path: root/net/spdy/spdy_test_util.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/spdy/spdy_test_util.h"

#include <string>

#include "base/basictypes.h"
#include "base/string_number_conversions.h"
#include "base/string_util.h"
#include "net/http/http_network_transaction.h"
#include "net/spdy/spdy_framer.h"

namespace net {

// Chop a frame into an array of MockWrites.
// |data| is the frame to chop.
// |length| is the length of the frame to chop.
// |num_chunks| is the number of chunks to create.
MockWrite* ChopWriteFrame(const char* data, int length, int num_chunks) {
  MockWrite* chunks = new MockWrite[num_chunks];
  int chunk_size = length / num_chunks;
  for (int index = 0; index < num_chunks; index++) {
    const char* ptr = data + (index * chunk_size);
    if (index == num_chunks - 1)
      chunk_size += length % chunk_size;  // The last chunk takes the remainder.
    chunks[index] = MockWrite(true, ptr, chunk_size);
  }
  return chunks;
}

// Chop a SpdyFrame into an array of MockWrites.
// |frame| is the frame to chop.
// |num_chunks| is the number of chunks to create.
MockWrite* ChopWriteFrame(const spdy::SpdyFrame& frame, int num_chunks) {
  return ChopWriteFrame(frame.data(),
                        frame.length() + spdy::SpdyFrame::size(),
                        num_chunks);
}

// Chop a frame into an array of MockReads.
// |data| is the frame to chop.
// |length| is the length of the frame to chop.
// |num_chunks| is the number of chunks to create.
MockRead* ChopReadFrame(const char* data, int length, int num_chunks) {
  MockRead* chunks = new MockRead[num_chunks];
  int chunk_size = length / num_chunks;
  for (int index = 0; index < num_chunks; index++) {
    const char* ptr = data + (index * chunk_size);
    if (index == num_chunks - 1)
      chunk_size += length % chunk_size;  // The last chunk takes the remainder.
    chunks[index] = MockRead(true, ptr, chunk_size);
  }
  return chunks;
}

// Chop a SpdyFrame into an array of MockReads.
// |frame| is the frame to chop.
// |num_chunks| is the number of chunks to create.
MockRead* ChopReadFrame(const spdy::SpdyFrame& frame, int num_chunks) {
  return ChopReadFrame(frame.data(),
                       frame.length() + spdy::SpdyFrame::size(),
                       num_chunks);
}

// Adds headers and values to a map.
// |extra_headers| is an array of { name, value } pairs, arranged as strings
// where the even entries are the header names, and the odd entries are the
// header values.
// |headers| gets filled in from |extra_headers|.
void AppendHeadersToSpdyFrame(const char* const extra_headers[],
                              int extra_header_count,
                              spdy::SpdyHeaderBlock* headers) {
  std::string this_header;
  std::string this_value;

  if (!extra_header_count)
    return;

  // Sanity check: Non-NULL header list.
  DCHECK(NULL != extra_headers) << "NULL header value pair list";
  // Sanity check: Non-NULL header map.
  DCHECK(NULL != headers) << "NULL header map";
  // Copy in the headers.
  for (int i = 0; i < extra_header_count; i++) {
    // Sanity check: Non-empty header.
    DCHECK_NE('\0', *extra_headers[i * 2]) << "Empty header value pair";
    this_header = extra_headers[i * 2];
    std::string::size_type header_len = this_header.length();
    if (!header_len)
      continue;
    this_value = extra_headers[1 + (i * 2)];
    std::string new_value;
    if (headers->find(this_header) != headers->end()) {
      // More than one entry in the header.
      // Don't add the header again, just the append to the value,
      // separated by a NULL character.

      // Adjust the value.
      new_value = (*headers)[this_header];
      // Put in a NULL separator.
      new_value.append(1, '\0');
      // Append the new value.
      new_value += this_value;
    } else {
      // Not a duplicate, just write the value.
      new_value = this_value;
    }
    (*headers)[this_header] = new_value;
  }
}

// Writes |val| to a location of size |len|, in big-endian format.
// in the buffer pointed to by |buffer_handle|.
// Updates the |*buffer_handle| pointer by |len|
// Returns the number of bytes written
int AppendToBuffer(int val,
                   int len,
                   unsigned char** buffer_handle,
                   int* buffer_len_remaining) {
  if (len <= 0)
    return 0;
  DCHECK((size_t) len <= sizeof(len)) << "Data length too long for data type";
  DCHECK(NULL != buffer_handle) << "NULL buffer handle";
  DCHECK(NULL != *buffer_handle) << "NULL pointer";
  DCHECK(NULL != buffer_len_remaining)
      << "NULL buffer remainder length pointer";
  DCHECK_GE(*buffer_len_remaining, len) << "Insufficient buffer size";
  for (int i = 0; i < len; i++) {
    int shift = (8 * (len - (i + 1)));
    unsigned char val_chunk = (val >> shift) & 0x0FF;
    *(*buffer_handle)++ = val_chunk;
    *buffer_len_remaining += 1;
  }
  return len;
}

// Construct a SPDY packet.
// |head| is the start of the packet, up to but not including
// the header value pairs.
// |extra_headers| are the extra header-value pairs, which typically
// will vary the most between calls.
// |tail| is any (relatively constant) header-value pairs to add.
// |buffer| is the buffer we're filling in.
// Returns a SpdyFrame.
spdy::SpdyFrame* ConstructSpdyPacket(const SpdyHeaderInfo& header_info,
                                     const char* const extra_headers[],
                                     int extra_header_count,
                                     const char* const tail[],
                                     int tail_header_count) {
  spdy::SpdyFramer framer;
  spdy::SpdyHeaderBlock headers;
  // Copy in the extra headers to our map.
  AppendHeadersToSpdyFrame(extra_headers, extra_header_count, &headers);
  // Copy in the tail headers to our map.
  if (tail && tail_header_count)
    AppendHeadersToSpdyFrame(tail, tail_header_count, &headers);
  spdy::SpdyFrame* frame = NULL;
  switch (header_info.kind) {
    case spdy::SYN_STREAM:
      frame = framer.CreateSynStream(header_info.id, header_info.assoc_id,
                                     header_info.priority,
                                     header_info.control_flags,
                                     header_info.compressed, &headers);
      break;
    case spdy::SYN_REPLY:
      frame = framer.CreateSynReply(header_info.id, header_info.control_flags,
                                    header_info.compressed, &headers);
      break;
    case spdy::RST_STREAM:
      frame = framer.CreateRstStream(header_info.id, header_info.status);
      break;
    default:
      frame = framer.CreateDataFrame(header_info.id, header_info.data,
                                     header_info.data_length,
                                     header_info.data_flags);
      break;
  }
  return frame;
}

// Construct an expected SPDY SETTINGS frame.
// |settings| are the settings to set.
// Returns the constructed frame.  The caller takes ownership of the frame.
spdy::SpdyFrame* ConstructSpdySettings(spdy::SpdySettings settings) {
  spdy::SpdyFramer framer;
  return framer.CreateSettings(settings);
}

// Construct a SPDY GOAWAY frame.
// Returns the constructed frame.  The caller takes ownership of the frame.
spdy::SpdyFrame* ConstructSpdyGoAway() {
  spdy::SpdyFramer framer;
  return framer.CreateGoAway(0);
}

// Construct a SPDY WINDOW_UPDATE frame.
// Returns the constructed frame.  The caller takes ownership of the frame.
spdy::SpdyFrame* ConstructSpdyWindowUpdate(
    const spdy::SpdyStreamId stream_id, uint32 delta_window_size) {
  spdy::SpdyFramer framer;
  return framer.CreateWindowUpdate(stream_id, delta_window_size);
}

// Construct a SPDY RST_STREAM frame.
// Returns the constructed frame.  The caller takes ownership of the frame.
spdy::SpdyFrame* ConstructSpdyRstStream(spdy::SpdyStreamId stream_id,
                                        spdy::SpdyStatusCodes status) {
  spdy::SpdyFramer framer;
  return framer.CreateRstStream(stream_id, status);
}

// Construct a single SPDY header entry, for validation.
// |extra_headers| are the extra header-value pairs.
// |buffer| is the buffer we're filling in.
// |index| is the index of the header we want.
// Returns the number of bytes written into |buffer|.
int ConstructSpdyHeader(const char* const extra_headers[],
                        int extra_header_count,
                        char* buffer,
                        int buffer_length,
                        int index) {
  const char* this_header = NULL;
  const char* this_value = NULL;
  if (!buffer || !buffer_length)
    return 0;
  *buffer = '\0';
  // Sanity check: Non-empty header list.
  DCHECK(NULL != extra_headers) << "NULL extra headers pointer";
  // Sanity check: Index out of range.
  DCHECK((index >= 0) && (index < extra_header_count))
      << "Index " << index
      << " out of range [0, " << extra_header_count << ")";
  this_header = extra_headers[index * 2];
  // Sanity check: Non-empty header.
  if (!*this_header)
    return 0;
  std::string::size_type header_len = strlen(this_header);
  if (!header_len)
    return 0;
  this_value = extra_headers[1 + (index * 2)];
  // Sanity check: Non-empty value.
  if (!*this_value)
    this_value = "";
  int n = base::snprintf(buffer,
                         buffer_length,
                         "%s: %s\r\n",
                         this_header,
                         this_value);
  return n;
}

spdy::SpdyFrame* ConstructSpdyControlFrame(const char* const extra_headers[],
                                           int extra_header_count,
                                           bool compressed,
                                           int stream_id,
                                           RequestPriority request_priority,
                                           spdy::SpdyControlType type,
                                           spdy::SpdyControlFlags flags,
                                           const char* const* kHeaders,
                                           int kHeadersSize) {
  return ConstructSpdyControlFrame(extra_headers,
                                   extra_header_count,
                                   compressed,
                                   stream_id,
                                   request_priority,
                                   type,
                                   flags,
                                   kHeaders,
                                   kHeadersSize,
                                   0);
}

spdy::SpdyFrame* ConstructSpdyControlFrame(const char* const extra_headers[],
                                           int extra_header_count,
                                           bool compressed,
                                           int stream_id,
                                           RequestPriority request_priority,
                                           spdy::SpdyControlType type,
                                           spdy::SpdyControlFlags flags,
                                           const char* const* kHeaders,
                                           int kHeadersSize,
                                           int associated_stream_id) {
  const SpdyHeaderInfo kSynStartHeader = {
    type,                         // Kind = Syn
    stream_id,                    // Stream ID
    associated_stream_id,         // Associated stream ID
    net::ConvertRequestPriorityToSpdyPriority(request_priority),
                                  // Priority
    flags,                        // Control Flags
    compressed,                   // Compressed
    spdy::INVALID,                // Status
    NULL,                         // Data
    0,                            // Length
    spdy::DATA_FLAG_NONE          // Data Flags
  };
  return ConstructSpdyPacket(kSynStartHeader,
                             extra_headers,
                             extra_header_count,
                             kHeaders,
                             kHeadersSize / 2);
}

// Constructs a standard SPDY GET SYN packet, optionally compressed
// for the url |url|.
// |extra_headers| are the extra header-value pairs, which typically
// will vary the most between calls.
// Returns a SpdyFrame.
spdy::SpdyFrame* ConstructSpdyGet(const char* const url,
                                  bool compressed,
                                  int stream_id,
                                  RequestPriority request_priority) {
  const SpdyHeaderInfo kSynStartHeader = {
    spdy::SYN_STREAM,             // Kind = Syn
    stream_id,                    // Stream ID
    0,                            // Associated stream ID
    net::ConvertRequestPriorityToSpdyPriority(request_priority),
                                  // Priority
    spdy::CONTROL_FLAG_FIN,       // Control Flags
    compressed,                   // Compressed
    spdy::INVALID,                // Status
    NULL,                         // Data
    0,                            // Length
    spdy::DATA_FLAG_NONE          // Data Flags
  };

  GURL gurl(url);

  // This is so ugly.  Why are we using char* in here again?
  std::string str_path = gurl.PathForRequest();
  std::string str_scheme = gurl.scheme();
  std::string str_host = gurl.host();  // TODO(mbelshe): should have a port.
  scoped_array<char> req(new char[str_path.size() + 1]);
  scoped_array<char> scheme(new char[str_scheme.size() + 1]);
  scoped_array<char> host(new char[str_host.size() + 1]);
  memcpy(req.get(), str_path.c_str(), str_path.size());
  memcpy(scheme.get(), str_scheme.c_str(), str_scheme.size());
  memcpy(host.get(), str_host.c_str(), str_host.size());
  req.get()[str_path.size()] = '\0';
  scheme.get()[str_scheme.size()] = '\0';
  host.get()[str_host.size()] = '\0';

  const char* const headers[] = {
    "method",
    "GET",
    "url",
    req.get(),
    "host",
    host.get(),
    "scheme",
    scheme.get(),
    "version",
    "HTTP/1.1"
  };
  return ConstructSpdyPacket(
      kSynStartHeader,
      NULL,
      0,
      headers,
      arraysize(headers) / 2);
}

// Constructs a standard SPDY GET SYN packet, optionally compressed.
// |extra_headers| are the extra header-value pairs, which typically
// will vary the most between calls.
// Returns a SpdyFrame.
spdy::SpdyFrame* ConstructSpdyGet(const char* const extra_headers[],
                                  int extra_header_count,
                                  bool compressed,
                                  int stream_id,
                                  RequestPriority request_priority) {
  return ConstructSpdyGet(extra_headers, extra_header_count, compressed,
                          stream_id, request_priority, true);
}

// Constructs a standard SPDY GET SYN packet, optionally compressed.
// |extra_headers| are the extra header-value pairs, which typically
// will vary the most between calls.
// Returns a SpdyFrame.
spdy::SpdyFrame* ConstructSpdyGet(const char* const extra_headers[],
                                  int extra_header_count,
                                  bool compressed,
                                  int stream_id,
                                  RequestPriority request_priority,
                                  bool direct) {
  const char* const kStandardGetHeaders[] = {
    "method",
    "GET",
    "url",
    (direct ? "/" : "http://www.google.com/"),
    "host",
    "www.google.com",
    "scheme",
    "http",
    "version",
    "HTTP/1.1"
  };
  return ConstructSpdyControlFrame(extra_headers,
                                   extra_header_count,
                                   compressed,
                                   stream_id,
                                   request_priority,
                                   spdy::SYN_STREAM,
                                   spdy::CONTROL_FLAG_FIN,
                                   kStandardGetHeaders,
                                   arraysize(kStandardGetHeaders));
}

// Constructs a standard SPDY SYN_STREAM frame for a CONNECT request.
spdy::SpdyFrame* ConstructSpdyConnect(const char* const extra_headers[],
                                      int extra_header_count,
                                      int stream_id) {
  const char* const kConnectHeaders[] = {
    "method", "CONNECT",
    "url", "www.google.com:443",
    "host", "www.google.com",
    "version", "HTTP/1.1",
  };
  return ConstructSpdyControlFrame(extra_headers,
                                   extra_header_count,
                                   /*compressed*/ false,
                                   stream_id,
                                   LOWEST,
                                   spdy::SYN_STREAM,
                                   spdy::CONTROL_FLAG_NONE,
                                   kConnectHeaders,
                                   arraysize(kConnectHeaders));
}

// Constructs a standard SPDY push SYN packet.
// |extra_headers| are the extra header-value pairs, which typically
// will vary the most between calls.
// Returns a SpdyFrame.
spdy::SpdyFrame* ConstructSpdyPush(const char* const extra_headers[],
                                   int extra_header_count,
                                   int stream_id,
                                   int associated_stream_id) {
  const char* const kStandardGetHeaders[] = {
    "hello",
    "bye",
    "status",
    "200",
    "version",
    "HTTP/1.1"
  };
  return ConstructSpdyControlFrame(extra_headers,
                                   extra_header_count,
                                   false,
                                   stream_id,
                                   LOWEST,
                                   spdy::SYN_STREAM,
                                   spdy::CONTROL_FLAG_NONE,
                                   kStandardGetHeaders,
                                   arraysize(kStandardGetHeaders),
                                   associated_stream_id);
}

spdy::SpdyFrame* ConstructSpdyPush(const char* const extra_headers[],
                                   int extra_header_count,
                                   int stream_id,
                                   int associated_stream_id,
                                   const char* path) {
  const char* const kStandardGetHeaders[] = {
    "hello",
    "bye",
    "path",
    path,
    "status",
    "200 OK",
    "url",
    path,
    "version",
    "HTTP/1.1"
  };
  return ConstructSpdyControlFrame(extra_headers,
                                   extra_header_count,
                                   false,
                                   stream_id,
                                   LOWEST,
                                   spdy::SYN_STREAM,
                                   spdy::CONTROL_FLAG_NONE,
                                   kStandardGetHeaders,
                                   arraysize(kStandardGetHeaders),
                                   associated_stream_id);

}
spdy::SpdyFrame* ConstructSpdyPush(const char* const extra_headers[],
                                   int extra_header_count,
                                   int stream_id,
                                   int associated_stream_id,
                                   const char* path,
                                   const char* status,
                                   const char* location,
                                   const char* url) {
  const char* const kStandardGetHeaders[] = {
    "hello",
    "bye",
    "path",
    path,
    "status",
    status,
    "location",
    location,
    "url",
    url,
    "version",
    "HTTP/1.1"
  };
  return ConstructSpdyControlFrame(extra_headers,
                                   extra_header_count,
                                   false,
                                   stream_id,
                                   LOWEST,
                                   spdy::SYN_STREAM,
                                   spdy::CONTROL_FLAG_NONE,
                                   kStandardGetHeaders,
                                   arraysize(kStandardGetHeaders),
                                   associated_stream_id);
}

// Constructs a standard SPDY SYN_REPLY packet with the specified status code.
// Returns a SpdyFrame.
spdy::SpdyFrame* ConstructSpdySynReplyError(
    const char* const status,
    const char* const* const extra_headers,
    int extra_header_count,
    int stream_id) {
  const char* const kStandardGetHeaders[] = {
    "hello",
    "bye",
    "status",
    status,
    "version",
    "HTTP/1.1"
  };
  return ConstructSpdyControlFrame(extra_headers,
                                   extra_header_count,
                                   false,
                                   stream_id,
                                   LOWEST,
                                   spdy::SYN_REPLY,
                                   spdy::CONTROL_FLAG_NONE,
                                   kStandardGetHeaders,
                                   arraysize(kStandardGetHeaders));
}

// Constructs a standard SPDY SYN_REPLY packet to match the SPDY GET.
// |extra_headers| are the extra header-value pairs, which typically
// will vary the most between calls.
// Returns a SpdyFrame.
spdy::SpdyFrame* ConstructSpdyGetSynReplyRedirect(int stream_id) {
  static const char* const kExtraHeaders[] = {
    "location",
    "http://www.foo.com/index.php",
  };
  return ConstructSpdySynReplyError("301 Moved Permanently", kExtraHeaders,
                                    arraysize(kExtraHeaders)/2, stream_id);
}

// Constructs a standard SPDY SYN_REPLY packet with an Internal Server
// Error status code.
// Returns a SpdyFrame.
spdy::SpdyFrame* ConstructSpdySynReplyError(int stream_id) {
  return ConstructSpdySynReplyError("500 Internal Server Error", NULL, 0, 1);
}




// Constructs a standard SPDY SYN_REPLY packet to match the SPDY GET.
// |extra_headers| are the extra header-value pairs, which typically
// will vary the most between calls.
// Returns a SpdyFrame.
spdy::SpdyFrame* ConstructSpdyGetSynReply(const char* const extra_headers[],
                                          int extra_header_count,
                                          int stream_id) {
  static const char* const kStandardGetHeaders[] = {
    "hello",
    "bye",
    "status",
    "200",
    "url",
    "/index.php",
    "version",
    "HTTP/1.1"
  };
  return ConstructSpdyControlFrame(extra_headers,
                                   extra_header_count,
                                   false,
                                   stream_id,
                                   LOWEST,
                                   spdy::SYN_REPLY,
                                   spdy::CONTROL_FLAG_NONE,
                                   kStandardGetHeaders,
                                   arraysize(kStandardGetHeaders));
}

// Constructs a standard SPDY POST SYN packet.
// |content_length| is the size of post data.
// |extra_headers| are the extra header-value pairs, which typically
// will vary the most between calls.
// Returns a SpdyFrame.
spdy::SpdyFrame* ConstructSpdyPost(int64 content_length,
                                   const char* const extra_headers[],
                                   int extra_header_count) {
  std::string length_str = base::Int64ToString(content_length);
  const char* post_headers[] = {
    "method",
    "POST",
    "url",
    "/",
    "host",
    "www.google.com",
    "scheme",
    "http",
    "version",
    "HTTP/1.1",
    "content-length",
    length_str.c_str()
  };
  return ConstructSpdyControlFrame(extra_headers,
                                   extra_header_count,
                                   false,
                                   1,
                                   LOWEST,
                                   spdy::SYN_STREAM,
                                   spdy::CONTROL_FLAG_NONE,
                                   post_headers,
                                   arraysize(post_headers));
}

// Constructs a standard SPDY SYN_REPLY packet to match the SPDY POST.
// |extra_headers| are the extra header-value pairs, which typically
// will vary the most between calls.
// Returns a SpdyFrame.
spdy::SpdyFrame* ConstructSpdyPostSynReply(const char* const extra_headers[],
                                           int extra_header_count) {
  static const char* const kStandardGetHeaders[] = {
    "hello",
    "bye",
    "status",
    "200",
    "url",
    "/index.php",
    "version",
    "HTTP/1.1"
  };
  return ConstructSpdyControlFrame(extra_headers,
                                   extra_header_count,
                                   false,
                                   1,
                                   LOWEST,
                                   spdy::SYN_REPLY,
                                   spdy::CONTROL_FLAG_NONE,
                                   kStandardGetHeaders,
                                   arraysize(kStandardGetHeaders));
}

// Constructs a single SPDY data frame with the default contents.
spdy::SpdyFrame* ConstructSpdyBodyFrame(int stream_id, bool fin) {
  spdy::SpdyFramer framer;
  return framer.CreateDataFrame(
      stream_id, kUploadData, kUploadDataSize,
      fin ? spdy::DATA_FLAG_FIN : spdy::DATA_FLAG_NONE);
}

// Constructs a single SPDY data frame with the given content.
spdy::SpdyFrame* ConstructSpdyBodyFrame(int stream_id, const char* data,
                                        uint32 len, bool fin) {
  spdy::SpdyFramer framer;
  return framer.CreateDataFrame(
      stream_id, data, len, fin ? spdy::DATA_FLAG_FIN : spdy::DATA_FLAG_NONE);
}

// Wraps |frame| in the payload of a data frame in stream |stream_id|.
spdy::SpdyFrame* ConstructWrappedSpdyFrame(
    const scoped_ptr<spdy::SpdyFrame>& frame,
    int stream_id) {
  return ConstructSpdyBodyFrame(stream_id, frame->data(),
                                frame->length() + spdy::SpdyFrame::size(),
                                false);
}

// Construct an expected SPDY reply string.
// |extra_headers| are the extra header-value pairs, which typically
// will vary the most between calls.
// |buffer| is the buffer we're filling in.
// Returns the number of bytes written into |buffer|.
int ConstructSpdyReplyString(const char* const extra_headers[],
                             int extra_header_count,
                             char* buffer,
                             int buffer_length) {
  int packet_size = 0;
  int header_count = 0;
  char* buffer_write = buffer;
  int buffer_left = buffer_length;
  spdy::SpdyHeaderBlock headers;
  if (!buffer || !buffer_length)
    return 0;
  // Copy in the extra headers.
  AppendHeadersToSpdyFrame(extra_headers, extra_header_count, &headers);
  header_count = headers.size();
  // The iterator gets us the list of header/value pairs in sorted order.
  spdy::SpdyHeaderBlock::iterator next = headers.begin();
  spdy::SpdyHeaderBlock::iterator last = headers.end();
  for ( ; next != last; ++next) {
    // Write the header.
    int value_len, current_len, offset;
    const char* header_string = next->first.c_str();
    packet_size += AppendToBuffer(header_string,
                                  next->first.length(),
                                  &buffer_write,
                                  &buffer_left);
    packet_size += AppendToBuffer(": ",
                                  strlen(": "),
                                  &buffer_write,
                                  &buffer_left);
    // Write the value(s).
    const char* value_string = next->second.c_str();
    // Check if it's split among two or more values.
    value_len = next->second.length();
    current_len = strlen(value_string);
    offset = 0;
    // Handle the first N-1 values.
    while (current_len < value_len) {
      // Finish this line -- write the current value.
      packet_size += AppendToBuffer(value_string + offset,
                                    current_len - offset,
                                    &buffer_write,
                                    &buffer_left);
      packet_size += AppendToBuffer("\n",
                                    strlen("\n"),
                                    &buffer_write,
                                    &buffer_left);
      // Advance to next value.
      offset = current_len + 1;
      current_len += 1 + strlen(value_string + offset);
      // Start another line -- add the header again.
      packet_size += AppendToBuffer(header_string,
                                    next->first.length(),
                                    &buffer_write,
                                    &buffer_left);
      packet_size += AppendToBuffer(": ",
                                    strlen(": "),
                                    &buffer_write,
                                    &buffer_left);
    }
    EXPECT_EQ(value_len, current_len);
    // Copy the last (or only) value.
    packet_size += AppendToBuffer(value_string + offset,
                                  value_len - offset,
                                  &buffer_write,
                                  &buffer_left);
    packet_size += AppendToBuffer("\n",
                                  strlen("\n"),
                                  &buffer_write,
                                  &buffer_left);
  }
  return packet_size;
}

// Create a MockWrite from the given SpdyFrame.
MockWrite CreateMockWrite(const spdy::SpdyFrame& req) {
  return MockWrite(
      true, req.data(), req.length() + spdy::SpdyFrame::size());
}

// Create a MockWrite from the given SpdyFrame and sequence number.
MockWrite CreateMockWrite(const spdy::SpdyFrame& req, int seq) {
  return CreateMockWrite(req, seq, true);
}

// Create a MockWrite from the given SpdyFrame and sequence number.
MockWrite CreateMockWrite(const spdy::SpdyFrame& req, int seq, bool async) {
  return MockWrite(
      async, req.data(), req.length() + spdy::SpdyFrame::size(), seq);
}

// Create a MockRead from the given SpdyFrame.
MockRead CreateMockRead(const spdy::SpdyFrame& resp) {
  return MockRead(
      true, resp.data(), resp.length() + spdy::SpdyFrame::size());
}

// Create a MockRead from the given SpdyFrame and sequence number.
MockRead CreateMockRead(const spdy::SpdyFrame& resp, int seq) {
  return CreateMockRead(resp, seq, true);
}

// Create a MockRead from the given SpdyFrame and sequence number.
MockRead CreateMockRead(const spdy::SpdyFrame& resp, int seq, bool async) {
  return MockRead(
      async, resp.data(), resp.length() + spdy::SpdyFrame::size(), seq);
}

// Combines the given SpdyFrames into the given char array and returns
// the total length.
int CombineFrames(const spdy::SpdyFrame** frames, int num_frames,
                  char* buff, int buff_len) {
  int total_len = 0;
  for (int i = 0; i < num_frames; ++i) {
    total_len += frames[i]->length() + spdy::SpdyFrame::size();
  }
  DCHECK_LE(total_len, buff_len);
  char* ptr = buff;
  for (int i = 0; i < num_frames; ++i) {
    int len = frames[i]->length() + spdy::SpdyFrame::size();
    memcpy(ptr, frames[i]->data(), len);
    ptr += len;
  }
  return total_len;
}

const SpdyHeaderInfo make_spdy_header(spdy::SpdyControlType type) {
  const SpdyHeaderInfo kHeader = {
    type,                         // Kind = Syn
    1,                            // Stream ID
    0,                            // Associated stream ID
    2,                            // Priority
    spdy::CONTROL_FLAG_FIN,       // Control Flags
    false,                        // Compressed
    spdy::INVALID,                // Status
    NULL,                         // Data
    0,                            // Length
    spdy::DATA_FLAG_NONE          // Data Flags
  };
  return kHeader;
}
}  // namespace net