branches/zip: Port the applicable parts of r4053 from branches/innodb+:

Implement the global variable innodb_change_buffering, with the
following values:

none - buffer nothing
inserts - buffer inserts (the default)

Approved by Ken Jacobs.

ChangeLog

@@ -1,3 +1,12 @@
+2009-01-29	The InnoDB Team
+
+	* handler/ha_innodb.cc, include/ibuf0ibuf.h, include/ibuf0ibuf.ic,
+	ibuf/ibuf0ibuf.c:
+	Implement the settable global variable innodb_change_buffering,
+	with the allowed values 'none' and 'inserts'.  The default value
+	'inserts' enables the buffering of inserts to non-unique secondary
+	index trees when the B-tree leaf page is not in the buffer pool.
+
 2009-01-27	The InnoDB Team
 
 	* buf/buf0lru.c:

handler/ha_innodb.cc

@@ -61,6 +61,7 @@ extern "C" {
 #include "../storage/innobase/include/dict0boot.h"
 #include "../storage/innobase/include/ha_prototypes.h"
 #include "../storage/innobase/include/ut0mem.h"
+#include "../storage/innobase/include/ibuf0ibuf.h"
 }
 
 #include "ha_innodb.h"
@@ -141,6 +142,7 @@ static char*	innobase_data_home_dir			= NULL;
 static char*	innobase_data_file_path			= NULL;
 static char*	innobase_log_group_home_dir		= NULL;
 static char*	innobase_file_format_name		= NULL;
+static char*	innobase_change_buffering		= NULL;
 
 /* Note: This variable can be set to on/off and any of the supported
 file formats in the configuration file, but can only be set to any
@@ -185,6 +187,12 @@ static hash_table_t*	innobase_open_tables;
 bool nw_panic = FALSE;
 #endif
 
+/** Allowed values of innodb_change_buffering */
+static const char* innobase_change_buffering_values[IBUF_USE_INSERT + 1] = {
+	"none",		/* IBUF_USE_NONE */
+	"inserts"	/* IBUF_USE_INSERT */
+};
+
 static INNOBASE_SHARE *get_share(const char *table_name);
 static void free_share(INNOBASE_SHARE *share);
 static int innobase_close_connection(handlerton *hton, THD* thd);
@@ -2069,6 +2077,10 @@ innobase_init(
 		}
 	}
 
+	ut_a((ulint) ibuf_use < UT_ARR_SIZE(innobase_change_buffering_values));
+	innobase_change_buffering = (char*)
+		innobase_change_buffering_values[ibuf_use];
+
 	/* --------------------------------------------------*/
 
 	srv_file_flush_method_str = innobase_unix_file_flush_method;
@@ -9350,6 +9362,72 @@ innodb_file_format_check_update(
 	}
 }
 
+/*****************************************************************
+Check if it is a valid value of innodb_change_buffering.  This function is
+registered as a callback with MySQL. */
+static
+int
+innodb_change_buffering_validate(
+/*=============================*/
+						/* out: 0 for valid
+						innodb_change_buffering */
+	THD*				thd,	/* in: thread handle */
+	struct st_mysql_sys_var*	var,	/* in: pointer to system
+						variable */
+	void*				save,	/* out: immediate result
+						for update function */
+	struct st_mysql_value*		value)	/* in: incoming string */
+{
+	const char*	change_buffering_input;
+	char		buff[STRING_BUFFER_USUAL_SIZE];
+	int		len = sizeof(buff);
+
+	ut_a(save != NULL);
+	ut_a(value != NULL);
+
+	change_buffering_input = value->val_str(value, buff, &len);
+
+	if (change_buffering_input != NULL) {
+		ulint	use;
+
+		for (use = 0; use < UT_ARR_SIZE(innobase_change_buffering_values);
+		     use++) {
+			if (!innobase_strcasecmp(
+				    change_buffering_input,
+				    innobase_change_buffering_values[use])) {
+				*(ibuf_use_t*) save = (ibuf_use_t) use;
+				return(0);
+			}
+		}
+	}
+
+	return(1);
+}
+
+/********************************************************************
+Update the system variable innodb_change_buffering using the "saved"
+value. This function is registered as a callback with MySQL. */
+static
+void
+innodb_change_buffering_update(
+/*===========================*/
+	THD*				thd,		/* in: thread handle */
+	struct st_mysql_sys_var*	var,		/* in: pointer to
+							system variable */
+	void*				var_ptr,	/* out: where the
+							formal string goes */
+	const void*			save)		/* in: immediate result
+							from check function */
+{
+	ut_a(var_ptr != NULL);
+	ut_a(save != NULL);
+	ut_a((*(ibuf_use_t*) save) <= IBUF_USE_INSERT);
+
+	ibuf_use = *(const ibuf_use_t*) save;
+
+	*(const char**) var_ptr = innobase_change_buffering_values[ibuf_use];
+}
+
 static int show_innodb_vars(THD *thd, SHOW_VAR *var, char *buff)
 {
   innodb_export_status();
@@ -9587,6 +9665,13 @@ static MYSQL_SYSVAR_BOOL(use_sys_malloc, srv_use_sys_malloc,
   "Use OS memory allocator instead of InnoDB's internal memory allocator",
   NULL, NULL, FALSE);
 
+static MYSQL_SYSVAR_STR(change_buffering, innobase_change_buffering,
+  PLUGIN_VAR_RQCMDARG,
+  "Buffer changes to reduce random access: "
+  "OFF, ON, inserting, deleting, changing, or purging.",
+  innodb_change_buffering_validate,
+  innodb_change_buffering_update, NULL);
+
 static struct st_mysql_sys_var* innobase_system_variables[]= {
   MYSQL_SYSVAR(additional_mem_pool_size),
   MYSQL_SYSVAR(autoextend_increment),
@@ -9634,6 +9719,7 @@ static struct st_mysql_sys_var* innobase_system_variables[]= {
   MYSQL_SYSVAR(autoinc_lock_mode),
   MYSQL_SYSVAR(version),
   MYSQL_SYSVAR(use_sys_malloc),
+  MYSQL_SYSVAR(change_buffering),
   NULL
 };
 

ibuf/ibuf0ibuf.c

@@ -140,7 +140,10 @@ access order rules. */
 /* Table name for the insert buffer. */
 #define IBUF_TABLE_NAME		"SYS_IBUF_TABLE"
 
-/* The insert buffer control structure */
+/** Operations that can currently be buffered. */
+UNIV_INTERN ibuf_use_t	ibuf_use		= IBUF_USE_INSERT;
+
+/** The insert buffer control structure */
 UNIV_INTERN ibuf_t*	ibuf			= NULL;
 
 UNIV_INTERN ulint	ibuf_flush_count	= 0;
@@ -2107,6 +2110,7 @@ ibuf_contract_ext(
 	mutex_enter(&ibuf_mutex);
 
 	if (ibuf->empty) {
+ibuf_is_empty:
 		mutex_exit(&ibuf_mutex);
 
 		return(0);
@@ -2135,9 +2139,7 @@ ibuf_contract_ext(
 		mtr_commit(&mtr);
 		btr_pcur_close(&pcur);
 
-		mutex_exit(&ibuf_mutex);
-
-		return(0);
+		goto ibuf_is_empty;
 	}
 
 	mutex_exit(&ibuf_mutex);
@@ -2766,6 +2768,13 @@ ibuf_insert(
 
 	ut_a(!dict_index_is_clust(index));
 
+	switch (ibuf_use) {
+	case IBUF_USE_NONE:
+		return(FALSE);
+	case IBUF_USE_INSERT:
+		break;
+	}
+
 	entry_size = rec_get_converted_size(index, entry, 0);
 
 	if (entry_size

include/ibuf0ibuf.h

@@ -17,7 +17,17 @@ Created 7/19/1997 Heikki Tuuri
 #include "ibuf0types.h"
 #include "fsp0fsp.h"
 
-extern ibuf_t*	ibuf;
+/** Combinations of operations that can be buffered. */
+typedef enum {
+	IBUF_USE_NONE = 0,
+	IBUF_USE_INSERT		/* insert */
+} ibuf_use_t;
+
+/** Operations that can currently be buffered. */
+extern ibuf_use_t	ibuf_use;
+
+/** The insert buffer control structure */
+extern ibuf_t*		ibuf;
 
 /* The purpose of the insert buffer is to reduce random disk access.
 When we wish to insert a record into a non-unique secondary index and

include/ibuf0ibuf.ic

@@ -79,7 +79,8 @@ ibuf_should_try(
 						a secondary index when we
 						decide */
 {
-	if (!dict_index_is_clust(index)
+	if (ibuf_use != IBUF_USE_NONE
+	    && !dict_index_is_clust(index)
 	    && (ignore_sec_unique || !dict_index_is_unique(index))) {
 
 		ibuf_flush_count++;