Basic database maintenance

Closes #169

CHANGELOG

@@ -13,6 +13,9 @@ Bug fixes:
 - Sort Tiny Tiny RSS special feeds according to special ordering
 - Invalidate sessions when passwords are changed
 
+Changes:
+- Perform regular database maintenance to improve long-term performance
+
 Version 0.7.1 (2019-03-25)
 ==========================
 

lib/Database.php

@@ -110,6 +110,11 @@ class Database {
         return $this->db->charsetAcceptable();
     }
 
+    /** Performs maintenance on the database to ensure good performance */
+    public function driverMaintenance(): bool {
+        return $this->db->maintenance();
+    }
+
     /** Computes the column and value text of an SQL "SET" clause, validating arbitrary input against a whitelist
      *
      * Returns an indexed array containing the clause text, an array of types, and another array of values
@@ -1788,10 +1793,11 @@ class Database {
             $limitUnread = Date::sub(Arsse::$conf->purgeArticlesUnread);
         }
         $feeds = $this->db->query("SELECT id, size from arsse_feeds")->getAll();
+        $deleted = 0;
         foreach ($feeds as $feed) {
-            $query->run($feed['id'], $feed['size'], $feed['id'], $limitUnread, $limitRead);
+            $deleted += $query->run($feed['id'], $feed['size'], $feed['id'], $limitUnread, $limitRead)->changes();
         }
-        return true;
+        return (bool) $deleted;
     }
 
     /** Ensures the specified article exists and raises an exception otherwise

lib/Db/Driver.php

@@ -82,4 +82,10 @@ interface Driver {
      * This functionality should be avoided in favour of using statement parameters whenever possible
      */
     public function literalString(string $str): string;
+
+    /** Performs implementation-specific database maintenance to ensure good performance
+     * 
+     * This should be restricted to quick maintenance; in SQLite terms it might include ANALYZE, but not VACUUM
+     */
+    public function maintenance(): bool;
 }

lib/Db/MySQL/Driver.php

@@ -216,4 +216,17 @@ class Driver extends \JKingWeb\Arsse\Db\AbstractDriver {
     public function literalString(string $str): string {
         return "'".$this->db->real_escape_string($str)."'";
     }
+
+    public function maintenance(): bool {
+        // with MySQL each table must be analyzed separately, so we first have to get a list of tables
+        foreach ($this->query("SHOW TABLES like 'arsse\\_%'") as $table) {
+            $table = array_pop($table);
+            if (!preg_match("/^arsse_[a-z_]+$/", $table)) {
+                // table is not one of ours
+                continue; // @codeCoverageIgnore
+            }
+            $this->query("ANALYZE TABLE $table");
+        }
+        return true;
+    }
 }

lib/Db/PostgreSQL/Driver.php

@@ -225,4 +225,10 @@ class Driver extends \JKingWeb\Arsse\Db\AbstractDriver {
     public function literalString(string $str): string {
         return pg_escape_literal($this->db, $str);
     }
+
+    public function maintenance(): bool {
+        // analyze the database
+        $this->exec("ANALYZE");
+        return true;
+    }
 }

lib/Db/SQLite3/Driver.php

@@ -188,4 +188,10 @@ class Driver extends \JKingWeb\Arsse\Db\AbstractDriver {
     public function literalString(string $str): string {
         return "'".\SQLite3::escapeString($str)."'";
     }
+
+    public function maintenance(): bool {
+        // analyze the database then checkpoint and truncate the write-ahead log
+        $this->exec("ANALYZE; PRAGMA wal_checkpoint(truncate)");
+        return true;
+    }
 }

lib/Service.php

@@ -92,7 +92,12 @@ class Service {
     }
 
     public static function cleanupPost(): bool {
-        // delete old articles, according to configured threasholds
-        return Arsse::$db->articleCleanup();
+        // delete old articles, according to configured thresholds
+        $deleted = Arsse::$db->articleCleanup();
+        // if any articles were deleted, perform database maintenance
+        if ($deleted) {
+            Arsse::$db->driverMaintenance();
+        }
+        return true;
     }
 }

tests/cases/Database/SeriesMiscellany.php

@@ -44,4 +44,8 @@ trait SeriesMiscellany {
     public function testCheckCharacterSetAcceptability() {
         $this->assertInternalType("bool", Arsse::$db->driverCharsetAcceptable());
     }
+
+    public function testPerformMaintenance() {
+        $this->assertTrue(Arsse::$db->driverMaintenance());
+    }
 }

tests/cases/Db/BaseDriver.php

@@ -382,4 +382,9 @@ abstract class BaseDriver extends \JKingWeb\Arsse\Test\AbstractTest {
     public function testProduceAStringLiteral() {
         $this->assertSame("'It''s a string!'", $this->drv->literalString("It's a string!"));
     }
+
+    public function testPerformMaintenance() {
+        // this performs maintenance in the absence of tables; see BaseUpdate.php for another test with tables
+        $this->assertTrue($this->drv->maintenance());
+    }
 }

tests/cases/Db/BaseUpdate.php

@@ -130,4 +130,9 @@ class BaseUpdate extends \JKingWeb\Arsse\Test\AbstractTest {
         $this->assertException("updateTooNew", "Db");
         $this->drv->schemaUpdate(-1, $this->base);
     }
+
+    public function testPerformMaintenance() {
+        $this->drv->schemaUpdate(Database::SCHEMA_VERSION);
+        $this->assertTrue($this->drv->maintenance());
+    }
 }