WebSVN – HelenOS – Diff – /branches/tracing/uspace/lib/libc/generic/io/vsnprintf.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.
 */
 
/** @addtogroup libc
 * @{
 */
/** @file
 */
 
#include <stdarg.h>
#include <stdio.h>
#include <string.h>
#include <io/printf_core.h>
#include <errno.h>
 
typedef struct {
    size_t size;    /* Total size of the buffer (in bytes) */
    size_t len;     /* Number of already used bytes */
    char *dst;      /* Destination */
} vsnprintf_data_t;
 
/** Write string to given buffer.
 *
 * Write at most data->size plain characters including trailing zero.
 * According to C99, snprintf() has to return number of characters that
 * would have been written if enough space had been available. Hence
 * the return value is not the number of actually printed characters
 * but size of the input string.
 *
 * @param str  Source string to print.
 * @param size Number of plain characters in str.
 * @param data Structure describing destination string, counter
 *             of used space and total string size.
 *
 * @return Number of characters to print (not characters actually
 *         printed).
 *
 */
static int vsnprintf_str_write(const char *str, size_t size, vsnprintf_data_t *data)
{
    size_t left = data->size - data->len;
   
    if (left == 0)
        return ((int) size);
   
    if (left == 1) {
        /* We have only one free byte left in buffer
         * -> store trailing zero
         */
        data->dst[data->size - 1] = 0;
        data->len = data->size;
        return ((int) size);
    }
   
    if (left <= size) {
        /* We do not have enough space for the whole string
         * with the trailing zero => print only a part
         * of string
         */
        size_t index = 0;
       
        while (index < size) {
            wchar_t uc = str_decode(str, &index, size);
           
            if (chr_encode(uc, data->dst, &data->len, data->size - 1) != EOK)
                break;
        }
       
        /* Put trailing zero at end, but not count it
         * into data->len so it could be rewritten next time
         */
        data->dst[data->len] = 0;
       
        return ((int) size);
    }
   
    /* Buffer is big enought to print the whole string */
    memcpy((void *)(data->dst + data->len), (void *) str, size);
    data->len += size;
   
    /* Put trailing zero at end, but not count it
     * into data->len so it could be rewritten next time
     */
    data->dst[data->len] = 0;
   
    return ((int) size);
}
 
/** Write wide string to given buffer.
 *
 * Write at most data->size plain characters including trailing zero.
 * According to C99, snprintf() has to return number of characters that
 * would have been written if enough space had been available. Hence
 * the return value is not the number of actually printed characters
 * but size of the input string.
 *
 * @param str  Source wide string to print.
 * @param size Number of bytes in str.
 * @param data Structure describing destination string, counter
 *             of used space and total string size.
 *
 * @return Number of wide characters to print (not characters actually
 *         printed).
 *
 */
static int vsnprintf_wstr_write(const wchar_t *str, size_t size, vsnprintf_data_t *data)
{
    size_t index = 0;
   
    while (index < (size / sizeof(wchar_t))) {
        size_t left = data->size - data->len;
       
        if (left == 0)
            return ((int) size);
       
        if (left == 1) {
            /* We have only one free byte left in buffer
             * -> store trailing zero
             */
            data->dst[data->size - 1] = 0;
            data->len = data->size;
            return ((int) size);
        }
       
        if (chr_encode(str[index], data->dst, &data->len, data->size - 1) != EOK)
            break;
       
        index++;
    }
   
    /* Put trailing zero at end, but not count it
     * into data->len so it could be rewritten next time
     */
    data->dst[data->len] = 0;
   
    return ((int) size);
}
 
int vsnprintf(char *str, size_t size, const char *fmt, va_list ap)
{
    vsnprintf_data_t data = {
        size,
        0,
        str
    };
    printf_spec_t ps = {
        (int(*) (const char *, size_t, void *)) vsnprintf_str_write,
        (int(*) (const wchar_t *, size_t, void *)) vsnprintf_wstr_write,
        &data
    };
   
    /* Print 0 at end of string - fix the case that nothing will be printed */
    if (size > 0)
        str[0] = 0;
   
    /* vsnprintf_write ensures that str will be terminated by zero. */
    return printf_core(fmt, &ps, ap);
}
 
/** @}
 */
 

Subversion Repositories HelenOS

(root)/branches/tracing/uspace/lib/libc/generic/io/vsnprintf.c – Rev 4377 → 4692

Rev 4377		Rev 4692
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	/** @addtogroup libc	29	/** @addtogroup libc
30	* @{	30	* @{
31	*/	31	*/
32	/** @file	32	/** @file
33	*/	33	*/
34		34
35	#include <stdarg.h>	35	#include <stdarg.h>
36	#include <stdio.h>	36	#include <stdio.h>
37	#include <string.h>	37	#include <string.h>
38	#include <io/printf_core.h>	38	#include <io/printf_core.h>
39	#include <errno.h>	39	#include <errno.h>
40		40
41	typedef struct {	41	typedef struct {
42	size_t size; /* Total size of the buffer (in bytes) */	42	size_t size; /* Total size of the buffer (in bytes) */
43	size_t len; /* Number of already used bytes */	43	size_t len; /* Number of already used bytes */
44	char dst; / Destination */	44	char dst; / Destination */
45	} vsnprintf_data_t;	45	} vsnprintf_data_t;
46		46
47	/** Write string to given buffer.	47	/** Write string to given buffer.
48	*	48	*
49	* Write at most data->size plain characters including trailing zero.	49	* Write at most data->size plain characters including trailing zero.
50	* According to C99, snprintf() has to return number of characters that	50	* According to C99, snprintf() has to return number of characters that
51	* would have been written if enough space had been available. Hence	51	* would have been written if enough space had been available. Hence
52	* the return value is not the number of actually printed characters	52	* the return value is not the number of actually printed characters
53	* but size of the input string.	53	* but size of the input string.
54	*	54	*
55	* @param str Source string to print.	55	* @param str Source string to print.
56	* @param size Number of plain characters in str.	56	* @param size Number of plain characters in str.
57	* @param data Structure describing destination string, counter	57	* @param data Structure describing destination string, counter
58	* of used space and total string size.	58	* of used space and total string size.
59	*	59	*
60	* @return Number of characters to print (not characters actually	60	* @return Number of characters to print (not characters actually
61	* printed).	61	* printed).
62	*	62	*
63	*/	63	*/
64	static int vsnprintf_str_write(const char str, size_t size, vsnprintf_data_t data)	64	static int vsnprintf_str_write(const char str, size_t size, vsnprintf_data_t data)
65	{	65	{
66	size_t left = data->size - data->len;	66	size_t left = data->size - data->len;
67		67
68	if (left == 0)	68	if (left == 0)
69	return ((int) size);	69	return ((int) size);
70		70
71	if (left == 1) {	71	if (left == 1) {
72	/* We have only one free byte left in buffer	72	/* We have only one free byte left in buffer
73	* -> store trailing zero	73	* -> store trailing zero
74	*/	74	*/
75	data->dst[data->size - 1] = 0;	75	data->dst[data->size - 1] = 0;
76	data->len = data->size;	76	data->len = data->size;
77	return ((int) size);	77	return ((int) size);
78	}	78	}
79		79
80	if (left <= size) {	80	if (left <= size) {
81	/* We do not have enough space for the whole string	81	/* We do not have enough space for the whole string
82	* with the trailing zero => print only a part	82	* with the trailing zero => print only a part
83	* of string	83	* of string
84	*/	84	*/
85	index_t index = 0;	85	size_t index = 0;
86		86
87	while (index < size) {	87	while (index < size) {
88	wchar_t uc = str_decode(str, &index, size);	88	wchar_t uc = str_decode(str, &index, size);
89		89
90	if (chr_encode(uc, data->dst, &data->len, data->size - 1) != EOK)	90	if (chr_encode(uc, data->dst, &data->len, data->size - 1) != EOK)
91	break;	91	break;
92	}	92	}
93		93
94	/* Put trailing zero at end, but not count it	94	/* Put trailing zero at end, but not count it
95	* into data->len so it could be rewritten next time	95	* into data->len so it could be rewritten next time
96	*/	96	*/
97	data->dst[data->len] = 0;	97	data->dst[data->len] = 0;
98		98
99	return ((int) size);	99	return ((int) size);
100	}	100	}
101		101
102	/* Buffer is big enought to print the whole string */	102	/* Buffer is big enought to print the whole string */
103	memcpy((void )(data->dst + data->len), (void ) str, size);	103	memcpy((void )(data->dst + data->len), (void ) str, size);
104	data->len += size;	104	data->len += size;
105		105
106	/* Put trailing zero at end, but not count it	106	/* Put trailing zero at end, but not count it
107	* into data->len so it could be rewritten next time	107	* into data->len so it could be rewritten next time
108	*/	108	*/
109	data->dst[data->len] = 0;	109	data->dst[data->len] = 0;
110		110
111	return ((int) size);	111	return ((int) size);
112	}	112	}
113		113
114	/** Write wide string to given buffer.	114	/** Write wide string to given buffer.
115	*	115	*
116	* Write at most data->size plain characters including trailing zero.	116	* Write at most data->size plain characters including trailing zero.
117	* According to C99, snprintf() has to return number of characters that	117	* According to C99, snprintf() has to return number of characters that
118	* would have been written if enough space had been available. Hence	118	* would have been written if enough space had been available. Hence
119	* the return value is not the number of actually printed characters	119	* the return value is not the number of actually printed characters
120	* but size of the input string.	120	* but size of the input string.
121	*	121	*
122	* @param str Source wide string to print.	122	* @param str Source wide string to print.
123	* @param size Number of bytes in str.	123	* @param size Number of bytes in str.
124	* @param data Structure describing destination string, counter	124	* @param data Structure describing destination string, counter
125	* of used space and total string size.	125	* of used space and total string size.
126	*	126	*
127	* @return Number of wide characters to print (not characters actually	127	* @return Number of wide characters to print (not characters actually
128	* printed).	128	* printed).
129	*	129	*
130	*/	130	*/
131	static int vsnprintf_wstr_write(const wchar_t str, size_t size, vsnprintf_data_t data)	131	static int vsnprintf_wstr_write(const wchar_t str, size_t size, vsnprintf_data_t data)
132	{	132	{
133	index_t index = 0;	133	size_t index = 0;
134		134
135	while (index < (size / sizeof(wchar_t))) {	135	while (index < (size / sizeof(wchar_t))) {
136	size_t left = data->size - data->len;	136	size_t left = data->size - data->len;
137		137
138	if (left == 0)	138	if (left == 0)
139	return ((int) size);	139	return ((int) size);
140		140
141	if (left == 1) {	141	if (left == 1) {
142	/* We have only one free byte left in buffer	142	/* We have only one free byte left in buffer
143	* -> store trailing zero	143	* -> store trailing zero
144	*/	144	*/
145	data->dst[data->size - 1] = 0;	145	data->dst[data->size - 1] = 0;
146	data->len = data->size;	146	data->len = data->size;
147	return ((int) size);	147	return ((int) size);
148	}	148	}
149		149
150	if (chr_encode(str[index], data->dst, &data->len, data->size - 1) != EOK)	150	if (chr_encode(str[index], data->dst, &data->len, data->size - 1) != EOK)
151	break;	151	break;
152		152
153	index++;	153	index++;
154	}	154	}
155		155
156	/* Put trailing zero at end, but not count it	156	/* Put trailing zero at end, but not count it
157	* into data->len so it could be rewritten next time	157	* into data->len so it could be rewritten next time
158	*/	158	*/
159	data->dst[data->len] = 0;	159	data->dst[data->len] = 0;
160		160
161	return ((int) size);	161	return ((int) size);
162	}	162	}
163		163
164	int vsnprintf(char str, size_t size, const char fmt, va_list ap)	164	int vsnprintf(char str, size_t size, const char fmt, va_list ap)
165	{	165	{
166	vsnprintf_data_t data = {	166	vsnprintf_data_t data = {
167	size,	167	size,
168	0,	168	0,
169	str	169	str
170	};	170	};
171	printf_spec_t ps = {	171	printf_spec_t ps = {
172	(int() (const char , size_t, void *)) vsnprintf_str_write,	172	(int() (const char , size_t, void *)) vsnprintf_str_write,
173	(int() (const wchar_t , size_t, void *)) vsnprintf_wstr_write,	173	(int() (const wchar_t , size_t, void *)) vsnprintf_wstr_write,
174	&data	174	&data
175	};	175	};
176		176
177	/* Print 0 at end of string - fix the case that nothing will be printed */	177	/* Print 0 at end of string - fix the case that nothing will be printed */
178	if (size > 0)	178	if (size > 0)
179	str[0] = 0;	179	str[0] = 0;
180		180
181	/* vsnprintf_write ensures that str will be terminated by zero. */	181	/* vsnprintf_write ensures that str will be terminated by zero. */
182	return printf_core(fmt, &ps, ap);	182	return printf_core(fmt, &ps, ap);
183	}	183	}
184		184
185	/** @}	185	/** @}
186	*/	186	*/
187		187