[BattOr] Make BattOr able to return firmware version.

tools/battor_agent/battor_agent.cc

Index: tools/battor_agent/battor_agent.cc
diff --git a/tools/battor_agent/battor_agent.cc b/tools/battor_agent/battor_agent.cc
index 6fc6ea17983b09ed662e617b9906fc6c3dbc2f94..370f1d4ccad493dff62eddddbaf439b16c62b283 100644
--- a/tools/battor_agent/battor_agent.cc
+++ b/tools/battor_agent/battor_agent.cc
@@ -1,7 +1,6 @@
 // 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_agent.h"
 
 #include <iomanip>
@@ -108,6 +107,14 @@ bool ParseSampleFrame(BattOrMessageType type,
   return true;
 }
 
+bool ParseGitHashFrame(BattOrMessageType type,

[charliea (OOO until 10-5), 2016/10/18 23:46:29]

I think it's probably okay to do this inline in OnMessageRead() rather than in a
separate function. The only reason that I ended up creating a separate function
for ParseSampleFrame is because the logic is so extensive for that.

[charliea (OOO until 10-5), 2016/10/18 23:46:29]

I think that, if you use an std::string, this entire translation can be written
as:

return std::string(msg.begin(), msg.end());

My reasoning is that strings have a constructor that accepts a begin and end
iterator, and a vector provides that.

[rnephew (Reviews Here), 2016/10/19 18:23:47]

Done.

+                       const vector<char>& msg,
+                       char* git_hash){
+  if (type !=  BATTOR_MESSAGE_TYPE_CONTROL_ACK)
+    return false;
+  memcpy(git_hash, msg.data(), msg.size());
+  return true;
+}
 }  // namespace
 
 BattOrAgent::BattOrAgent(
@@ -159,6 +166,13 @@ void BattOrAgent::RecordClockSyncMarker(const std::string& marker) {
   PerformAction(Action::REQUEST_CONNECTION);
 }
 
+void BattOrAgent::GetVersion() {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  command_ = Command::GET_VERSION;
+  PerformAction(Action::REQUEST_CONNECTION);
+}
+
 void BattOrAgent::BeginConnect() {
   DCHECK(thread_checker_.CalledOnValidThread());
 
@@ -187,6 +201,9 @@ void BattOrAgent::OnConnectionOpened(bool success) {
     case Command::RECORD_CLOCK_SYNC_MARKER:
       PerformAction(Action::SEND_CURRENT_SAMPLE_REQUEST);
       return;
+    case Command::GET_VERSION:
+      PerformAction(Action::SEND_GIT_HASH_REQUEST);
+      return;
     case Command::INVALID:
       NOTREACHED();
   }
@@ -228,6 +245,10 @@ void BattOrAgent::OnBytesSent(bool success) {
       num_read_attempts_ = 1;
       PerformAction(Action::READ_CURRENT_SAMPLE);
       return;
+    case Action::SEND_GIT_HASH_REQUEST:
+      num_read_attempts_ = 1;
+      PerformAction(Action::READ_GIT_HASH);
+      return;
     default:
       CompleteCommand(BATTOR_ERROR_UNEXPECTED_MESSAGE);
   }
@@ -244,6 +265,7 @@ void BattOrAgent::OnMessageRead(bool success,
 
   if (!success) {
     switch (last_action_) {
+      case Action::READ_GIT_HASH:
       case Action::READ_EEPROM:
       case Action::READ_CALIBRATION_FRAME:
       case Action::READ_DATA_FRAME:
@@ -387,6 +409,21 @@ void BattOrAgent::OnMessageRead(bool success,
       CompleteCommand(BATTOR_ERROR_NONE);
       return;
 
+    case Action::READ_GIT_HASH:
+      // Get size to allocate space for git_hash_.
+      if (bytes->size() <= 0 ){

[charliea (OOO until 10-5), 2016/10/18 23:46:29]

Also don't think this should be necessary once we use the iterator-based
constructor.

[rnephew (Reviews Here), 2016/10/19 18:23:47]

Done.

+        CompleteCommand(BATTOR_ERROR_UNEXPECTED_MESSAGE);
+        return;
+      }
+      git_hash_ = (char*) malloc(bytes->size());
+
+      if(!ParseGitHashFrame(type, *bytes, git_hash_)) {
+        CompleteCommand(BATTOR_ERROR_UNEXPECTED_MESSAGE);
+        return;
+      }
+      CompleteCommand(BATTOR_ERROR_NONE);
+      return;
+
     default:
       CompleteCommand(BATTOR_ERROR_UNEXPECTED_MESSAGE);
   }
@@ -473,6 +510,14 @@ void BattOrAgent::PerformAction(Action action) {
       connection_->ReadMessage(BATTOR_MESSAGE_TYPE_CONTROL_ACK);
       return;
 
+    case Action::SEND_GIT_HASH_REQUEST:
+      SendControlMessage(BATTOR_CONTROL_MESSAGE_TYPE_GET_GIT_HASH, 0, 0);
+      return;
+
+    case Action::READ_GIT_HASH:
+      connection_->ReadMessage(BATTOR_MESSAGE_TYPE_CONTROL_ACK);
+      return;
+
     case Action::INVALID:
       NOTREACHED();
   }
@@ -530,6 +575,12 @@ void BattOrAgent::CompleteCommand(BattOrError error) {
           FROM_HERE, base::Bind(&Listener::OnRecordClockSyncMarkerComplete,
                                 base::Unretained(listener_), error));
       break;
+    case Command::GET_VERSION:
+      base::ThreadTaskRunnerHandle::Get()->PostTask(
+          FROM_HERE, base::Bind(&Listener::OnGetVersionComplete,
+                                base::Unretained(listener_),
+                                git_hash_, error));
+      break;
     case Command::INVALID:
       NOTREACHED();
   }