YT-19324: move YT provider to ydb/library/yql

This commit is formed by the following script: https://paste.yandex-team.ru/6f92e4b8-efc5-4d34-948b-15ee2accd7e7/text.
This commit has zero effect on all projects that depend on YQL.

The summary of changes:
- `yql/providers/yt -> ydb/library/yql/providers/yt `- the whole implementation of YT provider is moved into YDB code base for further export as a part of YT YQL plugin shared library;
- `yql/providers/stat/{expr_nodes,uploader} -> ydb/library/yql/providers/stat/{expr_nodes,uploader}` - a small interface without implementation and the description of stat expr nodes;
- `yql/core/extract_predicate/ut -> ydb/library/yql/core/extract_predicate/ut`;
- `yql/core/{ut,ut_common} -> ydb/library/yql/core/{ut,ut_common}`;
- `yql/core` is gone;
- `yql/library/url_preprocessing -> ydb/library/yql/core/url_preprocessing`.

**NB**: all new targets inside `ydb/` are under `IF (NOT CMAKE_EXPORT)` clause which disables them from open-source cmake generation and ya make build. They will be enabled in the subsequent commits.

1 files changed, 69 insertions, 0 deletions

diff --git a/yt/cpp/mapreduce/client/client_writer.cpp b/yt/cpp/mapreduce/client/client_writer.cpp
new file mode 100644
index 0000000000..357abd32eb
--- /dev/null
+++ b/yt/cpp/mapreduce/client/client_writer.cpp
@@ -0,0 +1,69 @@
+#include "client_writer.h"
+
+#include "retryful_writer.h"
+#include "retryless_writer.h"
+
+#include <yt/cpp/mapreduce/interface/io.h>
+#include <yt/cpp/mapreduce/common/fwd.h>
+#include <yt/cpp/mapreduce/common/helpers.h>
+
+namespace NYT {
+
+////////////////////////////////////////////////////////////////////////////////
+
+TClientWriter::TClientWriter(
+    const TRichYPath& path,
+    IClientRetryPolicyPtr clientRetryPolicy,
+    ITransactionPingerPtr transactionPinger,
+    const TClientContext& context,
+    const TTransactionId& transactionId,
+    const TMaybe<TFormat>& format,
+    const TTableWriterOptions& options)
+    : BUFFER_SIZE(options.BufferSize_)
+{
+    if (options.SingleHttpRequest_) {
+        RawWriter_.Reset(new TRetrylessWriter(
+            context,
+            transactionId,
+            GetWriteTableCommand(context.Config->ApiVersion),
+            format,
+            path,
+            BUFFER_SIZE,
+            options));
+    } else {
+        RawWriter_.Reset(new TRetryfulWriter(
+            std::move(clientRetryPolicy),
+            std::move(transactionPinger),
+            context,
+            transactionId,
+            GetWriteTableCommand(context.Config->ApiVersion),
+            format,
+            path,
+            options));
+    }
+}
+
+size_t TClientWriter::GetStreamCount() const
+{
+    return 1;
+}
+
+IOutputStream* TClientWriter::GetStream(size_t tableIndex) const
+{
+    Y_UNUSED(tableIndex);
+    return RawWriter_.Get();
+}
+
+void TClientWriter::OnRowFinished(size_t)
+{
+    RawWriter_->NotifyRowEnd();
+}
+
+void TClientWriter::Abort()
+{
+    RawWriter_->Abort();
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+} // namespace NYT