MDEV-22871: Clean up btr_search_sys

btr_search_sys::parts[]: A single structure for the partitions of
the adaptive hash index. Replaces the 3 separate arrays:
btr_search_latches[], btr_search_sys->hash_tables,
btr_search_sys->hash_tables[i]->heap.

hash_table_t::heap, hash_table_t::adaptive: Remove.

ha0ha.cc: Remove. Move all code to btr0sea.cc.

8 files changed, 127 insertions, 259 deletions

diff --git a/storage/innobase/include/btr0sea.h b/storage/innobase/include/btr0sea.h
index a406676c6ed..e3de4926a57 100644
--- a/storage/innobase/include/btr0sea.h
+++ b/storage/innobase/include/btr0sea.h
@@ -30,13 +30,10 @@ Created 2/17/1996 Heikki Tuuri
 #include "dict0dict.h"
 #ifdef BTR_CUR_HASH_ADAPT
 #include "ha0ha.h"
+#include "sync0sync.h"
 
-/** Creates and initializes the adaptive search system at a database start.
-@param[in]	hash_size	hash table size. */
-void btr_search_sys_create(ulint hash_size);
-
-/** Frees the adaptive search system at a database shutdown. */
-void btr_search_sys_free();
+#define btr_search_sys_create() btr_search_sys.create()
+#define btr_search_sys_free() btr_search_sys.free()
 
 /** Disable the adaptive hash search system and empty the index. */
 void btr_search_disable();
@@ -162,19 +159,8 @@ static inline bool btr_search_own_any();
 /** Unlock all search latches from shared mode. */
 static inline void btr_search_s_unlock_all();
 
-/** Get the latch based on index attributes.
-A latch is selected from an array of latches using pair of index-id, space-id.
-@param[in]	index	index handler
-@return latch */
-static inline rw_lock_t* btr_get_search_latch(const dict_index_t* index);
-
-/** Get the hash-table based on index attributes.
-A table is selected from an array of tables using pair of index-id, space-id.
-@param[in]	index	index handler
-@return hash table */
-static inline hash_table_t* btr_get_search_table(const dict_index_t* index);
 #else /* BTR_CUR_HASH_ADAPT */
-# define btr_search_sys_create(size)
+# define btr_search_sys_create()
 # define btr_search_sys_free()
 # define btr_search_drop_page_hash_index(block)
 # define btr_search_s_lock_all(index)
@@ -259,31 +245,119 @@ struct btr_search_t{
 };
 
 #ifdef BTR_CUR_HASH_ADAPT
+/** The hash index system */
+struct btr_search_sys_t
+{
+  /** Partition of the hash table */
+  struct partition
+  {
+    /** latches protecting hash_table */
+    rw_lock_t latch;
+    /** mapping of dtuple_fold() to rec_t* in buf_block_t::frame */
+    hash_table_t table;
+    /** memory heap for table */
+    mem_heap_t *heap;
+
+    char pad[(CPU_LEVEL1_DCACHE_LINESIZE - sizeof(rw_lock_t) -
+              sizeof(hash_table_t) - sizeof(mem_heap_t)) &
+             (CPU_LEVEL1_DCACHE_LINESIZE - 1)];
+
+    void init()
+    {
+      memset((void*) this, 0, sizeof *this);
+      rw_lock_create(btr_search_latch_key, &latch, SYNC_SEARCH_SYS);
+    }
+
+    void alloc(ulint hash_size)
+    {
+      table.create(hash_size);
+      heap= mem_heap_create_typed(std::min<ulong>(4096,
+                                                  MEM_MAX_ALLOC_IN_BUF / 2
+                                                  - MEM_BLOCK_HEADER_SIZE
+                                                  - MEM_SPACE_NEEDED(0)),
+                                  MEM_HEAP_FOR_BTR_SEARCH);
+    }
+
+    void clear()
+    {
+      mem_heap_free(heap);
+      heap= nullptr;
+      ut_free(table.array);
+    }
+
+    void free()
+    {
+      rw_lock_free(&latch);
+      if (heap)
+        clear();
+    }
+  };
+
+  /** Partitions of the adaptive hash index */
+  partition *parts;
+
+  /** Get an adaptive hash index partition */
+  partition *get_part(index_id_t id, ulint space_id) const
+  {
+    return parts + ut_fold_ulint_pair(ulint(id), space_id) % btr_ahi_parts;
+  }
+
+  /** Get an adaptive hash index partition */
+  partition *get_part(const dict_index_t &index) const
+  {
+    ut_ad(index.table->space->id == index.table->space_id);
+    return get_part(ulint(index.id), index.table->space_id);
+  }
+
+  /** Get the search latch for the adaptive hash index partition */
+  rw_lock_t *get_latch(const dict_index_t &index) const
+  { return &get_part(index)->latch; }
+
+  /** Create and initialize at startup */
+  void create()
+  {
+    parts= static_cast<partition*>(ut_malloc(btr_ahi_parts * sizeof *parts,
+                                             mem_key_ahi));
+    for (ulong i= 0; i < btr_ahi_parts; ++i)
+      parts[i].init();
+    if (btr_search_enabled)
+      btr_search_enable();
+  }
+
+  void alloc(ulint hash_size)
+  {
+    hash_size/= btr_ahi_parts;
+    for (ulong i= 0; i < btr_ahi_parts; ++i)
+      parts[i].alloc(hash_size);
+  }
+
+  /** Clear when disabling the adaptive hash index */
+  void clear() { for (ulong i= 0; i < btr_ahi_parts; ++i) parts[i].clear(); }
+
+  /** Free at shutdown */
+  void free()
+  {
+    if (parts)
+      for (ulong i= 0; i < btr_ahi_parts; ++i)
+        parts[i].free();
+  }
+};
+
+/** The adaptive hash index */
+extern btr_search_sys_t btr_search_sys;
+
 /** @return number of leaf pages pointed to by the adaptive hash index */
 inline ulint dict_index_t::n_ahi_pages() const
 {
   if (!btr_search_enabled)
     return 0;
-  rw_lock_t *latch = btr_get_search_latch(this);
+  rw_lock_t *latch = &btr_search_sys.get_part(*this)->latch;
   rw_lock_s_lock(latch);
   ulint ref_count= search_info->ref_count;
   rw_lock_s_unlock(latch);
   return ref_count;
 }
 
-/** The hash index system */
-struct btr_search_sys_t{
-	hash_table_t**	hash_tables;	/*!< the adaptive hash tables,
-					mapping dtuple_fold values
-					to rec_t pointers on index pages */
-};
-
-/** Latches protecting access to adaptive hash index. */
-extern rw_lock_t**		btr_search_latches;
-
-/** The adaptive hash index */
-extern btr_search_sys_t*	btr_search_sys;
-
 #ifdef UNIV_SEARCH_PERF_STAT
 /** Number of successful adaptive hash index lookups */
 extern ulint	btr_search_n_succ;
diff --git a/storage/innobase/include/btr0sea.ic b/storage/innobase/include/btr0sea.ic
index 9db0084ce59..40eb5d86ead 100644
--- a/storage/innobase/include/btr0sea.ic
+++ b/storage/innobase/include/btr0sea.ic
@@ -88,7 +88,7 @@ btr_search_info_update(
 static inline void btr_search_x_lock_all()
 {
 	for (ulint i = 0; i < btr_ahi_parts; ++i) {
-		rw_lock_x_lock(btr_search_latches[i]);
+		rw_lock_x_lock(&btr_search_sys.parts[i].latch);
 	}
 }
 
@@ -96,7 +96,7 @@ static inline void btr_search_x_lock_all()
 static inline void btr_search_x_unlock_all()
 {
 	for (ulint i = 0; i < btr_ahi_parts; ++i) {
-		rw_lock_x_unlock(btr_search_latches[i]);
+		rw_lock_x_unlock(&btr_search_sys.parts[i].latch);
 	}
 }
 
@@ -104,7 +104,7 @@ static inline void btr_search_x_unlock_all()
 static inline void btr_search_s_lock_all()
 {
 	for (ulint i = 0; i < btr_ahi_parts; ++i) {
-		rw_lock_s_lock(btr_search_latches[i]);
+		rw_lock_s_lock(&btr_search_sys.parts[i].latch);
 	}
 }
 
@@ -112,7 +112,7 @@ static inline void btr_search_s_lock_all()
 static inline void btr_search_s_unlock_all()
 {
 	for (ulint i = 0; i < btr_ahi_parts; ++i) {
-		rw_lock_s_unlock(btr_search_latches[i]);
+		rw_lock_s_unlock(&btr_search_sys.parts[i].latch);
 	}
 }
 
@@ -124,7 +124,7 @@ static inline void btr_search_s_unlock_all()
 static inline bool btr_search_own_all(ulint mode)
 {
 	for (ulint i = 0; i < btr_ahi_parts; ++i) {
-		if (!rw_lock_own(btr_search_latches[i], mode)) {
+		if (!rw_lock_own(&btr_search_sys.parts[i].latch, mode)) {
 			return(false);
 		}
 	}
@@ -138,7 +138,7 @@ static inline bool btr_search_own_all(ulint mode)
 static inline bool btr_search_own_any(ulint mode)
 {
 	for (ulint i = 0; i < btr_ahi_parts; ++i) {
-		if (rw_lock_own(btr_search_latches[i], mode)) {
+		if (rw_lock_own(&btr_search_sys.parts[i].latch, mode)) {
 			return(true);
 		}
 	}
@@ -149,7 +149,7 @@ static inline bool btr_search_own_any(ulint mode)
 static inline bool btr_search_own_any()
 {
 	for (ulint i = btr_ahi_parts; i--; ) {
-		if (rw_lock_own_flagged(btr_search_latches[i],
+		if (rw_lock_own_flagged(&btr_search_sys.parts[i].latch,
 					RW_LOCK_FLAG_X | RW_LOCK_FLAG_S)) {
 			return true;
 		}
@@ -157,34 +157,4 @@ static inline bool btr_search_own_any()
 	return false;
 }
 #endif /* UNIV_DEBUG */
-
-/** Get the adaptive hash search index latch for a b-tree.
-@param[in]	index	b-tree index
-@return latch */
-static inline rw_lock_t* btr_get_search_latch(const dict_index_t* index)
-{
-	ut_ad(index != NULL);
-	ut_ad(!index->table->space
-	      || index->table->space->id == index->table->space_id);
-
-	ulint	ifold = ut_fold_ulint_pair(ulint(index->id),
-					   index->table->space_id);
-
-	return(btr_search_latches[ifold % btr_ahi_parts]);
-}
-
-/** Get the hash-table based on index attributes.
-A table is selected from an array of tables using pair of index-id, space-id.
-@param[in]	index	index handler
-@return hash table */
-static inline hash_table_t* btr_get_search_table(const dict_index_t* index)
-{
-	ut_ad(index != NULL);
-	ut_ad(index->table->space->id == index->table->space_id);
-
-	ulint	ifold = ut_fold_ulint_pair(ulint(index->id),
-					   index->table->space_id);
-
-	return(btr_search_sys->hash_tables[ifold % btr_ahi_parts]);
-}
 #endif /* BTR_CUR_HASH_ADAPT */
diff --git a/storage/innobase/include/buf0buf.h b/storage/innobase/include/buf0buf.h
index 71d06db01e9..6758e427c74 100644
--- a/storage/innobase/include/buf0buf.h
+++ b/storage/innobase/include/buf0buf.h
@@ -1131,7 +1131,7 @@ struct buf_block_t{
 	assigning block->index = NULL (and block->n_pointers = 0)
 	is allowed whenever btr_search_own_all(RW_LOCK_X).
 
-	Another exception is that ha_insert_for_fold_func() may
+	Another exception is that ha_insert_for_fold() may
 	decrement n_pointers without holding the appropriate latch
 	in btr_search_latches[]. Thus, n_pointers must be
 	protected by atomic memory access.
diff --git a/storage/innobase/include/ha0ha.h b/storage/innobase/include/ha0ha.h
index 3b3e511c9f5..561c322521e 100644
--- a/storage/innobase/include/ha0ha.h
+++ b/storage/innobase/include/ha0ha.h
@@ -43,125 +43,6 @@ ha_search_and_get_data(
 /*===================*/
 	hash_table_t*	table,	/*!< in: hash table */
 	ulint		fold);	/*!< in: folded value of the searched data */
-/*********************************************************//**
-Looks for an element when we know the pointer to the data and updates
-the pointer to data if found.
-@return TRUE if found */
-ibool
-ha_search_and_update_if_found_func(
-/*===============================*/
-	hash_table_t*	table,	/*!< in/out: hash table */
-	ulint		fold,	/*!< in: folded value of the searched data */
-	const rec_t*	data,	/*!< in: pointer to the data */
-#if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG
-	buf_block_t*	new_block,/*!< in: block containing new_data */
-#endif /* UNIV_AHI_DEBUG || UNIV_DEBUG */
-	const rec_t*	new_data);/*!< in: new pointer to the data */
-
-#if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG
-/** Looks for an element when we know the pointer to the data and
-updates the pointer to data if found.
-@param table in/out: hash table
-@param fold in: folded value of the searched data
-@param data in: pointer to the data
-@param new_block in: block containing new_data
-@param new_data in: new pointer to the data */
-# define ha_search_and_update_if_found(table,fold,data,new_block,new_data) \
-	ha_search_and_update_if_found_func(table,fold,data,new_block,new_data)
-#else /* UNIV_AHI_DEBUG || UNIV_DEBUG */
-/** Looks for an element when we know the pointer to the data and
-updates the pointer to data if found.
-@param table in/out: hash table
-@param fold in: folded value of the searched data
-@param data in: pointer to the data
-@param new_block ignored: block containing new_data
-@param new_data in: new pointer to the data */
-# define ha_search_and_update_if_found(table,fold,data,new_block,new_data) \
-	ha_search_and_update_if_found_func(table,fold,data,new_data)
-#endif /* UNIV_AHI_DEBUG || UNIV_DEBUG */
-#endif /* BTR_CUR_HASH_ADAPT */
-
-#ifdef BTR_CUR_HASH_ADAPT
-/*************************************************************//**
-Inserts an entry into a hash table. If an entry with the same fold number
-is found, its node is updated to point to the new data, and no new node
-is inserted.
-@return TRUE if succeed, FALSE if no more memory could be allocated */
-ibool
-ha_insert_for_fold_func(
-/*====================*/
-	hash_table_t*	table,	/*!< in: hash table */
-	ulint		fold,	/*!< in: folded value of data; if a node with
-				the same fold value already exists, it is
-				updated to point to the same data, and no new
-				node is created! */
-#if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG
-	buf_block_t*	block,	/*!< in: buffer block containing the data */
-#endif /* UNIV_AHI_DEBUG || UNIV_DEBUG */
-	const rec_t*	data);	/*!< in: data, must not be NULL */
-
-#if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG
-/**
-Inserts an entry into a hash table. If an entry with the same fold number
-is found, its node is updated to point to the new data, and no new node
-is inserted.
-@return TRUE if succeed, FALSE if no more memory could be allocated
-@param t in: hash table
-@param f in: folded value of data
-@param b in: buffer block containing the data
-@param d in: data, must not be NULL */
-# define ha_insert_for_fold(t,f,b,d) 	do {		\
-	ha_insert_for_fold_func(t,f,b,d);		\
-	MONITOR_INC(MONITOR_ADAPTIVE_HASH_ROW_ADDED);	\
-} while(0)
-#else /* UNIV_AHI_DEBUG || UNIV_DEBUG */
-/**
-Inserts an entry into a hash table. If an entry with the same fold number
-is found, its node is updated to point to the new data, and no new node
-is inserted.
-@return TRUE if succeed, FALSE if no more memory could be allocated
-@param t in: hash table
-@param f in: folded value of data
-@param b ignored: buffer block containing the data
-@param d in: data, must not be NULL */
-# define ha_insert_for_fold(t,f,b,d)	do {		\
-	ha_insert_for_fold_func(t,f,d);			\
-	MONITOR_INC(MONITOR_ADAPTIVE_HASH_ROW_ADDED);	\
-} while (0)
-#endif /* UNIV_AHI_DEBUG || UNIV_DEBUG */
-
-/*********************************************************//**
-Looks for an element when we know the pointer to the data and deletes
-it from the hash table if found.
-@return TRUE if found */
-UNIV_INLINE
-ibool
-ha_search_and_delete_if_found(
-/*==========================*/
-	hash_table_t*	table,	/*!< in: hash table */
-	ulint		fold,	/*!< in: folded value of the searched data */
-	const rec_t*	data);	/*!< in: pointer to the data */
-
-/*****************************************************************//**
-Removes from the chain determined by fold all nodes whose data pointer
-points to the page given. */
-void
-ha_remove_all_nodes_to_page(
-/*========================*/
-	hash_table_t*	table,	/*!< in: hash table */
-	ulint		fold,	/*!< in: fold value */
-	const page_t*	page);	/*!< in: buffer page */
-#if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG
-/*************************************************************//**
-Validates a given range of the cells in hash table.
-@return TRUE if ok */
-ibool
-ha_validate(
-/*========*/
-	hash_table_t*	table,		/*!< in: hash table */
-	ulint		start_index,	/*!< in: start index */
-	ulint		end_index);	/*!< in: end index */
-#endif /* defined UNIV_AHI_DEBUG || defined UNIV_DEBUG */
 
 /** The hash table external chain node */
 struct ha_node_t {
diff --git a/storage/innobase/include/ha0ha.ic b/storage/innobase/include/ha0ha.ic
index 57f21c02324..e358b1070eb 100644
--- a/storage/innobase/include/ha0ha.ic
+++ b/storage/innobase/include/ha0ha.ic
@@ -25,8 +25,6 @@ Created 8/18/1994 Heikki Tuuri
 *************************************************************************/
 
 #ifdef BTR_CUR_HASH_ADAPT
-#include "ut0rnd.h"
-#include "mem0mem.h"
 #include "btr0types.h"
 
 /******************************************************************//**
@@ -154,45 +152,4 @@ ha_search_with_data(
 	return(NULL);
 }
 
-/***********************************************************//**
-Deletes a hash node. */
-void
-ha_delete_hash_node(
-/*================*/
-	hash_table_t*	table,		/*!< in: hash table */
-	ha_node_t*	del_node);	/*!< in: node to be deleted */
-
-#ifdef UNIV_DEBUG
-/** Verify if latch corresponding to the hash table is x-latched
-@param table   hash table */
-void ha_btr_search_latch_x_locked(const hash_table_t* table);
-#endif /* UNIV_DEBUG */
-
-/*********************************************************//**
-Looks for an element when we know the pointer to the data, and deletes
-it from the hash table, if found.
-@return TRUE if found */
-UNIV_INLINE
-ibool
-ha_search_and_delete_if_found(
-/*==========================*/
-	hash_table_t*	table,	/*!< in: hash table */
-	ulint		fold,	/*!< in: folded value of the searched data */
-	const rec_t*	data)	/*!< in: pointer to the data */
-{
-	ha_node_t*	node;
-
-	ut_d(ha_btr_search_latch_x_locked(table));
-	ut_ad(btr_search_enabled);
-
-	node = ha_search_with_data(table, fold, data);
-
-	if (node) {
-		ha_delete_hash_node(table, node);
-
-		return(TRUE);
-	}
-
-	return(FALSE);
-}
 #endif /* BTR_CUR_HASH_ADAPT */
diff --git a/storage/innobase/include/hash0hash.h b/storage/innobase/include/hash0hash.h
index 29e242a540d..8d84e6e976c 100644
--- a/storage/innobase/include/hash0hash.h
+++ b/storage/innobase/include/hash0hash.h
@@ -24,11 +24,8 @@ The simple hash table utility
 Created 5/20/1997 Heikki Tuuri
 *******************************************************/
 
-#ifndef hash0hash_h
-#define hash0hash_h
-
-#include "mem0mem.h"
-#include "sync0rw.h"
+#pragma once
+#include "ut0rnd.h"
 
 struct hash_table_t;
 struct hash_cell_t{
@@ -259,26 +256,19 @@ do {\
 	}\
 } while (0)
 
-/* The hash table structure */
-struct hash_table_t {
-#ifdef BTR_CUR_HASH_ADAPT
-# if defined UNIV_AHI_DEBUG || defined UNIV_DEBUG
-	ibool			adaptive;/* TRUE if this is the hash
-					table of the adaptive hash
-					index */
-# endif /* UNIV_AHI_DEBUG || UNIV_DEBUG */
-#endif /* BTR_CUR_HASH_ADAPT */
-	ulint			n_cells;/* number of cells in the hash table */
-	hash_cell_t*		array;	/*!< pointer to cell array */
-	mem_heap_t*		heap;
-#ifdef UNIV_DEBUG
-	ulint			magic_n;
-# define HASH_TABLE_MAGIC_N	76561114
-#endif /* UNIV_DEBUG */
+/** Hash table with singly-linkde overflow lists */
+struct hash_table_t
+{
+  /** number of elements in array (a prime number) */
+  ulint n_cells;
+  /** the hash array */
+  hash_cell_t *array;
+
+  /** Create the hash table.
+  @param n  the lower bound of n_cells */
+  void create(ulint n);
 
   ulint calc_hash(ulint fold) const { return ut_hash_ulint(fold, n_cells); }
 };
 
 #include "hash0hash.ic"
-
-#endif
diff --git a/storage/innobase/include/hash0hash.ic b/storage/innobase/include/hash0hash.ic
index 63661b041fd..e6ca3b15bd0 100644
--- a/storage/innobase/include/hash0hash.ic
+++ b/storage/innobase/include/hash0hash.ic
@@ -35,7 +35,6 @@ hash_get_nth_cell(
 	ulint		n)	/*!< in: cell index */
 {
 	ut_ad(table);
-	ut_ad(table->magic_n == HASH_TABLE_MAGIC_N);
 	ut_ad(n < table->n_cells);
 
 	return(table->array + n);
@@ -50,7 +49,6 @@ hash_table_clear(
 	hash_table_t*	table)	/*!< in/out: hash table */
 {
 	ut_ad(table);
-	ut_ad(table->magic_n == HASH_TABLE_MAGIC_N);
 	memset(table->array, 0x0,
 	       table->n_cells * sizeof(*table->array));
 }
@@ -65,6 +63,5 @@ hash_get_n_cells(
 	hash_table_t*	table)	/*!< in: table */
 {
 	ut_ad(table);
-	ut_ad(table->magic_n == HASH_TABLE_MAGIC_N);
 	return(table->n_cells);
 }
diff --git a/storage/innobase/include/ut0new.h b/storage/innobase/include/ut0new.h
index 5137c8f3ae1..87249062a83 100644
--- a/storage/innobase/include/ut0new.h
+++ b/storage/innobase/include/ut0new.h
@@ -859,7 +859,6 @@ constexpr const char* const auto_event_names[] =
   "fts0tlex",
   "gis0sea",
   "ha_innodb",
-  "ha0ha",
   "handler0alter",
   "hash0hash",
   "i_s",