feat(upload): 添加华为 OBS 对象存储支持

- 在 addons.php 中添加了与华为 OBS 相关的钩子
- 新增了对华为 OBS 上传功能的实现，包括分片上传和合并
- 优化了上传参数处理和错误处理
- 支持客户端和服务端两种上传模式

addons/hwobs/library/Obs/Internal/Common/CheckoutStream.php

@@ -0,0 +1,63 @@
+<?php
+
+/**
+ * Copyright 2019 Huawei Technologies Co.,Ltd.
+ * Licensed under the Apache License, Version 2.0 (the "License"); you may not use
+ * this file except in compliance with the License.  You may obtain a copy of the
+ * License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software distributed
+ * under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR
+ * CONDITIONS OF ANY KIND, either express or implied.  See the License for the
+ * specific language governing permissions and limitations under the License.
+ *
+ */
+
+namespace Obs\Internal\Common;
+
+use Psr\Http\Message\StreamInterface;
+use GuzzleHttp\Psr7\StreamDecoratorTrait;
+use Obs\ObsException;
+
+class CheckoutStream implements StreamInterface {
+    use StreamDecoratorTrait;
+    
+    private $expectedLength;
+    private $readedCount = 0;
+
+    public function __construct(StreamInterface $stream, $expectedLength) {
+        $this->stream = $stream;
+        $this->expectedLength = $expectedLength;
+    }
+
+    public function getContents() {
+        $contents = $this->stream->getContents();
+        $length = strlen($contents);
+        if ($this->expectedLength !== null && floatval($length) !== $this->expectedLength) {
+            $this -> throwObsException($this->expectedLength, $length);
+        }
+        return $contents;
+    }
+
+    public function read($length) {
+        $string = $this->stream->read($length);
+        if ($this->expectedLength !== null) {
+            $this->readedCount += strlen($string);
+            if ($this->stream->eof()) {
+                if (floatval($this->readedCount) !== $this->expectedLength) {
+                    $this -> throwObsException($this->expectedLength, $this->readedCount);
+                }
+            }
+        }    
+        return $string;
+    }
+
+    public function throwObsException($expectedLength, $reaLength) {
+        $obsException = new ObsException('premature end of Content-Length delimiter message body (expected:' . $expectedLength . '; received:' . $reaLength . ')');
+        $obsException->setExceptionType('server');
+        throw $obsException;
+    }
+}
+