File identifier

controllers/StorageController.php

@@ -164,4 +164,67 @@ public function storagetransferbucket() {
 		Zotero_Storage::transferBucket('zoterofilestorage', 'zoterofilestoragetest');
 		exit;
 	}
+
+	public function identify() {
+		$this->allowMethods(array('POST'));
+
+		// 10 requests per second per IP with 100 requests burst
+		$rateLimit = [
+			'logOnly' => false,
+			'bucket' => $_SERVER['REMOTE_ADDR'],
+			'capacity' => 100,
+			'rate' => 10
+		];
+
+		// $this->requestLimiter must be initialized in ApiController
+		$requestsRemaining = $this->requestLimiter->checkBucketRate($rateLimit);
+
+		if (!$requestsRemaining) {
+			StatsD::increment("request.limit.identify.rate.rejected", 1);
+			Z_Core::logError('Request rate limit exceeded for' . $rateLimit['bucket']);
+
+			if (!$rateLimit['logOnly']) {
+				header("Retry-After: " . (int)$rateLimit['capacity'] / $rateLimit['rate']);
+				$this->e429();
+			}
+		}
+
+		if (!empty($_REQUEST['hash'])) {
+			$hash = $_REQUEST['hash'];
+			$fieldTypes = [
+				11, // ISBN
+				13, // ISSN
+				26 // DOI
+			];
+			$identifiers = [];
+
+			// Returns up to 10 identifiers and checks up to 5 libraries
+			$numIdentifiers = 0;
+			$numLibraries = 0;
+
+			$libraryIDs = Zotero_Storage::getHashLibraries($hash);
+			while (($libraryID = array_shift($libraryIDs))
+				&& $numIdentifiers < 10
+				&& $numLibraries++ < 5) {
+				$fields = Zotero_Storage::getFileSourceFields($libraryID, $hash, $fieldTypes);
+				foreach ($fields as $fieldID => $values) {
+					$fieldName = Zotero_ItemFields::getName($fieldID);
+					foreach ($values as $value) {
+						if (!isset($identifiers[$fieldName])) {
+							$identifiers[$fieldName] = [];
+						}
+
+						if (!in_array($value, $identifiers[$fieldName])) {
+							$identifiers[$fieldName][] = $value;
+							$numIdentifiers++;
+						}
+					}
+				}
+			}
+
+			echo Zotero_Utilities::formatJSON([
+				'identifiers' => $identifiers
+			]);
+		}
+	}
 }

include/config/routes.inc.php

@@ -34,6 +34,7 @@
 	$router->map('/users/i:objectUserID/publications/items/:objectKey/file/view', ['controller' => 'Items', 'extra' => ['allowHTTP' => true, 'file' => true, 'view' => true, 'publications' => true]]);
 	$router->map('/groups/i:objectGroupID/items/:objectKey/file', array('controller' => 'Items', 'extra' => array('allowHTTP' => true, 'file' => true)));
 	$router->map('/groups/i:objectGroupID/items/:objectKey/file/view', array('controller' => 'Items', 'extra' => array('allowHTTP' => true, 'file' => true, 'view' => true)));
+	$router->map('/identify', array('controller' => 'Storage', 'action' => 'identify'));
 
 	// Full-text content
 	$router->map('/users/i:objectUserID/items/:objectKey/fulltext', array('controller' => 'FullText', 'action' => 'itemContent'));

model/Storage.inc.php

@@ -904,6 +904,30 @@ public static function getUserUsage($userID) {
 		return $usage;
 	}
 
+	public static function getHashLibraries($hash) {
+		$sql = "SELECT libraryID FROM storageFiles JOIN storageFileLibraries USING (storageFileID) WHERE hash = ?";
+		return Zotero_DB::columnQuery($sql, $hash);
+	}
+
+	public static function getFileSourceFields($libraryID, $hash, $fieldTypes) {
+		// Limit sourceItem metadata fields per library, to give a chance
+		// for other libraries to impact result in case if
+		// one library has incorrect metadata.
+		// Only non-empty fields exist in itemData
+		$sql = "SELECT fieldID, `value` FROM itemData WHERE itemID IN 
+				(SELECT sourceItemID FROM itemAttachments
+				JOIN items USING (itemID) WHERE libraryID = ? AND storageHash = ?)
+				AND fieldID IN (" . implode(',', $fieldTypes) . ") LIMIT 2";
+		$rows = Zotero_DB::query($sql, array($libraryID, $hash), Zotero_Shards::getByLibraryID($libraryID));
+		$fields = [];
+		foreach ($rows as $row) {
+			if (!isset($fields[$row['fieldID']])) {
+				$fields[$row['fieldID']] = [];
+			}
+			$fields[$row['fieldID']][] = $row['value'];
+		}
+		return $fields;
+	}
 
 	private static function updateLastAdded($storageFileID) {
 		$sql = "UPDATE storageFiles SET lastAdded=NOW() WHERE storageFileID=?";