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, 46 insertions, 0 deletions

diff --git a/yt/cpp/mapreduce/io/job_reader.cpp b/yt/cpp/mapreduce/io/job_reader.cpp
new file mode 100644
index 0000000000..39056f00e2
--- /dev/null
+++ b/yt/cpp/mapreduce/io/job_reader.cpp
@@ -0,0 +1,46 @@
+#include "job_reader.h"
+
+#include <yt/cpp/mapreduce/interface/logging/yt_log.h>
+
+namespace NYT {
+
+////////////////////////////////////////////////////////////////////////////////
+
+TJobReader::TJobReader(int fd)
+    : TJobReader(Duplicate(fd))
+{ }
+
+TJobReader::TJobReader(const TFile& file)
+    : FdFile_(file)
+    , FdInput_(FdFile_)
+    , BufferedInput_(&FdInput_, BUFFER_SIZE)
+{ }
+
+bool TJobReader::Retry(const TMaybe<ui32>& /*rangeIndex*/, const TMaybe<ui64>& /*rowIndex*/)
+{
+    return false;
+}
+
+void TJobReader::ResetRetries()
+{ }
+
+bool TJobReader::HasRangeIndices() const
+{
+    return true;
+}
+
+size_t TJobReader::DoRead(void* buf, size_t len)
+{
+    return BufferedInput_.Read(buf, len);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+TRawTableReaderPtr CreateRawJobReader(int fd)
+{
+    return ::MakeIntrusive<TJobReader>(fd);
+}
+
+////////////////////////////////////////////////////////////////////////////////
+
+} // namespace NYT