From b7724150b3017af60b28e3491d971d9eab1d709e Mon Sep 17 00:00:00 2001
From: Alexandr Lyapunov <a.lyapunov@corp.mail.ru>
Date: Fri, 16 Sep 2016 17:49:30 +0300
Subject: [PATCH] Splitted vy_run_iterator_search into _search_page and
_search_in_page
Also removed vlsn from vy_run_iterator_search
---
src/box/vinyl.c | 193 +++++++++++++++++++++---------------------------
1 file changed, 85 insertions(+), 108 deletions(-)
diff --git a/src/box/vinyl.c b/src/box/vinyl.c
index fb2106d957..166c067c9b 100644
--- a/src/box/vinyl.c
+++ b/src/box/vinyl.c
@@ -5599,67 +5599,6 @@ vy_run_iterator_cmp_pos(struct vy_run_iterator_pos pos1,
pos1.pos_in_page > pos2.pos_in_page;
}
-/**
- * Specific middle wide position calculation for binary search
- * Till possible, returns position of first record in page
- * This behaviour allows to read keys from page index instead of disk
- * untill necessary page was found
- * @retval 0 success
- * @retval -1 or memory or read error
- * @retval 1 EOF (possible when page has no records, int bootstrap run)
- */
-static int
-vy_iterator_pos_mid(struct vy_run_iterator *itr,
- struct vy_run_iterator_pos pos1,
- struct vy_run_iterator_pos pos2,
- struct vy_run_iterator_pos *result)
-{
- assert(vy_run_iterator_cmp_pos(pos1, pos2) < 0);
- if (pos2.page_no - pos1.page_no > 1) {
- assert(pos1.pos_in_page == 0 && pos2.pos_in_page == 0);
- result->page_no =
- pos1.page_no + (pos2.page_no - pos1.page_no) / 2;
- result->pos_in_page = 0;
- return 0;
- }
- struct vy_page *page;
- int rc = vy_run_iterator_load_page(itr, pos1.page_no, &page);
- if (rc != 0)
- return rc;
- assert(pos1.page_no == pos2.page_no || pos2.pos_in_page == 0);
- uint32_t diff = pos1.page_no == pos2.page_no ?
- pos2.pos_in_page - pos1.pos_in_page :
- page->count - pos1.pos_in_page;
- result->page_no = pos1.page_no;
- result->pos_in_page = pos1.pos_in_page + diff / 2;
- return result->pos_in_page == page->count ? 1 : 0;
-}
-
-/**
- * Specific increment of middle wide position for binary search
- * Actually does not do increment until search in page was started.
- * @retval 0 success
- * @retval -1 memory or read error
- */
-static int
-vy_iterator_pos_mid_next(struct vy_run_iterator *itr,
- struct vy_run_iterator_pos mid,
- struct vy_run_iterator_pos end,
- struct vy_run_iterator_pos *result)
-{
- if (end.page_no - mid.page_no > 1) {
- *result = mid;
- return 0;
- }
- struct vy_page *page;
- int rc = vy_run_iterator_load_page(itr, mid.page_no, &page);
- if (rc != 0)
- return rc;
- mid.pos_in_page++;
- *result = mid.pos_in_page == page->count ? end : mid;
- return 0;
-}
-
/**
* Read key and lsn by a given wide position.
* For the first record in a page reads the result from the page
@@ -5685,60 +5624,98 @@ vy_run_iterator_read(struct vy_run_iterator *itr,
}
/**
- * Binary search in a run for the given key and lsn.
+ * Binary search in page index
+ * In terms of STL, makes lower_bound for EQ,GE,LT and upper_bound for GT,LE
+ * Additionally *equal_key argument is set to true if the found value is
+ * equal to given key (untouched otherwise)
+ */
+static void
+vy_run_iterator_search_page(struct vy_run_iterator *itr, char *key,
+ uint32_t *page_no, bool *equal_key)
+{
+ uint32_t beg = 0;
+ uint32_t end = itr->run->info.count;
+ /* for upper bound we change zero comparison result to -1 */
+ int zero_cmp = itr->order == VINYL_GT || itr->order == VINYL_LE ? -1 : 0;
+ while (beg != end) {
+ uint32_t mid = beg + (end - beg) / 2;
+ struct vy_page_info *page_info =
+ vy_run_page(itr->run, mid);
+ char *fnd_key = vy_run_min_key(itr->run, page_info);
+ int cmp = vy_tuple_compare(fnd_key, key, itr->index->key_def);
+ cmp = cmp ? cmp : zero_cmp;
+ *equal_key = *equal_key || cmp == 0;
+ if (cmp < 0)
+ beg = mid + 1;
+ else
+ end = mid;
+ }
+ *page_no = end;
+}
+
+/**
+ * Binary search in page
+ * In terms of STL, makes lower_bound for EQ,GE,LT and upper_bound for GT,LE
+ * Additionally *equal_key argument is set to true if the found value is
+ * equal to given key (untouched otherwise)
+ */
+static void
+vy_run_iterator_search_in_page(struct vy_run_iterator *itr, char *key,
+ struct vy_page *page, uint32_t *pos_in_page,
+ bool *equal_key)
+{
+ uint32_t beg = 0;
+ uint32_t end = page->count;
+ /* for upper bound we change zero comparison result to -1 */
+ int zero_cmp = itr->order == VINYL_GT || itr->order == VINYL_LE ? -1 : 0;
+ while (beg != end) {
+ uint32_t mid = beg + (end - beg) / 2;
+ struct vy_tuple_info *info;
+ const char *fnd_key = vy_page_tuple(page, mid, &info);
+ int cmp = vy_tuple_compare(fnd_key, key, itr->index->key_def);
+ cmp = cmp ? cmp : zero_cmp;
+ *equal_key = *equal_key || cmp == 0;
+ if (cmp < 0)
+ beg = mid + 1;
+ else
+ end = mid;
+ }
+ *pos_in_page = end;
+}
+
+/**
+ * Binary search in a run for the given key.
+ * In terms of STL, makes lower_bound for EQ,GE,LT and upper_bound for GT,LE
* Resulting wide position is stored it *pos argument
- * Note that run is sorted by key ASC and lsn DESC.
- * Normally sets the position to first record that greater than given key or
- * equal key and not greater lsn, i.e.
- * (record.key > key || (record.key == key && record lsn <= lsn)),
- * (!) but has a special case of order == VINYL_GT/VINYL_LE,
- * when position is set to first record that greater than given key, i.e.
- * (record.key > key),
- * If that value was not found then position is set to end_pos (invalid pos)
- * *equal_key is set to true if found value is equal to key of false otherwise
- * Beware of:
- * 1) VINYL_GT/VINYL_LE special case
- * 2) search with partial key and lsn != INT64_MAX is meaningless
- * and dangerous
- * 3) if return false, the position was set to maximal lsn of the
- * next key
+ * Additionally *equal_key argument is set to true if the found value is
+ * equal to given key (untouched otherwise)
*
* @retval 0 success
* @retval -1 read or memory error
*/
static int
-vy_run_iterator_search(struct vy_run_iterator *itr, char *key, int64_t vlsn,
+vy_run_iterator_search(struct vy_run_iterator *itr, char *key,
struct vy_run_iterator_pos *pos, bool *equal_key)
{
- struct vy_run_iterator_pos beg = {0, 0};
- struct vy_run_iterator_pos end = {itr->run->info.count, 0};
- *equal_key = false;
- while (vy_run_iterator_cmp_pos(beg, end) != 0) {
- struct vy_run_iterator_pos mid;
- int rc = vy_iterator_pos_mid(itr, beg, end, &mid);
- if (rc != 0)
- return rc;
- const char *fnd_key;
- int64_t fnd_lsn;
- rc = vy_run_iterator_read(itr, mid, &fnd_key, &fnd_lsn);
- if (rc != 0)
- return rc;
- int cmp = vy_tuple_compare(fnd_key, key, itr->index->key_def);
- bool is_equal_key = cmp == 0;
- if (cmp == 0 &&
- (itr->order == VINYL_GT || itr->order == VINYL_LE)) {
- cmp = -1;
- }
- cmp = cmp ? cmp : fnd_lsn > vlsn ? -1 : fnd_lsn < vlsn;
- if (cmp < 0) {
- if (vy_iterator_pos_mid_next(itr, mid, end, &beg) != 0)
- return -1;
- } else {
- end = mid;
- *equal_key = is_equal_key;
- }
+ vy_run_iterator_search_page(itr, key, &pos->page_no, equal_key);
+ if (pos->page_no == 0) {
+ pos->pos_in_page = 0;
+ return 0;
+ }
+ pos->page_no--;
+ struct vy_page *page;
+ int rc = vy_run_iterator_load_page(itr, pos->page_no, &page);
+ if (rc != 0)
+ return rc;
+ bool equal_in_page = false;
+ vy_run_iterator_search_in_page(itr, key, page, &pos->pos_in_page,
+ &equal_in_page);
+ if (pos->pos_in_page == page->count) {
+ pos->page_no++;
+ pos->pos_in_page = 0;
+ } else {
+ *equal_key = equal_in_page;
}
- *pos = end;
return 0;
}
@@ -5911,8 +5888,8 @@ vy_run_iterator_start(struct vy_run_iterator *itr)
bool equal_found = false;
int rc;
if (vy_tuple_key_part(itr->key, 0) != NULL) {
- rc = vy_run_iterator_search(itr, itr->key, INT64_MAX,
- &itr->curr_pos, &equal_found);
+ rc = vy_run_iterator_search(itr, itr->key, &itr->curr_pos,
+ &equal_found);
if (rc < 0)
return rc;
} else if (itr->order == VINYL_LE || itr->order == VINYL_LT) {
--
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