Implement serial API for Windows.

chrome/browser/extensions/api/serial/serial_connection.cc

Index: chrome/browser/extensions/api/serial/serial_connection.cc
diff --git a/chrome/browser/extensions/api/serial/serial_connection.cc b/chrome/browser/extensions/api/serial/serial_connection.cc
index 2d46b7931651b7fec04518e4a5e9b67f3add26cc..66e2a89d3437dbdd386255be20bacb69fb3fd1d8 100644
--- a/chrome/browser/extensions/api/serial/serial_connection.cc
+++ b/chrome/browser/extensions/api/serial/serial_connection.cc
@@ -6,8 +6,61 @@
 
 #include <string>
 
+#include "base/file_path.h"
+#include "base/string_util.h"
+
 namespace extensions {
 
 const char kSerialConnectionNotFoundError[] = "Serial connection not found";
 
+SerialConnection::SerialConnection(const std::string& port,
+                                   APIResourceEventNotifier* event_notifier)
+    : APIResource(APIResource::SerialConnectionResource, event_notifier),
+      port_(port),
+      file_(base::kInvalidPlatformFileValue) {
+}
+
+SerialConnection::~SerialConnection() {
+  Close();
+}
+
+bool SerialConnection::Open() {
+  bool created = false;
+
+  // It's the responsibility of the API wrapper around SerialConnection to
+  // validate the supplied path against the set of valid port names, and
+  // it is a reasonable assumption that serial port names are ASCII.
+  CHECK(IsStringASCII(port_));

[asargent_no_longer_on_chrome, 2012/05/24 22:43:03]

Does this really warrant a CHECK (eg all of chrome immediately exits) and not
just returning false?

[miket_OOO, 2012/05/24 23:44:43]

In this case, I'd say yes. It's because if this were to fail, it's a coding
error (we failed to validate the input). I'm afraid that the FromUTF8Unsafe()
call below might be... uh, unsafe, if I can't guarantee that the input is ASCII
(& thus UTF8). Better to kill the browser for a logic error than to pass
known-bad data to a function marked Unsafe.

+  FilePath file_path(FilePath::FromUTF8Unsafe(port_));
+
+  file_ = base::CreatePlatformFile(file_path,
+    base::PLATFORM_FILE_OPEN | base::PLATFORM_FILE_READ |
+    base::PLATFORM_FILE_WRITE | base::PLATFORM_FILE_EXCLUSIVE_READ |
+    base::PLATFORM_FILE_EXCLUSIVE_WRITE |
+    base::PLATFORM_FILE_TERMINAL_DEVICE, &created, NULL);
+  if (file_ == base::kInvalidPlatformFileValue) {
+    return false;
+  }
+  return PostOpen();
+}
+
+void SerialConnection::Close() {
+  if (file_ != base::kInvalidPlatformFileValue) {
+    base::ClosePlatformFile(file_);
+    file_ = base::kInvalidPlatformFileValue;
+  }
+}
+
+int SerialConnection::Read(uint8* byte) {
+  DCHECK(byte);
+  return base::ReadPlatformFile(file_, 0, reinterpret_cast<char*>(byte), 1);
+}
+
+int SerialConnection::Write(scoped_refptr<net::IOBuffer> io_buffer,
+                            int byte_count) {
+  DCHECK(io_buffer->data());
+  DCHECK(byte_count >= 0);
+  return base::WritePlatformFile(file_, 0, io_buffer->data(), byte_count);
+}
+
 }  // namespace extensions