wiredtiger_util.h

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// wiredtiger_util.h

#pragma once

#include <limits>
#include <wiredtiger.h>

#include "mongo/base/disallow_copying.h"
#include "mongo/base/status.h"
#include "mongo/base/status_with.h"
#include "mongo/bson/bsonobj.h"
#include "mongo/db/namespace_string.h"
#include "mongo/util/assert_util.h"

namespace mongo {

class BSONObjBuilder;
class OperationContext;
class WiredTigerConfigParser;
class WiredTigerKVEngine;
class WiredTigerSession;

inline bool wt_keeptxnopen() {
    return false;
}

Status wtRCToStatus_slow(int retCode, const char* prefix);

inline Status wtRCToStatus(int retCode, const char* prefix = NULL) {
    if (MONGO_likely(retCode == 0))
        return Status::OK();

    return wtRCToStatus_slow(retCode, prefix);
}

#define invariantWTOK(expression)                                                       \
    do {                                                                                \
        int _invariantWTOK_retCode = expression;                                        \
        if (MONGO_unlikely(_invariantWTOK_retCode != 0)) {                              \
            invariantOKFailed(                                                          \
                #expression, wtRCToStatus(_invariantWTOK_retCode), __FILE__, __LINE__); \
        }                                                                               \
    } while (false)

struct WiredTigerItem : public WT_ITEM {
    WiredTigerItem(const void* d, size_t s) {
        data = d;
        size = s;
    }
    WiredTigerItem(const std::string& str) {
        data = str.c_str();
        size = str.size();
    }
    // NOTE: do not call Get() on a temporary.
    // The pointer returned by Get() must not be allowed to live longer than *this.
    WT_ITEM* Get() {
        return this;
    }
    const WT_ITEM* Get() const {
        return this;
    }
};

class WiredTigerUtil {
    MONGO_DISALLOW_COPYING(WiredTigerUtil);

private:
    WiredTigerUtil();

public:
    static void fetchTypeAndSourceURI(OperationContext* opCtx,
                                      const std::string& tableUri,
                                      std::string* type,
                                      std::string* source);

    static Status exportTableToBSON(WT_SESSION* s,
                                    const std::string& uri,
                                    const std::string& config,
                                    BSONObjBuilder* bob);

    static void appendSnapshotWindowSettings(WiredTigerKVEngine* engine,
                                             WiredTigerSession* session,
                                             BSONObjBuilder* bob);

    static StatusWith<std::string> getMetadata(OperationContext* opCtx, StringData uri);

    static Status getApplicationMetadata(OperationContext* opCtx,
                                         StringData uri,
                                         BSONObjBuilder* bob);

    static StatusWith<BSONObj> getApplicationMetadata(OperationContext* opCtx, StringData uri);

    static StatusWith<int64_t> checkApplicationMetadataFormatVersion(OperationContext* opCtx,
                                                                     StringData uri,
                                                                     int64_t minimumVersion,
                                                                     int64_t maximumVersion);

    static Status checkTableCreationOptions(const BSONElement& configElem);

    static StatusWith<uint64_t> getStatisticsValue(WT_SESSION* session,
                                                   const std::string& uri,
                                                   const std::string& config,
                                                   int statisticsKey);

    template <typename ResultType>
    static StatusWith<ResultType> getStatisticsValueAs(WT_SESSION* session,
                                                       const std::string& uri,
                                                       const std::string& config,
                                                       int statisticsKey);

    template <typename ResultType>
    static StatusWith<ResultType> getStatisticsValueAs(WT_SESSION* session,
                                                       const std::string& uri,
                                                       const std::string& config,
                                                       int statisticsKey,
                                                       ResultType maximumResultType);

    static int64_t getIdentSize(WT_SESSION* s, const std::string& uri);


    static size_t getCacheSizeMB(double requestedCacheSizeGB);

    static WT_EVENT_HANDLER defaultEventHandlers();

    class ErrorAccumulator : public WT_EVENT_HANDLER {
    public:
        ErrorAccumulator(std::vector<std::string>* errors);

    private:
        static int onError(WT_EVENT_HANDLER* handler,
                           WT_SESSION* session,
                           int error,
                           const char* message);

        using ErrorHandler = int (*)(WT_EVENT_HANDLER*, WT_SESSION*, int, const char*);

        std::vector<std::string>* const _errors;
        const ErrorHandler _defaultErrorHandler;
    };

    static int verifyTable(OperationContext* opCtx,
                           const std::string& uri,
                           std::vector<std::string>* errors = NULL);

    static bool useTableLogging(NamespaceString ns, bool replEnabled);

    static Status setTableLogging(OperationContext* opCtx, const std::string& uri, bool on);

    static Status setTableLogging(WT_SESSION* session, const std::string& uri, bool on);

private:
    template <typename T>
    static T _castStatisticsValue(uint64_t statisticsValue);

    template <typename T>
    static T _castStatisticsValue(uint64_t statisticsValue, T maximumResultType);
};

class WiredTigerConfigParser {
    MONGO_DISALLOW_COPYING(WiredTigerConfigParser);

public:
    WiredTigerConfigParser(StringData config) {
        invariantWTOK(
            wiredtiger_config_parser_open(NULL, config.rawData(), config.size(), &_parser));
    }

    WiredTigerConfigParser(const WT_CONFIG_ITEM& nested) {
        invariant(nested.type == WT_CONFIG_ITEM::WT_CONFIG_ITEM_STRUCT);
        invariantWTOK(wiredtiger_config_parser_open(NULL, nested.str, nested.len, &_parser));
    }

    ~WiredTigerConfigParser() {
        invariantWTOK(_parser->close(_parser));
    }

    int next(WT_CONFIG_ITEM* key, WT_CONFIG_ITEM* value) {
        return _parser->next(_parser, key, value);
    }

    int get(const char* key, WT_CONFIG_ITEM* value) {
        return _parser->get(_parser, key, value);
    }

private:
    WT_CONFIG_PARSER* _parser;
};

// static
template <typename ResultType>
StatusWith<ResultType> WiredTigerUtil::getStatisticsValueAs(WT_SESSION* session,
                                                            const std::string& uri,
                                                            const std::string& config,
                                                            int statisticsKey) {
    return getStatisticsValueAs<ResultType>(
        session, uri, config, statisticsKey, std::numeric_limits<ResultType>::max());
}

// static
template <typename ResultType>
StatusWith<ResultType> WiredTigerUtil::getStatisticsValueAs(WT_SESSION* session,
                                                            const std::string& uri,
                                                            const std::string& config,
                                                            int statisticsKey,
                                                            ResultType maximumResultType) {
    StatusWith<uint64_t> result = getStatisticsValue(session, uri, config, statisticsKey);
    if (!result.isOK()) {
        return StatusWith<ResultType>(result.getStatus());
    }
    return StatusWith<ResultType>(
        _castStatisticsValue<ResultType>(result.getValue(), maximumResultType));
}

// static
template <typename ResultType>
ResultType WiredTigerUtil::_castStatisticsValue(uint64_t statisticsValue) {
    return _castStatisticsValue<ResultType>(statisticsValue,
                                            std::numeric_limits<ResultType>::max());
}

// static
template <typename ResultType>
ResultType WiredTigerUtil::_castStatisticsValue(uint64_t statisticsValue,
                                                ResultType maximumResultType) {
    return statisticsValue > static_cast<uint64_t>(maximumResultType)
        ? maximumResultType
        : static_cast<ResultType>(statisticsValue);
}

}  // namespace mongo