text: // Copyright 2013 The Chromium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #include "content/browser/loader/upload_data_stream_builder.h"
  
  #include "base/logging.h"
  #include "content/browser/fileapi/upload_file_system_file_element_reader.h"
  #include "content/common/resource_request_body.h"
  #include "net/base/upload_bytes_element_reader.h"
  #include "net/base/upload_data_stream.h"
  #include "net/base/upload_file_element_reader.h"
  #include "webkit/browser/blob/blob_data_handle.h"
  #include "webkit/browser/blob/blob_storage_context.h"
  
  using webkit_blob::BlobData;
  using webkit_blob::BlobDataHandle;
  using webkit_blob::BlobStorageContext;
  
  namespace content {
  namespace {
  
  // A subclass of net::UploadBytesElementReader which owns ResourceRequestBody.
  class BytesElementReader : public net::UploadBytesElementReader {
   public:
    BytesElementReader(ResourceRequestBody* resource_request_body,
                       const ResourceRequestBody::Element& element)
        : net::UploadBytesElementReader(element.bytes(), element.length()),
          resource_request_body_(resource_request_body) {
      DCHECK_EQ(ResourceRequestBody::Element::TYPE_BYTES, element.type());
    }
  
    virtual ~BytesElementReader() {}
  
   private:
    scoped_refptr<ResourceRequestBody> resource_request_body_;
  
    DISALLOW_COPY_AND_ASSIGN(BytesElementReader);
  };
  
  // A subclass of net::UploadFileElementReader which owns ResourceRequestBody.
  // This class is necessary to ensure the BlobData and any attached shareable
  // files survive until upload completion.
  class FileElementReader : public net::UploadFileElementReader {
   public:
    FileElementReader(ResourceRequestBody* resource_request_body,
                      base::TaskRunner* task_runner,
                      const ResourceRequestBody::Element& element)
        : net::UploadFileElementReader(task_runner,
                                       element.path(),
                                       element.offset(),
                                       element.length(),
                                       element.expected_modification_time()),
          resource_request_body_(resource_request_body) {
      DCHECK_EQ(ResourceRequestBody::Element::TYPE_FILE, element.type());
    }
  
    virtual ~FileElementReader() {}
  
   private:
    scoped_refptr<ResourceRequestBody> resource_request_body_;
  
    DISALLOW_COPY_AND_ASSIGN(FileElementReader);
  };
  
  void ResolveBlobReference(
      ResourceRequestBody* body,
      webkit_blob::BlobStorageContext* blob_context,
      const ResourceRequestBody::Element& element,
      std::vector<const ResourceRequestBody::Element*>* resolved_elements) {
    DCHECK(blob_context);
    scoped_ptr<webkit_blob::BlobDataHandle> handle =
        blob_context->GetBlobDataFromUUID(element.blob_uuid());
    DCHECK(handle);
    if (!handle)
      return;
  
    // If there is no element in the referred blob data, just return.
    if (handle->data()->items().empty())
      return;
  
    // Append the elements in the referenced blob data.
    for (size_t i = 0; i < handle->data()->items().size(); ++i) {
      const BlobData::Item& item = handle->data()->items().at(i);
      DCHECK_NE(BlobData::Item::TYPE_BLOB, item.type());
      resolved_elements->push_back(&item);
    }
  
    // Ensure the blob and any attached shareable files survive until
    // upload completion. The |body| takes ownership of |handle|.
    const void* key = handle.get();
    body->SetUserData(key, handle.release());
  }
  
  }  // namespace
  
  scoped_ptr<net::UploadDataStream> UploadDataStreamBuilder::Build(
      ResourceRequestBody* body,
      BlobStorageContext* blob_context,
      fileapi::FileSystemContext* file_system_context,
      base::TaskRunner* file_task_runner) {
    // Resolve all blob elements.
    std::vector<const ResourceRequestBody::Element*> resolved_elements;
    for (size_t i = 0; i < body->elements()->size(); ++i) {
      const ResourceRequestBody::Element& element = (*body->elements())[i];
      if (element.type() == ResourceRequestBody::Element::TYPE_BLOB)
        ResolveBlobReference(body, blob_context, element, &resolved_elements);
      else
        resolved_elements.push_back(&element);
    }
  
    ScopedVector<net::UploadElementReader> element_readers;
    for (size_t i = 0; i < resolved_elements.size(); ++i) {
      const ResourceRequestBody::Element& element = *resolved_elements[i];
      switch (element.type()) {
        case ResourceRequestBody::Element::TYPE_BYTES:
          element_readers.push_back(new BytesElementReader(body, element));
          break;
        case ResourceRequestBody::Element::TYPE_FILE:
          element_readers.push_back(
              new FileElementReader(body, file_task_runner, element));
          break;
        case ResourceRequestBody::Element::TYPE_FILE_FILESYSTEM:
          element_readers.push_back(
              new content::UploadFileSystemFileElementReader(
                  file_system_context,
                  element.filesystem_url(),
                  element.offset(),
                  element.length(),
                  element.expected_modification_time()));
          break;
        case ResourceRequestBody::Element::TYPE_BLOB:
          // Blob elements should be resolved beforehand.
          NOTREACHED();
          break;
        case ResourceRequestBody::Element::TYPE_UNKNOWN:
          NOTREACHED();
          break;
      }
    }
  
    return make_scoped_ptr(
        new net::UploadDataStream(element_readers.Pass(), body->identifier()));
  }
  
  }  // namespace content
  