sbin/hastd/ebuf.c

64 static int ebuf_head_extend(struct ebuf *eb, size_t size);
65 static int ebuf_tail_extend(struct ebuf *eb, size_t size);
70 	struct ebuf *eb;
73 	eb = malloc(sizeof(*eb));
74 	if (eb == NULL)
77 	eb->eb_start = malloc(size);
78 	if (eb->eb_start == NULL) {
80 		free(eb);
84 	eb->eb_end = eb->eb_start + size;
89 	eb->eb_used = eb->eb_start + PAGE_SIZE / 4;
90 	eb->eb_size = 0;
91 	eb->eb_magic = EBUF_MAGIC;
93 	return (eb);
97 ebuf_free(struct ebuf *eb)
100 	PJDLOG_ASSERT(eb != NULL && eb->eb_magic == EBUF_MAGIC);
102 	eb->eb_magic = 0;
104 	free(eb->eb_start);
105 	free(eb);
109 ebuf_add_head(struct ebuf *eb, const void *data, size_t size)
112 	PJDLOG_ASSERT(eb != NULL && eb->eb_magic == EBUF_MAGIC);
114 	if (size > (size_t)(eb->eb_used - eb->eb_start)) {
119 		if (ebuf_head_extend(eb, size) == -1)
122 	PJDLOG_ASSERT(size <= (size_t)(eb->eb_used - eb->eb_start));
124 	eb->eb_size += size;
125 	eb->eb_used -= size;
130 		bcopy(data, eb->eb_used, size);
136 ebuf_add_tail(struct ebuf *eb, const void *data, size_t size)
139 	PJDLOG_ASSERT(eb != NULL && eb->eb_magic == EBUF_MAGIC);
141 	if (size > (size_t)(eb->eb_end - (eb->eb_used + eb->eb_size))) {
146 		if (ebuf_tail_extend(eb, size) == -1)
150 	    (size_t)(eb->eb_end - (eb->eb_used + eb->eb_size)));
156 		bcopy(data, eb->eb_used + eb->eb_size, size);
157 	eb->eb_size += size;
163 ebuf_del_head(struct ebuf *eb, size_t size)
166 	PJDLOG_ASSERT(eb != NULL && eb->eb_magic == EBUF_MAGIC);
167 	PJDLOG_ASSERT(size <= eb->eb_size);
169 	eb->eb_used += size;
170 	eb->eb_size -= size;
174 ebuf_del_tail(struct ebuf *eb, size_t size)
177 	PJDLOG_ASSERT(eb != NULL && eb->eb_magic == EBUF_MAGIC);
178 	PJDLOG_ASSERT(size <= eb->eb_size);
180 	eb->eb_size -= size;
187 ebuf_data(struct ebuf *eb, size_t *sizep)
190 	PJDLOG_ASSERT(eb != NULL && eb->eb_magic == EBUF_MAGIC);
193 		*sizep = eb->eb_size;
194 	return (eb->eb_size > 0 ? eb->eb_used : NULL);
201 ebuf_size(struct ebuf *eb)
204 	PJDLOG_ASSERT(eb != NULL && eb->eb_magic == EBUF_MAGIC);
206 	return (eb->eb_size);
213 ebuf_head_extend(struct ebuf *eb, size_t size)
218 	PJDLOG_ASSERT(eb != NULL && eb->eb_magic == EBUF_MAGIC);
220 	newsize = eb->eb_end - eb->eb_start + (PAGE_SIZE / 4) + size;
226 	    newstart + (PAGE_SIZE / 4) + size + (eb->eb_used - eb->eb_start);
228 	bcopy(eb->eb_used, newused, eb->eb_size);
230 	eb->eb_start = newstart;
231 	eb->eb_used = newused;
232 	eb->eb_end = newstart + newsize;
241 ebuf_tail_extend(struct ebuf *eb, size_t size)
246 	PJDLOG_ASSERT(eb != NULL && eb->eb_magic == EBUF_MAGIC);
248 	newsize = eb->eb_end - eb->eb_start + size + ((3 * PAGE_SIZE) / 4);
250 	newstart = realloc(eb->eb_start, newsize);
254 	eb->eb_used = newstart + (eb->eb_used - eb->eb_start);
255 	eb->eb_start = newstart;
256 	eb->eb_end = newstart + newsize;