diff --git a/backup/controller/tests/controller_test.php b/backup/controller/tests/controller_test.php
index d5142f15376..c34ff288cac 100644
--- a/backup/controller/tests/controller_test.php
+++ b/backup/controller/tests/controller_test.php
@@ -149,6 +149,32 @@ class core_backup_controller_testcase extends advanced_testcase {
}
$this->assertTrue($alltrue);
}
+
+ /**
+ * Test restore of deadlock causing backup.
+ */
+ public function test_restore_of_deadlock_causing_backup() {
+ global $USER, $CFG;
+ $this->preventResetByRollback();
+
+ $foldername = 'deadlock';
+ $fp = get_file_packer('application/vnd.moodle.backup');
+ $tempdir = $CFG->dataroot . '/temp/backup/' . $foldername;
+ $files = $fp->extract_to_pathname($CFG->dirroot . '/backup/controller/tests/fixtures/deadlock.mbz', $tempdir);
+
+ $this->setAdminUser();
+ $controller = new restore_controller(
+ 'deadlock',
+ $this->courseid,
+ backup::INTERACTIVE_NO,
+ backup::MODE_GENERAL,
+ $USER->id,
+ backup::TARGET_NEW_COURSE
+ );
+ $this->assertTrue($controller->execute_precheck());
+ $controller->execute_plan();
+ $controller->destroy();
+ }
}
diff --git a/backup/controller/tests/fixtures/deadlock.mbz b/backup/controller/tests/fixtures/deadlock.mbz
new file mode 100644
index 00000000000..a95168c0d8c
Binary files /dev/null and b/backup/controller/tests/fixtures/deadlock.mbz differ
diff --git a/lib/ddl/mssql_sql_generator.php b/lib/ddl/mssql_sql_generator.php
index 4faa2b25aae..a71b2257235 100644
--- a/lib/ddl/mssql_sql_generator.php
+++ b/lib/ddl/mssql_sql_generator.php
@@ -652,36 +652,29 @@ class mssql_sql_generator extends sql_generator {
public static function getReservedWords() {
// This file contains the reserved words for MSSQL databases
// from http://msdn2.microsoft.com/en-us/library/ms189822.aspx
+ // Should be identical to sqlsrv_native_moodle_database::$reservewords.
$reserved_words = array (
- 'add', 'all', 'alter', 'and', 'any', 'as', 'asc', 'authorization',
- 'avg', 'backup', 'begin', 'between', 'break', 'browse', 'bulk',
- 'by', 'cascade', 'case', 'check', 'checkpoint', 'close', 'clustered',
- 'coalesce', 'collate', 'column', 'commit', 'committed', 'compute',
- 'confirm', 'constraint', 'contains', 'containstable', 'continue',
- 'controlrow', 'convert', 'count', 'create', 'cross', 'current',
- 'current_date', 'current_time', 'current_timestamp', 'current_user',
- 'cursor', 'database', 'dbcc', 'deallocate', 'declare', 'default', 'delete',
- 'deny', 'desc', 'disk', 'distinct', 'distributed', 'double', 'drop', 'dummy',
- 'dump', 'else', 'end', 'errlvl', 'errorexit', 'escape', 'except', 'exec',
- 'execute', 'exists', 'exit', 'external', 'fetch', 'file', 'fillfactor', 'floppy',
- 'for', 'foreign', 'freetext', 'freetexttable', 'from', 'full', 'function',
- 'goto', 'grant', 'group', 'having', 'holdlock', 'identity', 'identitycol',
- 'identity_insert', 'if', 'in', 'index', 'inner', 'insert', 'intersect', 'into',
- 'is', 'isolation', 'join', 'key', 'kill', 'left', 'level', 'like', 'lineno',
- 'load', 'max', 'min', 'mirrorexit', 'national', 'nocheck', 'nonclustered',
- 'not', 'null', 'nullif', 'of', 'off', 'offsets', 'on', 'once', 'only', 'open',
- 'opendatasource', 'openquery', 'openrowset', 'openxml', 'option', 'or', 'order',
- 'outer', 'over', 'percent', 'perm', 'permanent', 'pipe', 'pivot', 'plan', 'precision',
- 'prepare', 'primary', 'print', 'privileges', 'proc', 'procedure', 'processexit',
- 'public', 'raiserror', 'read', 'readtext', 'reconfigure', 'references',
- 'repeatable', 'replication', 'restore', 'restrict', 'return', 'revoke',
- 'right', 'rollback', 'rowcount', 'rowguidcol', 'rule', 'save', 'schema',
- 'select', 'serializable', 'session_user', 'set', 'setuser', 'shutdown', 'some',
- 'statistics', 'sum', 'system_user', 'table', 'tape', 'temp', 'temporary',
- 'textsize', 'then', 'to', 'top', 'tran', 'transaction', 'trigger', 'truncate',
- 'tsequal', 'uncommitted', 'union', 'unique', 'update', 'updatetext', 'use',
- 'user', 'values', 'varying', 'view', 'waitfor', 'when', 'where', 'while',
- 'with', 'work', 'writetext'
+ "add", "all", "alter", "and", "any", "as", "asc", "authorization", "avg", "backup", "begin", "between", "break",
+ "browse", "bulk", "by", "cascade", "case", "check", "checkpoint", "close", "clustered", "coalesce", "collate", "column",
+ "commit", "committed", "compute", "confirm", "constraint", "contains", "containstable", "continue", "controlrow",
+ "convert", "count", "create", "cross", "current", "current_date", "current_time", "current_timestamp", "current_user",
+ "cursor", "database", "dbcc", "deallocate", "declare", "default", "delete", "deny", "desc", "disk", "distinct",
+ "distributed", "double", "drop", "dummy", "dump", "else", "end", "errlvl", "errorexit", "escape", "except", "exec",
+ "execute", "exists", "exit", "external", "fetch", "file", "fillfactor", "floppy", "for", "foreign", "freetext",
+ "freetexttable", "from", "full", "function", "goto", "grant", "group", "having", "holdlock", "identity",
+ "identity_insert", "identitycol", "if", "in", "index", "inner", "insert", "intersect", "into", "is", "isolation",
+ "join", "key", "kill", "left", "level", "like", "lineno", "load", "max", "merge", "min", "mirrorexit", "national",
+ "nocheck", "nonclustered", "not", "null", "nullif", "of", "off", "offsets", "on", "once", "only", "open",
+ "opendatasource", "openquery", "openrowset", "openxml", "option", "or", "order", "outer", "over", "percent", "perm",
+ "permanent", "pipe", "pivot", "plan", "precision", "prepare", "primary", "print", "privileges", "proc", "procedure",
+ "processexit", "public", "raiserror", "read", "readtext", "reconfigure", "references", "repeatable", "replication",
+ "restore", "restrict", "return", "revert", "revoke", "right", "rollback", "rowcount", "rowguidcol", "rule", "save",
+ "schema", "securityaudit", "select", "semantickeyphrasetable", "semanticsimilaritydetailstable",
+ "semanticsimilaritytable", "serializable", "session_user", "set", "setuser", "shutdown", "some", "statistics", "sum",
+ "system_user", "table", "tablesample", "tape", "temp", "temporary", "textsize", "then", "to", "top", "tran",
+ "transaction", "trigger", "truncate", "try_convert", "tsequal", "uncommitted", "union", "unique", "unpivot", "update",
+ "updatetext", "use", "user", "values", "varying", "view", "waitfor", "when", "where", "while", "with", "within group",
+ "work", "writetext"
);
return $reserved_words;
}
diff --git a/lib/dml/sqlsrv_native_moodle_database.php b/lib/dml/sqlsrv_native_moodle_database.php
index b80191c5161..08f27357748 100644
--- a/lib/dml/sqlsrv_native_moodle_database.php
+++ b/lib/dml/sqlsrv_native_moodle_database.php
@@ -50,6 +50,31 @@ class sqlsrv_native_moodle_database extends moodle_database {
/** @var array list of open recordsets */
protected $recordsets = array();
+ /** @var array list of reserve words in MSSQL / Transact from http://msdn2.microsoft.com/en-us/library/ms189822.aspx */
+ protected $reservewords = [
+ "add", "all", "alter", "and", "any", "as", "asc", "authorization", "avg", "backup", "begin", "between", "break",
+ "browse", "bulk", "by", "cascade", "case", "check", "checkpoint", "close", "clustered", "coalesce", "collate", "column",
+ "commit", "committed", "compute", "confirm", "constraint", "contains", "containstable", "continue", "controlrow",
+ "convert", "count", "create", "cross", "current", "current_date", "current_time", "current_timestamp", "current_user",
+ "cursor", "database", "dbcc", "deallocate", "declare", "default", "delete", "deny", "desc", "disk", "distinct",
+ "distributed", "double", "drop", "dummy", "dump", "else", "end", "errlvl", "errorexit", "escape", "except", "exec",
+ "execute", "exists", "exit", "external", "fetch", "file", "fillfactor", "floppy", "for", "foreign", "freetext",
+ "freetexttable", "from", "full", "function", "goto", "grant", "group", "having", "holdlock", "identity",
+ "identity_insert", "identitycol", "if", "in", "index", "inner", "insert", "intersect", "into", "is", "isolation",
+ "join", "key", "kill", "left", "level", "like", "lineno", "load", "max", "merge", "min", "mirrorexit", "national",
+ "nocheck", "nonclustered", "not", "null", "nullif", "of", "off", "offsets", "on", "once", "only", "open",
+ "opendatasource", "openquery", "openrowset", "openxml", "option", "or", "order", "outer", "over", "percent", "perm",
+ "permanent", "pipe", "pivot", "plan", "precision", "prepare", "primary", "print", "privileges", "proc", "procedure",
+ "processexit", "public", "raiserror", "read", "readtext", "reconfigure", "references", "repeatable", "replication",
+ "restore", "restrict", "return", "revert", "revoke", "right", "rollback", "rowcount", "rowguidcol", "rule", "save",
+ "schema", "securityaudit", "select", "semantickeyphrasetable", "semanticsimilaritydetailstable",
+ "semanticsimilaritytable", "serializable", "session_user", "set", "setuser", "shutdown", "some", "statistics", "sum",
+ "system_user", "table", "tablesample", "tape", "temp", "temporary", "textsize", "then", "to", "top", "tran",
+ "transaction", "trigger", "truncate", "try_convert", "tsequal", "uncommitted", "union", "unique", "unpivot", "update",
+ "updatetext", "use", "user", "values", "varying", "view", "waitfor", "when", "where", "while", "with", "within group",
+ "work", "writetext"
+ ];
+
/**
* Constructor - instantiates the database, specifying if it's external (connect to other systems) or no (Moodle DB)
* note this has effect to decide if prefix checks must be performed or no
@@ -864,6 +889,10 @@ class sqlsrv_native_moodle_database extends moodle_database {
}
}
}
+
+ // Add WITH (NOLOCK) to any temp tables.
+ $sql = $this->add_no_lock_to_temp_tables($sql);
+
$result = $this->do_query($sql, $params, SQL_QUERY_SELECT, false, $needscrollable);
if ($needscrollable) { // Skip $limitfrom records.
@@ -872,6 +901,34 @@ class sqlsrv_native_moodle_database extends moodle_database {
return $this->create_recordset($result);
}
+ /**
+ * Use NOLOCK on any temp tables. Since it's a temp table and uncommitted reads are low risk anyway.
+ *
+ * @param string $sql the SQL select query to execute.
+ * @return string The SQL, with WITH (NOLOCK) added to all temp tables
+ */
+ protected function add_no_lock_to_temp_tables($sql) {
+ return preg_replace_callback('/(\{([a-z][a-z0-9_]*)\})(\s+(\w+))?/', function($matches) {
+ $table = $matches[1]; // With the braces, so we can put it back in the query.
+ $name = $matches[2]; // Without the braces, so we can check if it's a temptable.
+ $tail = isset($matches[3]) ? $matches[3] : ''; // Catch the next word afterwards so that we can check if it's an alias.
+ $replacement = $matches[0]; // The table and the word following it, so we can replace it back if no changes are needed.
+
+ if ($this->temptables && $this->temptables->is_temptable($name)) {
+ if (!empty($tail)) {
+ if (in_array(strtolower(trim($tail)), $this->reservewords)) {
+ // If the table is followed by a reserve word, it's not an alias so put the WITH (NOLOCK) in between.
+ return $table . ' WITH (NOLOCK)' . $tail;
+ }
+ }
+ // If the table is not followed by a reserve word, put the WITH (NOLOCK) after the whole match.
+ return $replacement . ' WITH (NOLOCK)';
+ } else {
+ return $replacement;
+ }
+ }, $sql);
+ }
+
/**
* Create a record set and initialize with first row
*
diff --git a/lib/dml/tests/sqlsrv_native_moodle_database_test.php b/lib/dml/tests/sqlsrv_native_moodle_database_test.php
new file mode 100644
index 00000000000..65cd4706e7a
--- /dev/null
+++ b/lib/dml/tests/sqlsrv_native_moodle_database_test.php
@@ -0,0 +1,168 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle. If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * Test sqlsrv dml support.
+ *
+ * @package core
+ * @category dml
+ * @copyright 2017 John Okely
+ * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+defined('MOODLE_INTERNAL') || die();
+
+global $CFG;
+require_once($CFG->dirroot.'/lib/dml/sqlsrv_native_moodle_database.php');
+
+/**
+ * Test case for sqlsrv dml support.
+ *
+ * @package core
+ * @category dml
+ * @copyright 2017 John Okely
+ * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class sqlsrv_native_moodle_database_testcase extends advanced_testcase {
+
+ public function setUp() {
+ parent::setUp();
+ $this->resetAfterTest();
+ }
+
+ /**
+ * Dataprovider for test_add_no_lock_to_temp_tables
+ * @return array Data for test_add_no_lock_to_temp_tables
+ */
+ public function add_no_lock_to_temp_tables_provider() {
+ return [
+ "Basic temp table, nothing following" => [
+ 'input' => 'SELECT * FROM {table_temp}',
+ 'expected' => 'SELECT * FROM {table_temp} WITH (NOLOCK)'
+ ],
+ "Basic temp table, with capitalised alias" => [
+ 'input' => 'SELECT * FROM {table_temp} MYTABLE',
+ 'expected' => 'SELECT * FROM {table_temp} MYTABLE WITH (NOLOCK)'
+ ],
+ "Temp table with alias, and another non-temp table" => [
+ 'input' => 'SELECT * FROM {table_temp} x WHERE y in (SELECT y from {table2})',
+ 'expected' => 'SELECT * FROM {table_temp} x WITH (NOLOCK) WHERE y in (SELECT y from {table2})'
+ ],
+ "Temp table with reserve word following, no alias" => [
+ 'input' => 'SELECT DISTINCT * FROM {table_temp} WHERE y in (SELECT y from {table2} nottemp)',
+ 'expected' => 'SELECT DISTINCT * FROM {table_temp} WITH (NOLOCK) WHERE y in (SELECT y from {table2} nottemp)'
+ ],
+ "Temp table with reserve word, lower case" => [
+ 'input' => 'SELECT DISTINCT * FROM {table_temp} where y in (SELECT y from {table2} nottemp)',
+ 'expected' => 'SELECT DISTINCT * FROM {table_temp} WITH (NOLOCK) where y in (SELECT y from {table2} nottemp)'
+ ],
+ "Another reserve word test" => [
+ 'input' => 'SELECT DISTINCT * FROM {table_temp} PIVOT y in (SELECT y from {table2} nottemp)',
+ 'expected' => 'SELECT DISTINCT * FROM {table_temp} WITH (NOLOCK) PIVOT y in (SELECT y from {table2} nottemp)'
+ ],
+ "Another reserve word test should fail" => [
+ 'input' => 'SELECT DISTINCT * FROM {table_temp} PIVOT y in (SELECT y from {table2} nottemp)',
+ 'expected' => 'SELECT DISTINCT * FROM {table_temp} WITH (NOLOCK) PIVOT y in (SELECT y from {table2} nottemp)'
+ ],
+ "Temp table with an alias starting with a keyword" => [
+ 'input' => 'SELECT * FROM {table_temp} asx',
+ 'expected' => 'SELECT * FROM {table_temp} asx WITH (NOLOCK)'
+ ],
+ "Keep alias with underscore" => [
+ 'input' => 'SELECT * FROM {table_temp} alias_for_table',
+ 'expected' => 'SELECT * FROM {table_temp} alias_for_table WITH (NOLOCK)'
+ ],
+ "Alias with number" => [
+ 'input' => 'SELECT * FROM {table_temp} a5 WHERE y',
+ 'expected' => 'SELECT * FROM {table_temp} a5 WITH (NOLOCK) WHERE y'
+ ],
+ "Alias with number and underscore" => [
+ 'input' => 'SELECT * FROM {table_temp} a_5 WHERE y',
+ 'expected' => 'SELECT * FROM {table_temp} a_5 WITH (NOLOCK) WHERE y'
+ ],
+ "Temp table in subquery" => [
+ 'input' => 'select * FROM (SELECT DISTINCT * FROM {table_temp})',
+ 'expected' => 'select * FROM (SELECT DISTINCT * FROM {table_temp} WITH (NOLOCK))'
+ ],
+ "Temp table in subquery, with following commands" => [
+ 'input' => 'select * FROM (SELECT DISTINCT * FROM {table_temp} ) WHERE y',
+ 'expected' => 'select * FROM (SELECT DISTINCT * FROM {table_temp} WITH (NOLOCK) ) WHERE y'
+ ],
+ "Temp table in subquery, with alias" => [
+ 'input' => 'select * FROM (SELECT DISTINCT * FROM {table_temp} x) WHERE y',
+ 'expected' => 'select * FROM (SELECT DISTINCT * FROM {table_temp} x WITH (NOLOCK)) WHERE y'
+ ],
+ ];
+ }
+
+ /**
+ * Test add_no_lock_to_temp_tables
+ *
+ * @param string $input The input SQL query
+ * @param string $expected The expected resultant query
+ * @dataProvider add_no_lock_to_temp_tables_provider
+ */
+ public function test_add_no_lock_to_temp_tables($input, $expected) {
+ $sqlsrv = new sqlsrv_native_moodle_database();
+
+ $reflector = new ReflectionObject($sqlsrv);
+
+ $method = $reflector->getMethod('add_no_lock_to_temp_tables');
+ $method->setAccessible(true);
+
+ $temptablesproperty = $reflector->getProperty('temptables');
+ $temptablesproperty->setAccessible(true);
+ $temptables = new temptables_tester();
+
+ $temptablesproperty->setValue($sqlsrv, $temptables);
+
+ $result = $method->invoke($sqlsrv, $input);
+
+ $temptablesproperty->setValue($sqlsrv, null);
+ $this->assertEquals($expected, $result);
+ }
+}
+
+/**
+ * Test class for testing temptables
+ *
+ * @copyright 2017 John Okely
+ * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class temptables_tester {
+ /**
+ * Returns if one table, based in the information present in the store, is a temp table
+ *
+ * For easy testing, anything with the word 'temp' in it is considered temporary.
+ *
+ * @param string $tablename name without prefix of the table we are asking about
+ * @return bool true if the table is a temp table (based in the store info), false if not
+ */
+ public function is_temptable($tablename) {
+ if (strpos($tablename, 'temp') === false) {
+ return false;
+ } else {
+ return true;
+ }
+ }
+ /**
+ * Dispose the temptables
+ *
+ * @return void
+ */
+ public function dispose() {
+ }
+}