summaryrefslogtreecommitdiff
path: root/src/mongo/db/client.h
blob: ef78f899154670285ad3703c4cafc8c04db124ab (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
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
/* @file db/client.h

   "Client" represents a connection to the database (the server-side) and corresponds
   to an open socket (or logical connection if pooling on sockets) from a client.

   todo: switch to asio...this will fit nicely with that.
*/

/**
*    Copyright (C) 2008 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 "mongo/db/client_basic.h"
#include "mongo/db/concurrency/d_concurrency.h"
#include "mongo/db/lasterror.h"
#include "mongo/db/operation_context.h"
#include "mongo/util/concurrency/threadlocal.h"
#include "mongo/util/paths.h"


namespace mongo {

    class AuthenticationInfo;
    class Database;
    class CurOp;
    class Client;
    class AbstractMessagingPort;


    TSP_DECLARE(Client, currentClient)

    typedef long long ConnectionId;

    /** the database's concept of an outside "client" */
    class Client : public ClientBasic {
    public:
        // always be in clientsMutex when manipulating this. killop stuff uses these.
        static std::set<Client*>& clients;
        static mongo::mutex& clientsMutex;

        ~Client();

        /** each thread which does db operations has a Client object in TLS.
         *  call this when your thread starts.
        */
        static void initThread(const char *desc, AbstractMessagingPort *mp = 0);

        static void initThreadIfNotAlready(const char *desc) { 
            if( currentClient.get() )
                return;
            initThread(desc);
        }

        /** this has to be called as the client goes away, but before thread termination
         *  @return true if anything was done
         */
        bool shutdown();

        std::string clientAddress(bool includePort=false) const;
        CurOp* curop() const { return _curOp; }
        const StringData desc() const { return _desc; }
        void setLastOp( OpTime op ) { _lastOp = op; }
        OpTime getLastOp() const { return _lastOp; }

        /* report what the last operation was.  used by getlasterror */
        void appendLastOp( BSONObjBuilder& b ) const;
        void reportState(BSONObjBuilder& builder);

        // TODO(spencer): SERVER-10228 SERVER-14779 Remove this/move it fully into OperationContext.
        bool isGod() const { return _god; } /* this is for map/reduce writes */
        bool setGod(bool newVal) { const bool prev = _god; _god = newVal; return prev; }

        void setRemoteID(const OID& rid) { _remoteId = rid;  }
        OID getRemoteID() const { return _remoteId; }
        ConnectionId getConnectionId() const { return _connectionId; }
        const std::string& getThreadId() const { return _threadId; }

        // XXX(hk): this is per-thread mmapv1 recovery unit stuff, move into that
        // impl of recovery unit
        void writeHappened() { _hasWrittenSinceCheckpoint = true; }
        bool hasWrittenSinceCheckpoint() const { return _hasWrittenSinceCheckpoint; }
        void checkpointHappened() { _hasWrittenSinceCheckpoint = false; }

        // XXX: this is really a method in the recovery unit iface to reset any state
        void newTopLevelRequest() {
            _hasWrittenSinceCheckpoint = false;
        }

    private:
        Client(const std::string& desc, AbstractMessagingPort *p = 0);
        friend class CurOp;
        ConnectionId _connectionId; // > 0 for things "conn", 0 otherwise
        std::string _threadId; // "" on non support systems
        CurOp * _curOp;
        bool _shutdown; // to track if Client::shutdown() gets called
        std::string _desc;
        bool _god;
        OpTime _lastOp;
        OID _remoteId; // Only used by master-slave

        bool _hasWrittenSinceCheckpoint;
        
    public:

        class Context;

        /** "read lock, and set my context, all in one operation" 
         *  This handles (if not recursively locked) opening an unopened database.
         */
        class ReadContext : boost::noncopyable { 
        public:
            ReadContext(OperationContext* txn,
                        const std::string& ns,
                        bool doVersion = true);
            Context& ctx() { return *_c.get(); }
        private:
            scoped_ptr<Lock::DBRead> _lk;
            scoped_ptr<Context> _c;
        };

        /* Set database we want to use, then, restores when we finish (are out of scope)
           Note this is also helpful if an exception happens as the state if fixed up.
        */
        class Context {
            MONGO_DISALLOW_COPYING(Context);
        public:
            /** this is probably what you want */
            Context(OperationContext* txn, const std::string& ns, bool doVersion = true);

            /** note: this does not call finishInit -- i.e., does not call 
                      ensureShardVersionOKOrThrow for example.
                see also: reset().
            */
            Context(OperationContext* txn, const std::string& ns, Database * db);

            // used by ReadContext
            Context(OperationContext* txn, const std::string& ns, Database *db, bool doVersion);

            ~Context();
            Client* getClient() const { return _client; }
            Database* db() const { return _db; }
            const char * ns() const { return _ns.c_str(); }

            /** @return if the db was created by this Context */
            bool justCreated() const { return _justCreated; }

            /** call before unlocking, so clear any non-thread safe state
             *  _db gets restored on the relock
             */
            void unlocked() { _db = 0; }

            /** call after going back into the lock, will re-establish non-thread safe stuff */
            void relocked() { _finishInit(); }

        private:
            friend class CurOp;
            void _finishInit();
            void checkNotStale() const;
            void checkNsAccess( bool doauth );
            void checkNsAccess( bool doauth, int lockState );
            Client * const _client;
            bool _justCreated;
            bool _doVersion;
            const std::string _ns;
            Database * _db;
            OperationContext* _txn;
            
            Timer _timer;
        }; // class Client::Context

        class WriteContext : boost::noncopyable {
        public:
            WriteContext(OperationContext* opCtx, const std::string& ns, bool doVersion = true);

            /** Commit any writes done so far in this context. */
            void commit();

            Context& ctx() { return _c; }

        private:
            Lock::DBWrite _lk;
            WriteUnitOfWork _wunit;
            Context _c;
        };


    }; // class Client


    /** get the Client object for this thread. */
    inline Client& cc() {
        Client * c = currentClient.get();
        verify( c );
        return *c;
    }

    inline bool haveClient() { return currentClient.get() != NULL; }

};