Revert of Creates a BattOrConnection for communicating with the BattOr

tools/battor_agent/battor_connection.cc

-// Copyright 2015 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 "tools/battor_agent/battor_connection.h"
-
-#include "base/bind.h"
-#include "base/callback.h"
-#include "device/serial/buffer.h"
-#include "device/serial/serial_io_handler.h"
-#include "net/base/io_buffer.h"
-
-using std::vector;
-
-namespace battor {
-
-namespace {
-
-// Serial configuration parameters for the BattOr.
-const uint32_t kBattOrBitrate = 2000000;
-const device::serial::DataBits kBattOrDataBits =
-    device::serial::DATA_BITS_EIGHT;
-const device::serial::ParityBit kBattOrParityBit =
-    device::serial::PARITY_BIT_NONE;
-const device::serial::StopBits kBattOrStopBit = device::serial::STOP_BITS_ONE;
-const bool kBattOrCtsFlowControl = true;
-const bool kBattOrHasCtsFlowControl = true;
-const uint32_t kMaxMessageSize = 50000;
-
-// MessageHealth describes the possible healthiness states that a partially
-// received message could be in.
-enum class MessageHealth {
-  INVALID,
-  INCOMPLETE,
-  COMPLETE,
-};
-
-// Parses the specified message.
-//   - message: The incoming message that needs to be parsed.
-//   - parsed_content: Output argument for the message content after removal of
-//     any start, end, type, and escape bytes.
-//   - health: Output argument for the health of the message.
-//   - type: Output argument for the type of message being parsed.
-//   - escape_byte_count: Output argument for the number of escape bytes
-//     removed from the parsed content.
-void ParseMessage(const vector<char>& message,
-                  vector<char>* parsed_content,
-                  MessageHealth* health,
-                  BattOrMessageType* type,
-                  size_t* escape_byte_count) {
-  *health = MessageHealth::INCOMPLETE;
-  *type = BATTOR_MESSAGE_TYPE_CONTROL;
-  *escape_byte_count = 0;
-  parsed_content->reserve(message.size());
-
-  if (message.size() == 0)
-    return;
-
-  // The first byte is the start byte.
-  if (message[0] != BATTOR_CONTROL_BYTE_START) {
-    *health = MessageHealth::INVALID;
-    return;
-  }
-
-  if (message.size() == 1)
-    return;
-
-  // The second byte specifies the message type.
-  *type = static_cast<BattOrMessageType>(message[1]);
-
-  if (*type < static_cast<uint8_t>(BATTOR_MESSAGE_TYPE_CONTROL) ||
-      *type > static_cast<uint8_t>(BATTOR_MESSAGE_TYPE_PRINT)) {
-    *health = MessageHealth::INVALID;
-    return;
-  }
-
-  // After that comes the message data.
-  bool escape_next_byte = false;
-  for (size_t i = 2; i < message.size(); i++) {
-    if (i >= kMaxMessageSize) {
-      *health = MessageHealth::INVALID;
-      return;
-    }
-
-    char next_byte = message[i];
-
-    if (escape_next_byte) {
-      parsed_content->push_back(next_byte);
-      escape_next_byte = false;
-      continue;
-    }
-
-    switch (next_byte) {
-      case BATTOR_CONTROL_BYTE_START:
-        // Two start bytes in a message is invalid.
-        *health = MessageHealth::INVALID;
-        return;
-
-      case BATTOR_CONTROL_BYTE_END:
-        if (i != message.size() - 1) {
-          // We're only parsing a single message here. If we received more bytes
-          // after the end byte, what we've received so far is *not* valid.
-          *health = MessageHealth::INVALID;
-          return;
-        }
-
-        *health = MessageHealth::COMPLETE;
-        return;
-
-      case BATTOR_CONTROL_BYTE_ESCAPE:
-        escape_next_byte = true;
-        (*escape_byte_count)++;
-        continue;
-
-      default:
-        parsed_content->push_back(next_byte);
-    }
-  }
-}
-
-}  // namespace
-
-BattOrConnection::BattOrConnection(
-    const std::string& path,
-    Listener* listener,
-    scoped_refptr<base::SingleThreadTaskRunner> file_thread_task_runner,
-    scoped_refptr<base::SingleThreadTaskRunner> ui_thread_task_runner)
-    : path_(path),
-      listener_(listener),
-      file_thread_task_runner_(file_thread_task_runner),
-      ui_thread_task_runner_(ui_thread_task_runner) {}
-
-BattOrConnection::~BattOrConnection() {}
-
-void BattOrConnection::Open() {
-  io_handler_ = CreateIoHandler();
-
-  device::serial::ConnectionOptions options;
-  options.bitrate = kBattOrBitrate;
-  options.data_bits = kBattOrDataBits;
-  options.parity_bit = kBattOrParityBit;
-  options.stop_bits = kBattOrStopBit;
-  options.cts_flow_control = kBattOrCtsFlowControl;
-  options.has_cts_flow_control = kBattOrHasCtsFlowControl;
-
-  io_handler_->Open(path_, options,
-                    base::Bind(&BattOrConnection::OnOpened, AsWeakPtr()));
-}
-
-void BattOrConnection::OnOpened(bool success) {
-  if (!success)
-    Close();
-
-  listener_->OnConnectionOpened(success);
-}
-
-bool BattOrConnection::IsOpen() {
-  return io_handler_;
-}
-
-void BattOrConnection::Close() {
-  io_handler_ = nullptr;
-}
-
-void BattOrConnection::SendBytes(BattOrMessageType type,
-                                 const void* buffer,
-                                 size_t bytes_to_send) {
-  const char* bytes = reinterpret_cast<const char*>(buffer);
-
-  // Reserve a send buffer with 3 extra bytes (start, type, and end byte) and
-  // twice as many bytes as we're actually sending, because each raw data byte
-  // might need to be escaped.
-  vector<char> data;
-  data.reserve(2 * bytes_to_send + 3);
-
-  data.push_back(BATTOR_CONTROL_BYTE_START);
-  data.push_back(type);
-
-  for (size_t i = 0; i < bytes_to_send; i++) {
-    if (bytes[i] == BATTOR_CONTROL_BYTE_START ||
-        bytes[i] == BATTOR_CONTROL_BYTE_END) {
-      data.push_back(BATTOR_CONTROL_BYTE_ESCAPE);
-    }
-
-    data.push_back(bytes[i]);
-  }
-
-  data.push_back(BATTOR_CONTROL_BYTE_END);
-
-  pending_write_length_ = data.size();
-  io_handler_->Write(make_scoped_ptr(new device::SendBuffer(
-      data, base::Bind(&BattOrConnection::OnBytesSent, AsWeakPtr()))));
-}
-
-void BattOrConnection::ReadBytes(size_t bytes_to_read) {
-  // Allocate a read buffer and reserve enough space in it to account for the
-  // start, type, end, and escape bytes.
-  pending_read_buffer_.reset(new vector<char>());
-  pending_read_buffer_->reserve(2 * bytes_to_read + 3);
-  pending_read_escape_byte_count_ = 0;
-
-  // Add 3 bytes to however many bytes the caller requested because we know
-  // we'll have to read the start, type, and end bytes.
-  bytes_to_read += 3;
-
-  ReadMoreBytes(bytes_to_read);
-}
-
-void BattOrConnection::Flush() {
-  io_handler_->Flush();
-}
-
-scoped_refptr<device::SerialIoHandler> BattOrConnection::CreateIoHandler() {
-  return device::SerialIoHandler::Create(file_thread_task_runner_,
-                                         ui_thread_task_runner_);
-}
-
-void BattOrConnection::ReadMoreBytes(size_t bytes_to_read) {
-  last_read_buffer_ = make_scoped_refptr(new net::IOBuffer(bytes_to_read));
-  auto on_receive_buffer_filled =
-      base::Bind(&BattOrConnection::OnBytesRead, AsWeakPtr());
-
-  pending_read_length_ = bytes_to_read;
-  io_handler_->Read(make_scoped_ptr(new device::ReceiveBuffer(
-      last_read_buffer_, bytes_to_read, on_receive_buffer_filled)));
-}
-
-void BattOrConnection::OnBytesRead(int bytes_read,
-                                   device::serial::ReceiveError error) {
-  if ((static_cast<size_t>(bytes_read) < pending_read_length_) ||
-      (error != device::serial::RECEIVE_ERROR_NONE)) {
-    listener_->OnBytesRead(false, BATTOR_MESSAGE_TYPE_CONTROL, nullptr);
-    return;
-  }
-
-  pending_read_buffer_->insert(pending_read_buffer_->end(),
-                               last_read_buffer_->data(),
-                               last_read_buffer_->data() + bytes_read);
-
-  scoped_ptr<vector<char>> parsed_content(new vector<char>());
-  MessageHealth health;
-  BattOrMessageType type;
-  size_t escape_byte_count;
-
-  ParseMessage(*pending_read_buffer_, parsed_content.get(), &health, &type,
-               &escape_byte_count);
-
-  if (health == MessageHealth::INVALID) {
-    // If we already have an invalid message, there's no sense in continuing to
-    // process it.
-    listener_->OnBytesRead(false, BATTOR_MESSAGE_TYPE_CONTROL, nullptr);
-    return;
-  }
-
-  size_t new_escape_bytes = escape_byte_count - pending_read_escape_byte_count_;
-  pending_read_escape_byte_count_ = escape_byte_count;
-
-  if (new_escape_bytes > 0) {
-    // When the caller requested that we read X additional bytes, they weren't
-    // taking into account any escape bytes that we received. Because we got
-    // some escape bytes, we need to fire off another read to get the rest of
-    // the data.
-    ReadMoreBytes(new_escape_bytes);
-    return;
-  }
-
-  if (health == MessageHealth::INCOMPLETE)
-    // If everything is valid and we didn't see any escape bytes, then we should
-    // have the whole message. If we don't, the message was malformed.
-    listener_->OnBytesRead(false, BATTOR_MESSAGE_TYPE_CONTROL, nullptr);
-
-  // If we've gotten this far, we've received the whole, well-formed message.
-  listener_->OnBytesRead(true, type, parsed_content.Pass());
-}
-
-void BattOrConnection::OnBytesSent(int bytes_sent,
-                                   device::serial::SendError error) {
-  bool success = (error == device::serial::SEND_ERROR_NONE) &&
-                 (pending_write_length_ == static_cast<size_t>(bytes_sent));
-  listener_->OnBytesSent(success);
-}
-
-}  // namespace battor