transmission/libtransmission/ptrarray.c

187 lines
3.9 KiB
C

/*
* This file Copyright (C) 2007 Charles Kerr <charles@rebelbase.com>
*
* This file is licensed by the GPL version 2. Works owned by the
* Transmission project are granted a special exemption to clause 2(b)
* so that the bulk of its code can remain under the MIT license.
* This exemption does not extend to derived works not owned by
* the Transmission project.
*/
#include <assert.h>
#include <stdlib.h>
#include <string.h> /* memmove */
#include "ptrarray.h"
#include "utils.h"
#define GROW 32
struct tr_ptrArray_s
{
void ** items;
int n_items;
int n_alloc;
};
tr_ptrArray_t*
tr_ptrArrayNew( void )
{
tr_ptrArray_t * p;
p = tr_new( tr_ptrArray_t, 1 );
p->n_items = 0;
p->n_alloc = GROW;
p->items = tr_new( void*, p->n_alloc );
return p;
}
void
tr_ptrArrayFree( tr_ptrArray_t * t )
{
assert( t != NULL );
assert( t->items != NULL );
tr_free( t->items );
tr_free( t );
}
void**
tr_ptrArrayPeek( tr_ptrArray_t * t, int * size )
{
*size = t->n_items;
return t->items;
}
int
tr_ptrArraySize( const tr_ptrArray_t * t )
{
return t->n_items;
}
int
tr_ptrArrayEmpty( const tr_ptrArray_t * t )
{
return t->n_items == 0;
}
void
tr_ptrArrayClear( tr_ptrArray_t * t )
{
t->n_items = 0;
}
int
tr_ptrArrayInsert( tr_ptrArray_t * t, void * ptr, int pos )
{
if( pos<0 || pos>t->n_items )
pos = t->n_items;
if( t->n_items >= t->n_alloc ) {
t->n_alloc = t->n_items + GROW;
t->items = tr_renew( void*, t->items, t->n_alloc );
}
memmove( t->items + pos + 1,
t->items + pos,
sizeof(void*) * (t->n_items - pos));
t->items[pos] = ptr;
t->n_items++;
return pos;
}
int
tr_ptrArrayAppend( tr_ptrArray_t * t, void * ptr )
{
return tr_ptrArrayInsert( t, ptr, -1 );
}
void
tr_ptrArrayErase( tr_ptrArray_t * t, int begin, int end )
{
assert( begin >= 0 );
if( end < 0 ) end = t->n_items;
assert( end > begin );
assert( end <= t->n_items );
memmove( t->items + begin,
t->items + end,
sizeof(void*) * (t->n_items - end) );
t->n_items -= (end - begin);
}
/**
***
**/
int
tr_ptrArrayLowerBound( const tr_ptrArray_t * t,
void * ptr,
int compare( const void *,const void * ),
int * exact_match )
{
int c = -1;
int len = t->n_items;
int first = 0;
while( len > 0 )
{
int half = len / 2;
int middle = first + half;
c = compare( t->items[middle], ptr );
if( c < 0 ) {
first = middle + 1;
len = len - half - 1;
} else if (!c ) {
if( exact_match )
*exact_match = 1;
return middle;
break;
} else {
len = half;
}
}
if( exact_match )
*exact_match = 0;
return first;
}
int
tr_ptrArrayInsertSorted( tr_ptrArray_t * t,
void * ptr,
int compare(const void*,const void*) )
{
const int pos = tr_ptrArrayLowerBound( t, ptr, compare, NULL );
return tr_ptrArrayInsert( t, ptr, pos );
}
void*
tr_ptrArrayFindSorted( tr_ptrArray_t * t,
void * ptr,
int compare(const void*,const void*) )
{
int match;
const int pos = tr_ptrArrayLowerBound( t, ptr, compare, &match );
return match ? t->items[pos] : NULL;
}
void*
tr_ptrArrayRemoveSorted( tr_ptrArray_t * t,
void * ptr,
int compare(const void*,const void*) )
{
void * ret = NULL;
int match;
const int pos = tr_ptrArrayLowerBound( t, ptr, compare, &match );
if( match ) {
ret = t->items[pos];
tr_ptrArrayErase( t, pos, pos+1 );
}
return ret;
}