From d3a2e81566760f06c7b3e01b2b67e30356a4de22 Mon Sep 17 00:00:00 2001
From: Vladislav Shpilevoy <v.shpilevoy@tarantool.org>
Date: Mon, 19 Jun 2017 15:56:37 +0300
Subject: [PATCH] vinyl: make UPSERT prepare use of a cache as a hint
Use a tuple cache to turn an UPSERT in the PREPARE, if the cache
contains a tuple with the exact same key. The UPSERT can be applied
to the cached tuples, because
1. The cache always contains only REPLACE statements;
2. The cache always contains only newest statements.
Closes #2520
---
src/box/vinyl.c | 43 ++++++++++++++++++++++++++++++++--------
src/box/vy_cache.c | 8 +++++++-
src/box/vy_cache.h | 5 ++++-
test/vinyl/upsert.result | 2 +-
4 files changed, 47 insertions(+), 11 deletions(-)
diff --git a/src/box/vinyl.c b/src/box/vinyl.c
index d0a2be9266..e05f6ea688 100644
--- a/src/box/vinyl.c
+++ b/src/box/vinyl.c
@@ -2644,7 +2644,7 @@ vy_index_commit_stmt(struct vy_index *index, struct vy_mem *mem,
vy_index_commit_upsert(index, mem, stmt);
/* Invalidate cache element. */
- vy_cache_on_write(&index->cache, stmt);
+ vy_cache_on_write(&index->cache, stmt, NULL);
}
/*
@@ -2660,7 +2660,7 @@ vy_index_rollback_stmt(struct vy_index *index, struct vy_mem *mem,
vy_mem_rollback_stmt(mem, stmt);
/* Invalidate cache element. */
- vy_cache_on_write(&index->cache, stmt);
+ vy_cache_on_write(&index->cache, stmt, NULL);
}
/**
@@ -2848,13 +2848,40 @@ vy_tx_write(struct vy_index *index, struct vy_mem *mem,
assert(*region_stmt == NULL ||
vy_stmt_is_region_allocated(*region_stmt));
- int rc = vy_index_set(index, mem, stmt, region_stmt);
-
/*
- * Invalidate cache element.
- */
- vy_cache_on_write(&index->cache, stmt);
- return rc;
+ * The UPSERT statement can be applied to the cached
+ * statement, because the cache always contains only
+ * newest REPLACE statements. In such a case the UPSERT,
+ * applied to the cached statement, can be inserted
+ * instead of the original UPSERT.
+ */
+ if (vy_stmt_type(stmt) == IPROTO_UPSERT) {
+ struct tuple *deleted = NULL;
+ /* Invalidate cache element. */
+ vy_cache_on_write(&index->cache, stmt, &deleted);
+ if (deleted != NULL) {
+ struct tuple *applied =
+ vy_apply_upsert(stmt, deleted, mem->key_def,
+ mem->format, mem->upsert_format,
+ false);
+ tuple_unref(deleted);
+ if (applied != NULL) {
+ assert(vy_stmt_type(applied) == IPROTO_REPLACE);
+ int rc = vy_index_set(index, mem, applied,
+ region_stmt);
+ tuple_unref(applied);
+ return rc;
+ }
+ /*
+ * Ignore a memory error, because it is
+ * not critical to apply the optimization.
+ */
+ }
+ } else {
+ /* Invalidate cache element. */
+ vy_cache_on_write(&index->cache, stmt, NULL);
+ }
+ return vy_index_set(index, mem, stmt, region_stmt);
}
/* {{{ Scheduler Task */
diff --git a/src/box/vy_cache.c b/src/box/vy_cache.c
index e31aa25c70..48f480ced7 100644
--- a/src/box/vy_cache.c
+++ b/src/box/vy_cache.c
@@ -349,7 +349,8 @@ vy_cache_add(struct vy_cache *cache, struct tuple *stmt,
}
void
-vy_cache_on_write(struct vy_cache *cache, const struct tuple *stmt)
+vy_cache_on_write(struct vy_cache *cache, const struct tuple *stmt,
+ struct tuple **deleted)
{
vy_cache_gc(cache->env);
bool exact = false;
@@ -409,6 +410,11 @@ vy_cache_on_write(struct vy_cache *cache, const struct tuple *stmt)
if (exact) {
cache->version++;
struct vy_cache_entry *to_delete = *entry;
+ assert(vy_stmt_type(to_delete->stmt) == IPROTO_REPLACE);
+ if (deleted != NULL) {
+ *deleted = to_delete->stmt;
+ tuple_ref(to_delete->stmt);
+ }
vy_cache_tree_delete(&cache->cache_tree, to_delete);
vy_cache_entry_delete(cache->env, to_delete);
}
diff --git a/src/box/vy_cache.h b/src/box/vy_cache.h
index f472b14e01..0e7792b554 100644
--- a/src/box/vy_cache.h
+++ b/src/box/vy_cache.h
@@ -190,9 +190,12 @@ vy_cache_add(struct vy_cache *cache, struct tuple *stmt,
* Invalidate possibly cached value due to its overwriting
* @param cache - pointer to tuple cache.
* @param stmt - overwritten statement.
+ * @param[out] deleted - If not NULL, then is set to deleted
+ * statement.
*/
void
-vy_cache_on_write(struct vy_cache *cache, const struct tuple *stmt);
+vy_cache_on_write(struct vy_cache *cache, const struct tuple *stmt,
+ struct tuple **deleted);
/**
diff --git a/test/vinyl/upsert.result b/test/vinyl/upsert.result
index 9f48d6136a..0d11b71db4 100644
--- a/test/vinyl/upsert.result
+++ b/test/vinyl/upsert.result
@@ -739,7 +739,7 @@ new_stat = box.info.vinyl().performance["iterator"].run.lookup_count
...
new_stat - old_stat
---
-- 2
+- 1
...
old_stat = new_stat
---
--
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