SERVER-11021: backport to 2.4

6 files changed, 308 insertions, 116 deletions

diff --git a/jstests/dbhash2.js b/jstests/dbhash2.js
new file mode 100644
index 00000000000..ac491291c2b
--- /dev/null
+++ b/jstests/dbhash2.js
@@ -0,0 +1,22 @@
+
+mydb = db.getSisterDB( "config" );
+
+t = mydb.foo;
+t.drop();
+
+t.insert( { x : 1 } );
+res1 = mydb.runCommand( "dbhash" );
+assert( res1.fromCache.indexOf( "config.foo" ) == -1 );
+
+res2 = mydb.runCommand( "dbhash" );
+assert( res2.fromCache.indexOf( "config.foo" ) >= 0 );
+assert.eq( res1.collections.foo, res2.collections.foo );
+
+t.insert( { x : 2 } );
+res3 = mydb.runCommand( "dbhash" );
+assert( res3.fromCache.indexOf( "config.foo" ) < 0 );
+assert.neq( res1.collections.foo, res3.collections.foo );
+
+
+
+
diff --git a/src/mongo/SConscript b/src/mongo/SConscript
index 816a6bfacf8..265cd4800e0 100644
--- a/src/mongo/SConscript
+++ b/src/mongo/SConscript
@@ -433,6 +433,7 @@ serverOnlyFiles = [ "db/curop.cpp",
                     "db/dbcommands_admin.cpp",
 
                     # most commands are only for mongod
+                    "db/commands/dbhash.cpp",
                     "db/commands/fsync.cpp",
                     "db/commands/distinct.cpp",
                     "db/commands/find_and_modify.cpp",
diff --git a/src/mongo/db/commands/dbhash.cpp b/src/mongo/db/commands/dbhash.cpp
new file mode 100644
index 00000000000..38a07cace56
--- /dev/null
+++ b/src/mongo/db/commands/dbhash.cpp
@@ -0,0 +1,216 @@
+// dbhash.cpp
+
+/**
+*    Copyright (C) 2013 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.
+*/
+
+#include "mongo/db/commands/dbhash.h"
+
+#include "mongo/db/btreecursor.h"
+#include "mongo/db/client.h"
+#include "mongo/db/commands.h"
+#include "mongo/db/database.h"
+#include "mongo/db/pdfile.h"
+#include "mongo/util/md5.hpp"
+#include "mongo/util/timer.h"
+
+namespace mongo {
+
+    DBHashCmd dbhashCmd;
+
+
+    void logOpForDbHash( const char* opstr,
+                         const char* ns,
+                         const BSONObj& obj,
+                         BSONObj* patt ) {
+        dbhashCmd.wipeCacheForCollection( ns );
+    }
+
+    // ----
+
+    DBHashCmd::DBHashCmd()
+        : Command( "dbHash", false, "dbhash" ),
+          _cachedHashedMutex( "_cachedHashedMutex" ){
+    }
+
+    void DBHashCmd::addRequiredPrivileges(const std::string& dbname,
+                                          const BSONObj& cmdObj,
+                                          std::vector<Privilege>* out) {
+        ActionSet actions;
+        actions.addAction(ActionType::dbHash);
+        out->push_back(Privilege(dbname, actions));
+    }
+
+    string DBHashCmd::hashCollection( const string& fullCollectionName, bool* fromCache ) {
+
+        scoped_ptr<scoped_lock> cachedHashedLock;
+
+        if ( isCachable( fullCollectionName ) ) {
+            cachedHashedLock.reset( new scoped_lock( _cachedHashedMutex ) );
+            string hash = _cachedHashed[fullCollectionName];
+            if ( hash.size() > 0 ) {
+                *fromCache = true;
+                return hash;
+            }
+        }
+
+        *fromCache = false;
+        NamespaceDetails * nsd = nsdetails( fullCollectionName );
+        verify( nsd );
+
+        // debug SERVER-761
+        NamespaceDetails::IndexIterator ii = nsd->ii();
+        while( ii.more() ) {
+            const IndexDetails &idx = ii.next();
+            if ( !idx.head.isValid() || !idx.info.isValid() ) {
+                log() << "invalid index for ns: " << fullCollectionName << " " << idx.head << " " << idx.info;
+                if ( idx.info.isValid() )
+                    log() << " " << idx.info.obj();
+                log() << endl;
+            }
+        }
+
+        int idNum = nsd->findIdIndex();
+
+        shared_ptr<Cursor> cursor;
+
+        if ( idNum >= 0 ) {
+            cursor.reset( BtreeCursor::make( nsd,
+                                             nsd->idx( idNum ),
+                                             BSONObj(),
+                                             BSONObj(),
+                                             false,
+                                             1 ) );
+        }
+        else if ( nsd->isCapped() ) {
+            cursor = findTableScan( fullCollectionName.c_str() , BSONObj() );
+        }
+        else {
+            log() << "can't find _id index for: " << fullCollectionName << endl;
+            return "no _id _index";
+        }
+
+        md5_state_t st;
+        md5_init(&st);
+
+        long long n = 0;
+
+        while ( cursor->ok() ) {
+            BSONObj c = cursor->current();
+            md5_append( &st , (const md5_byte_t*)c.objdata() , c.objsize() );
+            n++;
+            cursor->advance();
+        }
+
+        md5digest d;
+        md5_finish(&st, d);
+        string hash = digestToString( d );
+
+        if ( cachedHashedLock.get() ) {
+            _cachedHashed[fullCollectionName] = hash;
+        }
+
+        return hash;
+    }
+
+    bool DBHashCmd::run(const string& dbname , BSONObj& cmdObj, int, string& errmsg, BSONObjBuilder& result, bool) {
+        Timer timer;
+
+        set<string> desiredCollections;
+        if ( cmdObj["collections"].type() == Array ) {
+            BSONObjIterator i( cmdObj["collections"].Obj() );
+            while ( i.more() ) {
+                BSONElement e = i.next();
+                if ( e.type() != String ) {
+                    errmsg = "collections entries have to be strings";
+                    return false;
+                }
+                desiredCollections.insert( e.String() );
+            }
+        }
+
+        list<string> colls;
+        Database* db = cc().database();
+        if ( db )
+            db->namespaceIndex.getNamespaces( colls );
+        colls.sort();
+
+        result.appendNumber( "numCollections" , (long long)colls.size() );
+        result.append( "host" , prettyHostName() );
+
+        md5_state_t globalState;
+        md5_init(&globalState);
+
+        vector<string> cached;
+
+        BSONObjBuilder bb( result.subobjStart( "collections" ) );
+        for ( list<string>::iterator i=colls.begin(); i != colls.end(); i++ ) {
+            string fullCollectionName = *i;
+            string shortCollectionName = fullCollectionName.substr( dbname.size() + 1 );
+
+            if ( shortCollectionName.find( "system." ) == 0 )
+                continue;
+
+            if ( desiredCollections.size() > 0 &&
+                 desiredCollections.count( shortCollectionName ) == 0 )
+                continue;
+
+            bool fromCache = false;
+            string hash = hashCollection( fullCollectionName, &fromCache );
+
+            bb.append( shortCollectionName, hash );
+
+            md5_append( &globalState , (const md5_byte_t*)hash.c_str() , hash.size() );
+            if ( fromCache )
+                cached.push_back( fullCollectionName );
+        }
+        bb.done();
+
+        md5digest d;
+        md5_finish(&globalState, d);
+        string hash = digestToString( d );
+
+        result.append( "md5" , hash );
+        result.appendNumber( "timeMillis", timer.millis() );
+
+        result.append( "fromCache", cached );
+
+        return 1;
+    }
+
+    void DBHashCmd::wipeCacheForCollection( const StringData& ns ) {
+        if ( !isCachable( ns ) )
+            return;
+        scoped_lock lk( _cachedHashedMutex );
+        _cachedHashed.erase( ns.toString() );
+    }
+
+    bool DBHashCmd::isCachable( const StringData& ns ) const {
+        return ns.startsWith( "config." );
+    }
+
+}
diff --git a/src/mongo/db/commands/dbhash.h b/src/mongo/db/commands/dbhash.h
new file mode 100644
index 00000000000..262c6609868
--- /dev/null
+++ b/src/mongo/db/commands/dbhash.h
@@ -0,0 +1,67 @@
+// dbhash.h
+
+/**
+*    Copyright (C) 2013 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/commands.h"
+
+namespace mongo {
+
+    void logOpForDbHash( const char* opstr,
+                         const char* ns,
+                         const BSONObj& obj,
+                         BSONObj* patt );
+
+    class DBHashCmd : public Command {
+    public:
+        DBHashCmd();
+
+        virtual bool slaveOk() const { return true; }
+        virtual LockType locktype() const { return READ; }
+        virtual void addRequiredPrivileges(const std::string& dbname,
+                                           const BSONObj& cmdObj,
+                                           std::vector<Privilege>* out);
+
+        virtual bool run(const string& dbname , BSONObj& cmdObj, int, string& errmsg, BSONObjBuilder& result, bool);
+
+        void wipeCacheForCollection( const StringData& ns );
+
+    private:
+
+        bool isCachable( const StringData& ns ) const;
+
+        string hashCollection( const string& fullCollectionName, bool* fromCache );
+
+        map<string,string> _cachedHashed;
+        mutex _cachedHashedMutex;
+
+    };
+
+}
diff --git a/src/mongo/db/dbcommands.cpp b/src/mongo/db/dbcommands.cpp
index 33b77f455d6..8b8252f68a6 100644
--- a/src/mongo/db/dbcommands.cpp
+++ b/src/mongo/db/dbcommands.cpp
@@ -1689,122 +1689,6 @@ namespace mongo {
         }
         return Status::OK();
     }
-    
-    class DBHashCmd : public Command {
-    public:
-        DBHashCmd() : Command( "dbHash", false, "dbhash" ) {}
-        virtual bool slaveOk() const { return true; }
-        virtual LockType locktype() const { return READ; }
-        virtual void addRequiredPrivileges(const std::string& dbname,
-                                           const BSONObj& cmdObj,
-                                           std::vector<Privilege>* out) {
-            ActionSet actions;
-            actions.addAction(ActionType::dbHash);
-            out->push_back(Privilege(dbname, actions));
-        }
-        virtual bool run(const string& dbname , BSONObj& cmdObj, int, string& errmsg, BSONObjBuilder& result, bool) {
-            Timer timer;
-
-            set<string> desiredCollections;
-            if ( cmdObj["collections"].type() == Array ) {
-                BSONObjIterator i( cmdObj["collections"].Obj() );
-                while ( i.more() ) {
-                    BSONElement e = i.next();
-                    if ( e.type() != String ) {
-                        errmsg = "collections entries have to be strings";
-                        return false;
-                    }
-                    desiredCollections.insert( e.String() );
-                }
-            }
-
-            list<string> colls;
-            Database* db = cc().database();
-            if ( db )
-                db->namespaceIndex.getNamespaces( colls );
-            colls.sort();
-
-            result.appendNumber( "numCollections" , (long long)colls.size() );
-            result.append( "host" , prettyHostName() );
-
-            md5_state_t globalState;
-            md5_init(&globalState);
-
-            BSONObjBuilder bb( result.subobjStart( "collections" ) );
-            for ( list<string>::iterator i=colls.begin(); i != colls.end(); i++ ) {
-                string fullCollectionName = *i;
-                string shortCollectionName = fullCollectionName.substr( dbname.size() + 1 );
-
-                if ( shortCollectionName.find( "system." ) == 0 )
-                    continue;
-
-                if ( desiredCollections.size() > 0 &&
-                     desiredCollections.count( shortCollectionName ) == 0 )
-                    continue;
-
-                shared_ptr<Cursor> cursor;
-
-                NamespaceDetails * nsd = nsdetails( fullCollectionName );
-
-                // debug SERVER-761
-                NamespaceDetails::IndexIterator ii = nsd->ii();
-                while( ii.more() ) {
-                    const IndexDetails &idx = ii.next();
-                    if ( !idx.head.isValid() || !idx.info.isValid() ) {
-                        log() << "invalid index for ns: " << fullCollectionName << " " << idx.head << " " << idx.info;
-                        if ( idx.info.isValid() )
-                            log() << " " << idx.info.obj();
-                        log() << endl;
-                    }
-                }
-
-                int idNum = nsd->findIdIndex();
-                if ( idNum >= 0 ) {
-                    cursor.reset( BtreeCursor::make( nsd,
-                                                     nsd->idx( idNum ),
-                                                     BSONObj(),
-                                                     BSONObj(),
-                                                     false,
-                                                     1 ) );
-                }
-                else if ( nsd->isCapped() ) {
-                    cursor = findTableScan( fullCollectionName.c_str() , BSONObj() );
-                }
-                else {
-                    log() << "can't find _id index for: " << fullCollectionName << endl;
-                    continue;
-                }
-
-                md5_state_t st;
-                md5_init(&st);
-
-                long long n = 0;
-                while ( cursor->ok() ) {
-                    BSONObj c = cursor->current();
-                    md5_append( &st , (const md5_byte_t*)c.objdata() , c.objsize() );
-                    n++;
-                    cursor->advance();
-                }
-                md5digest d;
-                md5_finish(&st, d);
-                string hash = digestToString( d );
-
-                bb.append( shortCollectionName, hash );
-
-                md5_append( &globalState , (const md5_byte_t*)hash.c_str() , hash.size() );
-            }
-            bb.done();
-
-            md5digest d;
-            md5_finish(&globalState, d);
-            string hash = digestToString( d );
-
-            result.append( "md5" , hash );
-            result.appendNumber( "timeMillis", timer.millis() );
-            return 1;
-        }
-
-    } dbhashCmd;
 
     /* for diagnostic / testing purposes. Enabled via command line. */
     class CmdSleep : public Command {
diff --git a/src/mongo/db/oplog.cpp b/src/mongo/db/oplog.cpp
index 12f4742c256..86a2dcba6d5 100644
--- a/src/mongo/db/oplog.cpp
+++ b/src/mongo/db/oplog.cpp
@@ -26,6 +26,7 @@
 #include "mongo/db/auth/action_type.h"
 #include "mongo/db/auth/privilege.h"
 #include "mongo/db/commands.h"
+#include "mongo/db/commands/dbhash.h"
 #include "mongo/db/index_update.h"
 #include "mongo/db/instance.h"
 #include "mongo/db/namespacestring.h"
@@ -334,6 +335,7 @@ namespace mongo {
         }
 
         logOpForSharding( opstr , ns , obj , patt );
+        logOpForDbHash( opstr , ns , obj , patt );
     }
 
     void createOplog() {