1 /* SPDX-License-Identifier: GPL-2.0 */
16  * struct seq_buf - seq buffer structure
17  * @buffer:	pointer to the buffer
18  * @size:	size of the buffer
19  * @len:	the amount of data inside the buffer
22 	char			*buffer;  member
23 	size_t			size;  member
27 #define DECLARE_SEQ_BUF(NAME, SIZE)			\  argument
29 		.buffer = (char[SIZE]) { 0 },		\
30 		.size = SIZE,				\
35 	s->len = 0;  in seq_buf_clear()
36 	if (s->size)  in seq_buf_clear()
37 		s->buffer[0] = '\0';  in seq_buf_clear()
41 seq_buf_init(struct seq_buf *s, char *buf, unsigned int size)  in seq_buf_init()  argument
43 	s->buffer = buf;  in seq_buf_init()
44 	s->size = size;  in seq_buf_init()
49  * seq_buf have a buffer that might overflow. When this happens
50  * len is set to be greater than size.
55 	return s->len > s->size;  in seq_buf_has_overflowed()
61 	s->len = s->size + 1;  in seq_buf_set_overflow()
65  * How much buffer is left on the seq_buf?
73 	return s->size - s->len;  in seq_buf_buffer_left()
76 /* How much buffer was written? */
79 	return min(s->len, s->size);  in seq_buf_used()
83  * seq_buf_str - get NUL-terminated C string from seq_buf
86  * This makes sure that the buffer in @s is NUL-terminated and
89  * Note, if this is called when the buffer has overflowed, then
90  * the last byte of the buffer is zeroed, and the len will still
93  * After this function is called, s->buffer is safe to use
96  * Returns: @s->buf after making sure it is terminated.
100 	if (WARN_ON(s->size == 0))  in seq_buf_str()
104 		s->buffer[s->len] = 0;  in seq_buf_str()
106 		s->buffer[s->size - 1] = 0;  in seq_buf_str()
108 	return s->buffer;  in seq_buf_str()
112  * seq_buf_get_buf - get buffer to write arbitrary data to
114  * @bufp: the beginning of the buffer is stored here
116  * Returns: the number of bytes available in the buffer, or zero if
121 	WARN_ON(s->len > s->size + 1);  in seq_buf_get_buf()
123 	if (s->len < s->size) {  in seq_buf_get_buf()
124 		*bufp = s->buffer + s->len;  in seq_buf_get_buf()
125 		return s->size - s->len;  in seq_buf_get_buf()
133  * seq_buf_commit - commit data to the buffer
137  * Commit @num bytes of data written to a buffer previously acquired
147 		BUG_ON(s->len + num > s->size);  in seq_buf_commit()
148 		s->len += num;  in seq_buf_commit()