win: Implementation of CrashReportDatabase for Windows

client/crash_report_database_win.cc

+// Copyright 2015 The Crashpad Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "client/crash_report_database.h"
+
+#include <rpc.h>
+#include <time.h>
+#include <windows.h>
+
+#include "base/logging.h"
+#include "base/numerics/safe_math.h"
+#include "base/strings/stringprintf.h"
+#include "base/strings/utf_string_conversions.h"
+
+namespace crashpad {
+
+namespace {
+
+const wchar_t kDatabaseDirectoryName[] = L"Crashpad";
+
+const wchar_t kReportsDirectory[] = L"reports";
+const wchar_t kMetadataFileName[] = L"metadata";
+
+const wchar_t kCrashReportFileExtension[] = L"dmp";
+
+enum class ReportState : int {
+  //! \brief Created and filled out by caller, owned by database.
+  kPending,
+  //! \brief In the process of uploading, owned by caller.
+  kUploading,
+  //! \brief Upload completed or skipped, owned by database.
+  kCompleted,
+};
+
+using OperationStatus = CrashReportDatabase::OperationStatus;
+
+//! \brief Ensures that the node at path is a directory, and creates it if it
+//!     does not exist.
+//!
+//! \return If the path points to a file, rather than a directory, or the
+//!     directory could not be created, returns `false`. Otherwise, returns
+//!     `true`, indicating that path already was or now is a directory.
+bool CreateOrEnsureDirectoryExists(const base::FilePath& path) {
+  if (CreateDirectory(path.value().c_str(), nullptr)) {
+    return true;
+  } else if (GetLastError() == ERROR_ALREADY_EXISTS) {
+    DWORD fileattr = GetFileAttributes(path.value().c_str());
+    if (fileattr == INVALID_FILE_ATTRIBUTES) {
+      PLOG(ERROR) << "GetFileAttributes";
+      return false;
+    }
+    if ((fileattr & FILE_ATTRIBUTE_DIRECTORY) != 0)
+      return true;
+    LOG(ERROR) << "not a directory";
+    return false;
+  } else {
+    PLOG(ERROR) << "CreateDirectory";
+    return false;
+  }
+}
+
+//! \brief A private extension of the Report class that includes additional data
+//!     that's stored on disk in the metadata file.
+struct ReportDisk : public CrashReportDatabase::Report {
+  //! \brief The current state of the report.
+  ReportState state;
+};
+
+//! \brief A private extension of the NewReport class to hold the UUID during
+//!     initial write. We don't store metadata in dump's file attributes, and
+//!     use the UUID to identify the dump on write completion.
+struct NewReportDisk : public CrashReportDatabase::NewReport {
+  //! \brief The UUID for this crash report.
+  UUID uuid;
+};
+
+//! \brief Manages the metadata for the set of reports, handling serialization
+//!     to disk, and queries. Instances of this class should be created by using
+//!     CrashReportDatabaseWin::AcquireMetadata().
+class Metadata {
+ public:
+  //! \brief Writes any changes if necessary, unlocks and closes the file
+  //!     handle.
+  ~Metadata();
+
+  //! \brief Adds a new report to the set.
+  //!
+  //! \param[in] new_report_disk The record to add. The #state field must be set
+  //!     to kPending.
+  void AddNewRecord(const ReportDisk& new_report_disk);
+
+  //! \brief Finds all reports in a given state. The \a reports vector is only
+  //!     valid when CrashReportDatabase::kNoError is returned.
+  //!
+  //! \param[in] desired_state The state to match.
+  //! \param[out] reports Matching reports, must be empty on entry.
+  OperationStatus FindReports(
+      ReportState desired_state,
+      std::vector<const CrashReportDatabase::Report>* reports);
+
+  //! \brief Finds the report matching the given UUID.
+  //!
+  //! The returned report is only valid if CrashReportDatabase::kNoError is
+  //! returned.
+  //!
+  //! \param[in] uuid The report identifier.
+  //! \param[out] report_disk The found report, valid only if
+  //!     CrashReportDatabase::kNoError is returned. Ownership is not
+  //!     transferred to the caller, and the report may not be modified.
+  OperationStatus FindSingleReport(const UUID& uuid,
+                                   const ReportDisk** report_disk);
+
+  //! \brief Finds a single report matching the given UUID and in the desired
+  //!     state and calls the client-supplied mutator to modify the report.
+  //!
+  //! The mutator object must have an operator()(ReportDisk*) which makes the
+  //! desired changes.
+  //!
+  //! \return #kNoError on success. #kReportNotFound if there was no report with
+  //!     the specified UUID. #kBusyError if the report was not in the specified
+  //!     state.
+  template <class T>
+  OperationStatus MutateSingleReport(const UUID& uuid,
+                                     ReportState desired_state,
+                                     const T& mutator);
+
+ private:
+  static scoped_ptr<Metadata> Create(const base::FilePath& metadata_file,
+                                     const base::FilePath& report_dir);
+  friend class CrashReportDatabaseWin;
+
+  Metadata(FileHandle handle, const base::FilePath& report_dir);
+
+  bool Rewind();
+
+  void Read();
+  void Write();
+
+  //! \brief Confirms that the corresponding report actually exists on disk
+  //!     (that is, the dump file has not been removed), that the report is in
+  //!     the given state.
+  static OperationStatus VerifyReport(const ReportDisk& report_disk,
+                                      ReportState desired_state);
+  //! \brief Confirms that the corresponding report actually exists on disk
+  //!     (that is, the dump file has not been removed).
+  static OperationStatus VerifyReportAnyState(const ReportDisk& report_disk);
+
+  ScopedFileHandle handle_;
+  const base::FilePath report_dir_;
+  bool dirty_;  //! \brief Is a Write() required on destruction?
+  std::vector<ReportDisk> reports_;
+
+  DISALLOW_COPY_AND_ASSIGN(Metadata);
+};
+
+Metadata::Metadata(FileHandle handle, const base::FilePath& report_dir)
+    : handle_(handle), report_dir_(report_dir), dirty_(false), reports_() {
+}
+
+Metadata::~Metadata() {
+  if (dirty_)
+    Write();
+  // Not actually async, UnlockFileEx requires the Offset fields.
+  OVERLAPPED overlapped = {0};
+  if (!UnlockFileEx(handle_.get(), 0, MAXDWORD, MAXDWORD, &overlapped))
+    PLOG(ERROR) << "UnlockFileEx";
+}
+
+// The format of the metadata file is a MetadataFileHeader, followed by a
+// number of fixed size records of MetadataFileReportRecord, followed by a
+// string table in UTF8 format, where each string is \0 terminated.
+
+#pragma pack(push, 1)
+
+struct MetadataFileHeader {
+  uint32_t magic;
+  uint32_t version;
+  uint32_t num_records;
+  uint32_t padding;
+};
+
+struct MetadataFileReportRecord {
+  UUID uuid;  // UUID is a 16 byte, standard layout structure.
+  uint32_t file_path_index;  // Index into string table. File name is relative
+                             // to the reports directory when on disk.
+  uint32_t id_index;  // Index into string table.
+  int64_t creation_time;  // Holds a time_t.
+  int64_t last_upload_attempt_time;  // Holds a time_t.
+  int32_t upload_attempts;
+  int32_t state;  // A ReportState.
+  uint8_t uploaded;  // Boolean, 0 or 1.
+  uint8_t padding[7];
+};
+
+const uint32_t kMetadataFileHeaderMagic = 'CPAD';
+const uint32_t kMetadataFileVersion = 1;
+
+#pragma pack(pop)
+
+// Reads from the current file position to EOF and returns as uint8_t[].
+std::string ReadRestOfFileAsString(FileHandle file) {
+  FileOffset read_from = LoggingSeekFile(file, 0, SEEK_CUR);
+  FileOffset end = LoggingSeekFile(file, 0, SEEK_END);
+  FileOffset original = LoggingSeekFile(file, read_from, SEEK_SET);
+  if (read_from == -1 || end == -1 || original == -1)
+    return std::string();
+  DCHECK_EQ(read_from, original);
+  DCHECK_GE(end, read_from);
+  size_t data_length = static_cast<size_t>(end - read_from);
+  std::string buffer(data_length, '\0');
+  if (!LoggingReadFile(file, &buffer[0], data_length))
+    return std::string();
+  return buffer;
+}
+
+uint32_t AddStringToTable(std::string* string_table, const std::string& str) {
+  uint32_t offset = base::checked_cast<uint32_t>(string_table->size());
+  *string_table += str;
+  *string_table += '\0';
+  return offset;
+}
+
+uint32_t AddStringToTable(std::string* string_table, const std::wstring& str) {
+  return AddStringToTable(string_table, base::UTF16ToUTF8(str));
+}
+
+// static
+scoped_ptr<Metadata> Metadata::Create(const base::FilePath& metadata_file,
+                                      const base::FilePath& report_dir) {
+  // It is important that dwShareMode be non-zero so that concurrent access to
+  // this file results in a successful open. This allows us to get to LockFileEx
+  // which then blocks to guard access.
+  FileHandle handle = CreateFile(metadata_file.value().c_str(),
+                                 GENERIC_READ | GENERIC_WRITE,
+                                 FILE_SHARE_READ | FILE_SHARE_WRITE,
+                                 nullptr,
+                                 OPEN_ALWAYS,
+                                 FILE_ATTRIBUTE_NORMAL,
+                                 nullptr);
+  if (handle == kInvalidFileHandle)
+    return scoped_ptr<Metadata>();
+  // Not actually async, LockFileEx requires the Offset fields.
+  OVERLAPPED overlapped = {0};
+  if (!LockFileEx(handle,
+                  LOCKFILE_EXCLUSIVE_LOCK,
+                  0,
+                  MAXDWORD,
+                  MAXDWORD,
+                  &overlapped)) {
+    PLOG(ERROR) << "LockFileEx";
+    return scoped_ptr<Metadata>();
+  }
+
+  scoped_ptr<Metadata> metadata(new Metadata(handle, report_dir));
+  // If Read() fails, for whatever reason (corruption, etc.) metadata will not
+  // have been modified and will be in a clean empty state. We continue on and
+  // return an empty database to hopefully recover. This means that existing
+  // crash reports have been orphaned.
+  metadata->Read();
+  return metadata;
+}
+
+bool Metadata::Rewind() {
+  FileOffset result = LoggingSeekFile(handle_.get(), 0, SEEK_SET);
+  DCHECK_EQ(result, 0);
+  return result == 0;
+}
+
+void Metadata::Read() {
+  FileOffset length = LoggingSeekFile(handle_.get(), 0, SEEK_END);
+  if (length <= 0)  // Failed, or empty: Abort.
+    return;
+  if (!Rewind()) {
+    LOG(ERROR) << "failed to rewind to read";
+    return;
+  }
+
+  MetadataFileHeader header;
+  if (!LoggingReadFile(handle_.get(), &header, sizeof(header))) {
+    LOG(ERROR) << "failed to read header";
+    return;
+  }
+  if (header.magic != kMetadataFileHeaderMagic ||
+      header.version != kMetadataFileVersion) {
+    LOG(ERROR) << "unexpected header";
+    return;
+  }
+
+  auto records_size = base::CheckedNumeric<uint32_t>(header.num_records) *
+                      sizeof(MetadataFileReportRecord);
+  if (!records_size.IsValid()) {
+    LOG(ERROR) << "record size out of range";
+    return;
+  }
+
+  scoped_ptr<MetadataFileReportRecord[]> records(
+      new MetadataFileReportRecord[header.num_records]);
+  if (!LoggingReadFile(
+          handle_.get(), records.get(), records_size.ValueOrDie())) {
+    LOG(ERROR) << "failed to read records";
+    return;
+  }
+
+  std::string string_table = ReadRestOfFileAsString(handle_.get());
+  if (string_table.empty() || string_table.back() != 0) {

[Mark Mentovai, 2015/02/11 19:39:56]

Use '\0' since this is looking at a char now.

[scottmg, 2015/02/11 19:56:52]

Done.

+    LOG(ERROR) << "bad string table";
+    return;
+  }
+  for (uint32_t i = 0; i < header.num_records; ++i) {
+    ReportDisk r;
+    const MetadataFileReportRecord* record = &records[i];
+    r.uuid = record->uuid;
+    if (record->file_path_index >= string_table.size() ||
+        record->id_index >= string_table.size()) {
+      reports_.clear();
+      LOG(ERROR) << "invalid string table index";
+      return;
+    }
+    r.file_path = report_dir_.Append(
+        base::UTF8ToUTF16(&string_table[record->file_path_index]));
+    r.id = &string_table[record->id_index];
+    r.creation_time = record->creation_time;
+    r.uploaded = record->uploaded;
+    r.last_upload_attempt_time = record->last_upload_attempt_time;
+    r.upload_attempts = record->upload_attempts;
+    r.state = static_cast<ReportState>(record->state);
+    reports_.push_back(r);
+  }
+}
+
+void Metadata::Write() {
+  if (!Rewind()) {
+    LOG(ERROR) << "failed to rewind to write";
+    return;
+  }
+
+  // Truncate to ensure that a partial write doesn't cause a mix of old and new
+  // data causing an incorrect interpretation on read.
+  SetEndOfFile(handle_.get());

[Mark Mentovai, 2015/02/11 19:39:56]

Check the return value and PLOG and return on failure.

[scottmg, 2015/02/11 19:56:52]

Done.

+
+  size_t num_records = reports_.size();
+
+  // Fill and write out the header.
+  MetadataFileHeader header = {0};
+  header.magic = kMetadataFileHeaderMagic;
+  header.version = kMetadataFileVersion;
+  header.num_records = base::checked_cast<uint32_t>(num_records);
+  if (!LoggingWriteFile(handle_.get(), &header, sizeof(header))) {
+    LOG(ERROR) << "failed to write header";
+    return;
+  }
+
+  // Build the records and string table we're going to write.
+  std::string string_table;
+  scoped_ptr<MetadataFileReportRecord[]> records(
+      new MetadataFileReportRecord[num_records]);
+  memset(records.get(), 0, sizeof(MetadataFileReportRecord) * num_records);

[Mark Mentovai, 2015/02/11 19:39:56]

Good, I was hoping to see this. #include <string.h>.

[scottmg, 2015/02/11 19:56:52]

Done.

+  for (size_t i = 0; i < num_records; ++i) {
+    const ReportDisk& report = reports_[i];
+    MetadataFileReportRecord& record = records[i];
+    record.uuid = report.uuid;
+    const base::FilePath& path = report.file_path;
+    if (path.DirName() != report_dir_) {
+      LOG(ERROR) << path.value().c_str() << " expected to start with "

[Mark Mentovai, 2015/02/11 19:39:56]

I didn’t think you needed the c_str() here or on the next line, but if you do
(because you can use wchar_t* but not wstring?), it’s fine to keep.

[scottmg, 2015/02/11 19:56:52]

Yeah, there's no operator<< for wstring in ostream, and logging doesn't have its
own.

+                 << report_dir_.value().c_str() << " and does not";

[Mark Mentovai, 2015/02/11 19:39:56]

“and does not” is kind of obvious, save a few bytes.

[scottmg, 2015/02/11 19:56:52]

Done.

+      return;
+    }
+    record.file_path_index =
+        AddStringToTable(&string_table, path.BaseName().value().c_str());
+    record.id_index = AddStringToTable(&string_table, report.id);
+    record.creation_time = report.creation_time;
+    record.uploaded = report.uploaded;
+    record.last_upload_attempt_time = report.last_upload_attempt_time;
+    record.upload_attempts = report.upload_attempts;
+    record.state = static_cast<uint32_t>(report.state);
+  }
+
+  if (!LoggingWriteFile(handle_.get(),
+                        records.get(),
+                        num_records * sizeof(MetadataFileReportRecord))) {
+    LOG(ERROR) << "failed to write records";
+    return;
+  }
+  if (!LoggingWriteFile(
+          handle_.get(), string_table.c_str(), string_table.size())) {
+    LOG(ERROR) << "failed to write string table";
+    return;
+  }
+}
+
+void Metadata::AddNewRecord(const ReportDisk& new_report_disk) {
+  DCHECK(new_report_disk.state == ReportState::kPending);
+  reports_.push_back(new_report_disk);
+  dirty_ = true;
+}
+
+OperationStatus Metadata::FindReports(
+    ReportState desired_state,
+    std::vector<const CrashReportDatabase::Report>* reports) {
+  DCHECK(reports->empty());
+  for (const auto& report : reports_) {
+    if (report.state == desired_state) {
+      if (VerifyReport(report, desired_state) != CrashReportDatabase::kNoError)
+        continue;
+      reports->push_back(report);
+    }
+  }
+  return CrashReportDatabase::kNoError;
+}
+
+OperationStatus Metadata::FindSingleReport(const UUID& uuid,
+                                           const ReportDisk** out_report) {
+  for (size_t i = 0; i < reports_.size(); ++i) {
+    if (reports_[i].uuid == uuid) {
+      OperationStatus os = VerifyReportAnyState(reports_[i]);
+      if (os != CrashReportDatabase::kNoError)
+        return os;
+      *out_report = &reports_[i];
+      return CrashReportDatabase::kNoError;
+    }
+  }
+  return CrashReportDatabase::kReportNotFound;
+}
+
+template <class T>
+OperationStatus Metadata::MutateSingleReport(
+    const UUID& uuid,
+    ReportState desired_state,
+    const T& mutator) {
+  for (size_t i = 0; i < reports_.size(); ++i) {
+    if (reports_[i].uuid == uuid) {
+      OperationStatus os = VerifyReport(reports_[i], desired_state);
+      if (os != CrashReportDatabase::kNoError)
+        return os;
+      mutator(&reports_[i]);
+      dirty_ = true;
+      return CrashReportDatabase::kNoError;
+    }
+  }
+  return CrashReportDatabase::kReportNotFound;
+}
+
+// static
+OperationStatus Metadata::VerifyReportAnyState(const ReportDisk& report_disk) {
+  DWORD fileattr = GetFileAttributes(report_disk.file_path.value().c_str());
+  if (fileattr == INVALID_FILE_ATTRIBUTES)
+    return CrashReportDatabase::kReportNotFound;
+  if ((fileattr & FILE_ATTRIBUTE_DIRECTORY) != 0)
+    return CrashReportDatabase::kFileSystemError;
+  return CrashReportDatabase::kNoError;
+}
+
+// static
+OperationStatus Metadata::VerifyReport(const ReportDisk& report_disk,
+                                       ReportState desired_state) {
+  if (report_disk.state != desired_state)
+    return CrashReportDatabase::kBusyError;
+  return VerifyReportAnyState(report_disk);
+}
+
+class CrashReportDatabaseWin : public CrashReportDatabase {
+ public:
+  explicit CrashReportDatabaseWin(const base::FilePath& path);
+  ~CrashReportDatabaseWin() override;
+
+  bool Initialize();
+
+  // CrashReportDatabase:
+  OperationStatus PrepareNewCrashReport(NewReport** report) override;
+  OperationStatus FinishedWritingCrashReport(NewReport* report,
+                                             UUID* uuid) override;
+  OperationStatus ErrorWritingCrashReport(NewReport* report) override;
+  OperationStatus LookUpCrashReport(const UUID& uuid, Report* report) override;
+  OperationStatus GetPendingReports(
+      std::vector<const Report>* reports) override;
+  OperationStatus GetCompletedReports(
+      std::vector<const Report>* reports) override;
+  OperationStatus GetReportForUploading(const UUID& uuid,
+                                        const Report** report) override;
+  OperationStatus RecordUploadAttempt(const Report* report,
+                                      bool successful,
+                                      const std::string& id) override;
+  OperationStatus SkipReportUpload(const UUID& uuid) override;
+
+ private:
+  scoped_ptr<Metadata> AcquireMetadata();
+
+  base::FilePath base_dir_;
+
+  DISALLOW_COPY_AND_ASSIGN(CrashReportDatabaseWin);
+};
+
+CrashReportDatabaseWin::CrashReportDatabaseWin(const base::FilePath& path)
+    : CrashReportDatabase(), base_dir_(path) {
+}
+
+CrashReportDatabaseWin::~CrashReportDatabaseWin() {
+}
+
+bool CrashReportDatabaseWin::Initialize() {
+  // Check if the database already exists.
+  if (!CreateOrEnsureDirectoryExists(base_dir_))
+    return false;
+
+  // Create our reports subdirectory.
+  if (!CreateOrEnsureDirectoryExists(base_dir_.Append(kReportsDirectory)))
+    return false;
+
+  // TODO(scottmg): When are completed reports pruned from disk? Delete here or
+  // maybe on AcquireMetadata().
+
+  return true;
+}
+
+OperationStatus CrashReportDatabaseWin::PrepareNewCrashReport(
+    NewReport** out_report) {
+  scoped_ptr<NewReportDisk> report(new NewReportDisk());
+
+  ::UUID system_uuid;
+  if (UuidCreate(&system_uuid) != RPC_S_OK) {
+    return kFileSystemError;
+  }
+  static_assert(sizeof(system_uuid) == 16, "unexpected system uuid size");
+  static_assert(offsetof(::UUID, Data1) == 0, "unexpected uuid layout");
+  UUID uuid(reinterpret_cast<const uint8_t*>(&system_uuid.Data1));
+
+  report->uuid = uuid;
+  report->path =
+      base_dir_.Append(kReportsDirectory)
+          .Append(uuid.ToWideString() + L"." + kCrashReportFileExtension);
+  report->handle = LoggingOpenFileForWrite(
+      report->path, FileWriteMode::kCreateOrFail, FilePermissions::kOwnerOnly);
+  if (report->handle == INVALID_HANDLE_VALUE)
+    return kFileSystemError;
+
+  *out_report = report.release();
+  return kNoError;
+}
+
+OperationStatus CrashReportDatabaseWin::FinishedWritingCrashReport(
+    NewReport* report,
+    UUID* uuid) {
+  // Take ownership of the report, and cast to our private version with UUID.
+  scoped_ptr<NewReportDisk> scoped_report(static_cast<NewReportDisk*>(report));
+  // Take ownership of the file handle.
+  ScopedFileHandle handle(report->handle);
+
+  scoped_ptr<Metadata> metadata(AcquireMetadata());
+  if (!metadata)
+    return kDatabaseError;
+  ReportDisk report_disk;
+  report_disk.uuid = scoped_report->uuid;
+  report_disk.file_path = scoped_report->path;
+  report_disk.creation_time = time(nullptr);
+  report_disk.state = ReportState::kPending;
+  metadata->AddNewRecord(report_disk);
+  *uuid = report_disk.uuid;
+  return kNoError;
+}
+
+OperationStatus CrashReportDatabaseWin::ErrorWritingCrashReport(
+    NewReport* report) {
+  // Take ownership of the report, and cast to our private version with UUID.
+  scoped_ptr<NewReportDisk> scoped_report(static_cast<NewReportDisk*>(report));
+
+  // Close the outstanding handle.
+  LoggingCloseFile(report->handle);
+
+  // We failed to write, so remove the dump file. There's no entry in the
+  // metadata table yet.
+  if (!DeleteFile(scoped_report->path.value().c_str())) {
+    PLOG(ERROR) << "DeleteFile " << scoped_report->path.value().c_str();
+    return CrashReportDatabase::kFileSystemError;
+  }
+
+  return kNoError;
+}
+
+OperationStatus CrashReportDatabaseWin::LookUpCrashReport(const UUID& uuid,
+                                                          Report* report) {
+  scoped_ptr<Metadata> metadata(AcquireMetadata());
+  if (!metadata)
+    return kDatabaseError;
+  // Find and return a copy of the matching report.
+  const ReportDisk* report_disk;
+  OperationStatus os = metadata->FindSingleReport(uuid, &report_disk);
+  if (os != kNoError)
+    return os;
+  *report = *report_disk;
+  return kNoError;
+}
+
+OperationStatus CrashReportDatabaseWin::GetPendingReports(
+    std::vector<const Report>* reports) {
+  scoped_ptr<Metadata> metadata(AcquireMetadata());
+  if (!metadata)
+    return kDatabaseError;
+  return metadata->FindReports(ReportState::kPending, reports);
+}
+
+OperationStatus CrashReportDatabaseWin::GetCompletedReports(
+    std::vector<const Report>* reports) {
+  scoped_ptr<Metadata> metadata(AcquireMetadata());
+  if (!metadata)
+    return kDatabaseError;
+  return metadata->FindReports(ReportState::kCompleted, reports);
+}
+
+OperationStatus CrashReportDatabaseWin::GetReportForUploading(
+    const UUID& uuid,
+    const Report** report) {
+  scoped_ptr<Metadata> metadata(AcquireMetadata());
+  if (!metadata)
+    return kDatabaseError;
+  // TODO(scottmg): After returning this report to the client, there is no way
+  // to reap this report if the uploader fails to call RecordUploadAttempt() or
+  // SkipReportUpload() (if it crashed or was otherwise buggy). To resolve this,
+  // one possibility would be to change the interface to be FileHandle based, so
+  // that instead of giving the file_path back to the client and changing state
+  // to kUploading, we return an exclusive access handle, and use that as the
+  // signal that the upload is pending, rather than an update to state in the
+  // metadata. Alternatively, there could be a "garbage collection" at startup
+  // where any reports that are orphaned in the kUploading state are either
+  // reset to kPending to retry, or discarded.
+  return metadata->MutateSingleReport(
+      uuid, ReportState::kPending, [report](ReportDisk* report_disk) {
+        report_disk->state = ReportState::kUploading;
+        // Create a copy for passing back to client. This will be freed in
+        // RecordUploadAttempt.
+        *report = new Report(*report_disk);
+      });
+}
+
+OperationStatus CrashReportDatabaseWin::RecordUploadAttempt(
+    const Report* report,
+    bool successful,
+    const std::string& id) {
+  // Take ownership, allocated in GetReportForUploading.
+  scoped_ptr<const Report> upload_report(report);
+  scoped_ptr<Metadata> metadata(AcquireMetadata());
+  if (!metadata)
+    return kDatabaseError;
+  return metadata->MutateSingleReport(
+      report->uuid,
+      ReportState::kUploading,
+      [successful, id](ReportDisk* report_disk) {
+        report_disk->uploaded = successful;
+        report_disk->id = id;
+        report_disk->last_upload_attempt_time = time(nullptr);
+        report_disk->upload_attempts++;
+        report_disk->state =
+            successful ? ReportState::kCompleted : ReportState::kPending;
+      });
+}
+
+OperationStatus CrashReportDatabaseWin::SkipReportUpload(const UUID& uuid) {
+  scoped_ptr<Metadata> metadata(AcquireMetadata());
+  if (!metadata)
+    return kDatabaseError;
+  return metadata->MutateSingleReport(
+      uuid, ReportState::kPending, [](ReportDisk* report_disk) {
+        report_disk->state = ReportState::kCompleted;
+      });
+}
+
+scoped_ptr<Metadata> CrashReportDatabaseWin::AcquireMetadata() {
+  base::FilePath metadata_file = base_dir_.Append(kMetadataFileName);
+  return Metadata::Create(metadata_file, base_dir_.Append(kReportsDirectory));
+}
+
+}  // namespace
+
+// static
+scoped_ptr<CrashReportDatabase> CrashReportDatabase::Initialize(
+    const base::FilePath& path) {
+  scoped_ptr<CrashReportDatabaseWin> database_win(
+      new CrashReportDatabaseWin(path.Append(kDatabaseDirectoryName)));
+  if (!database_win->Initialize())
+    database_win.reset();
+
+  return scoped_ptr<CrashReportDatabase>(database_win.release());
+}
+
+}  // namespace crashpad