Merge "Fix uselang parameter in ApiWatch"

[lhc/web/wiklou.git] / includes / filebackend / FileBackend.php

diff --git a/includes/filebackend/FileBackend.php b/includes/filebackend/FileBackend.php
index 6ea042c..678491e 100644 (file)
--- a/includes/filebackend/FileBackend.php
+++ b/includes/filebackend/FileBackend.php
@@ -660,11 +660,21 @@ abstract class FileBackend {
         * otherwise safe from modification from other processes. Normally,
         * the file will be a new temp file, which should be adequate.
         *
+        * If a callback function is given, it will be called each time a segment is
+        * appended and when the overall concatenate operation completes or fails.
+        * The arguments passed in are:
+        *   - 1) A Status object containing errors if any problems occurred.
+        *   - 2) The index of the relevant segment (starting at 1) if a segment was appended
+        *        (including the last one) or null in the case of overall success or failure.
+        * When a good Status is returned with a null segment, then the operation completed.
+        * Callbacks should generally avoid throwing exceptions.
+        *
         * @param $params Array Operation parameters
         * $params include:
         *   - srcs        : ordered source storage paths (e.g. chunk1, chunk2, ...)
         *   - dst         : file system path to 0-byte temp file
         *   - parallelize : try to do operations in parallel when possible
+        *   - callback    : closure called when chunks are appended and on success/failure
         * @return Status
         */
        abstract public function concatenate( array $params );