Prototype of chunked transfer encoded POST.

net/base/upload_data.h

 // Copyright (c) 2010 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.
 
 #ifndef NET_BASE_UPLOAD_DATA_H_
 #define NET_BASE_UPLOAD_DATA_H_
 #pragma once
 
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/file_path.h"
 #include "base/gtest_prod_util.h"
 #include "base/ref_counted.h"
 #include "googleurl/src/gurl.h"
 #include "base/time.h"
 
 namespace net {
 
 class FileStream;
 
+// Interface implemented by callers who require callbacks when new chunks
+// of data are added.
+class ChunkCallback {
+ public:
+  // Invoked when a new data chunk was given for a chunked transfer upload.
+  virtual void OnChunkAvailable() = 0;
+
+ protected:
+  virtual ~ChunkCallback() {}
+};
+
 class UploadData : public base::RefCounted<UploadData> {
  public:
   enum Type {
     TYPE_BYTES,
     TYPE_FILE,
-    TYPE_BLOB
+    TYPE_BLOB,
+
+    // A block of bytes to be sent in chunked encoding immediately, without
+    // waiting for rest of the data.
+    TYPE_CHUNK,
   };
 
   class Element {
    public:
     Element();
     ~Element();
 
     Type type() const { return type_; }
     const std::vector<char>& bytes() const { return bytes_; }
     const FilePath& file_path() const { return file_path_; }
@@ skipping 27 matching lines @@
       expected_file_modification_time_ = expected_modification_time;
     }
 
     // TODO(jianli): UploadData should not contain any blob reference. We need
     // to define another structure to represent WebKit::WebHTTPBody.
     void SetToBlobUrl(const GURL& blob_url) {
       type_ = TYPE_BLOB;
       blob_url_ = blob_url;
     }
 
+    // Though similar to bytes, a chunk indicates that the element is sent via
+    // chunked transfer encoding and not buffered until the full upload data
+    // is available.
+    void SetToChunk(const char* bytes, int bytes_len);
+
+    bool is_last_chunk() const { return is_last_chunk_; }
+
     // Returns the byte-length of the element.  For files that do not exist, 0
     // is returned.  This is done for consistency with Mozilla.
     // Once called, this function will always return the same value.
     uint64 GetContentLength();
 
     // Returns a FileStream opened for reading for this element, positioned at
     // |file_range_offset_|.  The caller gets ownership and is responsible
     // for cleaning up the FileStream. Returns NULL if this element is not of
     // type TYPE_FILE or if the file is not openable.
     FileStream* NewFileStreamForReading();
 
    private:
     // Allows tests to override the result of GetContentLength.
     void SetContentLength(uint64 content_length) {
       override_content_length_ = true;
       content_length_ = content_length;
     }
 
     Type type_;
     std::vector<char> bytes_;
     FilePath file_path_;
     uint64 file_range_offset_;
     uint64 file_range_length_;
     base::Time expected_file_modification_time_;
     GURL blob_url_;
-    bool override_content_length_;
-    bool content_length_computed_;
+    bool is_last_chunk_ : 1;

[vandebo (ex-Chrome), 2011/01/21 18:08:41]

nit: Are the :1's needed?  I suspect not.

[wtc, 2011/01/21 19:35:54]

I also recommend removing ": 1".  By listing the bool members
consecutively, you already allow the compiler to pack them.

+    bool override_content_length_ : 1;
+    bool content_length_computed_ : 1;
     uint64 content_length_;
     FileStream* file_stream_;
 
     FRIEND_TEST_ALL_PREFIXES(UploadDataStreamTest, FileSmallerThanLength);
     FRIEND_TEST_ALL_PREFIXES(HttpNetworkTransactionTest,
                              UploadFileSmallerThanLength);
   };
 
   UploadData();
 
   void AppendBytes(const char* bytes, int bytes_len);
 
   void AppendFile(const FilePath& file_path);
 
   void AppendFileRange(const FilePath& file_path,
                        uint64 offset, uint64 length,
                        const base::Time& expected_modification_time);
 
   void AppendBlob(const GURL& blob_url);
 
+  void AppendChunk(const char* bytes, int bytes_len);

[vandebo (ex-Chrome), 2011/01/21 18:08:41]

nit: Add a comment about a zero size chunk indicating the last chunk.

+
+  // Sets the callback to be invoked when a new chunk is available to upload.
+  void set_chunk_callback(ChunkCallback* callback);
+
+  // Initializes the object to send chunks of upload data over time rather
+  // than all at once.
+  void set_is_chunked(bool set) { is_chunked_ = set; }
+  bool is_chunked() const { return is_chunked_; }
+
   // Returns the total size in bytes of the data to upload.
   uint64 GetContentLength();
 
   std::vector<Element>* elements() {
     return &elements_;
   }
 
   void SetElements(const std::vector<Element>& elements);
 
   void swap_elements(std::vector<Element>* elements) {
     elements_.swap(*elements);
   }
 
   // Identifies a particular upload instance, which is used by the cache to
   // formulate a cache key.  This value should be unique across browser
   // sessions.  A value of 0 is used to indicate an unspecified identifier.
   void set_identifier(int64 id) { identifier_ = id; }
   int64 identifier() const { return identifier_; }
 
  private:
   friend class base::RefCounted<UploadData>;
 
   ~UploadData();
 
   std::vector<Element> elements_;
   int64 identifier_;
+  ChunkCallback* chunk_callback_;
+  bool is_chunked_;
 
   DISALLOW_COPY_AND_ASSIGN(UploadData);
 };
 
 #if defined(UNIT_TEST)
 inline bool operator==(const UploadData::Element& a,
                        const UploadData::Element& b) {
   if (a.type() != b.type())
     return false;
   if (a.type() == UploadData::TYPE_BYTES)
@@ skipping 12 matching lines @@
 
 inline bool operator!=(const UploadData::Element& a,
                        const UploadData::Element& b) {
   return !(a == b);
 }
 #endif  // defined(UNIT_TEST)
 
 }  // namespace net
 
 #endif  // NET_BASE_UPLOAD_DATA_H_