tweak azure stream wrapper

classes/local/store/azure_blob_storage/client.php

@@ -20,6 +20,7 @@
 use tool_objectfs\local\store\object_client_base;
 
 // TODO does this fail when the plugin is not installed ?
+// e.g. when just using AWS?
 use local_azureblobstorage\api;
 use stdClass;
 use Throwable;

classes/local/store/azure_blob_storage/stream_wrapper.php

@@ -1,12 +1,36 @@
 <?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
 
 namespace tool_objectfs\local\store\azure_blob_storage;
 
+use GuzzleHttp\Psr7\CachingStream;
 use GuzzleHttp\Psr7\Stream;
 use GuzzleHttp\Psr7\Utils;
 use local_azureblobstorage\api;
 use Throwable;
 
+/**
+ * Stream wrapper.
+ * Allows you to use built in file function e.g. readfile, copy, unlink, etc... with blob:// file urls.
+ *
+ * @package    tool_objectfs
+ * @author     Matthew Hilton <[email protected]>
+ * @copyright  2024 Catalyst IT
+ * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
 class stream_wrapper {
     /** @var resource|null Stream context (this is set by PHP) */
     public $context;
@@ -107,13 +131,40 @@ private function open_read_stream() {
         $params = $this->getOptions(true);
 
         // TODO not sure if this is correct.
-        $promise = $client->get_blob($params['Key'])->wait();
-        $this->body = $promise->body;
+        $response = $client->get_blob($params['Key'])->wait();
+        $this->body = $response->getBody();
 
         // TODO implement checking
 
-        // TODO implement CachingStream
+        // Wrap the body in a caching entity body if seeking is allowed.
+        if ($this->getOption('seekable') && !$this->body->isSeekable()) {
+            $this->body = new CachingStream($this->body);
+        }
+
+        return true;
+    }
+
+    /**
+     * Reads from the stream
+     * @param int $count bytes to read
+     * @return string
+     */
+    public function stream_read($count) {
+        // If the file isn't readable, we need to return no content. Azure can emit XML here otherwise.
+        return $this->readable ? $this->body->read($count) : '';
+    }
+
+    /**
+     * Returns if stream is at end of file.
+     * @return bool
+     */
+    public function stream_eof() {
+        return $this->body->eof();
+    }
 
+    public function unlink($path) {
+        $info = $this->getcontainerkey($path);
+        $this->getclient()->delete_blob($info['Key'])->wait();
         return true;
     }
 
@@ -381,12 +432,13 @@ public function url_stat($path, $flags) {
 
         try {
             $params = $this->withPath($path);
-            $properties = $this->getclient()->get_blob_properties($params['Key'])->wait();
+            $res = $this->getclient()->get_blob_properties($params['Key'])->wait();
 
-            $stat['size'] = $stat[7] = $bp->getContentLength();
+            $stat['size'] = $stat[7] = current($res->getHeader('Content-Length'));
 
             // Set the modification time and last modified to the Last-Modified header.
-            $lastmodified = $bp->getLastModified()->getTimestamp();
+            // Convert from the 
+            $lastmodified = strtotime(current($res->getHeader('Last-Modified')));
 
             $stat['mtime'] = $stat[9] = $lastmodified;
             $stat['ctime'] = $stat[10] = $lastmodified;
@@ -398,7 +450,7 @@ public function url_stat($path, $flags) {
 
         // TODO better exception
         } catch (Throwable $ex) {
-            // The specified blob does not exist.
+            // It's most likely the specified blob does not exist.
             return false;
         }
     }
@@ -416,4 +468,27 @@ private function withpath($path) {
         // TODO rewrite
         return $this->getContainerKey($path) + $params;
     }
+
+    /**
+     * Returns the size of the opened object body.
+     *
+     * @return int|null
+     */
+    private function getsize() {
+        $size = $this->body->getSize();
+
+        return $size !== null ? $size : $this->size;
+    }
+
+    /**
+     * stream_stat
+     * @return array
+     */
+    public function stream_stat() {
+        $stat = $this->getStatTemplate();
+        $stat[7] = $stat['size'] = $this->getSize();
+        $stat[2] = $stat['mode'] = $this->mode;
+
+        return $stat;
+    }
 }