Bug 1201597 - Part 1: Implement an nsIOutputStream for ipc::FileDescriptor; r=mrbkap

devtools/shared/heapsnapshot/FileDescriptorOutputStream.cpp

@@ -0,0 +1,85 @@
+/* -*-  Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "mozilla/devtools/FileDescriptorOutputStream.h"
+#include "private/pprio.h"
+
+namespace mozilla {
+namespace devtools {
+
+/* static */ already_AddRefed<FileDescriptorOutputStream>
+FileDescriptorOutputStream::Create(const ipc::FileDescriptor& fileDescriptor)
+{
+  if (NS_WARN_IF(!fileDescriptor.IsValid()))
+    return nullptr;
+
+  PRFileDesc* prfd = PR_ImportFile(PROsfd(fileDescriptor.PlatformHandle()));
+  if (NS_WARN_IF(!prfd))
+    return nullptr;
+
+  nsRefPtr<FileDescriptorOutputStream> stream = new FileDescriptorOutputStream(prfd);
+  return stream.forget();
+}
+
+NS_IMPL_ISUPPORTS(FileDescriptorOutputStream, nsIOutputStream);
+
+NS_IMETHODIMP
+FileDescriptorOutputStream::Close()
+{
+  // Repeatedly closing is idempotent.
+  if (!fd)
+    return NS_OK;
+
+  if (PR_Close(fd) != PR_SUCCESS)
+    return NS_ERROR_FAILURE;
+  fd = nullptr;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FileDescriptorOutputStream::Write(const char* buf, uint32_t count, uint32_t* retval)
+{
+  if (NS_WARN_IF(!fd))
+    return NS_ERROR_FAILURE;
+
+  auto written = PR_Write(fd, buf, count);
+  if (written < 0)
+    return NS_ERROR_FAILURE;
+  *retval = written;
+  return NS_OK;
+}
+
+NS_IMETHODIMP
+FileDescriptorOutputStream::Flush()
+{
+  if (NS_WARN_IF(!fd))
+    return NS_ERROR_FAILURE;
+
+  return PR_Sync(fd) == PR_SUCCESS ? NS_OK : NS_ERROR_FAILURE;
+}
+
+NS_IMETHODIMP
+FileDescriptorOutputStream::WriteFrom(nsIInputStream* fromStream, uint32_t count,
+                                      uint32_t* retval)
+{
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+FileDescriptorOutputStream::WriteSegments(nsReadSegmentFun reader, void* closure,
+                                          uint32_t count, uint32_t* retval)
+{
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
+NS_IMETHODIMP
+FileDescriptorOutputStream::IsNonBlocking(bool* retval)
+{
+  *retval = false;
+  return NS_OK;
+}
+
+} // namespace devtools
+} // namespace mozilla

devtools/shared/heapsnapshot/FileDescriptorOutputStream.h

@@ -0,0 +1,41 @@
+/* -*-  Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_devtools_FileDescriptorOutputStream_h
+#define mozilla_devtools_FileDescriptorOutputStream_h
+
+#include <prio.h>
+
+#include "mozilla/AlreadyAddRefed.h"
+#include "mozilla/ipc/FileDescriptor.h"
+#include "nsIOutputStream.h"
+
+namespace mozilla {
+namespace devtools {
+
+class FileDescriptorOutputStream final : public nsIOutputStream
+{
+private:
+  PRFileDesc* fd;
+
+public:
+  static already_AddRefed<FileDescriptorOutputStream>
+    Create(const ipc::FileDescriptor& fileDescriptor);
+
+private:
+  explicit FileDescriptorOutputStream(PRFileDesc* prfd)
+    : fd(prfd)
+  { }
+
+  virtual ~FileDescriptorOutputStream() { }
+
+  NS_DECL_THREADSAFE_ISUPPORTS
+  NS_DECL_NSIOUTPUTSTREAM
+};
+
+} // namespace devtools
+} // namespace mozilla
+
+#endif // mozilla_devtools_FileDescriptorOutputStream_h

devtools/shared/heapsnapshot/moz.build

@@ -14,6 +14,7 @@ EXPORTS.mozilla.devtools += [
     'AutoMemMap.h',
     'CoreDump.pb.h',
     'DeserializedNode.h',
+    'FileDescriptorOutputStream.h',
     'HeapSnapshot.h',
     'ZeroCopyNSIOutputStream.h',
 ]
@@ -22,6 +23,7 @@ SOURCES += [
     'AutoMemMap.cpp',
     'CoreDump.pb.cc',
     'DeserializedNode.cpp',
+    'FileDescriptorOutputStream.cpp',
     'HeapSnapshot.cpp',
     'ZeroCopyNSIOutputStream.cpp',
 ]