zeek/src/logging/WriterBackend.cc

// See the file "COPYING" in the main distribution directory for copyright.

#include "zeek/logging/WriterBackend.h"

#include <broker/data.hh>
#include <span>

#include "zeek/logging/Manager.h"
#include "zeek/logging/WriterFrontend.h"
#include "zeek/threading/SerialTypes.h"
#include "zeek/util.h"

// Messages sent from backend to frontend (i.e., "OutputMessages").

using zeek::threading::Field;
using zeek::threading::Value;

namespace zeek::logging {

class RotationFinishedMessage final : public threading::OutputMessage<WriterFrontend> {
public:
    RotationFinishedMessage(WriterFrontend* writer, const char* new_name, const char* old_name, double open,
                            double close, bool success, bool terminating)
        : threading::OutputMessage<WriterFrontend>("RotationFinished", writer),
          new_name(util::copy_string(new_name)),
          old_name(util::copy_string(old_name)),
          open(open),
          close(close),
          success(success),
          terminating(terminating) {}

    ~RotationFinishedMessage() override {
        delete[] new_name;
        delete[] old_name;
    }

    bool Process() override {
        return log_mgr->FinishedRotation(Object(), new_name, old_name, open, close, success, terminating);
    }

private:
    const char* new_name;
    const char* old_name;
    double open;
    double close;
    bool success;
    bool terminating;
};

class DisableMessage final : public threading::OutputMessage<WriterFrontend> {
public:
    DisableMessage(WriterFrontend* writer) : threading::OutputMessage<WriterFrontend>("Disable", writer) {}

    bool Process() override {
        Object()->SetDisable();
        return true;
    }
};

// Backend methods.

broker::data WriterBackend::WriterInfo::ToBroker() const {
    auto t = broker::table();

    for ( const auto& [key, value] : config ) {
        t.emplace(std::string{key}, std::string{value});
    }

    auto bppf = post_proc_func ? post_proc_func : "";

    return broker::vector({path, rotation_base, rotation_interval, network_time, std::move(t), bppf});
}

bool WriterBackend::WriterInfo::FromBroker(broker::data d) {
    if ( ! broker::is<broker::vector>(d) )
        return false;

    auto v = broker::get<broker::vector>(d);
    auto bpath = broker::get_if<std::string>(&v[0]);
    auto brotation_base = broker::get_if<double>(&v[1]);
    auto brotation_interval = broker::get_if<double>(&v[2]);
    auto bnetwork_time = broker::get_if<double>(&v[3]);
    auto bconfig = broker::get_if<broker::table>(&v[4]);
    auto bppf = broker::get_if<std::string>(&v[5]);

    if ( ! (bpath && brotation_base && brotation_interval && bnetwork_time && bconfig && bppf) )
        return false;

    path = util::copy_string(bpath->c_str(), bpath->size());
    post_proc_func = util::copy_string(bppf->c_str());
    rotation_base = *brotation_base;
    rotation_interval = *brotation_interval;
    network_time = *bnetwork_time;

    for ( const auto& i : *bconfig ) {
        auto k = broker::get_if<std::string>(&i.first);
        auto v = broker::get_if<std::string>(&i.second);

        if ( ! (k && v) )
            return false;

        auto p = std::make_pair(util::copy_string(k->c_str(), k->size()), util::copy_string(v->c_str(), v->size()));
        config.insert(p);
    }

    return true;
}

WriterBackend::WriterBackend(WriterFrontend* arg_frontend) : MsgThread() {
    num_fields = 0;
    fields = nullptr;
    buffering = true;
    frontend = arg_frontend;
    info = new WriterInfo(frontend->Info());
    rotation_counter = 0;

    SetName(frontend->Name());
}

WriterBackend::~WriterBackend() {
    if ( fields ) {
        for ( int i = 0; i < num_fields; ++i )
            delete fields[i];

        delete[] fields;
    }

    delete info;
}

void WriterBackend::DeleteVals(int num_writes, Value*** vals) {
    for ( int j = 0; j < num_writes; ++j ) {
        // Note this code is duplicated in Manager::DeleteVals().
        for ( int i = 0; i < num_fields; i++ )
            delete vals[j][i];

        delete[] vals[j];
    }

    delete[] vals;
}

bool WriterBackend::FinishedRotation(const char* new_name, const char* old_name, double open, double close,
                                     bool terminating) {
    --rotation_counter;
    SendOut(new RotationFinishedMessage(frontend, new_name, old_name, open, close, true, terminating));
    return true;
}

bool WriterBackend::FinishedRotation() {
    --rotation_counter;
    SendOut(new RotationFinishedMessage(frontend, nullptr, nullptr, 0, 0, false, false));
    return true;
}

void WriterBackend::DisableFrontend() { SendOut(new DisableMessage(frontend)); }

bool WriterBackend::Init(int arg_num_fields, const Field* const* arg_fields) {
    SetOSName(Fmt("zk.%s", Name()));
    num_fields = arg_num_fields;
    fields = arg_fields;

    if ( Failed() )
        return true;

    if ( ! DoInit(*info, arg_num_fields, arg_fields) ) {
        DisableFrontend();
        return false;
    }

    return true;
}

bool WriterBackend::Write(int arg_num_fields, std::span<detail::LogRecord> records) {
    // Double-check that the arguments match. If we get this from remote,
    // something might be mixed up.
    if ( num_fields != arg_num_fields ) {
#ifdef DEBUG
        const char* msg =
            Fmt("Number of fields don't match in WriterBackend::Write() (%d vs. %d)", arg_num_fields, num_fields);
        Debug(DBG_LOGGING, msg);
#endif

        DisableFrontend();
        return false;
    }

    // Double-check all the types match.
    for ( const auto& record : records ) {
        for ( int i = 0; i < num_fields; ++i ) {
            if ( record[i].type != fields[i]->type ) {
#ifdef DEBUG
                const char* msg = Fmt("Field #%d type doesn't match in WriterBackend::Write() (%d vs. %d)", i,
                                      record[i].type, fields[i]->type);
                Debug(DBG_LOGGING, msg);
#endif
                DisableFrontend();
                return false;
            }
        }
    }

    bool success = true;

    if ( ! Failed() ) {
        // Populate a Value* array for backwards compat with plugin
        // provided WriterBackend implementations that expect to
        // receive a threading::Value**.
        //
        // We keep the raw pointer for this API, as threading::Value
        // itself manages strings, sets and vectors using raw pointers,
        // so this is more consistent than mixing.
        std::vector<Value*> valps;
        valps.reserve(num_fields);

        for ( auto& record : records ) {
            for ( int f = 0; f < num_fields; f++ )
                valps.emplace_back(&record[f]);

            success = DoWrite(num_fields, fields, &valps[0]);

            valps.clear();

            if ( ! success )
                break;
        }
    }

    if ( ! success )
        DisableFrontend();

    return success;
}

bool WriterBackend::SetBuf(bool enabled) {
    if ( enabled == buffering )
        // No change.
        return true;

    if ( Failed() )
        return true;

    buffering = enabled;

    if ( ! DoSetBuf(enabled) ) {
        DisableFrontend();
        return false;
    }

    return true;
}

bool WriterBackend::Rotate(const char* rotated_path, double open, double close, bool terminating) {
    if ( Failed() )
        return true;

    rotation_counter = 1;

    if ( ! DoRotate(rotated_path, open, close, terminating) ) {
        DisableFrontend();
        return false;
    }

    // Insurance against broken writers.
    if ( rotation_counter > 0 )
        InternalError(Fmt("writer %s did not call FinishedRotation() in DoRotation()", Name()));

    if ( rotation_counter < 0 )
        InternalError(Fmt("writer %s called FinishedRotation() more than once in DoRotation()", Name()));

    return true;
}

bool WriterBackend::Flush(double network_time) {
    if ( Failed() )
        return true;

    if ( ! DoFlush(network_time) ) {
        DisableFrontend();
        return false;
    }

    return true;
}

bool WriterBackend::OnFinish(double network_time) {
    if ( Failed() )
        return true;

    return DoFinish(network_time);
}

bool WriterBackend::OnHeartbeat(double network_time, double current_time) {
    if ( Failed() )
        return true;

    return DoHeartbeat(network_time, current_time);
}

} // namespace zeek::logging