7 #include "buffer_tree.h"
19 enum btr_buffer_flags {
20 /* changes the way the buffer is deallocated */
27 /** The number of references to this buffer. */
29 struct btr_pool *pool;
32 struct btr_buffer_reference {
33 struct btr_buffer *btrb;
35 /* Each buffer reference belongs to the buffer queue list of some buffer tree node. */
36 struct list_head node;
42 struct btr_node *parent;
43 /* The position of this btr node in the buffer tree. */
44 struct list_head node;
45 /* The children nodes of this btr node are linked together in a list. */
46 struct list_head children;
47 /* Time of first data transfer. */
50 * The input queue is a list of references to btr buffers. Each item on
51 * the list represents an input buffer which has not been completely
52 * used by this btr node.
54 struct list_head input_queue;
55 btr_command_handler execute;
59 struct btr_pool *btr_pool_new(const char *name, size_t area_size)
61 struct btr_pool *btrp;
63 PARA_INFO_LOG("%s, %zu bytes\n", name, area_size);
64 btrp = para_malloc(sizeof(*btrp));
65 btrp->area_start = para_malloc(area_size);
66 btrp->area_end = btrp->area_start + area_size;
67 btrp->rhead = btrp->area_start;
68 btrp->whead = btrp->area_start;
69 btrp->name = para_strdup(name);
73 /* whead = NULL means area full */
75 void btr_pool_free(struct btr_pool *btrp)
79 free(btrp->area_start);
84 size_t btr_pool_size(struct btr_pool *btrp)
86 return btrp->area_end - btrp->area_start;
89 size_t btr_pool_filled(struct btr_pool *btrp)
92 return btr_pool_size(btrp);
93 if (btrp->rhead <= btrp->whead)
94 return btrp->whead - btrp->rhead;
95 return btr_pool_size(btrp) - (btrp->rhead - btrp->whead);
98 size_t btr_pool_unused(struct btr_pool *btrp)
100 return btr_pool_size(btrp) - btr_pool_filled(btrp);
104 * Return maximal size available for one read. This is
105 * smaller than the value returned by btr_pool_unused().
107 size_t btr_pool_available(struct btr_pool *btrp)
111 if (btrp->rhead <= btrp->whead)
112 return btrp->area_end - btrp->whead;
113 return btrp->rhead - btrp->whead;
116 size_t btr_pool_get_buffer(struct btr_pool *btrp, char **result)
119 *result = btrp->whead;
120 return btr_pool_available(btrp);
123 void btr_pool_allocate(struct btr_pool *btrp, size_t size)
129 assert(size <= btr_pool_available(btrp));
130 end = btrp->whead + size;
131 assert(end <= btrp->area_end);
133 if (end == btrp->area_end) {
134 PARA_DEBUG_LOG("%s: end of pool area reached\n", btrp->name);
135 end = btrp->area_start;
137 if (end == btrp->rhead) {
138 PARA_DEBUG_LOG("%s btrp buffer full\n", btrp->name);
139 end = NULL; /* buffer full */
144 static void btr_pool_deallocate(struct btr_pool *btrp, size_t size)
146 char *end = btrp->rhead + size;
150 assert(end <= btrp->area_end);
151 assert(size <= btr_pool_filled(btrp));
152 if (end == btrp->area_end)
153 end = btrp->area_start;
155 btrp->whead = btrp->rhead;
157 if (btrp->rhead == btrp->whead)
158 btrp->rhead = btrp->whead = btrp->area_start;
161 #define FOR_EACH_CHILD(_tn, _btrn) list_for_each_entry((_tn), \
162 &((_btrn)->children), node)
163 #define FOR_EACH_CHILD_SAFE(_tn, _tmp, _btrn) \
164 list_for_each_entry_safe((_tn), (_tmp), &((_btrn)->children), node)
166 #define FOR_EACH_BUFFER_REF(_br, _btrn) \
167 list_for_each_entry((_br), &(_btrn)->input_queue, node)
168 #define FOR_EACH_BUFFER_REF_SAFE(_br, _tmp, _btrn) \
169 list_for_each_entry_safe((_br), (_tmp), &(_btrn)->input_queue, node)
173 (NULL, NULL): new, isolated node.
174 (p, NULL): new leaf node
175 (NULL, c): new node becomes root, c must be old root
176 (p, c): new internal node, ch must be child of p, not yet implemented
179 struct btr_node *btr_new_node(struct btr_node_description *bnd)
181 struct btr_node *btrn = para_malloc(sizeof(*btrn));
183 btrn->name = para_strdup(bnd->name);
184 btrn->parent = bnd->parent;
185 btrn->execute = bnd->handler;
186 btrn->context = bnd->context;
187 btrn->start.tv_sec = 0;
188 btrn->start.tv_usec = 0;
189 INIT_LIST_HEAD(&btrn->children);
190 INIT_LIST_HEAD(&btrn->input_queue);
193 list_add_tail(&btrn->node, &bnd->parent->children);
194 PARA_INFO_LOG("new leaf node: %s (child of %s)\n",
195 bnd->name, bnd->parent->name);
197 PARA_INFO_LOG("added %s as btr root\n", bnd->name);
201 assert(!bnd->child->parent);
202 PARA_INFO_LOG("new root: %s (was %s)\n",
203 bnd->name, bnd->child->name);
205 list_add_tail(&bnd->child->node, &btrn->children);
207 bnd->child->parent = btrn;
210 PARA_EMERG_LOG("inserting internal nodes not yet supported.\n");
212 assert(bnd->child->parent == bnd->parent);
218 * Allocate a new btr buffer.
220 * The freshly allocated buffer will have a zero refcount and will
221 * not be associated with a btr pool.
223 static struct btr_buffer *new_btrb(char *buf, size_t size)
225 struct btr_buffer *btrb = para_calloc(sizeof(*btrb));
232 static void dealloc_buffer(struct btr_buffer *btrb)
235 btr_pool_deallocate(btrb->pool, btrb->size);
240 static struct btr_buffer_reference *get_first_input_br(struct btr_node *btrn)
242 if (list_empty(&btrn->input_queue))
244 return list_first_entry(&btrn->input_queue,
245 struct btr_buffer_reference, node);
249 * Deallocate the reference, release the resources if refcount drops to zero.
251 static void btr_drop_buffer_reference(struct btr_buffer_reference *br)
253 struct btr_buffer *btrb = br->btrb;
258 if (btrb->refcount == 0) {
259 dealloc_buffer(btrb);
264 static void add_btrb_to_children(struct btr_buffer *btrb,
265 struct btr_node *btrn, size_t consumed)
269 if (btrn->start.tv_sec == 0)
271 FOR_EACH_CHILD(ch, btrn) {
272 struct btr_buffer_reference *br = para_calloc(sizeof(*br));
274 br->consumed = consumed;
275 list_add_tail(&br->node, &ch->input_queue);
277 if (ch->start.tv_sec == 0)
282 void btr_add_output(char *buf, size_t size, struct btr_node *btrn)
284 struct btr_buffer *btrb;
287 if (list_empty(&btrn->children)) {
291 btrb = new_btrb(buf, size);
292 add_btrb_to_children(btrb, btrn, 0);
295 void btr_add_output_pool(struct btr_pool *btrp, size_t size,
296 struct btr_node *btrn)
298 struct btr_buffer *btrb;
303 if (list_empty(&btrn->children))
305 avail = btr_pool_get_buffer(btrp, &buf);
306 assert(avail >= size);
307 btr_pool_allocate(btrp, size);
308 btrb = new_btrb(buf, size);
310 add_btrb_to_children(btrb, btrn, 0);
313 void btr_copy(const void *src, size_t n, struct btr_pool *btrp,
314 struct btr_node *btrn)
321 assert(n <= btr_pool_unused(btrp));
322 sz = btr_pool_get_buffer(btrp, &buf);
323 copy = PARA_MIN(sz, n);
324 memcpy(buf, src, copy);
325 btr_add_output_pool(btrp, copy, btrn);
328 sz = btr_pool_get_buffer(btrp, &buf);
329 assert(sz >= n - copy);
330 memcpy(buf, src + copy, n - copy);
331 btr_add_output_pool(btrp, n - copy, btrn);
334 static void btr_pushdown_br(struct btr_buffer_reference *br, struct btr_node *btrn)
336 add_btrb_to_children(br->btrb, btrn, br->consumed);
337 btr_drop_buffer_reference(br);
340 void btr_pushdown(struct btr_node *btrn)
342 struct btr_buffer_reference *br, *tmp;
344 FOR_EACH_BUFFER_REF_SAFE(br, tmp, btrn)
345 btr_pushdown_br(br, btrn);
348 int btr_pushdown_one(struct btr_node *btrn)
350 struct btr_buffer_reference *br;
352 if (list_empty(&btrn->input_queue))
354 br = list_first_entry(&btrn->input_queue, struct btr_buffer_reference, node);
355 btr_pushdown_br(br, btrn);
359 /* Return true if this node has no children. */
360 bool btr_no_children(struct btr_node *btrn)
362 return list_empty(&btrn->children);
365 bool btr_no_parent(struct btr_node *btrn)
367 return !btrn->parent;
370 bool btr_inplace_ok(struct btr_node *btrn)
374 return list_is_singular(&btrn->parent->children);
377 static inline size_t br_available_bytes(struct btr_buffer_reference *br)
379 return br->btrb->size - br->consumed;
382 size_t btr_get_buffer_by_reference(struct btr_buffer_reference *br, char **buf)
385 *buf = br->btrb->buf + br->consumed;
386 return br_available_bytes(br);
390 * \return zero if the input buffer queue is empty.
392 size_t btr_next_buffer(struct btr_node *btrn, char **bufp)
394 struct btr_buffer_reference *br;
395 char *buf, *result = NULL;
398 FOR_EACH_BUFFER_REF(br, btrn) {
399 sz = btr_get_buffer_by_reference(br, &buf);
409 if (result + rv != buf)
418 void btr_consume(struct btr_node *btrn, size_t numbytes)
420 struct btr_buffer_reference *br, *tmp;
425 br = get_first_input_br(btrn);
428 if (br->wrap_count == 0) {
430 * No wrap buffer. Drop buffer references whose buffer
431 * has been fully used. */
432 FOR_EACH_BUFFER_REF_SAFE(br, tmp, btrn) {
433 if (br->consumed + numbytes <= br->btrb->size) {
434 br->consumed += numbytes;
435 if (br->consumed == br->btrb->size)
436 btr_drop_buffer_reference(br);
439 numbytes -= br->btrb->size - br->consumed;
440 btr_drop_buffer_reference(br);
446 We have a wrap buffer, consume from it. If in total,
447 i.e. including previous calls to brt_consume(), less than
448 wrap_count has been consumed, there's nothing more we can do.
450 Otherwise we drop the wrap buffer and consume from subsequent
451 buffers of the input queue the correct amount of bytes. This
452 is the total number of bytes that have been consumed from the
455 PARA_DEBUG_LOG("consuming %zu/%zu bytes from wrap buffer\n", numbytes,
456 br_available_bytes(br));
458 assert(numbytes <= br_available_bytes(br));
459 if (br->consumed + numbytes < br->wrap_count) {
460 br->consumed += numbytes;
463 PARA_DEBUG_LOG("dropping wrap buffer (%zu bytes)\n", br->btrb->size);
464 /* get rid of the wrap buffer */
465 sz = br->consumed + numbytes;
466 btr_drop_buffer_reference(br);
467 return btr_consume(btrn, sz);
470 static void flush_input_queue(struct btr_node *btrn)
472 struct btr_buffer_reference *br, *tmp;
473 FOR_EACH_BUFFER_REF_SAFE(br, tmp, btrn)
474 btr_drop_buffer_reference(br);
477 void btr_free_node(struct btr_node *btrn)
485 void btr_remove_node(struct btr_node *btrn)
491 PARA_NOTICE_LOG("removing btr node %s from buffer tree\n", btrn->name);
492 FOR_EACH_CHILD(ch, btrn)
494 flush_input_queue(btrn);
496 list_del(&btrn->node);
499 size_t btr_get_input_queue_size(struct btr_node *btrn)
501 struct btr_buffer_reference *br;
502 size_t size = 0, wrap_consumed = 0;
504 FOR_EACH_BUFFER_REF(br, btrn) {
505 if (br->wrap_count != 0) {
506 wrap_consumed = br->consumed;
509 size += br_available_bytes(br);
511 assert(wrap_consumed <= size);
512 size -= wrap_consumed;
516 void btr_splice_out_node(struct btr_node *btrn)
518 struct btr_node *ch, *tmp;
521 PARA_NOTICE_LOG("splicing out %s\n", btrn->name);
524 list_del(&btrn->node);
525 FOR_EACH_CHILD_SAFE(ch, tmp, btrn) {
526 PARA_INFO_LOG("parent(%s): %s\n", ch->name,
527 btrn->parent? btrn->parent->name : "NULL");
528 ch->parent = btrn->parent;
530 list_move(&ch->node, &btrn->parent->children);
532 assert(list_empty(&btrn->children));
536 * Return the size of the largest input queue.
538 * Iterates over all children of the given node.
540 size_t btr_bytes_pending(struct btr_node *btrn)
545 FOR_EACH_CHILD(ch, btrn) {
546 size_t size = btr_get_input_queue_size(ch);
547 max_size = PARA_MAX(max_size, size);
552 int btr_exec(struct btr_node *btrn, const char *command, char **value_result)
555 return -ERRNO_TO_PARA_ERROR(EINVAL);
557 return -ERRNO_TO_PARA_ERROR(ENOTSUP);
558 return btrn->execute(btrn, command, value_result);
561 int btr_exec_up(struct btr_node *btrn, const char *command, char **value_result)
565 for (; btrn; btrn = btrn->parent) {
566 struct btr_node *parent = btrn->parent;
568 return -ERRNO_TO_PARA_ERROR(ENOTSUP);
569 if (!parent->execute)
571 PARA_INFO_LOG("parent: %s, cmd: %s\n", parent->name, command);
572 ret = parent->execute(parent, command, value_result);
573 if (ret == -ERRNO_TO_PARA_ERROR(ENOTSUP))
577 if (value_result && *value_result)
578 PARA_NOTICE_LOG("%s(%s): %s\n", command, parent->name,
582 return -ERRNO_TO_PARA_ERROR(ENOTSUP);
585 void *btr_context(struct btr_node *btrn)
587 return btrn->context;
590 static bool need_buffer_pool_merge(struct btr_node *btrn)
592 struct btr_buffer_reference *br = get_first_input_br(btrn);
596 if (br->wrap_count != 0)
603 static void merge_input_pool(struct btr_node *btrn, size_t dest_size)
605 struct btr_buffer_reference *br, *wbr = NULL;
606 int num_refs; /* including wrap buffer */
607 char *buf, *buf1 = NULL, *buf2 = NULL;
608 size_t sz, sz1 = 0, sz2 = 0, wsz;
610 br = get_first_input_br(btrn);
611 if (!br || br_available_bytes(br) >= dest_size)
614 FOR_EACH_BUFFER_REF(br, btrn) {
616 sz = btr_get_buffer_by_reference(br, &buf);
619 if (br->wrap_count != 0) {
621 assert(num_refs == 1);
632 if (buf1 + sz1 == buf) {
641 assert(buf2 + sz2 == buf);
644 if (sz1 + sz2 >= dest_size)
647 if (!buf2) /* nothing to do */
649 assert(buf1 && sz2 > 0);
651 * If the second buffer is large, we only take the first part of it to
652 * avoid having to memcpy() huge buffers.
654 sz2 = PARA_MIN(sz2, (size_t)(64 * 1024));
656 /* Make a new wrap buffer combining buf1 and buf2. */
658 buf = para_malloc(sz);
659 PARA_DEBUG_LOG("merging input buffers: (%p:%zu, %p:%zu) -> %p:%zu\n",
660 buf1, sz1, buf2, sz2, buf, sz);
661 memcpy(buf, buf1, sz1);
662 memcpy(buf + sz1, buf2, sz2);
663 br = para_calloc(sizeof(*br));
664 br->btrb = new_btrb(buf, sz);
665 br->btrb->refcount = 1;
667 /* This is a wrap buffer */
668 br->wrap_count = sz1;
669 para_list_add(&br->node, &btrn->input_queue);
672 PARA_DEBUG_LOG("increasing wrap buffer, sz1: %zu, sz2: %zu\n", sz1, sz2);
674 * We already have a wrap buffer, but it is too small. It might be
677 wsz = br_available_bytes(wbr);
678 if (wbr->wrap_count == sz1 && wbr->btrb->size >= sz1 + sz2) /* nothing we can do about it */
680 sz = sz1 + sz2 - wbr->btrb->size; /* amount of new data */
681 wbr->btrb->size += sz;
682 wbr->btrb->buf = para_realloc(wbr->btrb->buf, wbr->btrb->size);
683 /* copy the new data to the end of the reallocated buffer */
685 memcpy(wbr->btrb->buf + wbr->btrb->size - sz, buf2 + sz2 - sz, sz);
689 * Merge the first two input buffers into one.
691 * This is a quite expensive operation.
693 * \return The number of buffers that have been available (zero, one or two).
695 static int merge_input(struct btr_node *btrn)
697 struct btr_buffer_reference *brs[2], *br;
702 if (list_empty(&btrn->input_queue))
704 if (list_is_singular(&btrn->input_queue))
707 /* get references to the first two buffers */
708 FOR_EACH_BUFFER_REF(br, btrn) {
710 szs[i] = btr_get_buffer_by_reference(brs[i], bufs + i);
715 /* make a new btrb that combines the two buffers and a br to it. */
716 sz = szs[0] + szs[1];
717 buf = para_malloc(sz);
718 PARA_DEBUG_LOG("%s: memory merging input buffers: (%zu, %zu) -> %zu\n",
719 btrn->name, szs[0], szs[1], sz);
720 memcpy(buf, bufs[0], szs[0]);
721 memcpy(buf + szs[0], bufs[1], szs[1]);
723 br = para_calloc(sizeof(*br));
724 br->btrb = new_btrb(buf, sz);
725 br->btrb->refcount = 1;
727 /* replace the first two refs by the new one */
728 btr_drop_buffer_reference(brs[0]);
729 btr_drop_buffer_reference(brs[1]);
730 para_list_add(&br->node, &btrn->input_queue);
734 void btr_merge(struct btr_node *btrn, size_t dest_size)
736 if (need_buffer_pool_merge(btrn))
737 return merge_input_pool(btrn, dest_size);
740 size_t len = btr_next_buffer(btrn, &buf);
741 if (len >= dest_size)
743 PARA_DEBUG_LOG("input size = %zu < %zu = dest\n", len, dest_size);
744 if (merge_input(btrn) < 2)
749 bool btr_eof(struct btr_node *btrn)
752 size_t len = btr_next_buffer(btrn, &buf);
754 return (len == 0 && btr_no_parent(btrn));
757 void log_tree_recursively(struct btr_node *btrn, int loglevel, int depth)
760 const char spaces[] = " ", *space = spaces + 16 - depth;
764 para_log(loglevel, "%s%s\n", space, btrn->name);
765 FOR_EACH_CHILD(ch, btrn)
766 log_tree_recursively(ch, loglevel, depth + 1);
769 void btr_log_tree(struct btr_node *btrn, int loglevel)
771 return log_tree_recursively(btrn, loglevel, 0);
775 * \return \a root if \a name is \p NULL.
777 struct btr_node *btr_search_node(const char *name, struct btr_node *root)
783 if (!strcmp(root->name, name))
785 FOR_EACH_CHILD(ch, root) {
786 struct btr_node *result = btr_search_node(name, ch);
793 /** 640K ought to be enough for everybody ;) */
794 #define BTRN_MAX_PENDING (640 * 1024)
796 int btr_node_status(struct btr_node *btrn, size_t min_iqs,
797 enum btr_node_type type)
802 if (type != BTR_NT_LEAF) {
803 if (btr_no_children(btrn))
804 return -E_BTR_NO_CHILD;
805 if (btr_bytes_pending(btrn) > BTRN_MAX_PENDING)
808 if (type != BTR_NT_ROOT) {
811 iqs = btr_get_input_queue_size(btrn);
812 if (iqs == 0) /* we have a parent, because not eof */
814 if (iqs < min_iqs && !btr_no_parent(btrn))
820 void btr_get_node_start(struct btr_node *btrn, struct timeval *tv)