WebSVN – HelenOS-historic – Diff – /uspace/trunk/kbd/generic/key_buffer.c


/*
 * Copyright (C) 2006 Josef Cejka
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
 
#include <key_buffer.h>
#include <libadt/fifo.h>
 
#define KBD_BUFFER_SIZE 128 /**< Size of buffer for pressed keys */
 
FIFO_INITIALIZE_STATIC(buffer, char, KBD_BUFFER_SIZE);  /**< Fifo for storing pressed keys */
fifo_count_t buffer_items;  /**< Counter of used items for prevent fifo overflow */
 
/** Clear key buffer.
 */
void key_buffer_free(void)
{
    buffer_items = 0;
    buffer.head = buffer.tail = 0;
}
 
/** Key buffer initialization.
 *
 */
void key_buffer_init(void)
{
    key_buffer_free();
}
 
/** Get free space in buffer.
 * This function is useful for processing some scancodes that are translated
 * to more than one character.
 * @return empty buffer space
 */
int key_buffer_available(void)
{
    return KBD_BUFFER_SIZE - buffer_items;
}
 
/**
 * @return nonzero, if buffer is not empty.
 */
int key_buffer_empty(void)
{
    return (buffer_items == 0);
}
 
/** Push key to key buffer.
 * If buffer is full, character is ignored.
 * @param key code of stored key
 */
void key_buffer_push(char key)
{
    if (buffer_items < KBD_BUFFER_SIZE) {
        fifo_push(buffer, key);
        buffer_items++;
    }
}
 
/** Pop character from buffer.
 * @param c pointer to space where to store character from buffer.
 * @return zero on empty buffer, nonzero else
 */
int key_buffer_pop(char *c)
{
    if (buffer_items > 0) {
        buffer_items--;
        *c = fifo_pop(buffer);
        return 1;
    }
    return 0;
}
 
 
 

Rev 1344	Rev 1392
1	/*	1	/*
2	* Copyright (C) 2006 Josef Cejka	2	* Copyright (C) 2006 Josef Cejka
3	* All rights reserved.	3	* All rights reserved.
4	*	4	*
5	* Redistribution and use in source and binary forms, with or without	5	* Redistribution and use in source and binary forms, with or without
6	* modification, are permitted provided that the following conditions	6	* modification, are permitted provided that the following conditions
7	* are met:	7	* are met:
8	*	8	*
9	* - Redistributions of source code must retain the above copyright	9	* - Redistributions of source code must retain the above copyright
10	* notice, this list of conditions and the following disclaimer.	10	* notice, this list of conditions and the following disclaimer.
11	* - Redistributions in binary form must reproduce the above copyright	11	* - Redistributions in binary form must reproduce the above copyright
12	* notice, this list of conditions and the following disclaimer in the	12	* notice, this list of conditions and the following disclaimer in the
13	* documentation and/or other materials provided with the distribution.	13	* documentation and/or other materials provided with the distribution.
14	* - The name of the author may not be used to endorse or promote products	14	* - The name of the author may not be used to endorse or promote products
15	* derived from this software without specific prior written permission.	15	* derived from this software without specific prior written permission.
16	*	16	*
17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR	17	* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES	18	* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.	19	* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,	20	* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT	21	* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,	22	* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY	23	* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT	24	* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF	25	* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.	26	* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27	*/	27	*/
28		28
29	#include <key_buffer.h>	29	#include <key_buffer.h>
30	#include <fifo.h>	30	#include <libadt/fifo.h>
31		31
32	#define KBD_BUFFER_SIZE 128 /*< Size of buffer for pressed keys /	32	#define KBD_BUFFER_SIZE 128 /*< Size of buffer for pressed keys /
33		33
34	FIFO_INITIALIZE_STATIC(buffer, char, KBD_BUFFER_SIZE); /*< Fifo for storing pressed keys /	34	FIFO_INITIALIZE_STATIC(buffer, char, KBD_BUFFER_SIZE); /*< Fifo for storing pressed keys /
35	fifo_count_t buffer_items; /*< Counter of used items for prevent fifo overflow /	35	fifo_count_t buffer_items; /*< Counter of used items for prevent fifo overflow /
36		36
37	/** Clear key buffer.	37	/** Clear key buffer.
38	*/	38	*/
39	void key_buffer_free(void)	39	void key_buffer_free(void)
40	{	40	{
41	buffer_items = 0;	41	buffer_items = 0;
42	buffer.head = buffer.tail = 0;	42	buffer.head = buffer.tail = 0;
43	}	43	}
44		44
45	/** Key buffer initialization.	45	/** Key buffer initialization.
46	*	46	*
47	*/	47	*/
48	void key_buffer_init(void)	48	void key_buffer_init(void)
49	{	49	{
50	key_buffer_free();	50	key_buffer_free();
51	}	51	}
52		52
53	/** Get free space in buffer.	53	/** Get free space in buffer.
54	* This function is useful for processing some scancodes that are translated	54	* This function is useful for processing some scancodes that are translated
55	* to more than one character.	55	* to more than one character.
56	* @return empty buffer space	56	* @return empty buffer space
57	*/	57	*/
58	int key_buffer_available(void)	58	int key_buffer_available(void)
59	{	59	{
60	return KBD_BUFFER_SIZE - buffer_items;	60	return KBD_BUFFER_SIZE - buffer_items;
61	}	61	}
62		62
63	/**	63	/**
64	* @return nonzero, if buffer is not empty.	64	* @return nonzero, if buffer is not empty.
65	*/	65	*/
66	int key_buffer_empty(void)	66	int key_buffer_empty(void)
67	{	67	{
68	return (buffer_items == 0);	68	return (buffer_items == 0);
69	}	69	}
70		70
71	/** Push key to key buffer.	71	/** Push key to key buffer.
72	* If buffer is full, character is ignored.	72	* If buffer is full, character is ignored.
73	* @param key code of stored key	73	* @param key code of stored key
74	*/	74	*/
75	void key_buffer_push(char key)	75	void key_buffer_push(char key)
76	{	76	{
77	if (buffer_items < KBD_BUFFER_SIZE) {	77	if (buffer_items < KBD_BUFFER_SIZE) {
78	fifo_push(buffer, key);	78	fifo_push(buffer, key);
79	buffer_items++;	79	buffer_items++;
80	}	80	}
81	}	81	}
82		82
83	/** Pop character from buffer.	83	/** Pop character from buffer.
84	* @param c pointer to space where to store character from buffer.	84	* @param c pointer to space where to store character from buffer.
85	* @return zero on empty buffer, nonzero else	85	* @return zero on empty buffer, nonzero else
86	*/	86	*/
87	int key_buffer_pop(char *c)	87	int key_buffer_pop(char *c)
88	{	88	{
89	if (buffer_items > 0) {	89	if (buffer_items > 0) {
90	buffer_items--;	90	buffer_items--;
91	*c = fifo_pop(buffer);	91	*c = fifo_pop(buffer);
92	return 1;	92	return 1;
93	}	93	}
94	return 0;	94	return 0;
95	}	95	}
96		96
97		97
98		98

Subversion Repositories HelenOS-historic

(root)/uspace/trunk/kbd/generic/key_buffer.c – Rev 1344 → 1392