Collect stats to investigate the viability of UDP

net/curvecp/test_data_stream.h

-// Copyright (c) 2011 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_CURVECP_TEST_DATA_STREAM_H_
-#define NET_CURVECP_TEST_DATA_STREAM_H_
-#pragma once
-
-#include <string.h>  // for memcpy()
-#include <algorithm>
-
-// This is a test class for generating an infinite stream of data which can
-// be verified independently to be the correct stream of data.
-
-namespace net {
-
-class TestDataStream {
- public:
-  TestDataStream() {
-    Reset();
-  }
-
-  // Fill |buffer| with |length| bytes of data from the stream.
-  void GetBytes(char* buffer, int length) {
-    while (length) {
-      AdvanceIndex();
-      int bytes_to_copy = std::min(length, bytes_remaining_);
-      memcpy(buffer, buffer_ptr_, bytes_to_copy);
-      buffer += bytes_to_copy;
-      Consume(bytes_to_copy);
-      length -= bytes_to_copy;
-    }
-  }
-
-  // Verify that |buffer| contains the expected next |length| bytes from the
-  // stream.  Returns true if correct, false otherwise.
-  bool VerifyBytes(const char *buffer, int length) {
-    while (length) {
-      AdvanceIndex();
-      int bytes_to_compare = std::min(length, bytes_remaining_);
-      if (memcmp(buffer, buffer_ptr_, bytes_to_compare))
-        return false;
-      Consume(bytes_to_compare);
-      length -= bytes_to_compare;
-      buffer += bytes_to_compare;
-    }
-    return true;
-  }
-
-  void Reset() {
-    index_ = 0;
-    bytes_remaining_ = 0;
-    buffer_ptr_ = buffer_;
-  }
-
- private:
-  // If there is no data spilled over from the previous index, advance the
-  // index and fill the buffer.
-  void AdvanceIndex() {
-    if (bytes_remaining_ == 0) {
-      // Convert it to ascii, but don't bother to reverse it.
-      // (e.g. 12345 becomes "54321")
-      int val = index_++;
-      do {
-        buffer_[bytes_remaining_++] = (val % 10) + '0';
-      } while ((val /= 10) > 0);
-      buffer_[bytes_remaining_++] = '.';
-    }
-  }
-
-  // Consume data from the spill buffer.
-  void Consume(int bytes) {
-    bytes_remaining_ -= bytes;
-    if (bytes_remaining_)
-      buffer_ptr_ += bytes;
-    else
-      buffer_ptr_ = buffer_;
-  }
-
-  int index_;
-  int bytes_remaining_;
-  char buffer_[16];
-  char* buffer_ptr_;
-};
-
-}  // namespace net
-
-#endif  // NET_CURVECP_TEST_DATA_STREAM_H_