize;
}
}
/* Increase the size of the dynarray by a given amount */
void
extend_dynarray(dynarray *this, long increment)
{
resize_dynarray(this, this->size + increment);
}
/* Get pointer to the element one past the current end of the dynamic
* array. Resize it if necessary. Returns a pointer-to-void to that
* element. */
void GPHUGE *
nextfrom_dynarray(dynarray *this)
{
if (!this->v)
int_error(NO_CARET, init_failure_msg);
if (this->end >= this->size)
extend_dynarray(this, this->increment);
return (void *)((char *)(this->v) + this->entry_size * (this->end++));
}
/* Release the element at the current end of the dynamic array, by
* moving the 'end' index one element backwards */
void
droplast_dynarray(dynarray *this)
{
if (!this->v)
int_error(NO_CARET, init_failure_msg);
if (this->end)
this->end--;
}