C++ OwnedPointerVector::begin方法代码示例

IndexBounds ChunkManager::getIndexBoundsForQuery(const BSONObj& key,
                                                 const CanonicalQuery& canonicalQuery) {
    // $text is not allowed in planning since we don't have text index on mongos.
    //
    // TODO: Treat $text query as a no-op in planning. So with shard key {a: 1},
    //       the query { a: 2, $text: { ... } } will only target to {a: 2}.
    if (QueryPlannerCommon::hasNode(canonicalQuery.root(), MatchExpression::TEXT)) {
        IndexBounds bounds;
        IndexBoundsBuilder::allValuesBounds(key, &bounds);  // [minKey, maxKey]
        return bounds;
    }

    // Consider shard key as an index
    string accessMethod = IndexNames::findPluginName(key);
    dassert(accessMethod == IndexNames::BTREE || accessMethod == IndexNames::HASHED);

    // Use query framework to generate index bounds
    QueryPlannerParams plannerParams;
    // Must use "shard key" index
    plannerParams.options = QueryPlannerParams::NO_TABLE_SCAN;
    IndexEntry indexEntry(key,
                          accessMethod,
                          false /* multiKey */,
                          false /* sparse */,
                          false /* unique */,
                          "shardkey",
                          NULL /* filterExpr */,
                          BSONObj());
    plannerParams.indices.push_back(indexEntry);

    OwnedPointerVector<QuerySolution> solutions;
    Status status = QueryPlanner::plan(canonicalQuery, plannerParams, &solutions.mutableVector());
    uassert(status.code(), status.reason(), status.isOK());

    IndexBounds bounds;

    for (vector<QuerySolution*>::const_iterator it = solutions.begin();
         bounds.size() == 0 && it != solutions.end();
         it++) {
        // Try next solution if we failed to generate index bounds, i.e. bounds.size() == 0
        bounds = collapseQuerySolution((*it)->root.get());
    }

    if (bounds.size() == 0) {
        // We cannot plan the query without collection scan, so target to all shards.
        IndexBoundsBuilder::allValuesBounds(key, &bounds);  // [minKey, maxKey]
    }
    return bounds;
}

    BSONObj buildApplyOpsCmd( const OwnedPointerVector<ChunkType>& chunksToMerge,
                              const ChunkVersion& currShardVersion,
                              const ChunkVersion& newMergedVersion ) {

        BSONObjBuilder applyOpsCmdB;
        BSONArrayBuilder updatesB( applyOpsCmdB.subarrayStart( "applyOps" ) );

        // The chunk we'll be "expanding" is the first chunk
        const ChunkType* chunkToMerge = *chunksToMerge.begin();

        // Fill in details not tracked by metadata
        ChunkType mergedChunk;
        chunkToMerge->cloneTo( &mergedChunk );
        mergedChunk.setName( Chunk::genID( chunkToMerge->getNS(), chunkToMerge->getMin() ) );
        mergedChunk.setMax( ( *chunksToMerge.vector().rbegin() )->getMax() );
        mergedChunk.setVersion( newMergedVersion );

        updatesB.append( buildOpMergeChunk( mergedChunk ) );

        // Don't remove chunk we're expanding
        OwnedPointerVector<ChunkType>::const_iterator it = chunksToMerge.begin();
        for ( ++it; it != chunksToMerge.end(); ++it ) {
            ChunkType* chunkToMerge = *it;
            chunkToMerge->setName( Chunk::genID( chunkToMerge->getNS(), chunkToMerge->getMin() ) );
            updatesB.append( buildOpRemoveChunk( *chunkToMerge ) );
        }

        updatesB.done();

        applyOpsCmdB.append( "preCondition",
                             buildOpPrecond( chunkToMerge->getNS(),
                                             chunkToMerge->getShard(),
                                             currShardVersion ) );

        return applyOpsCmdB.obj();
    }

    BSONObj buildMergeLogEntry( const OwnedPointerVector<ChunkType>& chunksToMerge,
                                const ChunkVersion& currShardVersion,
                                const ChunkVersion& newMergedVersion ) {

        BSONObjBuilder logDetailB;

        BSONArrayBuilder mergedB( logDetailB.subarrayStart( "merged" ) );

        for ( OwnedPointerVector<ChunkType>::const_iterator it = chunksToMerge.begin();
                it != chunksToMerge.end(); ++it ) {
            ChunkType* chunkToMerge = *it;
            mergedB.append( chunkToMerge->toBSON() );
        }

        mergedB.done();

        currShardVersion.addToBSON( logDetailB, "prevShardVersion" );
        newMergedVersion.addToBSON( logDetailB, "mergedVersion" );

        return logDetailB.obj();
    }

    BSONObj generateSection(OperationContext* txn, const BSONElement& configElement) const {
        RangeDeleter* deleter = getDeleter();
        if (!deleter) {
            return BSONObj();
        }

        BSONObjBuilder result;

        OwnedPointerVector<DeleteJobStats> statsList;
        deleter->getStatsHistory(&statsList.mutableVector());
        BSONArrayBuilder oldStatsBuilder;
        for (OwnedPointerVector<DeleteJobStats>::const_iterator it = statsList.begin();
             it != statsList.end();
             ++it) {
            BSONObjBuilder entryBuilder;
            entryBuilder.append("deletedDocs", (*it)->deletedDocCount);

            if ((*it)->queueEndTS > Date_t()) {
                entryBuilder.append("queueStart", (*it)->queueStartTS);
                entryBuilder.append("queueEnd", (*it)->queueEndTS);
            }

            if ((*it)->deleteEndTS > Date_t()) {
                entryBuilder.append("deleteStart", (*it)->deleteStartTS);
                entryBuilder.append("deleteEnd", (*it)->deleteEndTS);

                if ((*it)->waitForReplEndTS > Date_t()) {
                    entryBuilder.append("waitForReplStart", (*it)->waitForReplStartTS);
                    entryBuilder.append("waitForReplEnd", (*it)->waitForReplEndTS);
                }
            }

            oldStatsBuilder.append(entryBuilder.obj());
        }
        result.append("lastDeleteStats", oldStatsBuilder.arr());

        return result.obj();
    }

// static
Status ListFilters::list(const QuerySettings& querySettings, BSONObjBuilder* bob) {
    invariant(bob);

    // Format of BSON result:
    //
    // {
    //     hints: [
    //         {
    //             query: <query>,
    //             sort: <sort>,
    //             projection: <projection>,
    //             indexes: [<index1>, <index2>, <index3>, ...]
    //         }
    //  }
    BSONArrayBuilder hintsBuilder(bob->subarrayStart("filters"));
    OwnedPointerVector<AllowedIndexEntry> entries;
    entries.mutableVector() = querySettings.getAllAllowedIndices();
    for (vector<AllowedIndexEntry*>::const_iterator i = entries.begin();
            i != entries.end(); ++i) {
        AllowedIndexEntry* entry = *i;
        invariant(entry);

        BSONObjBuilder hintBob(hintsBuilder.subobjStart());
        hintBob.append("query", entry->query);
        hintBob.append("sort", entry->sort);
        hintBob.append("projection", entry->projection);
        BSONArrayBuilder indexesBuilder(hintBob.subarrayStart("indexes"));
        for (vector<BSONObj>::const_iterator j = entry->indexKeyPatterns.begin();
                j != entry->indexKeyPatterns.end(); ++j) {
            const BSONObj& index = *j;
            indexesBuilder.append(index);
        }
        indexesBuilder.doneFast();
    }
    hintsBuilder.doneFast();
    return Status::OK();
}

//.........这里部分代码省略.........
        ChunkVersion mergeVersion = metadata->getCollVersion();
        mergeVersion.incMinor();

        OwnedPointerVector<ChunkType> chunksToMerge;

        ChunkType itChunk;
        itChunk.setMin( minKey );
        itChunk.setMax( minKey );
        itChunk.setNS( nss.ns() );
        itChunk.setShard( shardingState.getShardName() );

        while ( itChunk.getMax().woCompare( maxKey ) < 0 &&
                metadata->getNextChunk( itChunk.getMax(), &itChunk ) ) {
            auto_ptr<ChunkType> saved( new ChunkType );
            itChunk.cloneTo( saved.get() );
            chunksToMerge.mutableVector().push_back( saved.release() );
        }

        if ( chunksToMerge.empty() ) {

            *errMsg = stream() << "could not merge chunks, collection " << nss.ns()
                               << " range starting at " << minKey
                               << " and ending at " << maxKey
                               << " does not belong to shard " << shardingState.getShardName();

            warning() << *errMsg << endl;
            return false;
        }

        //
        // Validate the range starts and ends at chunks and has no holes, error if not valid
        //

        BSONObj firstDocMin = ( *chunksToMerge.begin() )->getMin();
        BSONObj firstDocMax = ( *chunksToMerge.begin() )->getMax();
        // minKey is inclusive
        bool minKeyInRange = rangeContains( firstDocMin, firstDocMax, minKey );

        if ( !minKeyInRange ) {

            *errMsg = stream() << "could not merge chunks, collection " << nss.ns()
                               << " range starting at " << minKey
                               << " does not belong to shard " << shardingState.getShardName();

            warning() << *errMsg << endl;
            return false;
        }

        BSONObj lastDocMin = ( *chunksToMerge.rbegin() )->getMin();
        BSONObj lastDocMax = ( *chunksToMerge.rbegin() )->getMax();
        // maxKey is exclusive
        bool maxKeyInRange = lastDocMin.woCompare( maxKey ) < 0 &&
                lastDocMax.woCompare( maxKey ) >= 0;

        if ( !maxKeyInRange ) {
            *errMsg = stream() << "could not merge chunks, collection " << nss.ns()
                               << " range ending at " << maxKey
                               << " does not belong to shard " << shardingState.getShardName();

            warning() << *errMsg << endl;
            return false;
        }

        bool validRangeStartKey = firstDocMin.woCompare( minKey ) == 0;
        bool validRangeEndKey = lastDocMax.woCompare( maxKey ) == 0;

// static
Status ClearFilters::clear(QuerySettings* querySettings, PlanCache* planCache,
                           const std::string& ns, const BSONObj& cmdObj) {
    invariant(querySettings);

    // According to the specification, the planCacheClearFilters command runs in two modes:
    // - clear all hints; or
    // - clear hints for single query shape when a query shape is described in the
    //   command arguments.
    if (cmdObj.hasField("query")) {
        CanonicalQuery* cqRaw;
        Status status = PlanCacheCommand::canonicalize(ns, cmdObj, &cqRaw);
        if (!status.isOK()) {
            return status;
        }

        scoped_ptr<CanonicalQuery> cq(cqRaw);
        querySettings->removeAllowedIndices(*cq);

        // Remove entry from plan cache
        planCache->remove(*cq);
        return Status::OK();
    }

    // If query is not provided, make sure sort and projection are not in arguments.
    // We do not want to clear the entire cache inadvertently when the user
    // forgot to provide a value for "query".
    if (cmdObj.hasField("sort") || cmdObj.hasField("projection")) {
        return Status(ErrorCodes::BadValue, "sort or projection provided without query");
    }

    // Get entries from query settings. We need to remove corresponding entries from the plan
    // cache shortly.
    OwnedPointerVector<AllowedIndexEntry> entries;
    entries.mutableVector() = querySettings->getAllAllowedIndices();

    // OK to proceed with clearing entire cache.
    querySettings->clearAllowedIndices();

    const NamespaceString nss(ns);
    const WhereCallbackReal whereCallback(nss.db());

    // Remove corresponding entries from plan cache.
    // Admin hints affect the planning process directly. If there were
    // plans generated as a result of applying index filter, these need to be
    // invalidated. This allows the planner to re-populate the plan cache with
    // non-filtered indexed solutions next time the query is run.
    // Resolve plan cache key from (query, sort, projection) in query settings entry.
    // Concurrency note: There's no harm in removing plan cache entries one at at time.
    // Only way that PlanCache::remove() can fail is when the query shape has been removed from
    // the cache by some other means (re-index, collection info reset, ...). This is OK since
    // that's the intended effect of calling the remove() function with the key from the hint entry.
    for (vector<AllowedIndexEntry*>::const_iterator i = entries.begin();
            i != entries.end(); ++i) {
        AllowedIndexEntry* entry = *i;
        invariant(entry);

        // Create canonical query.
        CanonicalQuery* cqRaw;
        Status result = CanonicalQuery::canonicalize(
                            ns, entry->query, entry->sort, entry->projection, &cqRaw, whereCallback);
        invariant(result.isOK());
        scoped_ptr<CanonicalQuery> cq(cqRaw);

        // Remove plan cache entry.
        planCache->remove(*cq);
    }

    return Status::OK();
}

// static
Status ClearFilters::clear(OperationContext* txn,
                           QuerySettings* querySettings,
                           PlanCache* planCache,
                           const std::string& ns,
                           const BSONObj& cmdObj) {
    invariant(querySettings);

    // According to the specification, the planCacheClearFilters command runs in two modes:
    // - clear all hints; or
    // - clear hints for single query shape when a query shape is described in the
    //   command arguments.
    if (cmdObj.hasField("query")) {
        auto statusWithCQ = PlanCacheCommand::canonicalize(txn, ns, cmdObj);
        if (!statusWithCQ.isOK()) {
            return statusWithCQ.getStatus();
        }

        unique_ptr<CanonicalQuery> cq = std::move(statusWithCQ.getValue());
        querySettings->removeAllowedIndices(planCache->computeKey(*cq));

        // Remove entry from plan cache
        planCache->remove(*cq);

        LOG(0) << "Removed index filter on " << ns << " " << cq->toStringShort();

        return Status::OK();
    }

    // If query is not provided, make sure sort and projection are not in arguments.
    // We do not want to clear the entire cache inadvertently when the user
    // forgot to provide a value for "query".
    if (cmdObj.hasField("sort") || cmdObj.hasField("projection")) {
        return Status(ErrorCodes::BadValue, "sort or projection provided without query");
    }

    // Get entries from query settings. We need to remove corresponding entries from the plan
    // cache shortly.
    OwnedPointerVector<AllowedIndexEntry> entries;
    entries.mutableVector() = querySettings->getAllAllowedIndices();

    // OK to proceed with clearing entire cache.
    querySettings->clearAllowedIndices();

    const NamespaceString nss(ns);
    const ExtensionsCallbackReal extensionsCallback(txn, &nss);

    // Remove corresponding entries from plan cache.
    // Admin hints affect the planning process directly. If there were
    // plans generated as a result of applying index filter, these need to be
    // invalidated. This allows the planner to re-populate the plan cache with
    // non-filtered indexed solutions next time the query is run.
    // Resolve plan cache key from (query, sort, projection) in query settings entry.
    // Concurrency note: There's no harm in removing plan cache entries one at at time.
    // Only way that PlanCache::remove() can fail is when the query shape has been removed from
    // the cache by some other means (re-index, collection info reset, ...). This is OK since
    // that's the intended effect of calling the remove() function with the key from the hint entry.
    for (vector<AllowedIndexEntry*>::const_iterator i = entries.begin(); i != entries.end(); ++i) {
        AllowedIndexEntry* entry = *i;
        invariant(entry);

        // Create canonical query.
        auto qr = stdx::make_unique<QueryRequest>(nss);
        qr->setFilter(entry->query);
        qr->setSort(entry->sort);
        qr->setProj(entry->projection);
        auto statusWithCQ = CanonicalQuery::canonicalize(txn, std::move(qr), extensionsCallback);
        invariantOK(statusWithCQ.getStatus());
        std::unique_ptr<CanonicalQuery> cq = std::move(statusWithCQ.getValue());

        // Remove plan cache entry.
        planCache->remove(*cq);
    }

    LOG(0) << "Removed all index filters for collection: " << ns;

    return Status::OK();
}