net: Move the logic reading upload elements to UploadData::Element.

net/base/upload_data.cc

 // Copyright (c) 2012 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 <algorithm>
 
 #include "base/bind.h"
 #include "base/file_util.h"
@@ skipping 19 matching lines @@
 }  // namespace
 
 UploadData::Element::Element()
     : type_(TYPE_BYTES),
       file_range_offset_(0),
       file_range_length_(kuint64max),
       is_last_chunk_(false),
       override_content_length_(false),
       content_length_computed_(false),
       content_length_(-1),
+      offset_(0),
       file_stream_(NULL) {
 }
 
 UploadData::Element::~Element() {
   // In the common case |file__stream_| will be null.
   if (file_stream_) {
     // Temporarily allow until fix: http://crbug.com/72001.
     base::ThreadRestrictions::ScopedAllowIO allow_io;
     file_stream_->CloseSync();
     delete file_stream_;
@@ skipping 25 matching lines @@
   // 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
   // to lock the file or somehow protect against this error condition.
 
   content_length_computed_ = true;
   content_length_ = 0;
 
   // We need to open the file here to decide if we should report the file's
   // size or zero.  We cache the open file, so that we can still read it when
   // it comes time to.
-  file_stream_ = NewFileStreamForReading();
+  file_stream_ = OpenFileStream();
   if (!file_stream_)
     return 0;
 
   int64 length = 0;
   if (!file_util::GetFileSize(file_path_, &length))
       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_;
 }
 
-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;
+int UploadData::Element::ReadSync(char* buf, int buf_len) {
+  if (type_ == UploadData::TYPE_BYTES || type_ == UploadData::TYPE_CHUNK) {
+    return ReadFromMemorySync(buf, buf_len);
+  } else if (type_ == UploadData::TYPE_FILE) {
+    return ReadFromFileSync(buf, buf_len);
   }
 
+  NOTREACHED();
+  return 0;
+}
+
+uint64 UploadData::Element::BytesRemaining() {
+  return GetContentLength() - offset_;
+}
+
+FileStream* UploadData::Element::OpenFileStream() {
   scoped_ptr<FileStream> file(new FileStream(NULL));
   int64 rv = file->OpenSync(
       file_path_,
       base::PLATFORM_FILE_OPEN | base::PLATFORM_FILE_READ);
   if (rv != OK) {
     // If the file can't be opened, we'll just upload an empty file.
     DLOG(WARNING) << "Failed to open \"" << file_path_.value()
                   << "\" for reading: " << rv;
     return NULL;
   }
   if (file_range_offset_) {
     rv = file->Seek(FROM_BEGIN, file_range_offset_);
     if (rv < 0) {
       DLOG(WARNING) << "Failed to seek \"" << file_path_.value()
                     << "\" to offset: " << file_range_offset_ << " (" << rv
                     << ")";
       return NULL;
     }
   }
 
   return file.release();
 }
 
+int UploadData::Element::ReadFromMemorySync(char* buf, int buf_len) {

[willchan no longer on Chromium, 2012/02/24 21:54:40]

Can you DCHECK that buf_len is positive (it shouldn't be 0, right?)?

[satorux1, 2012/02/24 22:35:22]

Done. Updated the comment as well.

+  DCHECK(type_ == UploadData::TYPE_BYTES || type_ == UploadData::TYPE_CHUNK);
+
+  const size_t num_bytes_to_read = std::min(BytesRemaining(),
+                                            static_cast<size_t>(buf_len));
+
+  // Check if we have anything to copy first, because we are getting
+  // the address of an element in |bytes_| and that will throw an
+  // exception if |bytes_| is an empty vector.
+  if (num_bytes_to_read > 0) {
+    memcpy(buf, &bytes_[offset_], num_bytes_to_read);
+  }
+
+  offset_ += num_bytes_to_read;
+  return num_bytes_to_read;
+}
+
+int UploadData::Element::ReadFromFileSync(char* buf, int buf_len) {

[willchan no longer on Chromium, 2012/02/24 21:54:40]

Ditto on DCHECK'ing |buf_len|'s values.

[satorux1, 2012/02/24 22:35:22]

Done.

+  DCHECK_EQ(UploadData::TYPE_FILE, type_);
+
+  // Open the file of the current element if not yet opened.
+  // In common usage, GetContentLength() opened it already.
+  if (!file_stream_) {
+    // Temporarily allow until fix: http://crbug.com/72001.
+    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    file_stream_ = OpenFileStream();
+  }
+
+  const int num_bytes_to_read =
+      static_cast<int>(std::min(BytesRemaining(),
+                                static_cast<uint64>(buf_len)));
+  if (num_bytes_to_read > 0) {
+    int num_bytes_consumed = 0;
+    // Temporarily allow until fix: http://crbug.com/72001.
+    base::ThreadRestrictions::ScopedAllowIO allow_io;
+    // file_stream_ is NULL if the target file is
+    // missing or not readable.
+    if (file_stream_) {
+      num_bytes_consumed =
+          file_stream_->ReadSync(buf, num_bytes_to_read);
+    }
+    if (num_bytes_consumed <= 0) {
+      // If there's less data to read than we initially observed, then
+      // pad with zero.  Otherwise the server will hang waiting for the
+      // rest of the data.
+      memset(buf, 0, num_bytes_to_read);
+    }
+  }
+
+  offset_ += num_bytes_to_read;
+  return num_bytes_to_read;
+}
+
 UploadData::UploadData()
     : identifier_(0),
       chunk_callback_(NULL),
       is_chunked_(false) {
 }
 
 void UploadData::AppendBytes(const char* bytes, int bytes_len) {
   DCHECK(!is_chunked_);
   if (bytes_len > 0) {
     elements_.push_back(Element());
@@ skipping 74 matching lines @@
     return;
 
   for (size_t i = 0; i < elements_.size(); ++i)
     *content_length += elements_[i].GetContentLength();
 }
 
 UploadData::~UploadData() {
 }
 
 }  // namespace net