Improved timeout handling for both SQlite and PostgreSQL

lib/Conf.php

@@ -19,12 +19,16 @@ class Conf {
     public $dbDriver                = Db\SQLite3\Driver::class;
     /** @var boolean Whether to attempt to automatically update the database when updated to a new version with schema changes */
     public $dbAutoUpdate            = true;
+    /** @var float Number of seconds to wait before returning a timeout error when connecting to a database (zero waits forever; not applicable to SQLite) */
+    public $dbTimeoutConnect        = 5.0;
+    /** @var float Number of seconds to wait before returning a timeout error when executing a database operation (zero waits forever; not applicable to SQLite) */
+    public $dbTimeoutExec           = 0.0;
     /** @var string|null Full path and file name of SQLite database (if using SQLite) */
     public $dbSQLite3File           = null;
     /** @var string Encryption key to use for SQLite database (if using a version of SQLite with SEE) */
     public $dbSQLite3Key            = "";
-    /** @var integer Number of seconds for SQLite to wait before returning a timeout error when writing to the database */
-    public $dbSQLite3Timeout        = 60;
+    /** @var float Number of seconds for SQLite to wait before returning a timeout error when trying to acquire a write lock on the database (zero does not wait) */
+    public $dbSQLite3Timeout        = 60.0;
     /** @var string Host name, address, or socket path of PostgreSQL database server (if using PostgreSQL) */
     public $dbPostgreSQLHost        = "";
     /** @var string Log-in user name for PostgreSQL database server (if using PostgreSQL) */

lib/Db/PDOError.php

@@ -19,6 +19,9 @@ trait PDOError {
             case "23000":
             case "23502":
                 return [ExceptionInput::class, "constraintViolation", $err[2]];
+            case "55P03":
+            case "57014":
+                return [ExceptionTimeout::class, 'general', $err[2]];
             case "HY000":
                 // engine-specific errors
                 switch ($this->db->getAttribute(\PDO::ATTR_DRIVER_NAME)) {

lib/Db/PostgreSQL/Driver.php

@@ -35,6 +35,7 @@ class Driver extends \JKingWeb\Arsse\Db\AbstractDriver {
         $base = [
             'client_encoding' => "UTF8",
             'application_name' => "arsse",
+            'connect_timeout' => (string) ceil(Arsse::$conf->dbTimeoutConnect ?? 0),
         ];
         $out = [];
         if ($service != "") {
@@ -66,9 +67,11 @@ class Driver extends \JKingWeb\Arsse\Db\AbstractDriver {
     }
 
     public static function makeSetupQueries(string $schema = ""): array {
+        $timeout = ceil(Arsse::$conf->dbTimeoutExec * 1000);
         $out = [
             "SET TIME ZONE UTC",
-            "SET DateStyle = 'ISO, MDY'"
+            "SET DateStyle = 'ISO, MDY'",
+            "SET statement_timeout = '$timeout'",
         ];
         if (strlen($schema) > 0) {
             $out[] = 'SET search_path = \'"'.str_replace('"', '""', $schema).'", "$user", public\'';
@@ -100,8 +103,30 @@ class Driver extends \JKingWeb\Arsse\Db\AbstractDriver {
         return $this->query("SELECT pg_encoding_to_char(encoding) from pg_database where datname = current_database()")->getValue() == "UTF8";
     }
 
+    public function savepointCreate(bool $lock = false): int {
+        if (!$this->transDepth) {
+            $this->exec("BEGIN TRANSACTION");
+        }
+        return parent::savepointCreate($lock);
+    }
+
+    public function savepointRelease(int $index = null): bool {
+        $out = parent::savepointUndo($index);
+        if ($out && !$this->transDepth) {
+            $this->exec("COMMIT TRANSACTION");
+        }
+        return $out;
+    }
+
+    public function savepointUndo(int $index = null): bool {
+        $out = parent::savepointUndo($index);
+        if ($out && !$this->transDepth) {
+            $this->exec("ROLLBACK TRANSACTION");
+        }
+        return $out;
+    }
+
     protected function lock(): bool {
-        $this->exec("BEGIN TRANSACTION");
         if ($this->schemaVersion()) {
             $this->exec("LOCK TABLE arsse_meta IN EXCLUSIVE MODE NOWAIT");
         }

lib/Db/SQLite3/Driver.php

@@ -27,13 +27,8 @@ class Driver extends \JKingWeb\Arsse\Db\AbstractDriver {
         }
         // if no database file is specified in the configuration, use a suitable default
         $dbFile = $dbFile ?? Arsse::$conf->dbSQLite3File ?? \JKingWeb\Arsse\BASE."arsse.db";
-        $timeout = Arsse::$conf->dbSQLite3Timeout * 1000;
         try {
             $this->makeConnection($dbFile, Arsse::$conf->dbSQLite3Key);
-            // set the timeout; parameters are not allowed for pragmas, but this usage should be safe
-            $this->exec("PRAGMA busy_timeout = $timeout");
-            // set other initial options
-            $this->exec("PRAGMA foreign_keys = yes");
         } catch (\Throwable $e) {
             // if opening the database doesn't work, check various pre-conditions to find out what the problem might be
             $files = [
@@ -55,6 +50,11 @@ class Driver extends \JKingWeb\Arsse\Db\AbstractDriver {
             // otherwise the database is probably corrupt
             throw new Exception("fileCorrupt", $dbFile);
         }
+        // set the timeout
+        $timeout = (int) ceil((Arsse::$conf->dbSQLite3Timeout ?? 0) * 1000);
+        $this->setTimeout($timeout);
+        // set other initial options
+        $this->exec("PRAGMA foreign_keys = yes");
     }
 
     public static function requirementsMet(): bool {
@@ -67,6 +67,10 @@ class Driver extends \JKingWeb\Arsse\Db\AbstractDriver {
         $this->db->enableExceptions(true);
     }
 
+    protected function setTimeout(int $msec) {
+        $this->exec("PRAGMA busy_timeout = $msec");
+    }
+
     public function __destruct() {
         try {
             $this->db->close();
@@ -157,7 +161,13 @@ class Driver extends \JKingWeb\Arsse\Db\AbstractDriver {
     }
 
     protected function lock(): bool {
-        $this->exec("BEGIN EXCLUSIVE TRANSACTION");
+        $timeout = (int) $this->query("PRAGMA busy_timeout")->getValue();
+        $this->setTimeout(0);
+        try {
+            $this->exec("BEGIN EXCLUSIVE TRANSACTION");
+        } finally {
+            $this->setTimeout($timeout);
+        }
         return true;
     }
 

tests/cases/Db/PostgreSQL/TestDriver.php → tests/cases/Db/PostgreSQL/TestCreation.php

@@ -6,14 +6,17 @@
 declare(strict_types=1);
 namespace JKingWeb\Arsse\TestCase\Db\PostgreSQL;
 
+use JKingWeb\Arsse\Arsse;
 use JKingWeb\Arsse\Db\PostgreSQL\Driver;
 
 /**
  * @covers \JKingWeb\Arsse\Db\PostgreSQL\Driver<extended> */
-class TestDriver extends \JKingWeb\Arsse\Test\AbstractTest {
+class TestCreation extends \JKingWeb\Arsse\Test\AbstractTest {
     /** @dataProvider provideConnectionStrings */
     public function testGenerateConnectionString(bool $pdo, string $user, string $pass, string $db, string $host, int $port, string $service, string $exp) {
-        $postfix = "application_name='arsse' client_encoding='UTF8'";
+        $this->setConf();
+        $timeout = (string) ceil(Arsse::$conf->dbTimeoutConnect ?? 0);
+        $postfix = "application_name='arsse' client_encoding='UTF8' connect_timeout='$timeout'";
         $act = Driver::makeConnectionString($pdo, $user, $pass, $db, $host, $port, $service);
         if ($act==$postfix) {
             $this->assertSame($exp, "");

tests/phpunit.xml

@@ -56,7 +56,7 @@
         <file>cases/Db/SQLite3PDO/TestDriver.php</file>
         <file>cases/Db/SQLite3PDO/TestUpdate.php</file>
 
-        <file>cases/Db/PostgreSQL/TestDriver.php</file>
+        <file>cases/Db/PostgreSQL/TestCreation.php</file>
     </testsuite>
     <testsuite name="Database functions">
         <file>cases/Db/SQLite3/Database/TestMiscellany.php</file>