d5ec8d807b179a2a7deaece42290b94d37276c70
2 * mlt_deque.c -- double ended queue
3 * Copyright (C) 2003-2004 Ushodaya Enterprises Limited
4 * Author: Charles Yates <charles.yates@pandora.be>
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License as published by
8 * the Free Software Foundation; either version 2 of the License, or
9 * (at your option) any later version.
11 * This program is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 * GNU General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software Foundation,
18 * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
22 #include "mlt_deque.h"
24 // System header files
35 /** Private structure.
48 mlt_deque
mlt_deque_init( )
50 mlt_deque
this = malloc( sizeof( struct mlt_deque_s
) );
60 /** Return the number of items in the deque.
63 int mlt_deque_count( mlt_deque
this )
68 /** Allocate space on the deque.
71 static int mlt_deque_allocate( mlt_deque
this )
73 if ( this->count
== this->size
)
75 this->list
= realloc( this->list
, sizeof( deque_entry
) * ( this->size
+ 20 ) );
78 return this->list
== NULL
;
81 /** Push an item to the end.
84 int mlt_deque_push_back( mlt_deque
this, void *item
)
86 int error
= mlt_deque_allocate( this );
89 this->list
[ this->count
++ ].addr
= item
;
97 void *mlt_deque_pop_back( mlt_deque
this )
99 return this->count
> 0 ?
this->list
[ -- this->count
].addr
: NULL
;
102 /** Queue an item at the start.
105 int mlt_deque_push_front( mlt_deque
this, void *item
)
107 int error
= mlt_deque_allocate( this );
111 memmove( &this->list
[ 1 ], this->list
, ( this->count
++ ) * sizeof( deque_entry
) );
112 this->list
[ 0 ].addr
= item
;
118 /** Remove an item from the start.
121 void *mlt_deque_pop_front( mlt_deque
this )
125 if ( this->count
> 0 )
127 item
= this->list
[ 0 ].addr
;
128 memmove( this->list
, &this->list
[ 1 ], ( -- this->count
) * sizeof( deque_entry
) );
134 /** Inquire on item at back of deque but don't remove.
137 void *mlt_deque_peek_back( mlt_deque
this )
139 return this->count
> 0 ?
this->list
[ this->count
- 1 ].addr
: NULL
;
142 /** Inquire on item at front of deque but don't remove.
145 void *mlt_deque_peek_front( mlt_deque
this )
147 return this->count
> 0 ?
this->list
[ 0 ].addr
: NULL
;
150 /** Push an item to the end.
153 int mlt_deque_push_back_int( mlt_deque
this, int item
)
155 int error
= mlt_deque_allocate( this );
158 this->list
[ this->count
++ ].value
= item
;
166 int mlt_deque_pop_back_int( mlt_deque
this )
168 return this->count
> 0 ?
this->list
[ -- this->count
].value
: 0;
171 /** Queue an item at the start.
174 int mlt_deque_push_front_int( mlt_deque
this, int item
)
176 int error
= mlt_deque_allocate( this );
180 memmove( &this->list
[ 1 ], this->list
, ( this->count
++ ) * sizeof( deque_entry
) );
181 this->list
[ 0 ].value
= item
;
187 /** Remove an item from the start.
190 int mlt_deque_pop_front_int( mlt_deque
this )
194 if ( this->count
> 0 )
196 item
= this->list
[ 0 ].value
;
197 memmove( this->list
, &this->list
[ 1 ], ( -- this->count
) * sizeof( deque_entry
) );
203 /** Inquire on item at back of deque but don't remove.
206 int mlt_deque_peek_back_int( mlt_deque
this )
208 return this->count
> 0 ?
this->list
[ this->count
- 1 ].value
: 0;
211 /** Inquire on item at front of deque but don't remove.
214 int mlt_deque_peek_front_int( mlt_deque
this )
216 return this->count
> 0 ?
this->list
[ 0 ].value
: 0;
222 void mlt_deque_close( mlt_deque
this )