YT: Move IYsonBuilder from ORM to core yson/ library

commit_hash:3d8bdd14cc5420209534498f0b1e61dea8e4aa1e

5 files changed, 262 insertions, 0 deletions

diff --git a/yt/yt/core/ya.make b/yt/yt/core/ya.make
index 857e56920b..a958bb1c6a 100644
--- a/yt/yt/core/ya.make
+++ b/yt/yt/core/ya.make
@@ -269,6 +269,7 @@ SRCS(
     yson/string_merger.cpp
     yson/ypath_designated_consumer.cpp
     yson/ypath_filtering_consumer.cpp
+    yson/yson_builder.cpp
     yson/depth_limiting_yson_consumer.cpp
     yson/list_verb_lazy_yson_consumer.cpp
     yson/attributes_stripper.cpp
diff --git a/yt/yt/core/yson/unittests/ya.make b/yt/yt/core/yson/unittests/ya.make
index 59a807fca4..8f8fc7dfc0 100644
--- a/yt/yt/core/yson/unittests/ya.make
+++ b/yt/yt/core/yson/unittests/ya.make
@@ -14,6 +14,7 @@ SRCS(
     protobuf_yson_ut.cpp
     ypath_designated_yson_consumer_ut.cpp
     ypath_filtering_yson_consumer_ut.cpp
+    yson_builder_ut.cpp
     yson_parser_ut.cpp
     yson_pull_parser_ut.cpp
     yson_token_writer_ut.cpp
diff --git a/yt/yt/core/yson/unittests/yson_builder_ut.cpp b/yt/yt/core/yson/unittests/yson_builder_ut.cpp
new file mode 100644
index 0000000000..c3353a56de
--- /dev/null
+++ b/yt/yt/core/yson/unittests/yson_builder_ut.cpp
@@ -0,0 +1,87 @@
+#include <yt/yt/core/yson/consumer.h>
+#include <yt/yt/core/yson/string.h>
+#include <yt/yt/core/yson/yson_builder.h>
+
+#include <yt/yt/core/test_framework/framework.h>
+
+namespace NYT::NYson {
+namespace {
+
+////////////////////////////////////////////////////////////////////////////////
+
+TEST(TYsonStringBuilderTest, Simple)
+{
+    NYson::TYsonStringBuilder builder;
+    builder->OnStringScalar("some_scalar");
+    ASSERT_EQ(builder.Flush().ToString(), TString{"\1\x16some_scalar"});
+    ASSERT_TRUE(builder.IsEmpty());
+}
+
+TEST(TYsonStringBuilderTest, Reusing)
+{
+    NYson::TYsonStringBuilder builder;
+    builder->OnStringScalar("some_scalar1");
+    ASSERT_EQ(builder.Flush().ToString(), TString{"\1\x18some_scalar1"});
+    ASSERT_TRUE(builder.IsEmpty());
+
+    builder->OnStringScalar("some_scalar2");
+    ASSERT_EQ(builder.Flush().ToString(), TString{"\1\x18some_scalar2"});
+    ASSERT_TRUE(builder.IsEmpty());
+}
+
+TEST(TYsonStringBuilderTest, Checkpoints)
+{
+    NYson::TYsonStringBuilder builder;
+    builder->OnStringScalar("some_scalar");
+
+    auto checkpoint = builder.CreateCheckpoint();
+    builder.CreateCheckpoint();
+    builder.RestoreCheckpoint(checkpoint);
+    builder.RestoreCheckpoint(checkpoint);
+
+    ASSERT_EQ(builder.Flush().ToString(), TString{"\1\x16some_scalar"});
+    ASSERT_TRUE(builder.IsEmpty());
+}
+
+TEST(TYsonStringBuilderTest, MapCheckpoints)
+{
+    NYson::TYsonStringBuilder builder(NYson::EYsonFormat::Text);
+
+    builder->OnBeginMap();
+
+    builder->OnKeyedItem("key1");
+    builder->OnEntity();
+
+    auto checkpoint = builder.CreateCheckpoint();
+    builder->OnKeyedItem("key2");
+    builder->OnEntity();
+    builder.RestoreCheckpoint(checkpoint);
+
+    builder->OnEndMap();
+
+    ASSERT_EQ(builder.Flush().ToString(), TString{R"({"key1"=#;})"});
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+TEST(TYsonBuilderTest, Forwarding)
+{
+    NYson::TYsonStringBuilder stringBuilder(NYson::EYsonFormat::Text);
+    NYson::TYsonBuilder builder(
+        NYson::EYsonBuilderForwardingPolicy::Forward,
+        &stringBuilder,
+        stringBuilder.GetConsumer());
+    builder->OnBeginMap();
+    auto checkpoint = builder.CreateCheckpoint();
+    builder->OnKeyedItem("key");
+    builder->OnEntity();
+    builder.RestoreCheckpoint(checkpoint);
+    builder->OnEndMap();
+
+    ASSERT_EQ(stringBuilder.Flush().ToString(), TString{R"({})"});
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+} // namespace
+} // namespace NYT::NYson
diff --git a/yt/yt/core/yson/yson_builder.cpp b/yt/yt/core/yson/yson_builder.cpp
new file mode 100644
index 0000000000..a17b9b8772
--- /dev/null
+++ b/yt/yt/core/yson/yson_builder.cpp
@@ -0,0 +1,97 @@
+#include "yson_builder.h"
+
+#include "writer.h"
+
+namespace NYT::NYson {
+
+////////////////////////////////////////////////////////////////////////////////
+
+IYsonConsumer* IYsonBuilder::operator->()
+{
+    return GetConsumer();
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+TYsonStringBuilder::TYsonStringBuilder(EYsonFormat format, EYsonType type, bool enableRaw)
+    : Output_(ValueString_)
+    , Writer_(CreateYsonWriter(&Output_, format, type, enableRaw))
+{ }
+
+IYsonConsumer* TYsonStringBuilder::GetConsumer()
+{
+    return Writer_.get();
+}
+
+IYsonBuilder::TCheckpoint TYsonStringBuilder::CreateCheckpoint()
+{
+    Writer_->Flush();
+    return IYsonBuilder::TCheckpoint(std::ssize(ValueString_));
+}
+
+void TYsonStringBuilder::RestoreCheckpoint(IYsonBuilder::TCheckpoint checkpoint)
+{
+    Writer_->Flush();
+    int checkpointSize = checkpoint.Underlying();
+    YT_VERIFY(checkpointSize >= 0 && checkpointSize <= std::ssize(ValueString_));
+    ValueString_.resize(static_cast<size_t>(checkpointSize));
+}
+
+TYsonString TYsonStringBuilder::Flush()
+{
+    Writer_->Flush();
+    auto result = TYsonString(ValueString_);
+    ValueString_.clear();
+    return result;
+}
+
+bool TYsonStringBuilder::IsEmpty()
+{
+    Writer_->Flush();
+    return ValueString_.empty();
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+TYsonBuilder::TYsonBuilder(
+    EYsonBuilderForwardingPolicy policy,
+    IYsonBuilder* underlying,
+    IYsonConsumer* consumer)
+    : Policy_(policy)
+    , Underlying_(underlying)
+    , Consumer_(consumer)
+{ }
+
+IYsonConsumer* TYsonBuilder::GetConsumer()
+{
+    return Consumer_;
+}
+
+IYsonBuilder::TCheckpoint TYsonBuilder::CreateCheckpoint()
+{
+    switch (Policy_) {
+        case EYsonBuilderForwardingPolicy::Forward:
+            return Underlying_->CreateCheckpoint();
+        case EYsonBuilderForwardingPolicy::Crash:
+            return IYsonBuilder::TCheckpoint{};
+        case EYsonBuilderForwardingPolicy::Ignore:
+            return IYsonBuilder::TCheckpoint{};
+    }
+}
+
+void TYsonBuilder::RestoreCheckpoint(TCheckpoint checkpoint)
+{
+    switch (Policy_) {
+        case EYsonBuilderForwardingPolicy::Forward:
+            Underlying_->RestoreCheckpoint(checkpoint);
+            break;
+        case EYsonBuilderForwardingPolicy::Crash:
+            YT_ABORT();
+        case EYsonBuilderForwardingPolicy::Ignore:
+            break;
+    }
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+} // namespace NYT::NYson
diff --git a/yt/yt/core/yson/yson_builder.h b/yt/yt/core/yson/yson_builder.h
new file mode 100644
index 0000000000..5f483124e8
--- /dev/null
+++ b/yt/yt/core/yson/yson_builder.h
@@ -0,0 +1,76 @@
+#pragma once
+
+#include "public.h"
+
+#include <library/cpp/yt/misc/strong_typedef.h>
+
+namespace NYT::NYson {
+
+////////////////////////////////////////////////////////////////////////////////
+
+struct IYsonBuilder
+{
+    YT_DEFINE_STRONG_TYPEDEF(TCheckpoint, int);
+
+    virtual ~IYsonBuilder() = default;
+
+    virtual IYsonConsumer* GetConsumer() = 0;
+    virtual TCheckpoint CreateCheckpoint() = 0;
+    virtual void RestoreCheckpoint(TCheckpoint checkpoint) = 0;
+
+    IYsonConsumer* operator->();
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+class TYsonStringBuilder
+    : public IYsonBuilder
+{
+public:
+    TYsonStringBuilder(
+        NYson::EYsonFormat format = NYson::EYsonFormat::Binary,
+        NYson::EYsonType type = NYson::EYsonType::Node,
+        bool enableRaw = true);
+
+    NYson::IYsonConsumer* GetConsumer() override;
+    IYsonBuilder::TCheckpoint CreateCheckpoint() override;
+    void RestoreCheckpoint(IYsonBuilder::TCheckpoint checkpoint) override;
+
+    NYson::TYsonString Flush();
+    bool IsEmpty();
+
+private:
+    TString ValueString_;
+    TStringOutput Output_;
+    const std::unique_ptr<NYson::IFlushableYsonConsumer> Writer_;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+DEFINE_ENUM(EYsonBuilderForwardingPolicy,
+    (Forward)
+    (Ignore)
+    (Crash)
+);
+
+////////////////////////////////////////////////////////////////////////////////
+
+class TYsonBuilder
+    : public IYsonBuilder
+{
+public:
+    TYsonBuilder(EYsonBuilderForwardingPolicy policy, IYsonBuilder* underlying, IYsonConsumer* consumer);
+
+    IYsonConsumer* GetConsumer() override;
+    IYsonBuilder::TCheckpoint CreateCheckpoint() override;
+    void RestoreCheckpoint(TCheckpoint checkpoint) override;
+
+private:
+    const EYsonBuilderForwardingPolicy Policy_;
+    IYsonBuilder* const Underlying_;
+    NYson::IYsonConsumer* const Consumer_;
+};
+
+////////////////////////////////////////////////////////////////////////////////
+
+} // namespace NYT::NYson