summaryrefslogtreecommitdiff
path: root/src/mongo/base/initializer.h
blob: a8abc6603b3e73f538fbe554caa1717e30f117f6 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
/*    Copyright 2012 10gen Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
 *    as published by the Free Software Foundation.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU Affero General Public License for more details.
 *
 *    You should have received a copy of the GNU Affero General Public License
 *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 *
 *    As a special exception, the copyright holders give permission to link the
 *    code of portions of this program with the OpenSSL library under certain
 *    conditions as described in each individual source file and distribute
 *    linked combinations including the program with the OpenSSL library. You
 *    must comply with the GNU Affero General Public License in all respects
 *    for all of the code used other than as permitted herein. If you modify
 *    file(s) with this exception, you may extend this exception to your
 *    version of the file(s), but you are not obligated to do so. If you do not
 *    wish to do so, delete this exception statement from your version. If you
 *    delete this exception statement from all source files in the program,
 *    then also delete it in the license file.
 */

#pragma once

#include <string>
#include <vector>

#include "mongo/base/disallow_copying.h"
#include "mongo/base/initializer_context.h"
#include "mongo/base/initializer_dependency_graph.h"
#include "mongo/base/status.h"

namespace mongo {

    /**
     * Class representing an initialization process.
     *
     * Such a process is described by a directed acyclic graph of initialization operations, the
     * InitializerDependencyGraph.  One constructs an initialization process by adding nodes and
     * edges to the graph.  Then, one executes the process, causing each initialization operation to
     * execute in an order that respects the programmer-established prerequistes.
     */
    class Initializer {
        MONGO_DISALLOW_COPYING(Initializer);
    public:
        Initializer();
        ~Initializer();

        /**
         * Get the initializer dependency graph, presumably for the purpose of adding more nodes.
         */
        InitializerDependencyGraph& getInitializerDependencyGraph() { return _graph; }

        /**
         * Execute the initializer process, using the given argv and environment data as input.
         *
         * Returns Status::OK on success.  All other returns constitute initialization failures,
         * and the thing being initialized should be considered dead in the water.
         */
        Status execute(const InitializerContext::ArgumentVector& args,
                       const InitializerContext::EnvironmentMap& env) const;

    private:

        InitializerDependencyGraph _graph;
    };

    /**
     * Run the global initializers.
     *
     * It's a programming error for this to fail, but if it does it will return a status other
     * than Status::OK.
     *
     * This means that the few initializers that might want to terminate the program by failing
     * should probably arrange to terminate the process themselves.
     */
    Status runGlobalInitializers(const InitializerContext::ArgumentVector& args,
                                                  const InitializerContext::EnvironmentMap& env);

    Status runGlobalInitializers(
            int argc, const char* const* argv, const char* const* envp);

    /**
     * Same as runGlobalInitializers(), except prints a brief message to std::cerr
     * and terminates the process on failure.
     */
    void runGlobalInitializersOrDie(
            int argc, const char* const* argv, const char* const* envp);

}  // namespace mongo