WIP: Locking/unlocking just as required

lib/filesystem.php

@@ -163,13 +163,21 @@ function slackemon_file_get_contents( $filename, $purpose, $acquire_lock = false
  * @param string $purpose  The purpose of the write - 'cache' or 'store'.
  * @link http://php.net/file_put_contents
  */
-function slackemon_file_put_contents( $filename, $data, $purpose ) {
+function slackemon_file_put_contents( $filename, $data, $purpose, $warn_if_not_locked = true ) {
 
   // Support $data being an array, like file_put_contents() does.
   if ( is_array( $data ) ) {
     $data = implode( '', $data );
   }
 
+  // Warn if we're trying to write to a data store file that we don't own a lock on
+  if ( 'store' === $purpose && $warn_if_not_locked && ! slackemon_is_file_owned( $filename ) ) {
+    slackemon_lock_debug(
+      'WARNING: Writing to ' . $filename . ' without a file lock.' . PHP_EOL .
+      print_r( debug_backtrace( DEBUG_BACKTRACE_IGNORE_ARGS, 3 ), true )
+    );
+  }
+
   switch ( slackemon_get_data_method( $purpose ) ) {
 
     case 'local':
@@ -668,6 +676,7 @@ function slackemon_get_data_method( $purpose ) {
 function slackemon_lock_file( $filename ) {
   global $_slackemon_file_locks;
 
+  // If file locking is not enabled, just return true so we don't prevent things from running
   if ( ! SLACKEMON_ENABLE_FILE_LOCKING ) {
     return true;
   }
@@ -681,8 +690,8 @@ function slackemon_lock_file( $filename ) {
     clearstatcache(); // Required to ensure the file_exists call doesn't rely on its cache
   }
 
-  if ( slackemon_file_put_contents( $lock_filename, time(), 'store' ) ) {
-    $_slackemon_file_locks[] = $filename;
+  if ( slackemon_file_put_contents( $lock_filename, time(), 'store', false ) ) {
+    $_slackemon_file_locks[ md5( $filename ) ] = $filename;
     slackemon_lock_debug( 'Lock acquired on ' . $filename );
     return true;
   } else {
@@ -692,6 +701,31 @@ function slackemon_lock_file( $filename ) {
 
 } // Function slackemon_lock_file
 
+function slackemon_unlock_file( $filename ) {
+  global $_slackemon_file_locks;
+
+  if ( ! SLACKEMON_ENABLE_FILE_LOCKING ) {
+    return true;
+  }
+
+  $lock_filename = slackemon_get_lock_filename( $filename );
+
+  if ( slackemon_unlink( $lock_filename, 'store' ) ) {
+    slackemon_lock_debug( 'Lock individually removed on ' . $filename );
+    unset( $_slackemon_file_locks[ md5( $filename ) ] );
+    return true;
+  } else {
+    slackemon_lock_debug( 'WARNING: Lock COULD NOT be REMOVED on ' . $filename, true );
+    return false;
+  }
+
+} // Function slackemon_unlock_file
+
+function slackemon_is_file_owned( $filename ) {
+  global $_slackemon_file_locks;
+  return array_key_exists( md5( $filename ), $_slackemon_file_locks );
+}
+
 function slackemon_remove_file_locks() {
   global $_slackemon_file_locks;
 

src/items.php

@@ -98,6 +98,8 @@ function slackemon_item_spawn( $trigger = [], $region = false, $timestamp = fals
     return slackemon_item_spawn( $trigger, $region, $timestamp );
   }
 
+  slackemon_spawn_debug( 'Ok, will spawn a ' . slackemon_readable( $item_data->name ) . '.' );
+
   // Store details of the item spawn
   $spawn = [
   	'id'          => $item_data->id,

src/players.php

@@ -41,20 +41,26 @@ function slackemon_register_player( $user_id = USER_ID ) {
 
 } // Function slackemon_register_player
 
-function slackemon_save_player_data( $player_data, $user_id = USER_ID ) {
+function slackemon_save_player_data( $player_data, $user_id = USER_ID, $relinquish_lock = false ) {
   global $data_folder, $_cached_slackemon_player_data;
 
   $player_filename = $data_folder . '/players/' . $user_id;
 
   $_cached_slackemon_player_data[ $user_id ] = $player_data;
-  return slackemon_file_put_contents( $player_filename, json_encode( $player_data ), 'store' );
+  $return = slackemon_file_put_contents( $player_filename, json_encode( $player_data ), 'store' );
+
+  if ( $relinquish_lock ) {
+    slackemon_unlock_file( $player_filename );
+  }
+
+  return $return;
 
 } // Function slackemon_save_player_data
 
-function slackemon_get_player_data( $user_id = USER_ID ) {
+function slackemon_get_player_data( $user_id = USER_ID, $for_writing = false ) {
   global $data_folder, $_cached_slackemon_player_data;
 
-  if ( isset( $_cached_slackemon_player_data[ $user_id ] ) ) {
+  if ( ! $for_writing && isset( $_cached_slackemon_player_data[ $user_id ] ) ) {
     return $_cached_slackemon_player_data[ $user_id ];
   }
 
@@ -66,7 +72,7 @@ function slackemon_get_player_data( $user_id = USER_ID ) {
     return false;
   }
 
-  $player_data = json_decode( slackemon_file_get_contents( $player_filename, 'store', true ) );
+  $player_data = json_decode( slackemon_file_get_contents( $player_filename, 'store', $for_writing ) );
   $_cached_slackemon_player_data[ $user_id ] = $player_data;
 
   // Ensure player is not caught in a cancelled region if the available regions change
@@ -358,10 +364,10 @@ function slackemon_get_player_menu_mode( $user_id = USER_ID ) {
 
 function slackemon_set_player_menu_mode( $menu_mode, $user_id = USER_ID ) {
 
-  $player_data = slackemon_get_player_data( $user_id );
+  $player_data = slackemon_get_player_data( $user_id, true );
   $player_data->menu_mode = $menu_mode;
 
-  return slackemon_save_player_data( $player_data, $user_id );
+  return slackemon_save_player_data( $player_data, $user_id, true );
 
 } // Function slackemon_set_player_menu_mode
 

src/spawns.php

@@ -240,6 +240,8 @@ function( $_pokemon ) use ( $region_pokedex ) {
     return slackemon_spawn( $trigger, $region, $timestamp );
   }
 
+  slackemon_spawn_debug( 'Ok, will spawn a ' . slackemon_readable( $pokemon->name ) . '.' );
+
   // Determine nature
   $natures = slackemon_get_natures();
   $nature = $natures[ array_rand( $natures ) ];
@@ -333,7 +335,7 @@ function slackemon_save_spawn_data( $spawn_data ) {
   $spawn_filename = $data_folder . '/spawns/' . $spawn_id;
 
   $_cached_slackemon_spawn_data[ $spawn_id ] = $spawn_data;
-  return slackemon_file_put_contents( $spawn_filename, json_encode( $spawn_data ), 'store' );
+  return slackemon_file_put_contents( $spawn_filename, json_encode( $spawn_data ), 'store', false );
 
 } // Function slackemon_save_spawn_data
 
@@ -580,7 +582,7 @@ function slackemon_notify_spawn( $spawn ) {
 function slackemon_record_spawn_for_user( $user_id, $spawn ) {
   global $data_folder;
 
-  $player_data = slackemon_get_player_data( $user_id );
+  $player_data = slackemon_get_player_data( $user_id, true );
 
   // Can we increment the 'seen' value on an existing spawn?
   $found_entry = false;
@@ -611,9 +613,9 @@ function slackemon_record_spawn_for_user( $user_id, $spawn ) {
     'cp'      => $spawn['cp'],
     'hp'      => $spawn['stats']['hp'],
   ];
-  slackemon_file_put_contents( $spawn_filename, json_encode( $spawn_data ), 'store' );
+  slackemon_file_put_contents( $spawn_filename, json_encode( $spawn_data ), 'store', false );
 
-  return slackemon_save_player_data( $player_data, $user_id );
+  return slackemon_save_player_data( $player_data, $user_id, true );
 
 } // Function slackemon_record_spawn