Experimental native MySQL driver

No testing has been performed yet, but changes are extensive enough to
warrant a commit. Of particular note:

- SQL states are enumerated in a separate trait to reduce duplication
- PDOStatement is now an abstract class to avoid duplication of
engine-specific error handling
- Error handling has been cleaned up somewhat

lib/Db/AbstractDriver.php

@@ -9,13 +9,15 @@ namespace JKingWeb\Arsse\Db;
 use JKingWeb\Arsse\Arsse;
 
 abstract class AbstractDriver implements Driver {
+    use SQLState;
+
     protected $locked = false;
     protected $transDepth = 0;
     protected $transStatus = [];
 
     abstract protected function lock(): bool;
     abstract protected function unlock(bool $rollback = false): bool;
-    abstract protected function getError(): string;
+    abstract protected static function buildEngineException($code, string $msg): array;
 
     public function schemaUpdate(int $to, string $basePath = null): bool {
         $ver = $this->schemaVersion();
@@ -46,7 +48,7 @@ abstract class AbstractDriver implements Driver {
                 try {
                     $this->exec($sql);
                 } catch (\Throwable $e) {
-                    throw new Exception("updateFileError", ['file' => $file, 'driver_name' => $this->driverName(), 'current' => $a, 'message' => $this->getError()]);
+                    throw new Exception("updateFileError", ['file' => $file, 'driver_name' => $this->driverName(), 'current' => $a, 'message' => $e->getMessage()]);
                 }
                 if ($this->schemaVersion() != $a+1) {
                     throw new Exception("updateFileIncomplete", ['file' => $file, 'driver_name' => $this->driverName(), 'current' => $a]);

lib/Db/AbstractStatement.php

@@ -10,12 +10,15 @@ use JKingWeb\Arsse\Misc\Date;
 use JKingWeb\Arsse\Misc\ValueInfo;
 
 abstract class AbstractStatement implements Statement {
+    use SQLState;
+
     protected $types = [];
     protected $isNullable = [];
 
     abstract public function runArray(array $values = []): Result;
     abstract protected function bindValue($value, string $type, int $position): bool;
     abstract protected function prepare(string $query): bool;
+    abstract protected static function buildEngineException($code, string $msg): array;
 
     public function run(...$values): Result {
         return $this->runArray($values);

lib/Db/MySQL/Driver.php

@@ -13,11 +13,15 @@ use JKingWeb\Arsse\Db\ExceptionInput;
 use JKingWeb\Arsse\Db\ExceptionTimeout;
 
 class Driver extends \JKingWeb\Arsse\Db\AbstractDriver {
+    use ExceptionBuilder;
+
     const SQL_MODE = "ANSI_QUOTES,HIGH_NOT_PRECEDENCE,NO_BACKSLASH_ESCAPES,NO_ENGINE_SUBSTITUTION,PIPES_AS_CONCAT,STRICT_ALL_TABLES";
     const TRANSACTIONAL_LOCKS = false;
 
+    /** @var \mysql */
     protected $db;
     protected $transStart = 0;
+    protected $packetSize = 4194304;
 
     public function __construct() {
         // check to make sure required extension is loaded
@@ -26,7 +30,7 @@ class Driver extends \JKingWeb\Arsse\Db\AbstractDriver {
         }
         $host = Arsse::$conf->dbMySQLHost;
         if ($host[0] == "/") {
-            // host is a socket
+            // host is a Unix socket
             $socket = $host;
             $host = "";
         } elseif(substr($host, 0, 9) == "\\\\.\\pipe\\") {
@@ -38,9 +42,22 @@ class Driver extends \JKingWeb\Arsse\Db\AbstractDriver {
         $pass = Arsse::$conf->dbMySQLPass ?? "";
         $port = Arsse::$conf->dbMySQLPost ?? 3306;
         $db = Arsse::$conf->dbMySQLDb ?? "arsse";
+        // make the connection
         $this->makeConnection($user, $pass, $db, $host, $port, $socket ?? "");
-        $this->exec("SET lock_wait_timeout = 1");
+        // set session variables
-        $this->exec("SET time_zone = '+00:00'");
+        foreach (static::makeSetupQueries() as $q) {
+            $this->exec($q);
+        }
+        // get the maximum packet size; parameter strings larger than this size need to be chunked
+        $this->packetSize = $this->query("select variable_value from performance_schema.session_variables where variable_name = 'max_allowed_packet'")->getValue();
+    }
+
+    public static function makeSetupQueries(): array {
+        return [
+            "SET sql_mode = '".self::SQL_MODE."'",
+            "SET time_zone = '+00:00'",
+            "SET lock_wait_timeout = 1",
+        ];
     }
 
     /** @codeCoverageIgnore */
@@ -148,17 +165,47 @@ class Driver extends \JKingWeb\Arsse\Db\AbstractDriver {
     }
 
     protected function makeConnection(string $db, string $user, string $password, string $host, int $port, string $socket) {
+        try {
+            $this->db = new \mysqli($host, $user, $password, $db, $port, $socket);
+            if ($this->db->connect_errno) {
+                echo $this->db->connect_errno.": ".$this->db->connect_error;
+            }
+            $this->db->set_character_set("utf8mb4");
+        } catch (\Exception $e) {
+            throw $e;
         }
-
-    protected function getError(): string {
     }
 
     public function exec(string $query): bool {
+        $this->dispatch($query);
+        return true;
+    }
+
+    protected function dispatch(string $query) {
+        $r = $this->db->query($query);
+        if ($this->db->sqlstate != "00000") {
+            if ($this->db->sqlstate == "HY000") {
+                list($excClass, $excMsg, $excData) = $this->buildEngineException($this->db->errno, $this->db->error);
+            } else {
+                list($excClass, $excMsg, $excData) = $this->buildStandardException($this->db->sqlstate, $this->db->error);
+            }
+            throw new $excClass($excMsg, $excData);
+        }
+        return $r;
     }
 
     public function query(string $query): \JKingWeb\Arsse\Db\Result {
+        $r = $this->dispatch($query);
+        $rows = (int) $this->db->affected_rows;
+        $id = (int) $this->db->insert_id;
+        if ($r === true) {
+            return new \JKingWeb\Arsse\Db\ResultEmpty($rows, $id);
+        } else {
+            return new ResultE($r, [$rows, $id]);
+        }
     }
 
     public function prepareArray(string $query, array $paramTypes): \JKingWeb\Arsse\Db\Statement {
+        return new Statement($this->db, $query, $paramTypes, $this->packetSize);
     }
 }

lib/Db/MySQL/ExceptionBuilder.php

@@ -0,0 +1,30 @@
+<?php
+/** @license MIT
+ * Copyright 2017 J. King, Dustin Wilson et al.
+ * See LICENSE and AUTHORS files for details */
+
+declare(strict_types=1);
+namespace JKingWeb\Arsse\Db\MySQL;
+
+use JKingWeb\Arsse\Db\Exception;
+use JKingWeb\Arsse\Db\ExceptionInput;
+use JKingWeb\Arsse\Db\ExceptionTimeout;
+
+trait ExceptionBuilder {
+    protected function buildException(): array {
+        return self::buildEngineException($this->db->errno, $this->db->error);
+    }
+
+    public static function buildEngineException($code, string $msg): array {
+        switch ($code) {
+            case 1205:
+                return [ExceptionTimeout::class, 'general', $msg];
+            case 1364:
+                return [ExceptionInput::class, "constraintViolation", $msg];
+            case 1366:
+                return [ExceptionInput::class, 'engineTypeViolation', $msg];
+            default:
+                return [Exception::class, 'engineErrorGeneral', $msg];
+        }
+    }
+}

lib/Db/MySQL/PDODriver.php

@@ -33,7 +33,6 @@ class PDODriver extends Driver {
         $dsn = "mysql:".implode(";", $dsn);
         $this->db = new \PDO($dsn, $user, $password, [
             \PDO::ATTR_ERRMODE => \PDO::ERRMODE_EXCEPTION,
-            \PDO::MYSQL_ATTR_INIT_COMMAND => "SET sql_mode = '".self::SQL_MODE."'",
         ]);
     }
 

lib/Db/MySQL/PDOStatement.php

@@ -7,15 +7,10 @@ declare(strict_types=1);
 namespace JKingWeb\Arsse\Db\MySQL;
 
 class PDOStatement extends \JKingWeb\Arsse\Db\PDOStatement {
+    use ExceptionBuilder;
+    use \JKingWeb\Arsse\Db\PDOError;
+
     public static function mungeQuery(string $query, array $types, ...$extraData): string {
-        $query = explode("?", $query);
+        return Statement::mungeQuery($query, $types);
-        $out = "";
-        for ($b = 1; $b < sizeof($query); $b++) {
-            $a = $b - 1;
-            $mark = (($types[$a] ?? "") == "datetime") ? "cast(? as datetime(0))" : "?";
-            $out .= $query[$a].$mark;
-        }
-        $out .= array_pop($query);
-        return $out;
     }
 }

lib/Db/MySQL/Result.php

@@ -0,0 +1,51 @@
+<?php
+/** @license MIT
+ * Copyright 2017 J. King, Dustin Wilson et al.
+ * See LICENSE and AUTHORS files for details */
+
+declare(strict_types=1);
+namespace JKingWeb\Arsse\Db\MySQL;
+
+use JKingWeb\Arsse\Db\Exception;
+
+class Result extends \JKingWeb\Arsse\Db\AbstractResult {
+    protected $st;
+    protected $set;
+    protected $cur = null;
+    protected $rows = 0;
+    protected $id = 0;
+
+    // actual public methods
+
+    public function changes(): int {
+        return $this->rows;
+    }
+
+    public function lastId(): int {
+        return $this->id;
+    }
+
+    // constructor/destructor
+
+    public function __construct(\mysqli_result $result, array $changes = [0,0], Statement $statement = null) {
+        $this->st = $statement; //keeps the statement from being destroyed, invalidating the result set
+        $this->set = $result;
+        $this->rows = $changes[0];
+        $this->id = $changes[1];
+    }
+
+    public function __destruct() {
+        try {
+            $this->set->free();
+        } catch (\Throwable $e) { // @codeCoverageIgnore
+        }
+        unset($this->set);
+    }
+
+    // PHP iterator methods
+
+    public function valid() {
+        $this->cur = $this->set->fetch_assoc();
+        return ($this->cur !== null);
+    }
+}

lib/Db/MySQL/Statement.php

@@ -0,0 +1,107 @@
+<?php
+/** @license MIT
+ * Copyright 2017 J. King, Dustin Wilson et al.
+ * See LICENSE and AUTHORS files for details */
+
+declare(strict_types=1);
+namespace JKingWeb\Arsse\Db\MySQL;
+
+use JKingWeb\Arsse\Db\Exception;
+use JKingWeb\Arsse\Db\ExceptionInput;
+use JKingWeb\Arsse\Db\ExceptionTimeout;
+
+class Statement extends \JKingWeb\Arsse\Db\AbstractStatement {
+    use ExceptionBuilder;
+
+    const BINDINGS = [
+        "integer"   => "i",
+        "float"     => "d",
+        "datetime"  => "s",
+        "binary"    => "b",
+        "string"    => "s",
+        "boolean"   => "i",
+    ];
+
+    protected $db;
+    protected $st;
+    protected $query;
+    protected $packetSize;
+
+    protected $values;
+    protected $types;
+
+    public function __construct(\mysqli $db, string $query, array $bindings = [], int $packetSize) {
+        $this->db = $db;
+        $this->query = $query;
+        $this->packetSize = $packetSize;
+        $this->retypeArray($bindings);
+    }
+
+    protected function prepare(string $query): bool {
+        $this->st = $this->db->prepare($query);
+        if (!$this->st) {
+            list($excClass, $excMsg, $excData) = $this->buildEngineException($this->db->errno, $this->db->error);
+            throw new $excClass($excMsg, $excData);
+        }
+        return true;
+    }
+
+    public function __destruct() {
+        try {
+            $this->st->close();
+        } catch (\Throwable $e) { // @codeCoverageIgnore
+        }
+        unset($this->st);
+    }
+
+    public function runArray(array $values = []): \JKingWeb\Arsse\Db\Result {
+        $this->st->reset();
+        // prepare values and them all at once
+        $this->bindValues($values);
+        $this->st->bind_params($this->types, ...$this->values);
+        // execute the statement
+        $this->st->execute();
+        // clear normalized values
+        $this->types = "";
+        $this->values = [];
+        // check for errors
+        if ($this->st->sqlstate != "00000") {
+            if ($this->st->sqlstate == "HY000") {
+                list($excClass, $excMsg, $excData) = $this->buildEngineException($this->st->errno, $this->st->error);
+            } else {
+                list($excClass, $excMsg, $excData) = $this->buildStandardException($this->st->sqlstate, $this->st->error);
+            }
+            throw new $excClass($excMsg, $excData);
+        }
+        // create a result-set instance
+        $r = $this->st->get_result();
+        $changes = $this->st->affected_rows;
+        $lastId = $this->st->insert_id;
+        return new Result($r, [$changes, $lastId], $this);
+    }
+
+    protected function bindValue($value, string $type, int $position): bool {
+        // this is a bit of a hack: we collect values (and MySQL bind types) here so that we can take 
+        // advantage of the work done by bindValues() even though MySQL requires everything to be bound 
+        // all at once; we also packetize large values here if necessary
+        if (is_string($value) && strlen($value) > $this->packetSize) {
+            $this->values[] = null;
+            $this->st->send_long_data($position - 1, $value);
+        } else {
+            $this->values[] = $value;
+            $this->types .= self::BINDINGS[$type];
+        }
+        return true;
+    }
+    public static function mungeQuery(string $query, array $types, ...$extraData): string {
+        $query = explode("?", $query);
+        $out = "";
+        for ($b = 1; $b < sizeof($query); $b++) {
+            $a = $b - 1;
+            $mark = (($types[$a] ?? "") == "datetime") ? "cast(? as datetime(0))" : "?";
+            $out .= $query[$a].$mark;
+        }
+        $out .= array_pop($query);
+        return $out;
+    }
+}

lib/Db/PDODriver.php

@@ -14,7 +14,7 @@ trait PDODriver {
             $this->db->exec($query);
             return true;
         } catch (\PDOException $e) {
-            list($excClass, $excMsg, $excData) = $this->exceptionBuild();
+            list($excClass, $excMsg, $excData) = $this->buildPDOException();
             throw new $excClass($excMsg, $excData);
         }
     }
@@ -23,13 +23,9 @@ trait PDODriver {
         try {
             $r = $this->db->query($query);
         } catch (\PDOException $e) {
-            list($excClass, $excMsg, $excData) = $this->exceptionBuild();
+            list($excClass, $excMsg, $excData) = $this->buildPDOException();
             throw new $excClass($excMsg, $excData);
         }
         return new PDOResult($this->db, $r);
     }
-
-    public function prepareArray(string $query, array $paramTypes): Statement {
-        return new PDOStatement($this->db, $query, $paramTypes);
-    }
 }

lib/Db/PDOError.php

@@ -6,56 +6,19 @@
 declare(strict_types=1);
 namespace JKingWeb\Arsse\Db;
 
-use JKingWeb\Arsse\Db\SQLite3\Driver as SQLite3;
-
 trait PDOError {
-    public function exceptionBuild(bool $statementError = false): array {
+    use SQLState;
+
+    protected function buildPDOException(bool $statementError = false): array {
         if ($statementError) {
             $err = $this->st->errorInfo();
         } else {
             $err = $this->db->errorInfo();
         }
-        switch ($err[0]) {
+        if ($err[0]=="HY000") {
-            case "22007":
+            return static::buildEngineException($err[1], $err[2]);
-            case "22P02":
+        } else {
-            case "42804":
+            return static::buildStandardException($err[0], $err[2]);
-                return [ExceptionInput::class, 'engineTypeViolation', $err[2]];
-            case "23000":
-            case "23502":
-            case "23505":
-                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)) {
-                    case "sqlite":
-                        switch ($err[1]) {
-                            case SQLite3::SQLITE_BUSY:
-                                return [ExceptionTimeout::class, 'general', $err[2]];
-                            case SQLite3::SQLITE_MISMATCH:
-                                return [ExceptionInput::class, 'engineTypeViolation', $err[2]];
         }
-                        break; // @codeCoverageIgnore
-                    case "mysql":
-                        switch ($err[1]) {
-                            case 1205:
-                                return [ExceptionTimeout::class, 'general', $err[2]];
-                            case 1364:
-                                return [ExceptionInput::class, "constraintViolation", $err[2]];
-                            case 1366:
-                                return [ExceptionInput::class, 'engineTypeViolation', $err[2]];
-                        }
-                        break; // @codeCoverageIgnore
-                }
-                return [Exception::class, "engineErrorGeneral", $err[0]."/".$err[1].": ".$err[2]]; // @codeCoverageIgnore
-            default:
-                return [Exception::class, "engineErrorGeneral", $err[0].": ".$err[2]]; // @codeCoverageIgnore
-        }
-    }
-
-    public function getError(): string {
-        return (string) $this->db->errorInfo()[2];
     }
 }

lib/Db/PDOStatement.php

@@ -6,7 +6,7 @@
 declare(strict_types=1);
 namespace JKingWeb\Arsse\Db;
 
-class PDOStatement extends AbstractStatement {
+abstract class PDOStatement extends AbstractStatement {
     use PDOError;
 
     const BINDINGS = [
@@ -34,7 +34,7 @@ class PDOStatement extends AbstractStatement {
             $this->st = $this->db->prepare($query);
             return true;
         } catch (\PDOException $e) { // @codeCoverageIgnore
-            list($excClass, $excMsg, $excData) = $this->exceptionBuild(); // @codeCoverageIgnore
+            list($excClass, $excMsg, $excData) = $this->buildPDOException(); // @codeCoverageIgnore
             throw new $excClass($excMsg, $excData); // @codeCoverageIgnore
         }
     }
@@ -49,7 +49,7 @@ class PDOStatement extends AbstractStatement {
         try {
             $this->st->execute();
         } catch (\PDOException $e) {
-            list($excClass, $excMsg, $excData) = $this->exceptionBuild(true);
+            list($excClass, $excMsg, $excData) = $this->buildPDOException(true);
             throw new $excClass($excMsg, $excData);
         }
         return new PDOResult($this->db, $this->st);

lib/Db/PostgreSQL/Dispatch.php

@@ -6,37 +6,19 @@
 declare(strict_types=1);
 namespace JKingWeb\Arsse\Db\PostgreSQL;
 
-use JKingWeb\Arsse\Arsse;
-use JKingWeb\Arsse\Conf;
-use JKingWeb\Arsse\Db\Exception;
-use JKingWeb\Arsse\Db\ExceptionInput;
-use JKingWeb\Arsse\Db\ExceptionTimeout;
-
 trait Dispatch {
     protected function dispatchQuery(string $query, array $params = []) {
         pg_send_query_params($this->db, $query, $params);
         $result = pg_get_result($this->db);
         if (($code = pg_result_error_field($result, \PGSQL_DIAG_SQLSTATE)) && isset($code) && $code) {
-            return $this->buildException($code, pg_result_error($result));
+            return $this->buildStandardException($code, pg_result_error($result));
         } else {
             return $result;
         }
     }
 
-    protected function buildException(string $code, string $msg): array {
+    public static function buildEngineException($code, string $msg): array {
-        switch ($code) {
+        // PostgreSQL uses SQLSTATE exclusively, so this is not used
-            case "22P02":
+        return [];
-            case "42804":
-                return [ExceptionInput::class, 'engineTypeViolation', $msg];
-            case "23000":
-            case "23502":
-            case "23505":
-                return [ExceptionInput::class, "engineConstraintViolation", $msg];
-            case "55P03":
-            case "57014":
-                return [ExceptionTimeout::class, 'general', $msg];
-            default:
-                return [Exception::class, "engineErrorGeneral", $code.": ".$msg]; // @codeCoverageIgnore
-        }
     }
 }

lib/Db/PostgreSQL/Driver.php

@@ -20,7 +20,7 @@ class Driver extends \JKingWeb\Arsse\Db\AbstractDriver {
     protected $db;
     protected $transStart = 0;
 
-    public function __construct(string $user = null, string $pass = null, string $db = null, string $host = null, int $port = null, string $schema = null, string $service = null) {
+    public function __construct() {
         // check to make sure required extension is loaded
         if (!static::requirementsMet()) {
             throw new Exception("extMissing", static::driverName()); // @codeCoverageIgnore
@@ -193,16 +193,11 @@ class Driver extends \JKingWeb\Arsse\Db\AbstractDriver {
         }
     }
 
-    protected function getError(): string {
-        // stub
-        return "";
-    }
-
     public function exec(string $query): bool {
         pg_send_query($this->db, $query);
         while ($result = pg_get_result($this->db)) {
             if (($code = pg_result_error_field($result, \PGSQL_DIAG_SQLSTATE)) && isset($code) && $code) {
-                list($excClass, $excMsg, $excData) = $this->buildException($code, pg_result_error($result));
+                list($excClass, $excMsg, $excData) = $this->buildStandardException($code, pg_result_error($result));
                 throw new $excClass($excMsg, $excData);
             }
         }

lib/Db/PostgreSQL/PDOStatement.php

@@ -10,4 +10,9 @@ class PDOStatement extends \JKingWeb\Arsse\Db\PDOStatement {
     public static function mungeQuery(string $query, array $types, ...$extraData): string {
         return Statement::mungeQuery($query, $types, false);
     }
+
+    public static function buildEngineException($code, string $msg): array {
+        // PostgreSQL uses SQLSTATE exclusively, so this is not used
+        return [];
+    }
 }

lib/Db/PostgreSQL/Statement.php

@@ -38,6 +38,7 @@ class Statement extends \JKingWeb\Arsse\Db\AbstractStatement {
         $this->in = [];
         $this->bindValues($values);
         $r = $this->dispatchQuery($this->qMunged, $this->in);
+        $this->in = [];
         if (is_resource($r)) {
             return new Result($this->db, $r);
         } else {

lib/Db/ResultEmpty.php

@@ -9,12 +9,20 @@ namespace JKingWeb\Arsse\Db;
 use JKingWeb\Arsse\Db\Exception;
 
 class ResultEmpty extends AbstractResult {
+    protected $changes = 0;
+    protected $id = 0;
+    
+    public function __construct(int $changes = 0, int $id = 0) {
+        $this->changes = $changes;
+        $this->id = $id;
+    }
+
     public function changes(): int {
-        return 0;
+        return $this->changes;
     }
 
     public function lastId(): int {
-        return 0;
+        return $this->id;
     }
 
     // PHP iterator methods

lib/Db/SQLState.php

@@ -0,0 +1,31 @@
+<?php
+/** @license MIT
+ * Copyright 2017 J. King, Dustin Wilson et al.
+ * See LICENSE and AUTHORS files for details */
+
+declare(strict_types=1);
+namespace JKingWeb\Arsse\Db;
+
+use JKingWeb\Arsse\Db\Exception;
+use JKingWeb\Arsse\Db\ExceptionInput;
+use JKingWeb\Arsse\Db\ExceptionTimeout;
+
+trait SQLState {
+    protected static function buildStandardException(string $code, string $msg): array {
+        switch ($code) {
+            case "22007":
+            case "22P02":
+            case "42804":
+                return [ExceptionInput::class, 'engineTypeViolation', $msg];
+            case "23000":
+            case "23502":
+            case "23505":
+                return [ExceptionInput::class, "constraintViolation", $msg];
+            case "55P03":
+            case "57014":
+                return [ExceptionTimeout::class, 'general', $msg];
+            default:
+                return [Exception::class, "engineErrorGeneral", "SQLSTATE $code: $msg"]; // @codeCoverageIgnore
+        }
+    }
+}

lib/Db/SQLite3/Driver.php

@@ -22,7 +22,7 @@ class Driver extends \JKingWeb\Arsse\Db\AbstractDriver {
 
     protected $db;
 
-    public function __construct(string $dbFile = null, string $dbKey = null) {
+    public function __construct() {
         // check to make sure required extension is loaded
         if (!static::requirementsMet()) {
             throw new Exception("extMissing", static::driverName()); // @codeCoverageIgnore
@@ -140,15 +140,11 @@ class Driver extends \JKingWeb\Arsse\Db\AbstractDriver {
         return true;
     }
 
-    protected function getError(): string {
-        return $this->db->lastErrorMsg();
-    }
-
     public function exec(string $query): bool {
         try {
             return (bool) $this->db->exec($query);
         } catch (\Exception $e) {
-            list($excClass, $excMsg, $excData) = $this->exceptionBuild();
+            list($excClass, $excMsg, $excData) = $this->buildException();
             throw new $excClass($excMsg, $excData);
         }
     }
@@ -157,7 +153,7 @@ class Driver extends \JKingWeb\Arsse\Db\AbstractDriver {
         try {
             $r = $this->db->query($query);
         } catch (\Exception $e) {
-            list($excClass, $excMsg, $excData) = $this->exceptionBuild();
+            list($excClass, $excMsg, $excData) = $this->buildException();
             throw new $excClass($excMsg, $excData);
         }
         $changes = $this->db->changes();

lib/Db/SQLite3/ExceptionBuilder.php

@@ -11,16 +11,20 @@ use JKingWeb\Arsse\Db\ExceptionInput;
 use JKingWeb\Arsse\Db\ExceptionTimeout;
 
 trait ExceptionBuilder {
-    public function exceptionBuild(): array {
+    protected function buildException(): array {
-        switch ($this->db->lastErrorCode()) {
+        return self::buildEngineException($this->db->lastErrorCode(), $this->db->lastErrorMsg());
-            case self::SQLITE_BUSY:
+    }
-                return [ExceptionTimeout::class, 'general', $this->db->lastErrorMsg()];
+
-            case self::SQLITE_CONSTRAINT:
+    public static function buildEngineException($code, string $msg): array {
-                return [ExceptionInput::class, 'engineConstraintViolation', $this->db->lastErrorMsg()];
+        switch ($code) {
-            case self::SQLITE_MISMATCH:
+            case Driver::SQLITE_BUSY:
-                return [ExceptionInput::class, 'engineTypeViolation', $this->db->lastErrorMsg()];
+                return [ExceptionTimeout::class, 'general', $msg];
+            case Driver::SQLITE_CONSTRAINT:
+                return [ExceptionInput::class, 'engineConstraintViolation', $msg];
+            case Driver::SQLITE_MISMATCH:
+                return [ExceptionInput::class, 'engineTypeViolation', $msg];
             default:
-                return [Exception::class, 'engineErrorGeneral', $this->db->lastErrorMsg()];
+                return [Exception::class, 'engineErrorGeneral', $msg];
         }
     }
 }

lib/Db/SQLite3/PDODriver.php

@@ -45,4 +45,8 @@ class PDODriver extends Driver {
     public static function driverName(): string {
         return Arsse::$lang->msg("Driver.Db.SQLite3PDO.Name");
     }
+
+    public function prepareArray(string $query, array $paramTypes): \JKingWeb\Arsse\Db\Statement {
+        return new PDOStatement($this->db, $query, $paramTypes);
+    }
 }

lib/Db/SQLite3/PDOStatement.php

@@ -0,0 +1,12 @@
+<?php
+/** @license MIT
+ * Copyright 2017 J. King, Dustin Wilson et al.
+ * See LICENSE and AUTHORS files for details */
+
+declare(strict_types=1);
+namespace JKingWeb\Arsse\Db\SQLite3;
+
+class PDOStatement extends \JKingWeb\Arsse\Db\PDOStatement {
+    use ExceptionBuilder;
+    use \JKingWeb\Arsse\Db\PDOError;
+}

lib/Db/SQLite3/Statement.php

@@ -41,7 +41,7 @@ class Statement extends \JKingWeb\Arsse\Db\AbstractStatement {
             $this->st = $this->db->prepare($query);
             return true;
         } catch (\Exception $e) { // @codeCoverageIgnore
-            list($excClass, $excMsg, $excData) = $this->exceptionBuild(); // @codeCoverageIgnore
+            list($excClass, $excMsg, $excData) = $this->buildException(); // @codeCoverageIgnore
             throw new $excClass($excMsg, $excData); // @codeCoverageIgnore
         }
     }
@@ -60,7 +60,7 @@ class Statement extends \JKingWeb\Arsse\Db\AbstractStatement {
         try {
             $r = $this->st->execute();
         } catch (\Exception $e) {
-            list($excClass, $excMsg, $excData) = $this->exceptionBuild();
+            list($excClass, $excMsg, $excData) = $this->buildException();
             throw new $excClass($excMsg, $excData);
         }
         $changes = $this->db->changes();

tests/lib/DatabaseInformation.php

@@ -228,7 +228,7 @@ class DatabaseInformation {
             'PDO SQLite 3' => [
                 'pdo' => true,
                 'backend' => "SQLite 3",
-                'statementClass' => \JKingWeb\Arsse\Db\PDOStatement::class,
+                'statementClass' => \JKingWeb\Arsse\Db\SQLite3\PDOStatement::class,
                 'resultClass' => \JKingWeb\Arsse\Db\PDOResult::class,
                 'driverClass' => \JKingWeb\Arsse\Db\SQLite3\PDODriver::class,
                 'stringOutput' => true,