From 030d28f55fa855a7cd967078e61a55aced523e30 Mon Sep 17 00:00:00 2001
From: Kirill Yukhin <kyukhin@tarantool.org>
Date: Wed, 24 Oct 2018 16:13:37 +0300
Subject: [PATCH] schema: add space name cache
Since SQL is heavily using name -> space mapping, introduce (instead of
scanning _space space) dedicated cache, which maps space name to space
pointer.
@locker: code cleanup
---
src/box/schema.cc | 67 +++++++++++++++++++++++++++++++++++++++++++++++
src/box/schema.h | 8 ++++++
2 files changed, 75 insertions(+)
diff --git a/src/box/schema.cc b/src/box/schema.cc
index 9327322b84..8625d92eac 100644
--- a/src/box/schema.cc
+++ b/src/box/schema.cc
@@ -55,6 +55,7 @@
/** All existing spaces. */
static struct mh_i32ptr_t *spaces;
+static struct mh_strnptr_t *spaces_by_name;
static struct mh_i32ptr_t *funcs;
static struct mh_strnptr_t *funcs_by_name;
static struct mh_i32ptr_t *sequences;
@@ -95,6 +96,17 @@ space_by_id(uint32_t id)
return (struct space *) mh_i32ptr_node(spaces, space)->val;
}
+/** Return space by its name */
+struct space *
+space_by_name(const char *name)
+{
+ mh_int_t space = mh_strnptr_find_inp(spaces_by_name, name,
+ strlen(name));
+ if (space == mh_end(spaces_by_name))
+ return NULL;
+ return (struct space *)mh_strnptr_node(spaces_by_name, space)->val;
+}
+
/** Return current schema version */
uint32_t
box_schema_version()
@@ -163,6 +175,27 @@ space_cache_replace(struct space *old_space, struct space *new_space)
{
assert(new_space != NULL || old_space != NULL);
if (new_space != NULL) {
+ /*
+ * If the replaced space has a different name, we
+ * must explicitly delete it from @spaces_by_name
+ * cache. Note, since a space id never changes, we
+ * don't need to do so for @spaces cache.
+ */
+ struct space *old_space_by_name = NULL;
+ if (old_space != NULL && strcmp(space_name(old_space),
+ space_name(new_space)) != 0) {
+ const char *name = space_name(old_space);
+ mh_int_t k = mh_strnptr_find_inp(spaces_by_name, name,
+ strlen(name));
+ assert(k != mh_end(spaces_by_name));
+ old_space_by_name = (struct space *)
+ mh_strnptr_node(spaces_by_name, k)->val;
+ mh_strnptr_del(spaces_by_name, k, NULL);
+ }
+ /*
+ * Insert @new_space into @spaces cache, replacing
+ * @old_space if it's not NULL.
+ */
const struct mh_i32ptr_node_t node_p = { space_id(new_space),
new_space };
struct mh_i32ptr_node_t old, *p_old = &old;
@@ -175,7 +208,28 @@ space_cache_replace(struct space *old_space, struct space *new_space)
(struct space *)p_old->val : NULL;
assert(old_space_by_id == old_space);
(void)old_space_by_id;
+ /*
+ * Insert @new_space into @spaces_by_name cache.
+ */
+ const char *name = space_name(new_space);
+ uint32_t name_len = strlen(name);
+ uint32_t name_hash = mh_strn_hash(name, name_len);
+ const struct mh_strnptr_node_t node_s = { name, name_len,
+ name_hash, new_space };
+ struct mh_strnptr_node_t old_s, *p_old_s = &old_s;
+ k = mh_strnptr_put(spaces_by_name, &node_s, &p_old_s, NULL);
+ if (k == mh_end(spaces_by_name)) {
+ panic_syserror("Out of memory for the data "
+ "dictionary cache.");
+ }
+ if (old_space_by_name == NULL && p_old_s != NULL)
+ old_space_by_name = (struct space *)p_old_s->val;
+ assert(old_space_by_name == old_space);
+ (void)old_space_by_name;
} else {
+ /*
+ * Delete @old_space from @spaces cache.
+ */
mh_int_t k = mh_i32ptr_find(spaces, space_id(old_space), NULL);
assert(k != mh_end(spaces));
struct space *old_space_by_id =
@@ -183,6 +237,17 @@ space_cache_replace(struct space *old_space, struct space *new_space)
assert(old_space_by_id == old_space);
(void)old_space_by_id;
mh_i32ptr_del(spaces, k, NULL);
+ /*
+ * Delete @old_space from @spaces_by_name cache.
+ */
+ const char *name = space_name(old_space);
+ k = mh_strnptr_find_inp(spaces_by_name, name, strlen(name));
+ assert(k != mh_end(spaces_by_name));
+ struct space *old_space_by_name =
+ (struct space *)mh_strnptr_node(spaces_by_name, k)->val;
+ assert(old_space_by_name == old_space);
+ (void)old_space_by_name;
+ mh_strnptr_del(spaces_by_name, k, NULL);
}
space_cache_version++;
}
@@ -302,6 +367,7 @@ schema_init()
/* Initialize the space cache. */
spaces = mh_i32ptr_new();
+ spaces_by_name = mh_strnptr_new();
funcs = mh_i32ptr_new();
funcs_by_name = mh_strnptr_new();
sequences = mh_i32ptr_new();
@@ -450,6 +516,7 @@ schema_free(void)
space_delete(space);
}
mh_i32ptr_delete(spaces);
+ mh_strnptr_delete(spaces_by_name);
while (mh_size(funcs) > 0) {
mh_int_t i = mh_first(funcs);
diff --git a/src/box/schema.h b/src/box/schema.h
index 958e308452..f3df08b48b 100644
--- a/src/box/schema.h
+++ b/src/box/schema.h
@@ -58,6 +58,14 @@ extern struct latch schema_lock;
struct space *
space_by_id(uint32_t id);
+/**
+ * Try to look up a space by space name in the space name cache.
+ *
+ * @return NULL if space not found, otherwise space object.
+ */
+struct space *
+space_by_name(const char *name);
+
uint32_t
box_schema_version();
--
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