1 // Copyright 2015 The Crashpad Authors. All rights reserved.
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 //     http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 
15 #ifndef CRASHPAD_CLIENT_PRUNE_CRASH_REPORTS_H_
16 #define CRASHPAD_CLIENT_PRUNE_CRASH_REPORTS_H_
17 
18 #include <sys/types.h>
19 #include <time.h>
20 
21 #include <memory>
22 
23 #include "base/macros.h"
24 #include "client/crash_report_database.h"
25 
26 namespace crashpad {
27 
28 class PruneCondition;
29 
30 //! \brief Deletes crash reports from \a database that match \a condition.
31 //!
32 //! This function can be used to remove old or large reports from the database.
33 //! The \a condition will be evaluated against each report in the \a database,
34 //! sorted in descending order by CrashReportDatabase::Report::creation_time.
35 //! This guarantee allows conditions to be stateful.
36 //!
37 //! \param[in] database The database from which crash reports will be deleted.
38 //! \param[in] condition The condition against which all reports in the database
39 //!     will be evaluated.
40 //!
41 //! \return The number of deleted crash reports.
42 size_t PruneCrashReportDatabase(CrashReportDatabase* database,
43                                 PruneCondition* condition);
44 
45 std::unique_ptr<PruneCondition> GetDefaultDatabasePruneCondition();
46 
47 //! \brief An abstract base class for evaluating crash reports for deletion.
48 //!
49 //! When passed to PruneCrashReportDatabase(), each crash report in the
50 //! database will be evaluated according to ShouldPruneReport(). The reports
51 //! are evaluated serially in descending sort order by
52 //! CrashReportDatabase::Report::creation_time.
53 class PruneCondition {
54  public:
55   //! \brief Returns a sensible default condition for removing obsolete crash
56   //!     reports.
57   //!
58   //! The default is to keep reports for one year or a maximum database size
59   //! of 128 MB.
60   //!
61   //! \return A PruneCondition for use with PruneCrashReportDatabase().
62   static std::unique_ptr<PruneCondition> GetDefault();
63 
~PruneCondition()64   virtual ~PruneCondition() {}
65 
66   //! \brief Evaluates a crash report for deletion.
67   //!
68   //! \param[in] report The crash report to evaluate.
69   //!
70   //! \return `true` if the crash report should be deleted, `false` if it
71   //!     should be kept.
72   virtual bool ShouldPruneReport(const CrashReportDatabase::Report& report) = 0;
73 };
74 
75 //! \brief A PruneCondition that deletes reports older than the specified number
76 //!     days.
77 class AgePruneCondition final : public PruneCondition {
78  public:
79   //! \brief Creates a PruneCondition based on Report::creation_time.
80   //!
81   //! \param[in] max_age_in_days Reports created more than this many days ago
82   //!     will be deleted.
83   explicit AgePruneCondition(int max_age_in_days);
84   ~AgePruneCondition();
85 
86   bool ShouldPruneReport(const CrashReportDatabase::Report& report) override;
87 
88  private:
89   const time_t oldest_report_time_;
90 
91   DISALLOW_COPY_AND_ASSIGN(AgePruneCondition);
92 };
93 
94 //! \brief A PruneCondition that deletes older reports to keep the total
95 //!     Crashpad database size under the specified limit.
96 class DatabaseSizePruneCondition final : public PruneCondition {
97  public:
98   //! \brief Creates a PruneCondition that will keep newer reports, until the
99   //!     sum of the size of all reports is not smaller than \a max_size_in_kb.
100   //!     After the limit is reached, older reports will be pruned.
101   //!
102   //! \param[in] max_size_in_kb The maximum number of kilobytes that all crash
103   //!     reports should consume.
104   explicit DatabaseSizePruneCondition(size_t max_size_in_kb);
105   ~DatabaseSizePruneCondition();
106 
107   bool ShouldPruneReport(const CrashReportDatabase::Report& report) override;
108 
109  private:
110   const size_t max_size_in_kb_;
111   size_t measured_size_in_kb_;
112 
113   DISALLOW_COPY_AND_ASSIGN(DatabaseSizePruneCondition);
114 };
115 
116 //! \brief A PruneCondition that conjoins two other PruneConditions.
117 class BinaryPruneCondition final : public PruneCondition {
118  public:
119   enum Operator {
120     AND,
121     OR,
122   };
123 
124   //! \brief Evaluates two sub-conditions according to the specified logical
125   //!     operator.
126   //!
127   //! This implements left-to-right evaluation. For Operator::AND, this means
128   //! if the \a lhs is `false`, the \a rhs will not be consulted. Similarly,
129   //! with Operator::OR, if the \a lhs is `true`, the \a rhs will not be
130   //! consulted.
131   //!
132   //! \param[in] op The logical operator to apply on \a lhs and \a rhs.
133   //! \param[in] lhs The left-hand side of \a op. This class takes ownership.
134   //! \param[in] rhs The right-hand side of \a op. This class takes ownership.
135   BinaryPruneCondition(Operator op, PruneCondition* lhs, PruneCondition* rhs);
136   ~BinaryPruneCondition();
137 
138   bool ShouldPruneReport(const CrashReportDatabase::Report& report) override;
139 
140  private:
141   const Operator op_;
142   std::unique_ptr<PruneCondition> lhs_;
143   std::unique_ptr<PruneCondition> rhs_;
144 
145   DISALLOW_COPY_AND_ASSIGN(BinaryPruneCondition);
146 };
147 
148 }  // namespace crashpad
149 
150 #endif  // CRASHPAD_CLIENT_PRUNE_CRASH_REPORTS_H_
151