SQLite concurrency tweaks; fixes #131

lib/Database.php

@@ -663,7 +663,6 @@ class Database {
     }
     
     public function feedUpdate($feedID, bool $throwError = false): bool {
-        $tr = $this->db->begin();
         // check to make sure the feed exists
         if (!ValueInfo::id($feedID)) {
             throw new Db\ExceptionInput("typeViolation", ["action" => __FUNCTION__, "field" => "feed", 'id' => $feedID, 'type' => "int > 0"]);
@@ -682,7 +681,6 @@ class Database {
             if (!$feed->modified) {
                 // if the feed hasn't changed, just compute the next fetch time and record it
                 $this->db->prepare("UPDATE arsse_feeds SET updated = CURRENT_TIMESTAMP, next_fetch = ? WHERE id is ?", 'datetime', 'int')->run($feed->nextFetch, $feedID);
-                $tr->commit();
                 return false;
             }
         } catch (Feed\Exception $e) {
@@ -691,7 +689,6 @@ class Database {
                 "UPDATE arsse_feeds SET updated = CURRENT_TIMESTAMP, next_fetch = ?, err_count = err_count + 1, err_msg = ? WHERE id is ?",
                 'datetime', 'str', 'int'
             )->run(Feed::nextFetchOnError($f['err_count']), $e->getMessage(), $feedID);
-            $tr->commit();
             if ($throwError) {
                 throw $e;
             }
@@ -719,6 +716,7 @@ class Database {
             );
         }
         // actually perform updates
+        $tr = $this->db->begin();
         foreach ($feed->newItems as $article) {
             $articleID = $qInsertArticle->run(
                 $article->url,

lib/Db/SQLite3/Driver.php

@@ -31,9 +31,11 @@ class Driver extends \JKingWeb\Arsse\Db\AbstractDriver {
         $timeout = Arsse::$conf->dbSQLite3Timeout * 1000;
         try {
             $this->db = $this->makeConnection($dbFile, $mode, Arsse::$conf->dbSQLite3Key);
-            // set initial options
+            // enable exceptions
             $this->db->enableExceptions(true);
-            $this->exec("PRAGMA journal_mode = wal");
+            // 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
@@ -56,8 +58,6 @@ class Driver extends \JKingWeb\Arsse\Db\AbstractDriver {
             // otherwise the database is probably corrupt
             throw new Exception("fileCorrupt", $dbFile);
         }
-        // finally set the timeout; parameters are not allowed for pragmas, but this usage should be safe
-        $this->exec("PRAGMA busy_timeout = $timeout");
     }
 
     protected function makeConnection(string $file, int $opts, string $key) {

sql/SQLite3/0.sql

@@ -2,6 +2,9 @@
 -- Copyright 2017 J. King, Dustin Wilson et al.
 -- See LICENSE and AUTHORS files for details
 
+-- Make the database WAL-journalled; this is persitent
+PRAGMA journal_mode = wal;
+
 -- metadata
 create table arsse_meta(
     key text primary key not null,                                                                          -- metadata key