Stability instrumentation Crashpad integration

components/browser_watcher/stability_report_user_stream_data_source.cc

Index: components/browser_watcher/stability_report_user_stream_data_source.cc
diff --git a/components/browser_watcher/stability_report_user_stream_data_source.cc b/components/browser_watcher/stability_report_user_stream_data_source.cc
new file mode 100644
index 0000000000000000000000000000000000000000..ea23c7d58932e690917908a7b4e7ecb79bc612b0
--- /dev/null
+++ b/components/browser_watcher/stability_report_user_stream_data_source.cc
@@ -0,0 +1,123 @@
+// Copyright 2017 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 "components/browser_watcher/stability_report_user_stream_data_source.h"
+
+#include <string>
+#include <utility>
+
+#include "base/files/file.h"
+#include "base/files/file_util.h"
+#include "base/memory/ptr_util.h"
+#include "base/strings/string16.h"
+#include "base/time/time.h"
+#include "components/browser_watcher/minidump_user_streams.h"
+#include "components/browser_watcher/stability_paths.h"
+#include "components/browser_watcher/stability_report_extractor.h"
+#include "third_party/crashpad/crashpad/minidump/minidump_user_extension_stream_data_source.h"
+#include "third_party/crashpad/crashpad/snapshot/process_snapshot.h"
+
+namespace browser_watcher {
+
+namespace {
+
+bool GetStabilityFileName(const base::string16& user_data_dir,
+                          crashpad::ProcessSnapshot* process_snapshot,
+                          base::FilePath* stability_file) {
+  DCHECK(process_snapshot);
+  DCHECK(stability_file);
+
+  timeval creation_time{};
+  process_snapshot->ProcessStartTime(&creation_time);
+
+  *stability_file =
+      GetStabilityFileForProcess(process_snapshot->ProcessID(), creation_time,
+                                 base::FilePath(user_data_dir));
+  return true;
+}
+
+std::unique_ptr<std::string> CollectReport(const base::FilePath& path) {
+  StabilityReport report;
+  CollectionStatus status = Extract(path, &report);
+  if (status != SUCCESS)
+    return nullptr;
+
+  std::unique_ptr<std::string> serialized_report(new std::string());
+  if (!report.SerializeToString(serialized_report.get()))
+    return nullptr;
+
+  // Open (with delete) and then immediately close the file by going out of
+  // scope. This should cause the stability debugging file to be deleted prior
+  // to the next execution.
+  // TODO(manzagop): set the persistent allocator file's state to deleted in
+  //     case the file can't be deleted.
+  base::File file(path, base::File::FLAG_OPEN | base::File::FLAG_READ |
+                            base::File::FLAG_DELETE_ON_CLOSE);
+
+  return serialized_report;
+}
+
+class BufferExtensionStreamDataSource final
+    : public crashpad::MinidumpUserExtensionStreamDataSource {
+ public:
+  BufferExtensionStreamDataSource(uint32_t stream_type,
+                                  std::unique_ptr<std::string> data);

[Sigurður Ásgeirsson, 2017/05/11 13:48:32]

why not construct this with the StabilityReport proto, and have it stash the
data into a straight-up string member?

[manzagop (departed), 2017/05/11 14:54:45]

Done. Note the string might be empty if the serialization fails, but I'll still
return a datasource.

[Sigurður Ásgeirsson, 2017/05/11 15:33:40]

Interesting distinction, is this helpful or harmful? You could construct, test
the length and return a nullptr if it's zero - assuming the distinction is
helpful.

[manzagop (departed), 2017/05/11 19:14:53]

Went with early pruning. Done.

+
+  size_t StreamDataSize() override;
+  bool ReadStreamData(Delegate* delegate) override;
+
+ private:
+  std::unique_ptr<std::string> data_;
+
+  DISALLOW_COPY_AND_ASSIGN(BufferExtensionStreamDataSource);
+};
+
+BufferExtensionStreamDataSource::BufferExtensionStreamDataSource(
+    uint32_t stream_type,
+    std::unique_ptr<std::string> data)
+    : crashpad::MinidumpUserExtensionStreamDataSource(stream_type),
+      data_(std::move(data)) {
+  DCHECK(data_);
+}
+
+size_t BufferExtensionStreamDataSource::StreamDataSize() {
+  return data_->size();
+}
+
+bool BufferExtensionStreamDataSource::ReadStreamData(Delegate* delegate) {
+  return delegate->ExtensionStreamDataSourceRead(
+      data_->size() ? data_->data() : nullptr, data_->size());
+}
+
+}  // namespace
+
+StabilityReportUserStreamDataSource::StabilityReportUserStreamDataSource(
+    const base::string16& user_data_dir)
+    : user_data_dir_(user_data_dir) {}
+
+std::unique_ptr<crashpad::MinidumpUserExtensionStreamDataSource>
+StabilityReportUserStreamDataSource::ProduceStreamData(
+    crashpad::ProcessSnapshot* process_snapshot) {
+  DCHECK(process_snapshot);
+
+  if (user_data_dir_.empty())
+    return nullptr;
+
+  base::FilePath stability_file;
+  GetStabilityFileName(user_data_dir_, process_snapshot, &stability_file);
+  if (!PathExists(stability_file)) {
+    // Either this is not an instrumented process, or the stability file cannot
+    // be found.
+    return nullptr;
+  }
+
+  std::unique_ptr<std::string> report = CollectReport(stability_file);

[Sigurður Ásgeirsson, 2017/05/11 13:48:32]

yups, just return the extension stream thingy from CollectReport?

[manzagop (departed), 2017/05/11 14:54:45]

Done.

+  if (!report)
+    return nullptr;
+
+  return base::WrapUnique(new BufferExtensionStreamDataSource(
+      kStabilityReportStreamType, std::move(report)));
+}
+
+}  // namespace browser_watcher