Create CrashReportDatabase interface, a test, and a Mac implementation.

client/crash_report_database.h

+// 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.
+
+#ifndef CRASHPAD_CLIENT_CRASH_REPORT_DATABASE_H_
+#define CRASHPAD_CLIENT_CRASH_REPORT_DATABASE_H_
+
+#include <time.h>
+
+#include <string>
+#include <vector>
+
+#include "base/basictypes.h"
+#include "base/files/file_path.h"
+#include "base/memory/scoped_ptr.h"
+#include "util/file/file_io.h"
+#include "util/misc/uuid.h"
+
+namespace crashpad {
+
+//! \brief An interface for managing a collection of crash report files and
+//!     metadata associated with the crash reports.
+//!
+//! All Report objects that are returned by this class are logically const.
+//! They are snapshots of the database at the time the query was run, and the
+//! data returned is liable to change after the query is executed.
+//!
+//! The lifecycle of a crash report has three stages:
+//!
+//!   1. New: A crash report is created with PrepareNewCrashReport(), the
+//!      the client then writes the report, and then calls
+//!      FinishedWritingCrashReport() to make the report Pending.
+//!   2. Pending: The report has been written but has not been locally
+//!      processed.
+//!   3. Completed: The report has been locally processed, either by uploading
+//!      it to a collection server and calling RecordUploadAttempt(), or by
+//!      calling SkipReportUpload().
+class CrashReportDatabase {
+ public:
+  //! \brief A crash report record.
+  //!
+  //! This represents the metadata for a crash report, as well as the location
+  //! of the report itself. A CrashReportDatabase maintains at least this
+  //! information.
+  struct Report {
+    Report();
+
+    //! A unique identifier by which this report will always be known to the
+    //! database.
+    UUID uuid;
+
+    //! The current location of the crash report on the client’s filesystem.
+    //! The location of a crash report may change over time, so the UUID should
+    //! be used as the canonical identifier.
+    base::FilePath file_path;
+
+    //! An identifier issued to this crash report by a collection server.
+    std::string id;
+
+    //! The time at which the report was generated.
+    time_t creation_time;
+
+    //! Whether this crash report was successfully uploaded to a collection
+    //! server.
+    bool uploaded;
+
+    //! The last timestamp at which an attempt was made to submit this crash
+    //! report to a collection server. If this is zero, then the report has
+    //! never been uploaded. If #uploaded is true, then this timestamp is the
+    //! time at which the report was uploaded, and no other attempts to upload
+    //! this report will be made.
+    time_t last_upload_attempt_time;
+
+    //! The number of times an attempt was made to submit this report to
+    //! a collection server. If this is more than zero, then
+    //! #last_upload_attempt_time will be set to the timestamp of the most
+    //! recent attempt.
+    int upload_attempts;
+  };
+
+  //! \brief A crash report that is in the process of being written.
+  //!
+  //! An instance of this struct should be created via PrepareNewCrashReport()
+  //! and destroyed with FinishedWritingCrashReport().
+  struct NewReport {
+    //! The file handle to which the report should be written.
+    FileHandle handle;
+
+    //! The path to the crash report being written.
+    base::FilePath path;
+  };
+
+  //! \brief The result code for operations performed on a database.
+  enum OperationStatus {
+    //! \brief No error occurred.
+    kNoError = 0,
+
+    //! \brief The report that was requested could not be located.
+    kReportNotFound,
+
+    //! \brief An error occured while performing a file operation on a crash
+    //!     report.
+    //!
+    //! A database is responsible for managing both the metadata about a report
+    //! and the actual crash report itself. This error is returned when an
+    //! error occurred when managing the report file. Additional information
+    //! will be logged.
+    kFileSystemError,
+
+    //! \brief An error occured while recording metadata for a crash report.
+    //!
+    //! A database is responsible for managing both the metadata about a report
+    //! and the actual crash report itself. This error is returned when an
+    //! error occurred when managing the metadata about a crash report.
+    //! Additional information will be logged.
+    kDatabaseError,
+
+    //! \brief The operation could not be completed because a concurrent
+    //!     operation affecting the report is occurring.
+    kBusyError,
+  };
+
+  virtual ~CrashReportDatabase() {}
+
+  //! \brief Initializes a database of crash reports.
+  //!
+  //! \param[in] path A path to a writable directory, where the database can
+  //!     be created or opened.
+  //!
+  //! \return A database object on success, `nullptr` on failure with an error
+  //!     logged.
+  static scoped_ptr<CrashReportDatabase> Initialize(const base::FilePath& path);
+
+  //! \brief Creates a record of a new crash report.
+  //!
+  //! Callers can then write the crash report using the file handle provided.
+  //! The caller does not own this handle, and it must be explicitly closed with
+  //! FinishedWritingCrashReport().
+  //!
+  //! \param[out] report A file handle to which the crash report data should be
+  //!     written. Only valid if this returns #kNoError. The caller must not
+  //!     close this handle.
+  //!
+  //! \return The operation status code.
+  virtual OperationStatus PrepareNewCrashReport(NewReport** report) = 0;
+
+  //! \brief Informs the database that a crash report has been written.
+  //!
+  //! After calling this method, the database is permitted to move and rename
+  //! the file at Report::file_path.
+  //!
+  //! \param[in] report A handle obtained with PrepareNewCrashReport(). The
+  //!     handle will be invalidated as part of this call.
+  //! \param[out] uuid The UUID of this crash report.
+  //!
+  //! \return The operation status code.
+  virtual OperationStatus FinishedWritingCrashReport(NewReport* report,
+                                                     UUID* uuid) = 0;
+
+  //! \brief Returns the crash report record for the unique identifier.
+  //!
+  //! \param[in] uuid The crash report record unique identifier.
+  //! \param[out] report A crash report record. Only valid if this returns
+  //!     #kNoError.
+  //!
+  //! \return The operation status code.
+  virtual OperationStatus LookUpCrashReport(const UUID& uuid,
+                                            Report* report) = 0;
+
+  //! \brief Returns a list of crash report records that have not been uploaded.
+  //!
+  //! \param[out] reports A list of crash report record objects. This must be
+  //!     empty on entry. Only valid if this returns #kNoError.
+  //!
+  //! \return The operation status code.
+  virtual OperationStatus GetPendingReports(
+      std::vector<const Report>* reports) = 0;
+
+  //! \brief Returns a list of crash report records that have been completed,
+  //!     either by being uploaded or by skipping upload.
+  //!
+  //! \param[out] reports A list of crash report record objects. This must be
+  //!     empty on entry. Only valid if this returns #kNoError.
+  //!
+  //! \return The operation status code.
+  virtual OperationStatus GetCompletedReports(
+      std::vector<const Report>* reports) = 0;
+
+  //! \brief Obtains a report object for uploading to a collection server.
+  //!
+  //! The file at Report::file_path should be uploaded by the caller, and then
+  //! the returned Report object must be disposed of via a call to
+  //! RecordUploadAttempt().
+  //!
+  //! A subsequent call to this method with the same \a uuid is illegal until
+  //! RecordUploadAttempt() has been called.
+  //!
+  //! \param[in] uuid The unique identifier for the crash report record.
+  //! \param[out] report A crash report record for the report to be uploaded.
+  //!     The caller does not own this object. Only valid if this returns
+  //!     #kNoError.
+  //!
+  //! \return The operation status code.
+  virtual OperationStatus GetReportForUploading(const UUID& uuid,
+                                                const Report** report) = 0;
+
+  //! \brief Adjusts a crash report record’s metadata to account for an upload
+  //!     attempt.
+  //!
+  //! After calling this method, the database is permitted to move and rename
+  //! the file at Report::file_path.
+  //!
+  //! \param[in] report The report object obtained from
+  //!     GetReportForUploading(). This object is invalidated after this call.
+  //! \param[in] successful Whether the upload attempt was successful.
+  //! \param[in] id The identifier assigned to this crash report by the
+  //!     collection server. Must be empty if \a successful is `false`; may be
+  //!     empty if it is `true`.
+  //!
+  //! \return The operation status code.
+  virtual OperationStatus RecordUploadAttempt(const Report* report,
+                                              bool successful,
+                                              const std::string& id) = 0;
+
+  //! \brief Moves a report from the pending state to the completed state, but
+  //!     without the report being uploaded.
+  //!
+  //! This can be used if the user has disabled crash report collection, but
+  //! crash generation is still enabled in the product.
+  //!
+  //! \param[in] uuid The unique identifier for the crash report record.
+  //!
+  //! \return The operation status code.
+  virtual OperationStatus SkipReportUpload(const UUID& uuid) = 0;
+
+ protected:
+  CrashReportDatabase() {}
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(CrashReportDatabase);
+};
+
+}  // namespace crashpad
+
+#endif  // CRASHPAD_CLIENT_CRASH_REPORT_DATABASE_H_