intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

9 files changed, 1178 insertions, 0 deletions

diff --git a/library/cpp/monlib/encode/legacy_protobuf/legacy_proto_decoder.cpp b/library/cpp/monlib/encode/legacy_protobuf/legacy_proto_decoder.cpp
new file mode 100644
index 0000000000..f87a2d7e8f
--- /dev/null
+++ b/library/cpp/monlib/encode/legacy_protobuf/legacy_proto_decoder.cpp
@@ -0,0 +1,527 @@
+#include "legacy_protobuf.h"
+
+#include <library/cpp/monlib/encode/legacy_protobuf/protos/metric_meta.pb.h>
+#include <library/cpp/monlib/metrics/metric_consumer.h>
+#include <library/cpp/monlib/metrics/labels.h>
+
+#include <util/generic/yexception.h>
+#include <util/generic/maybe.h>
+#include <util/datetime/base.h>
+#include <util/string/split.h>
+
+#include <google/protobuf/reflection.h>
+
+#include <algorithm>
+
+#ifdef LEGACY_PB_TRACE
+#define TRACE(msg) \
+    Cerr << msg << Endl
+#else
+#define TRACE(...) ;
+#endif
+
+namespace NMonitoring {
+    namespace {
+        using TMaybeMeta = TMaybe<NMonProto::TMetricMeta>;
+
+        TString ReadLabelValue(const NProtoBuf::Message& msg, const NProtoBuf::FieldDescriptor* d, const NProtoBuf::Reflection& r) {
+            using namespace NProtoBuf;
+
+            switch (d->type()) {
+                case FieldDescriptor::TYPE_UINT32:
+                    return ::ToString(r.GetUInt32(msg, d));
+                case FieldDescriptor::TYPE_UINT64:
+                    return ::ToString(r.GetUInt64(msg, d));
+                case FieldDescriptor::TYPE_STRING:
+                    return r.GetString(msg, d);
+                case FieldDescriptor::TYPE_ENUM: {
+                    auto val = r.GetEnumValue(msg, d);
+                    auto* valDesc = d->enum_type()->FindValueByNumber(val);
+                    return valDesc->name();
+                }
+
+                default:
+                    ythrow yexception() << "type " << d->type_name() << " cannot be used as a field value";
+            }
+
+            return {};
+        }
+
+        double ReadFieldAsDouble(const NProtoBuf::Message& msg, const NProtoBuf::FieldDescriptor* d, const NProtoBuf::Reflection& r) {
+            using namespace NProtoBuf;
+
+            switch (d->type()) {
+                case FieldDescriptor::TYPE_DOUBLE:
+                    return r.GetDouble(msg, d);
+                case FieldDescriptor::TYPE_BOOL:
+                    return r.GetBool(msg, d) ? 1 : 0;
+                case FieldDescriptor::TYPE_INT32:
+                    return r.GetInt32(msg, d);
+                case FieldDescriptor::TYPE_INT64:
+                    return r.GetInt64(msg, d);
+                case FieldDescriptor::TYPE_UINT32:
+                    return r.GetUInt32(msg, d);
+                case FieldDescriptor::TYPE_UINT64:
+                    return r.GetUInt64(msg, d);
+                case FieldDescriptor::TYPE_SINT32:
+                    return r.GetInt32(msg, d);
+                case FieldDescriptor::TYPE_SINT64:
+                    return r.GetInt64(msg, d);
+                case FieldDescriptor::TYPE_FIXED32:
+                    return r.GetUInt32(msg, d);
+                case FieldDescriptor::TYPE_FIXED64:
+                    return r.GetUInt64(msg, d);
+                case FieldDescriptor::TYPE_SFIXED32:
+                    return r.GetInt32(msg, d);
+                case FieldDescriptor::TYPE_SFIXED64:
+                    return r.GetInt64(msg, d);
+                case FieldDescriptor::TYPE_FLOAT:
+                    return r.GetFloat(msg, d);
+                case FieldDescriptor::TYPE_ENUM:
+                    return r.GetEnumValue(msg, d);
+                default:
+                    ythrow yexception() << "type " << d->type_name() << " cannot be used as a field value";
+            }
+
+            return std::numeric_limits<double>::quiet_NaN();
+        }
+
+        double ReadRepeatedAsDouble(const NProtoBuf::Message& msg, const NProtoBuf::FieldDescriptor* d, const NProtoBuf::Reflection& r, size_t i) {
+            using namespace NProtoBuf;
+
+            switch (d->type()) {
+                case FieldDescriptor::TYPE_DOUBLE:
+                    return r.GetRepeatedDouble(msg, d, i);
+                case FieldDescriptor::TYPE_BOOL:
+                    return r.GetRepeatedBool(msg, d, i) ? 1 : 0;
+                case FieldDescriptor::TYPE_INT32:
+                    return r.GetRepeatedInt32(msg, d, i);
+                case FieldDescriptor::TYPE_INT64:
+                    return r.GetRepeatedInt64(msg, d, i);
+                case FieldDescriptor::TYPE_UINT32:
+                    return r.GetRepeatedUInt32(msg, d, i);
+                case FieldDescriptor::TYPE_UINT64:
+                    return r.GetRepeatedUInt64(msg, d, i);
+                case FieldDescriptor::TYPE_SINT32:
+                    return r.GetRepeatedInt32(msg, d, i);
+                case FieldDescriptor::TYPE_SINT64:
+                    return r.GetRepeatedInt64(msg, d, i);
+                case FieldDescriptor::TYPE_FIXED32:
+                    return r.GetRepeatedUInt32(msg, d, i);
+                case FieldDescriptor::TYPE_FIXED64:
+                    return r.GetRepeatedUInt64(msg, d, i);
+                case FieldDescriptor::TYPE_SFIXED32:
+                    return r.GetRepeatedInt32(msg, d, i);
+                case FieldDescriptor::TYPE_SFIXED64:
+                    return r.GetRepeatedInt64(msg, d, i);
+                case FieldDescriptor::TYPE_FLOAT:
+                    return r.GetRepeatedFloat(msg, d, i);
+                case FieldDescriptor::TYPE_ENUM:
+                    return r.GetRepeatedEnumValue(msg, d, i);
+                default:
+                    ythrow yexception() << "type " << d->type_name() << " cannot be used as a field value";
+            }
+
+            return std::numeric_limits<double>::quiet_NaN();
+        }
+
+        TString LabelFromField(const NProtoBuf::Message& msg, const TString& name) {
+            const auto* fieldDesc = msg.GetDescriptor()->FindFieldByName(name);
+            const auto* reflection = msg.GetReflection();
+            Y_ENSURE(fieldDesc && reflection, "Unable to get meta for field " << name);
+
+            auto s = ReadLabelValue(msg, fieldDesc, *reflection);
+            std::replace(std::begin(s), s.vend(), ' ', '_');
+
+            return s;
+        }
+
+        TMaybeMeta MaybeGetMeta(const NProtoBuf::FieldOptions& opts) {
+            if (opts.HasExtension(NMonProto::Metric)) {
+                return opts.GetExtension(NMonProto::Metric);
+            }
+
+            return Nothing();
+        }
+
+        class ILabelGetter: public TThrRefBase {
+        public:
+            enum class EType {
+                Fixed = 1,
+                Lazy = 2,
+            };
+
+            virtual TLabel Get(const NProtoBuf::Message&) = 0;
+            virtual EType Type() const = 0;
+        };
+
+        class TFixedLabel: public ILabelGetter {
+        public:
+            explicit TFixedLabel(TLabel&& l)
+                : Label_{std::move(l)}
+            {
+                TRACE("found fixed label " << l);
+            }
+
+            EType Type() const override {
+                return EType::Fixed;
+            }
+            TLabel Get(const NProtoBuf::Message&) override {
+                return Label_;
+            }
+
+        private:
+            TLabel Label_;
+        };
+
+        using TFunction = std::function<TLabel(const NProtoBuf::Message&)>;
+
+        class TLazyLabel: public ILabelGetter {
+        public:
+            TLazyLabel(TFunction&& fn)
+                : Fn_{std::move(fn)}
+            {
+                TRACE("found lazy label");
+            }
+
+            EType Type() const override {
+                return EType::Lazy;
+            }
+            TLabel Get(const NProtoBuf::Message& msg) override {
+                return Fn_(msg);
+            }
+
+        private:
+            TFunction Fn_;
+        };
+
+        class TDecoderContext {
+        public:
+            void Init(const NProtoBuf::Message* msg) {
+                Message_ = msg;
+                Y_ENSURE(Message_);
+                Reflection_ = msg->GetReflection();
+                Y_ENSURE(Reflection_);
+
+                for (auto it = Labels_.begin(); it != Labels_.end(); ++it) {
+                    if ((*it)->Type() == ILabelGetter::EType::Lazy) {
+                        auto l = (*it)->Get(Message());
+                        *it = ::MakeIntrusive<TFixedLabel>(std::move(l));
+                    } else {
+                        auto l = (*it)->Get(Message());
+                    }
+                }
+            }
+
+            void Clear() noexcept {
+                Message_ = nullptr;
+                Reflection_ = nullptr;
+            }
+
+            TDecoderContext CreateChildFromMeta(const NMonProto::TMetricMeta& metricMeta, const TString& name, i64 repeatedIdx = -1) {
+                TDecoderContext child{*this};
+                child.Clear();
+
+                if (metricMeta.HasCustomPath()) {
+                    if (const auto& nodePath = metricMeta.GetCustomPath()) {
+                        child.AppendPath(nodePath);
+                    }
+                } else if (metricMeta.GetPath()) {
+                    child.AppendPath(name);
+                }
+
+                if (metricMeta.HasKeys()) {
+                    child.ParseKeys(metricMeta.GetKeys(), repeatedIdx);
+                }
+
+                return child;
+            }
+
+            TDecoderContext CreateChildFromRepeatedScalar(const NMonProto::TMetricMeta& metricMeta, i64 repeatedIdx = -1) {
+                TDecoderContext child{*this};
+                child.Clear();
+
+                if (metricMeta.HasKeys()) {
+                    child.ParseKeys(metricMeta.GetKeys(), repeatedIdx);
+                }
+
+                return child;
+            }
+
+            TDecoderContext CreateChildFromEls(const TString& name, const NMonProto::TExtraLabelMetrics& metrics, size_t idx, TMaybeMeta maybeMeta) {
+                TDecoderContext child{*this};
+                child.Clear();
+
+                auto usePath = [&maybeMeta] {
+                    return !maybeMeta->HasPath() || maybeMeta->GetPath();
+                };
+
+                if (!name.empty() && (!maybeMeta || usePath())) {
+                    child.AppendPath(name);
+                }
+
+                child.Labels_.push_back(::MakeIntrusive<TLazyLabel>(
+                    [ labelName = metrics.GetlabelName(), idx, &metrics ](const auto&) {
+                        const auto& val = metrics.Getvalues(idx);
+                        TString labelVal;
+                        const auto uintLabel = val.GetlabelValueUint();
+
+                        if (uintLabel) {
+                            labelVal = ::ToString(uintLabel);
+                        } else {
+                            labelVal = val.GetlabelValue();
+                        }
+
+                        return TLabel{labelName, labelVal};
+                    }));
+
+                return child;
+            }
+
+            void ParseKeys(TStringBuf keys, i64 repeatedIdx = -1) {
+                auto parts = StringSplitter(keys)
+                                 .Split(' ')
+                                 .SkipEmpty();
+
+                for (auto part : parts) {
+                    auto str = part.Token();
+
+                    TStringBuf lhs, rhs;
+
+                    const bool isDynamic = str.TrySplit(':', lhs, rhs);
+                    const bool isIndexing = isDynamic && rhs == TStringBuf("#");
+
+                    if (isIndexing) {
+                        TRACE("parsed index labels");
+
+                        // <label_name>:# means that we should use index of the repeated
+                        // field as label value
+                        Y_ENSURE(repeatedIdx != -1);
+                        Labels_.push_back(::MakeIntrusive<TLazyLabel>([=](const auto&) {
+                            return TLabel{lhs, ::ToString(repeatedIdx)};
+                        }));
+                    } else if (isDynamic) {
+                        TRACE("parsed dynamic labels");
+
+                        // <label_name>:<field_name> means that we need to take label value
+                        // later from message's field
+                        Labels_.push_back(::MakeIntrusive<TLazyLabel>([=](const auto& msg) {
+                            return TLabel{lhs, LabelFromField(msg, TString{rhs})};
+                        }));
+                    } else if (str.TrySplit('=', lhs, rhs)) {
+                        TRACE("parsed static labels");
+
+                        // <label_name>=<label_value> stands for constant label
+                        Labels_.push_back(::MakeIntrusive<TFixedLabel>(TLabel{lhs, rhs}));
+                    } else {
+                        ythrow yexception() << "Incorrect Keys format";
+                    }
+                }
+            }
+
+            void AppendPath(TStringBuf fieldName) {
+                Path_ += '/';
+                Path_ += fieldName;
+            }
+
+            const TString& Path() const {
+                return Path_;
+            }
+
+            TLabels Labels() const {
+                TLabels result;
+                for (auto&& l : Labels_) {
+                    result.Add(l->Get(Message()));
+                }
+
+                return result;
+            }
+
+            const NProtoBuf::Message& Message() const {
+                Y_VERIFY_DEBUG(Message_);
+                return *Message_;
+            }
+
+            const NProtoBuf::Reflection& Reflection() const {
+                return *Reflection_;
+            }
+
+        private:
+            const NProtoBuf::Message* Message_{nullptr};
+            const NProtoBuf::Reflection* Reflection_{nullptr};
+
+            TString Path_;
+            TVector<TIntrusivePtr<ILabelGetter>> Labels_;
+        };
+
+        class TDecoder {
+        public:
+            TDecoder(IMetricConsumer* consumer, const NProtoBuf::Message& message, TInstant timestamp)
+                : Consumer_{consumer}
+                , Message_{message}
+                , Timestamp_{timestamp}
+            {
+            }
+
+            void Decode() const {
+                Consumer_->OnStreamBegin();
+                DecodeToStream();
+                Consumer_->OnStreamEnd();
+            }
+
+            void DecodeToStream() const {
+                DecodeImpl(Message_, {});
+            }
+
+        private:
+            static const NMonProto::TExtraLabelMetrics& ExtractExtraMetrics(TDecoderContext& ctx, const NProtoBuf::FieldDescriptor& f) {
+                const auto& parent = ctx.Message();
+                const auto& reflection = ctx.Reflection();
+                auto& subMessage = reflection.GetMessage(parent, &f);
+
+                return dynamic_cast<const NMonProto::TExtraLabelMetrics&>(subMessage);
+            }
+
+            void DecodeImpl(const NProtoBuf::Message& msg, TDecoderContext ctx) const {
+                std::vector<const NProtoBuf::FieldDescriptor*> fields;
+
+                ctx.Init(&msg);
+
+                ctx.Reflection().ListFields(msg, &fields);
+
+                for (const auto* f : fields) {
+                    Y_ENSURE(f);
+
+                    const auto& opts = f->options();
+                    const auto isMessage = f->type() == NProtoBuf::FieldDescriptor::TYPE_MESSAGE;
+                    const auto isExtraLabelMetrics = isMessage && f->message_type()->full_name() == "NMonProto.TExtraLabelMetrics";
+                    const auto maybeMeta = MaybeGetMeta(opts);
+
+                    if (!(maybeMeta || isExtraLabelMetrics)) {
+                        continue;
+                    }
+
+                    if (isExtraLabelMetrics) {
+                        const auto& extra = ExtractExtraMetrics(ctx, *f);
+                        RecurseExtraLabelMetrics(ctx, extra, f->name(), maybeMeta);
+                    } else if (isMessage) {
+                        RecurseMessage(ctx, *maybeMeta, *f);
+                    } else if (f->is_repeated()) {
+                        RecurseRepeatedScalar(ctx, *maybeMeta, *f);
+                    } else if (maybeMeta->HasType()) {
+                        const auto val = ReadFieldAsDouble(msg, f, ctx.Reflection());
+                        const bool isRate = maybeMeta->GetType() == NMonProto::EMetricType::RATE;
+                        WriteMetric(val, ctx, f->name(), isRate);
+                    }
+                }
+            }
+
+            void RecurseRepeatedScalar(TDecoderContext ctx, const NMonProto::TMetricMeta& meta, const NProtoBuf::FieldDescriptor& f) const {
+                auto&& msg = ctx.Message();
+                auto&& reflection = ctx.Reflection();
+                const bool isRate = meta.GetType() == NMonProto::EMetricType::RATE;
+
+                // this is a repeated scalar field, which makes metric only if it's indexing
+                for (auto i = 0; i < reflection.FieldSize(msg, &f); ++i) {
+                    auto subCtx = ctx.CreateChildFromRepeatedScalar(meta, i);
+                    subCtx.Init(&msg);
+                    auto val = ReadRepeatedAsDouble(msg, &f, reflection, i);
+                    WriteMetric(val, subCtx, f.name(), isRate);
+                }
+            }
+
+            void RecurseExtraLabelMetrics(TDecoderContext ctx, const NMonProto::TExtraLabelMetrics& msg, const TString& name, const TMaybeMeta& meta) const {
+                auto i = 0;
+                for (const auto& val : msg.Getvalues()) {
+                    auto subCtx = ctx.CreateChildFromEls(name, msg, i++, meta);
+                    subCtx.Init(&val);
+
+                    const bool isRate = val.Hastype()
+                             ? val.Gettype() == NMonProto::EMetricType::RATE
+                             : meta->GetType() == NMonProto::EMetricType::RATE;
+
+                    double metricVal{0};
+                    if (isRate) {
+                        metricVal = val.GetlongValue();
+                    } else {
+                        metricVal = val.GetdoubleValue();
+                    }
+
+                    WriteMetric(metricVal, subCtx, "", isRate);
+
+                    for (const auto& child : val.Getchildren()) {
+                        RecurseExtraLabelMetrics(subCtx, child, "", meta);
+                    }
+                }
+            }
+
+            void RecurseMessage(TDecoderContext ctx, const NMonProto::TMetricMeta& metricMeta, const NProtoBuf::FieldDescriptor& f) const {
+                const auto& msg = ctx.Message();
+                const auto& reflection = ctx.Reflection();
+
+                if (f.is_repeated()) {
+                    TRACE("recurse into repeated message " << f.name());
+                    for (auto i = 0; i < reflection.FieldSize(msg, &f); ++i) {
+                        auto& subMessage = reflection.GetRepeatedMessage(msg, &f, i);
+                        DecodeImpl(subMessage, ctx.CreateChildFromMeta(metricMeta, f.name(), i));
+                    }
+                } else {
+                    TRACE("recurse into message " << f.name());
+                    auto& subMessage = reflection.GetMessage(msg, &f);
+                    DecodeImpl(subMessage, ctx.CreateChildFromMeta(metricMeta, f.name()));
+                }
+            }
+
+            inline void WriteValue(ui64 value) const {
+                Consumer_->OnUint64(Timestamp_, value);
+            }
+
+            inline void WriteValue(double value) const {
+                Consumer_->OnDouble(Timestamp_, value);
+            }
+
+            void WriteMetric(double value, const TDecoderContext& ctx, const TString& name, bool isRate) const {
+                if (isRate) {
+                    Consumer_->OnMetricBegin(EMetricType::RATE);
+                    WriteValue(static_cast<ui64>(value));
+                } else {
+                    Consumer_->OnMetricBegin(EMetricType::GAUGE);
+                    WriteValue(static_cast<double>(value));
+                }
+
+                Consumer_->OnLabelsBegin();
+
+                for (const auto& label : ctx.Labels()) {
+                    Consumer_->OnLabel(label.Name(), label.Value());
+                }
+
+                const auto fullPath = name.empty()
+                                          ? ctx.Path()
+                                          : ctx.Path() + '/' + name;
+
+                if (fullPath) {
+                    Consumer_->OnLabel("path", fullPath);
+                }
+
+                Consumer_->OnLabelsEnd();
+                Consumer_->OnMetricEnd();
+            }
+
+        private:
+            IMetricConsumer* Consumer_{nullptr};
+            const NProtoBuf::Message& Message_;
+            TInstant Timestamp_;
+        };
+
+    }
+
+    void DecodeLegacyProto(const NProtoBuf::Message& data, IMetricConsumer* consumer, TInstant ts) {
+        Y_ENSURE(consumer);
+        TDecoder(consumer, data, ts).Decode();
+    }
+
+    void DecodeLegacyProtoToStream(const NProtoBuf::Message& data, IMetricConsumer* consumer, TInstant ts) {
+        Y_ENSURE(consumer);
+        TDecoder(consumer, data, ts).DecodeToStream();
+    }
+}
diff --git a/library/cpp/monlib/encode/legacy_protobuf/legacy_protobuf.h b/library/cpp/monlib/encode/legacy_protobuf/legacy_protobuf.h
new file mode 100644
index 0000000000..7cf8985d65
--- /dev/null
+++ b/library/cpp/monlib/encode/legacy_protobuf/legacy_protobuf.h
@@ -0,0 +1,16 @@
+#pragma once
+
+#include <google/protobuf/message.h>
+#include <util/datetime/base.h>
+
+namespace NMonitoring {
+    // Unsupported features of the original format:
+    // - histograms;
+    // - memOnly;
+    // - dropHost/ignorePath
+
+    void DecodeLegacyProto(const NProtoBuf::Message& data, class IMetricConsumer* c, TInstant ts = TInstant::Zero());
+
+    /// Does not open/close consumer stream unlike the above function.
+    void DecodeLegacyProtoToStream(const NProtoBuf::Message& data, class IMetricConsumer* c, TInstant ts = TInstant::Zero());
+}
diff --git a/library/cpp/monlib/encode/legacy_protobuf/legacy_protobuf_ut.cpp b/library/cpp/monlib/encode/legacy_protobuf/legacy_protobuf_ut.cpp
new file mode 100644
index 0000000000..53683cb39c
--- /dev/null
+++ b/library/cpp/monlib/encode/legacy_protobuf/legacy_protobuf_ut.cpp
@@ -0,0 +1,422 @@
+#include "legacy_protobuf.h"
+
+#include <library/cpp/testing/unittest/registar.h>
+
+#include <library/cpp/monlib/encode/legacy_protobuf/ut/test_cases.pb.h>
+#include <library/cpp/monlib/encode/legacy_protobuf/protos/metric_meta.pb.h>
+
+#include <library/cpp/monlib/encode/protobuf/protobuf.h>
+#include <library/cpp/monlib/encode/text/text.h>
+#include <library/cpp/monlib/metrics/labels.h>
+
+#include <util/generic/algorithm.h>
+#include <util/generic/hash_set.h>
+
+using namespace NMonitoring;
+
+TSimple MakeSimpleMessage() {
+    TSimple msg;
+
+    msg.SetFoo(1);
+    msg.SetBar(2.);
+    msg.SetBaz(42.);
+
+    return msg;
+}
+
+IMetricEncoderPtr debugPrinter = EncoderText(&Cerr);
+
+namespace NMonitoring {
+    inline bool operator<(const TLabel& lhs, const TLabel& rhs) {
+        return lhs.Name() < rhs.Name() ||
+               (lhs.Name() == rhs.Name() && lhs.Value() < rhs.Value());
+    }
+
+}
+
+void SetLabelValue(NMonProto::TExtraLabelMetrics::TValue& val, TString s) {
+    val.SetlabelValue(s);
+}
+
+void SetLabelValue(NMonProto::TExtraLabelMetrics::TValue& val, ui64 u) {
+    val.SetlabelValueUint(u);
+}
+
+template <typename T, typename V>
+NMonProto::TExtraLabelMetrics MakeExtra(TString labelName, V labelValue, T value, bool isDeriv) {
+    NMonProto::TExtraLabelMetrics metric;
+    auto* val = metric.Addvalues();
+
+    metric.SetlabelName(labelName);
+    SetLabelValue(*val, labelValue);
+
+    if (isDeriv) {
+        val->SetlongValue(value);
+    } else {
+        val->SetdoubleValue(value);
+    }
+
+    return metric;
+}
+
+void AssertLabels(const TLabels& expected, const NProto::TMultiSample& actual) {
+    UNIT_ASSERT_EQUAL(actual.LabelsSize(), expected.Size());
+
+    TSet<TLabel> actualSet;
+    TSet<TLabel> expectedSet;
+    Transform(expected.begin(), expected.end(), std::inserter(expectedSet, expectedSet.end()), [] (auto&& l) {
+        return TLabel{l.Name(), l.Value()};
+    });
+
+    const auto& l = actual.GetLabels();
+    Transform(std::begin(l), std::end(l), std::inserter(actualSet, std::begin(actualSet)),
+              [](auto&& elem) -> TLabel {
+                  return {elem.GetName(), elem.GetValue()};
+              });
+
+    TVector<TLabel> diff;
+    SetSymmetricDifference(std::begin(expectedSet), std::end(expectedSet),
+                           std::begin(actualSet), std::end(actualSet), std::back_inserter(diff));
+
+    if (diff.size() > 0) {
+        for (auto&& l : diff) {
+            Cerr << l << Endl;
+        }
+
+        UNIT_FAIL("Labels don't match");
+    }
+}
+
+void AssertSimpleMessage(const NProto::TMultiSamplesList& samples, TString pathPrefix = "/") {
+    UNIT_ASSERT_EQUAL(samples.SamplesSize(), 3);
+
+    THashSet<TString> expectedValues{pathPrefix + "Foo", pathPrefix + "Bar", pathPrefix + "Baz"};
+
+    for (const auto& s : samples.GetSamples()) {
+        UNIT_ASSERT_EQUAL(s.LabelsSize(), 1);
+        UNIT_ASSERT_EQUAL(s.PointsSize(), 1);
+
+        const auto labelVal = s.GetLabels(0).GetValue();
+        UNIT_ASSERT(expectedValues.contains(labelVal));
+
+        if (labelVal == pathPrefix + "Foo") {
+            UNIT_ASSERT_EQUAL(s.GetMetricType(), NProto::GAUGE);
+            UNIT_ASSERT_DOUBLES_EQUAL(s.GetPoints(0).GetFloat64(), 1, 1e-6);
+        } else if (labelVal == pathPrefix + "Bar") {
+            UNIT_ASSERT_EQUAL(s.GetMetricType(), NProto::GAUGE);
+            UNIT_ASSERT_DOUBLES_EQUAL(s.GetPoints(0).GetFloat64(), 2, 1e-6);
+        } else if (labelVal == pathPrefix + "Baz") {
+            UNIT_ASSERT_EQUAL(s.GetMetricType(), NProto::RATE);
+            UNIT_ASSERT_EQUAL(s.GetPoints(0).GetUint64(), 42);
+        }
+    }
+}
+
+Y_UNIT_TEST_SUITE(TLegacyProtoDecoderTest) {
+    Y_UNIT_TEST(SimpleProto) {
+        NProto::TMultiSamplesList samples;
+        IMetricEncoderPtr e = EncoderProtobuf(&samples);
+
+        auto msg = MakeSimpleMessage();
+        DecodeLegacyProto(msg, e.Get());
+
+        AssertSimpleMessage(samples);
+    };
+
+    Y_UNIT_TEST(RepeatedProto) {
+        NProto::TMultiSamplesList samples;
+        IMetricEncoderPtr e = EncoderProtobuf(&samples);
+
+        auto simple = MakeSimpleMessage();
+        TRepeated msg;
+        msg.AddMessages()->CopyFrom(simple);
+
+        DecodeLegacyProto(msg, e.Get());
+
+        AssertSimpleMessage(samples);
+    }
+
+    Y_UNIT_TEST(RepeatedProtoWithPath) {
+        NProto::TMultiSamplesList samples;
+        IMetricEncoderPtr e = EncoderProtobuf(&samples);
+
+        auto simple = MakeSimpleMessage();
+        TRepeatedWithPath msg;
+        msg.AddNamespace()->CopyFrom(simple);
+
+        DecodeLegacyProto(msg, e.Get());
+
+        AssertSimpleMessage(samples, "/Namespace/");
+    }
+
+    Y_UNIT_TEST(DeepNesting) {
+        NProto::TMultiSamplesList samples;
+        IMetricEncoderPtr e = EncoderProtobuf(&samples);
+
+        auto simple = MakeSimpleMessage();
+        TRepeatedWithPath internal;
+        internal.AddNamespace()->CopyFrom(simple);
+
+        TDeepNesting msg;
+        msg.MutableNested()->CopyFrom(internal);
+
+        DecodeLegacyProto(msg, e.Get());
+
+        AssertSimpleMessage(samples, "/Namespace/");
+    }
+
+    Y_UNIT_TEST(Keys) {
+        NProto::TMultiSamplesList samples;
+        IMetricEncoderPtr e = EncoderProtobuf(&samples);
+
+        auto simple = MakeSimpleMessage();
+        simple.SetLabel("my_label_value");
+
+        TNestedWithKeys msg;
+        msg.AddNamespace()->CopyFrom(simple);
+
+        DecodeLegacyProto(msg, e.Get());
+
+        auto i = 0;
+        for (const auto& s : samples.GetSamples()) {
+            UNIT_ASSERT_EQUAL(s.LabelsSize(), 4);
+
+            bool foundLabel = false;
+            bool foundFixed = false;
+            bool foundNumbered = false;
+
+            for (const auto& label : s.GetLabels()) {
+                if (label.GetName() == "my_label") {
+                    foundLabel = true;
+                    UNIT_ASSERT_STRINGS_EQUAL(label.GetValue(), "my_label_value");
+                } else if (label.GetName() == "fixed_label") {
+                    foundFixed = true;
+                    UNIT_ASSERT_STRINGS_EQUAL(label.GetValue(), "fixed_value");
+                } else if (label.GetName() == "numbered") {
+                    foundNumbered = true;
+                    UNIT_ASSERT_STRINGS_EQUAL(label.GetValue(), ::ToString(i));
+                }
+            }
+
+            UNIT_ASSERT(foundLabel);
+            UNIT_ASSERT(foundFixed);
+            UNIT_ASSERT(foundNumbered);
+        }
+    }
+
+    Y_UNIT_TEST(NonStringKeys) {
+        NProto::TMultiSamplesList samples;
+        IMetricEncoderPtr e = EncoderProtobuf(&samples);
+
+        TNonStringKeys msg;
+        msg.SetFoo(42);
+        msg.SetEnum(ENUM);
+        msg.SetInt(43);
+
+        TRepeatedNonStringKeys msgs;
+        msgs.AddNested()->CopyFrom(msg);
+
+        DecodeLegacyProto(msgs, e.Get());
+
+        for (const auto& s : samples.GetSamples()) {
+            bool foundEnum = false;
+            bool foundInt = false;
+
+            for (const auto& label : s.GetLabels()) {
+                if (label.GetName() == "enum") {
+                    foundEnum = true;
+                    UNIT_ASSERT_STRINGS_EQUAL(label.GetValue(), "ENUM");
+                } else if (label.GetName() == "int") {
+                    foundInt = true;
+                    UNIT_ASSERT_STRINGS_EQUAL(label.GetValue(), "43");
+                }
+            }
+
+            UNIT_ASSERT(foundEnum);
+            UNIT_ASSERT(foundInt);
+
+            UNIT_ASSERT_DOUBLES_EQUAL(s.GetPoints(0).GetFloat64(), 42, 1e-6);
+        }
+    }
+
+    Y_UNIT_TEST(KeysFromNonLeafNodes) {
+        NProto::TMultiSamplesList samples;
+        IMetricEncoderPtr e = EncoderProtobuf(&samples);
+
+        auto simple = MakeSimpleMessage();
+        simple.SetLabel("label_value");
+
+        TRepeatedWithName nested;
+        nested.SetName("my_name");
+        nested.AddNested()->CopyFrom(simple);
+
+        TKeysFromNonLeaf msg;
+        msg.AddNested()->CopyFrom(nested);
+
+        DecodeLegacyProto(msg, e.Get());
+
+        AssertLabels({{"my_label", "label_value"}, {"path", "/Nested/Nested/Foo"}, {"name", "my_name"}}, samples.GetSamples(0));
+    }
+
+    Y_UNIT_TEST(SpacesAreGetReplaced) {
+        NProto::TMultiSamplesList samples;
+        IMetricEncoderPtr e = EncoderProtobuf(&samples);
+
+        auto simple = MakeSimpleMessage();
+        simple.SetLabel("my label_value");
+
+        TNestedWithKeys msg;
+        msg.AddNamespace()->CopyFrom(simple);
+
+        DecodeLegacyProto(msg, e.Get());
+
+        for (const auto& s : samples.GetSamples()) {
+            UNIT_ASSERT_EQUAL(s.LabelsSize(), 4);
+
+            bool foundLabel = false;
+
+            for (const auto& label : s.GetLabels()) {
+                if (label.GetName() == "my_label") {
+                    foundLabel = true;
+                    UNIT_ASSERT_STRINGS_EQUAL(label.GetValue(), "my_label_value");
+                }
+            }
+
+            UNIT_ASSERT(foundLabel);
+        }
+    }
+
+    Y_UNIT_TEST(ExtraLabels) {
+        NProto::TMultiSamplesList samples;
+        IMetricEncoderPtr e = EncoderProtobuf(&samples);
+
+        TExtraLabels msg;
+        msg.MutableExtraAsIs()->CopyFrom(MakeExtra("label", "foo", 42, false));
+        msg.MutableExtraDeriv()->CopyFrom(MakeExtra("deriv_label", "deriv_foo", 43, true));
+
+        DecodeLegacyProto(msg, e.Get());
+
+        UNIT_ASSERT_EQUAL(samples.SamplesSize(), 2);
+        {
+            auto s = samples.GetSamples(0);
+            AssertLabels({{"label", "foo"}, {"path", "/ExtraAsIs"}}, s);
+
+            UNIT_ASSERT_EQUAL(s.PointsSize(), 1);
+            auto point = s.GetPoints(0);
+            UNIT_ASSERT_DOUBLES_EQUAL(point.GetFloat64(), 42, 1e-6);
+        }
+
+        {
+            auto s = samples.GetSamples(1);
+            AssertLabels({{"deriv_label", "deriv_foo"}, {"path", "/ExtraDeriv"}}, s);
+
+            UNIT_ASSERT_EQUAL(s.PointsSize(), 1);
+            auto point = s.GetPoints(0);
+            UNIT_ASSERT_EQUAL(point.GetUint64(), 43);
+        }
+    }
+
+    Y_UNIT_TEST(NestedExtraLabels) {
+        NProto::TMultiSamplesList samples;
+        IMetricEncoderPtr e = EncoderProtobuf(&samples);
+
+        TExtraLabels msg;
+        auto extra = MakeExtra("label", "foo", 42, false);
+        auto* val = extra.Mutablevalues(0);
+        {
+            auto child = MakeExtra("child1", "label1", 24, true);
+            child.Mutablevalues(0)->Settype(NMonProto::EMetricType::RATE);
+            val->Addchildren()->CopyFrom(child);
+        }
+
+        {
+            auto child = MakeExtra("child2", 34, 23, false);
+            val->Addchildren()->CopyFrom(child);
+        }
+        msg.MutableExtraAsIs()->CopyFrom(extra);
+
+        DecodeLegacyProto(msg, e.Get());
+
+        UNIT_ASSERT_EQUAL(samples.SamplesSize(), 3);
+        {
+            auto s = samples.GetSamples(0);
+            AssertLabels({{"label", "foo"}, {"path", "/ExtraAsIs"}}, s);
+
+            UNIT_ASSERT_EQUAL(s.PointsSize(), 1);
+            auto point = s.GetPoints(0);
+            UNIT_ASSERT_DOUBLES_EQUAL(point.GetFloat64(), 42, 1e-6);
+        }
+
+        {
+            auto s = samples.GetSamples(1);
+            AssertLabels({{"label", "foo"}, {"child1", "label1"}, {"path", "/ExtraAsIs"}}, s);
+
+            UNIT_ASSERT_EQUAL(s.PointsSize(), 1);
+            auto point = s.GetPoints(0);
+            UNIT_ASSERT_EQUAL(point.GetUint64(), 24);
+        }
+
+        {
+            auto s = samples.GetSamples(2);
+            AssertLabels({{"label", "foo"}, {"child2", "34"}, {"path", "/ExtraAsIs"}}, s);
+
+            UNIT_ASSERT_EQUAL(s.PointsSize(), 1);
+            auto point = s.GetPoints(0);
+            UNIT_ASSERT_EQUAL(point.GetFloat64(), 23);
+        }
+    }
+
+    Y_UNIT_TEST(RobotLabels) {
+        NProto::TMultiSamplesList samples;
+        IMetricEncoderPtr e = EncoderProtobuf(&samples);
+
+        TNamedCounter responses;
+        responses.SetName("responses");
+        responses.SetCount(42);
+
+        TCrawlerCounters::TStatusCounters statusCounters;
+        statusCounters.AddZoraResponses()->CopyFrom(responses);
+
+        TCrawlerCounters::TPolicyCounters policyCounters;
+        policyCounters.SetSubComponent("mySubComponent");
+        policyCounters.SetName("myComponentName");
+        policyCounters.SetZone("myComponentZone");
+        policyCounters.MutableStatusCounters()->CopyFrom(statusCounters);
+
+        TCrawlerCounters counters;
+        counters.SetComponent("myComponent");
+        counters.AddPoliciesCounters()->CopyFrom(policyCounters);
+
+        DecodeLegacyProto(counters, e.Get());
+        UNIT_ASSERT_EQUAL(samples.SamplesSize(), 1);
+        auto s = samples.GetSamples(0);
+        AssertLabels({
+            {"SubComponent", "mySubComponent"}, {"Policy", "myComponentName"}, {"Zone", "myComponentZone"},
+            {"ZoraResponse", "responses"}, {"path", "/PoliciesCounters/StatusCounters/ZoraResponses/Count"}}, s);
+    }
+
+    Y_UNIT_TEST(ZoraLabels) {
+        NProto::TMultiSamplesList samples;
+        IMetricEncoderPtr e = EncoderProtobuf(&samples);
+
+        TTimeLogHist hist;
+        hist.AddBuckets(42);
+        hist.AddBuckets(0);
+
+        TKiwiCounters counters;
+        counters.MutableTimes()->CopyFrom(hist);
+
+        DecodeLegacyProto(counters, e.Get());
+
+        UNIT_ASSERT_EQUAL(samples.SamplesSize(), 2);
+
+        auto s = samples.GetSamples(0);
+        AssertLabels({{"slot", "0"}, {"path", "/Times/Buckets"}}, s);
+        UNIT_ASSERT_EQUAL(s.PointsSize(), 1);
+        UNIT_ASSERT_EQUAL(s.GetPoints(0).GetUint64(), 42);
+
+        s = samples.GetSamples(1);
+        AssertLabels({{"slot", "1"}, {"path", "/Times/Buckets"}}, s);
+        UNIT_ASSERT_EQUAL(s.GetPoints(0).GetUint64(), 0);
+    }
+}
diff --git a/library/cpp/monlib/encode/legacy_protobuf/protos/metric_meta.proto b/library/cpp/monlib/encode/legacy_protobuf/protos/metric_meta.proto
new file mode 100644
index 0000000000..fd23eb372b
--- /dev/null
+++ b/library/cpp/monlib/encode/legacy_protobuf/protos/metric_meta.proto
@@ -0,0 +1,73 @@
+import "google/protobuf/descriptor.proto";
+
+package NMonProto;
+
+option java_package = "ru.yandex.monlib.proto";
+option java_outer_classname = "MetricMetaProto";
+
+enum EMetricType {
+    GAUGE = 1;
+    RATE = 2;
+}
+
+enum EMemOnly {
+    DEFAULT = 0;
+    STORE = 1;
+    MEM_ONLY = 2;
+}
+
+message TMetricMeta {
+    optional EMetricType Type = 1;
+    optional bool Path = 2;
+    optional string Keys = 3;
+    optional bool MemOnly = 4;
+    optional bool IgnorePath = 5;
+    optional string CustomPath = 6;
+}
+
+enum THistogramBase {
+    MICROSECOND = 3;
+    MILLISECOND = 6;
+    SECOND      = 9;
+    MINUTE      = 12;
+    HOUR        = 15;
+}
+
+message THistogramEntry {
+    optional uint64 Multiplier = 1;
+    optional double Value = 2;
+}
+
+message THistogram {
+    optional THistogramBase Base = 1;
+    optional string BaseStr = 2;
+    repeated THistogramEntry Entries = 5;
+}
+
+// field of this type is recognized by Solomon
+message TExtraLabelMetrics {
+    optional string labelName = 1;
+
+    message TValue {
+        optional string labelValue = 1;
+        // used only if != 0
+        optional uint64 labelValueUint = 21;
+
+        optional uint64 longValue = 2;
+        optional double doubleValue = 3;
+        optional THistogram histogramValue = 4;
+
+        optional EMetricType type = 7;
+        optional EMemOnly memOnly = 8;
+        optional bool dropHost = 9;
+
+        repeated TExtraLabelMetrics children = 17;
+    }
+
+    repeated TValue values = 2;
+}
+
+extend google.protobuf.FieldOptions {
+    optional TMetricMeta Metric = 1719;
+}
+
diff --git a/library/cpp/monlib/encode/legacy_protobuf/protos/python/ya.make b/library/cpp/monlib/encode/legacy_protobuf/protos/python/ya.make
new file mode 100644
index 0000000000..095b307b01
--- /dev/null
+++ b/library/cpp/monlib/encode/legacy_protobuf/protos/python/ya.make
@@ -0,0 +1,3 @@
+OWNER(g:solomon)
+
+PY_PROTOS_FOR(library/cpp/monlib/encode/legacy_protobuf/protos)
diff --git a/library/cpp/monlib/encode/legacy_protobuf/protos/ya.make b/library/cpp/monlib/encode/legacy_protobuf/protos/ya.make
new file mode 100644
index 0000000000..489f361ab1
--- /dev/null
+++ b/library/cpp/monlib/encode/legacy_protobuf/protos/ya.make
@@ -0,0 +1,13 @@
+PROTO_LIBRARY()
+
+OWNER(g:solomon)
+
+SRCS(
+    metric_meta.proto
+)
+
+IF (NOT PY_PROTOS_FOR)
+    EXCLUDE_TAGS(GO_PROTO)
+ENDIF()
+
+END()
diff --git a/library/cpp/monlib/encode/legacy_protobuf/ut/test_cases.proto b/library/cpp/monlib/encode/legacy_protobuf/ut/test_cases.proto
new file mode 100644
index 0000000000..37e901de48
--- /dev/null
+++ b/library/cpp/monlib/encode/legacy_protobuf/ut/test_cases.proto
@@ -0,0 +1,90 @@
+import "library/cpp/monlib/encode/legacy_protobuf/protos/metric_meta.proto";
+
+message TSimple {
+    optional uint64 Foo = 1       [ (NMonProto.Metric).Type = GAUGE ];
+    optional double Bar = 2        [ (NMonProto.Metric).Type = GAUGE ];
+    optional double Baz = 3        [ (NMonProto.Metric).Type = RATE ];
+    optional string Label = 4;
+}
+
+message TRepeated {
+    repeated TSimple Messages = 1 [ (NMonProto.Metric).Path = false ];
+};
+
+message TRepeatedWithPath {
+    repeated TSimple Namespace = 1 [ (NMonProto.Metric).Path = true ];
+};
+
+message TNestedWithKeys {
+    repeated TSimple Namespace = 1 [ (NMonProto.Metric).Path = true, (NMonProto.Metric).Keys = "my_label:Label fixed_label=fixed_value numbered:#" ];
+};
+
+message TDeepNesting {
+    optional TRepeatedWithPath Nested = 1 [ (NMonProto.Metric).Path = false ];
+};
+
+enum EEnum {
+    MY = 1;
+    ENUM = 2;
+};
+
+message TNonStringKeys {
+    optional uint32 Foo = 1 [ (NMonProto.Metric).Type = GAUGE ];
+    optional EEnum Enum = 2;
+    optional uint32 Int = 3;
+};
+
+message TRepeatedNonStringKeys {
+    repeated TNonStringKeys Nested = 1 [ (NMonProto.Metric).Path = true, (NMonProto.Metric).Keys = "enum:Enum int:Int" ];
+};
+
+message TExtraLabels {
+    optional NMonProto.TExtraLabelMetrics ExtraAsIs = 1 [ (NMonProto.Metric).Type = GAUGE ];
+    optional NMonProto.TExtraLabelMetrics ExtraDeriv = 2 [ (NMonProto.Metric).Type = RATE ];
+};
+
+message TRepeatedWithName {
+    optional string Name = 1;
+    repeated TSimple Nested = 2 [ (NMonProto.Metric).Path = true, (NMonProto.Metric).Keys = "my_label:Label" ];
+};
+
+message TKeysFromNonLeaf {
+    repeated TRepeatedWithName Nested = 1 [ (NMonProto.Metric).Path = true, (NMonProto.Metric).Keys = "name:Name" ];
+};
+
+
+message TNamedCounter {
+    optional string Name = 1;
+    optional uint64 Count = 2 [ (NMonProto.Metric).Type = RATE ];
+}
+
+message TCrawlerCounters {
+    message TStatusCounters {
+        repeated TNamedCounter ZoraResponses = 3 [ (NMonProto.Metric).Path = true, (NMonProto.Metric).Keys = "ZoraResponse:Name" ];
+        repeated TNamedCounter FetcherResponses = 4 [ (NMonProto.Metric).Path = true, (NMonProto.Metric).Keys = "SpiderResponse:Name" ];
+        repeated TNamedCounter RotorResponses = 5 [ (NMonProto.Metric).Path = true, (NMonProto.Metric).Keys = "SpiderResponse:Name" ];
+        repeated TNamedCounter PDFetchResponses = 6 [ (NMonProto.Metric).Path = true, (NMonProto.Metric).Keys = "PDFetchResponse:Name" ];
+        repeated TNamedCounter CalcResponses = 7 [ (NMonProto.Metric).Path = true, (NMonProto.Metric).Keys = "CalcResponse:Name" ];
+        repeated TNamedCounter Responses = 8 [ (NMonProto.Metric).Path = true, (NMonProto.Metric).Keys = "AggregatedResponse:Name" ];
+    }
+
+    message TPolicyCounters {
+        optional string SubComponent = 1;
+        optional string Name = 2;
+        optional string Zone = 3;
+
+        optional TStatusCounters StatusCounters = 4 [ (NMonProto.Metric).Path = true ];
+    }
+
+    optional string Component = 1;
+    repeated TPolicyCounters PoliciesCounters = 3 [ (NMonProto.Metric).Path = true, (NMonProto.Metric).Keys = "SubComponent:SubComponent Policy:Name Zone:Zone" ];
+}
+
+message TTimeLogHist {
+    optional uint32 MinBucketMillisec = 1;
+    repeated uint64 Buckets = 2 [ (NMonProto.Metric).Type = RATE, (NMonProto.Metric).Keys = "slot:#" ];
+}
+
+message TKiwiCounters {
+    optional TTimeLogHist Times = 22 [ (NMonProto.Metric).Path = true ];
+}
diff --git a/library/cpp/monlib/encode/legacy_protobuf/ut/ya.make b/library/cpp/monlib/encode/legacy_protobuf/ut/ya.make
new file mode 100644
index 0000000000..479a0c46c9
--- /dev/null
+++ b/library/cpp/monlib/encode/legacy_protobuf/ut/ya.make
@@ -0,0 +1,18 @@
+UNITTEST_FOR(library/cpp/monlib/encode/legacy_protobuf)
+
+OWNER(
+    g:solomon
+    msherbakov
+)
+
+SRCS(
+    legacy_protobuf_ut.cpp
+    test_cases.proto
+)
+
+PEERDIR(
+    library/cpp/monlib/encode/protobuf
+    library/cpp/monlib/encode/text
+)
+
+END()
diff --git a/library/cpp/monlib/encode/legacy_protobuf/ya.make b/library/cpp/monlib/encode/legacy_protobuf/ya.make
new file mode 100644
index 0000000000..74c82aac93
--- /dev/null
+++ b/library/cpp/monlib/encode/legacy_protobuf/ya.make
@@ -0,0 +1,16 @@
+LIBRARY()
+
+OWNER(
+    g:solomon
+    msherbakov
+)
+
+SRCS(
+    legacy_proto_decoder.cpp
+)
+
+PEERDIR(
+    library/cpp/monlib/encode/legacy_protobuf/protos
+)
+
+END()