ngircd-tor/src/ngircd/array.c

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/*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
* Please read the file COPYING, README and AUTHORS for more information.
*
* functions to dynamically allocate arrays.
* Copyright (c) 2005 Florian Westphal (westphal@foo.fh-furtwangen.de)
*
*/
#include "array.h"
static char UNUSED id[] = "$Id: array.c,v 1.3 2005/07/11 14:10:53 fw Exp $";
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#include <assert.h>
#include <stdlib.h>
#include <string.h>
#include "log.h"
#define array_UNUSABLE(x) ( ! x->mem || (0 == x->allocated) )
#define ALIGN_32U(x) ((x | 0x1fU) +1)
#define ALIGN_1024U(x) ((x | 0x3ffU) +1)
#define ALIGN_4096U(x) ((x | 0xfffU) +1)
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static bool
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safemult_uint(unsigned int a, unsigned int b, unsigned int *res)
{
unsigned int tmp;
if (!a || !b) {
*res = 0;
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return true;
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}
tmp = a * b;
if (tmp / b != a)
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return false;
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*res = tmp;
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return true;
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}
/* if realloc() fails, array_alloc return NULL. otherwise return pointer to elem pos in array */
void *
array_alloc(array * a, unsigned int size, unsigned int pos)
{
unsigned int alloc, pos_plus1 = pos + 1;
unsigned int aligned = 0;
char *tmp;
assert(size > 0);
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if (pos_plus1 < pos)
return NULL;
if (!safemult_uint(size, pos_plus1, &alloc))
return NULL;
if (a->allocated < alloc) {
if (alloc < 128) {
aligned = ALIGN_32U(alloc);
} else {
if (alloc < 4096) {
aligned = ALIGN_1024U(alloc);
} else {
aligned = ALIGN_4096U(alloc);
}
}
#ifdef DEBUG
Log(LOG_DEBUG, "Rounded %u to %u byte.", alloc, aligned);
#endif
assert(aligned >= alloc);
if (aligned < alloc) /* rounding overflow */
return NULL;
alloc = aligned;
#ifdef DEBUG
Log(LOG_DEBUG, "array_alloc: changing size from %u to %u byte",
a->allocated, aligned);
#endif
tmp = realloc(a->mem, alloc);
if (!tmp)
return NULL;
a->mem = tmp;
a->allocated = alloc;
assert(a->allocated > a->used);
memset(a->mem + a->used, 0, a->allocated - a->used);
a->used = alloc;
}
return a->mem + (pos * size);
}
/*return number of initialized ELEMS in a. */
unsigned int
array_length(const array * const a, unsigned int membersize)
{
assert(a != NULL);
assert(membersize > 0);
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if (array_UNUSABLE(a))
return 0;
return membersize ? a->used / membersize : 0;
}
/* copy array src to array dest */
bool
array_copy(array * dest, const array * const src)
{
if (array_UNUSABLE(src))
return false;
return array_copyb(dest, src->mem, src->used);
}
/* return false if we could not append src (realloc failure, invalid src/dest array) */
bool
array_copyb(array * dest, const char *src, unsigned int len)
{
assert(dest != NULL);
assert(src != NULL );
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if (!len || !src)
return true;
if (!array_alloc(dest, 1, len))
return false;
dest->used = len;
memcpy(dest->mem, src, len);
#ifdef DEBUG
Log(LOG_DEBUG,
"array_copyb: copied %u bytes to array (%u total bytes allocated)",
len, dest->allocated);
#endif
return true;
}
/* copy string to dest */
bool
array_copys(array * dest, const char *src)
{
return array_copyb(dest, src, strlen(src));
}
/* append len bytes from src to the array dest.
return false if we could not append all bytes (realloc failure, invalid src/dest array) */
bool
array_catb(array * dest, const char *src, unsigned int len)
{
unsigned int tmp;
unsigned int used;
char *ptr;
assert(dest != NULL);
assert(src != NULL);
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if (!len)
return true;
if (!src || !dest)
return false;
used = dest->used;
tmp = used + len;
if (tmp < used || tmp < len) /* integer overflow */
return false;
if (!array_alloc(dest, 1, tmp))
return false;
ptr = dest->mem;
assert(ptr != NULL);
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#ifdef DEBUG
Log(LOG_DEBUG,
"array_catb: appending %u bytes to array (now %u total bytes in array)",
len, tmp);
#endif
memcpy(ptr + used, src, len);
dest->used = tmp;
return true;
}
/* append string to dest */
bool
array_cats(array * dest, const char *src)
{
return array_catb(dest, src, strlen(src));
}
/* append trailing NUL byte to array */
bool
array_cat0(array * a)
{
return array_catb(a, "", 1);
}
/* add contents of array src to array dest. */
bool
array_cat(array * dest, const array * const src)
{
if (array_UNUSABLE(src))
return false;
return array_catb(dest, src->mem, src->used);
}
/* return pointer to the element at pos.
return NULL if the array is unallocated, or if pos is larger than
the number of elements stored int the array. */
void *
array_get(array * a, unsigned int membersize, unsigned int pos)
{
unsigned int totalsize;
assert(membersize > 0);
assert(a != NULL);
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if (array_UNUSABLE(a))
return NULL;
if (!safemult_uint(pos, membersize, &totalsize))
return NULL;
if (a->allocated < totalsize)
return NULL;
return a->mem + pos * membersize;
}
void
array_free(array * a)
{
assert(a != NULL);
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#ifdef DEBUG
Log(LOG_DEBUG,
"array_free: %u bytes free'd (%u bytes still used at time of free())",
a->allocated, a->used);
#endif
free(a->mem);
a->mem = NULL;
a->allocated = 0;
a->used = 0;
}
void
array_free_wipe(array * a)
{
if (!array_UNUSABLE(a))
memset(a->mem, 0, a->allocated);
array_free(a);
}
void *
array_start(const array * const a)
{
assert(a != NULL);
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return a->mem;
}
void
array_trunc(array * a)
{
assert(a != NULL);
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a->used = 0;
}
void
array_truncate(array * a, unsigned int membersize, unsigned int len)
{
unsigned int newlen;
assert(a != NULL);
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if (!safemult_uint(membersize, len, &newlen))
return;
if (newlen <= a->allocated)
a->used = newlen;
}
/* move elements starting at pos to beginning of array */
void
array_moveleft(array * a, unsigned int membersize, unsigned int pos)
{
unsigned int bytepos;
assert(a != NULL);
assert(membersize > 0);
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if (!pos)
return;
if (!safemult_uint(membersize, pos, &bytepos)) {
a->used = 0;
return;
}
if (!bytepos)
return; /* nothing to do */
#ifdef DEBUG
Log(LOG_DEBUG,
"array_moveleft: %u used bytes in array, move to beginning, starting at pos %u",
a->used, bytepos);
#endif
if (a->used <= bytepos) {
a->used = 0;
return;
}
a->used -= bytepos;
memmove(a->mem, a->mem + bytepos, a->used);
}
/* -eof- */