Prototype of chunked transfer encoded POST.

net/base/upload_data.cc

 // 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.
 
 #include "net/base/upload_data.h"
 
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "net/base/file_stream.h"
+#include "base/string_util.h"
 #include "net/base/net_errors.h"
 
 namespace net {
 
 UploadData::Element::Element()
     : type_(TYPE_BYTES),
       file_range_offset_(0),
       file_range_length_(kuint64max),
       override_content_length_(false),
       content_length_computed_(false),
       content_length_(-1),
       file_stream_(NULL) {
 }
 
 UploadData::Element::~Element() {
   // In the common case |file__stream_| will be null.
   delete file_stream_;
 }
 
 uint64 UploadData::Element::GetContentLength() {
   if (override_content_length_ || content_length_computed_)
     return content_length_;
 
-  if (type_ == TYPE_BYTES)
+  if (type_ == TYPE_BYTES || type_ == TYPE_CHUNK)

[vandebo (ex-Chrome), 2011/01/14 05:53:44]

GetContentLength doesn't make sense for TYPE_CHUNK.  Could you now DCHECK(type_
!= TYPE_CHUNK) ?

[Satish, 2011/01/14 18:09:29]

This is UploadData::Element and GetContentLength makes sense for this class
since it just returns the length of bytes in this chunk alone.

     return static_cast<uint64>(bytes_.size());
   else if (type_ == TYPE_BLOB)
     // The blob reference will be resolved later.
     return 0;
 
   DCHECK_EQ(TYPE_FILE, type_);
   DCHECK(!file_stream_);
 
   // TODO(darin): This size calculation could be out of sync with the state of
   // the file when we get around to reading it.  We should probably find a way
@@ skipping 14 matching lines @@
     return 0;
 
   if (file_range_offset_ >= static_cast<uint64>(length))
     return 0;  // range is beyond eof
 
   // compensate for the offset and clip file_range_length_ to eof
   content_length_ =  std::min(length - file_range_offset_, file_range_length_);
   return content_length_;
 }
 
+void UploadData::Element::SetToChunk(const char* bytes, int bytes_len) {
+  std::string chunk_length = StringPrintf("%X\r\n", bytes_len);
+  bytes_.clear();
+  bytes_.insert(bytes_.end(), chunk_length.c_str(),
+                chunk_length.c_str() + chunk_length.length());
+  bytes_.insert(bytes_.end(), bytes, bytes + bytes_len);
+  const char* crlf = "\r\n";
+  bytes_.insert(bytes_.end(), crlf, crlf + 2);
+  type_ = TYPE_CHUNK;
+}
+
+void UploadData::Element::SetToLastChunk() {

[wtc, 2011/01/14 03:09:31]

Let's name this method SetToEndOfChunksMarker.

In HTTP 1.1, "last chunk" means
       last-chunk     = 1*("0") [ chunk-extension ] CRLF

[Satish, 2011/01/14 18:09:29]

Done.

+  bytes_.clear();

[vandebo (ex-Chrome), 2011/01/14 05:53:44]

Doesn't this need to be "0\r\n\r\n"?  It might be easier to just call
SetToChunk("", 0);

[Satish, 2011/01/14 18:09:29]

No, the previous chunk would be "0\r\n\r\n". This is the marker after that.

+  type_ = TYPE_CHUNK;
+}
+
 FileStream* UploadData::Element::NewFileStreamForReading() {
   // In common usage GetContentLength() will call this first and store the
   // result into |file_| and a subsequent call (from UploadDataStream) will
   // get the cached open FileStream.
   if (file_stream_) {
     FileStream* file = file_stream_;
     file_stream_ = NULL;
     return file;
   }
 
@@ skipping 12 matching lines @@
       DLOG(WARNING) << "Failed to seek \"" << file_path_.value()
                     << "\" to offset: " << file_range_offset_ << " (" << rv
                     << ")";
       return NULL;
     }
   }
 
   return file.release();
 }
 
-UploadData::UploadData() : identifier_(0) {
+UploadData::UploadData()
+    : identifier_(0),
+      chunk_callback_(NULL),
+      is_chunked_(false) {

[vandebo (ex-Chrome), 2011/01/14 05:53:44]

Instead of an explicit is_chunked_, could you just check
elements_.front().type() == TYPE_CHUNK?  Especially since it's only used for
DCHECKs.

[Satish, 2011/01/14 18:09:29]

This flag is also used by UploadDataStream and URLRequest as the one place to
check if the upload is a chunked stream. And we need this flag for DCHECKs even
before any elements are added. Hence leaving it as is.

 }
 
 void UploadData::AppendBytes(const char* bytes, int bytes_len) {
+  DCHECK(!is_chunked_);
   if (bytes_len > 0) {
     elements_.push_back(Element());
     elements_.back().SetToBytes(bytes, bytes_len);
   }
 }
 
 void UploadData::AppendFile(const FilePath& file_path) {
+  DCHECK(!is_chunked_);
   elements_.push_back(Element());
   elements_.back().SetToFilePath(file_path);
 }
 
 void UploadData::AppendFileRange(const FilePath& file_path,
                                  uint64 offset, uint64 length,
                                  const base::Time& expected_modification_time) {
+  DCHECK(!is_chunked_);
   elements_.push_back(Element());
   elements_.back().SetToFilePathRange(file_path, offset, length,
                                       expected_modification_time);
 }
 
 void UploadData::AppendBlob(const GURL& blob_url) {
+  DCHECK(!is_chunked_);
   elements_.push_back(Element());
   elements_.back().SetToBlobUrl(blob_url);
 }
 
+void UploadData::AppendChunk(const char* bytes, int bytes_len) {
+  DCHECK(is_chunked_);
+  elements_.push_back(Element());
+  elements_.back().SetToChunk(bytes, bytes_len);
+  if (!bytes_len) {
+    // End of chunked stream is marked internally with a chunk of length 0.

[wtc, 2011/01/14 03:09:31]

"a chunk of length 0" is not accurate.  You may want to be
more precise: "a chunk with an empty bytes_".

[Satish, 2011/01/14 18:09:29]

Done.

+    elements_.push_back(Element());
+    elements_.back().SetToLastChunk();
+  }
+  if (chunk_callback_)
+    chunk_callback_->OnChunkAvailable();
+}
+
+void UploadData::set_chunk_callback(ChunkCallback* callback) {
+  DCHECK(!chunk_callback_);
+  chunk_callback_ = callback;
+}
+
 uint64 UploadData::GetContentLength() {
   uint64 len = 0;
   std::vector<Element>::iterator it = elements_.begin();
   for (; it != elements_.end(); ++it)
     len += (*it).GetContentLength();
   return len;
 }
 
 void UploadData::SetElements(const std::vector<Element>& elements) {
   elements_ = elements;
 }
 
 UploadData::~UploadData() {
 }
 
 }  // namespace net