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, 128 insertions, 0 deletions

diff --git a/library/cpp/containers/concurrent_hash/concurrent_hash.h b/library/cpp/containers/concurrent_hash/concurrent_hash.h
new file mode 100644
index 0000000000..f15a1c3d6e
--- /dev/null
+++ b/library/cpp/containers/concurrent_hash/concurrent_hash.h
@@ -0,0 +1,128 @@
+#pragma once
+
+#include <util/generic/hash.h>
+#include <util/system/spinlock.h>
+
+#include <array>
+
+template <typename K, typename V, size_t BucketCount = 64, typename L = TAdaptiveLock>
+class TConcurrentHashMap {
+public:
+    using TActualMap = THashMap<K, V>;
+    using TLock = L;
+
+    struct TBucket {
+        friend class TConcurrentHashMap;
+
+    private:
+        TActualMap Map;
+        mutable TLock Mutex;
+
+    public:
+        TLock& GetMutex() const {
+            return Mutex;
+        }
+
+        TActualMap& GetMap() {
+            return Map;
+        }
+        const TActualMap& GetMap() const {
+            return Map;
+        }
+
+        const V& GetUnsafe(const K& key) const {
+            typename TActualMap::const_iterator it = Map.find(key);
+            Y_VERIFY(it != Map.end(), "not found by key");
+            return it->second;
+        }
+
+        V& GetUnsafe(const K& key) {
+            typename TActualMap::iterator it = Map.find(key);
+            Y_VERIFY(it != Map.end(), "not found by key");
+            return it->second;
+        }
+
+        V RemoveUnsafe(const K& key) {
+            typename TActualMap::iterator it = Map.find(key);
+            Y_VERIFY(it != Map.end(), "removing non-existent key");
+            V r = std::move(it->second);
+            Map.erase(it);
+            return r;
+        }
+
+        bool HasUnsafe(const K& key) const {
+            typename TActualMap::const_iterator it = Map.find(key);
+            return (it != Map.end());
+        }
+    };
+
+    std::array<TBucket, BucketCount> Buckets;
+
+public:
+    TBucket& GetBucketForKey(const K& key) {
+        return Buckets[THash<K>()(key) % BucketCount];
+    }
+
+    const TBucket& GetBucketForKey(const K& key) const {
+        return Buckets[THash<K>()(key) % BucketCount];
+    }
+
+    void Insert(const K& key, const V& value) {
+        TBucket& bucket = GetBucketForKey(key);
+        TGuard<TLock> guard(bucket.Mutex);
+        bucket.Map[key] = value;
+    }
+
+    void InsertUnique(const K& key, const V& value) {
+        TBucket& bucket = GetBucketForKey(key);
+        TGuard<TLock> guard(bucket.Mutex);
+        if (!bucket.Map.insert(std::make_pair(key, value)).second) {
+            Y_FAIL("non-unique key");
+        }
+    }
+
+    V& InsertIfAbsent(const K& key, const V& value) {
+        TBucket& bucket = GetBucketForKey(key);
+        TGuard<TLock> guard(bucket.Mutex);
+        return bucket.Map.insert(std::make_pair(key, value)).first->second;
+    }
+
+    template <typename Callable>
+    V& InsertIfAbsentWithInit(const K& key, Callable initFunc) {
+        TBucket& bucket = GetBucketForKey(key);
+        TGuard<TLock> guard(bucket.Mutex);
+        if (bucket.HasUnsafe(key)) {
+            return bucket.GetUnsafe(key);
+        }
+
+        return bucket.Map.insert(std::make_pair(key, initFunc())).first->second;
+    }
+
+    V Get(const K& key) const {
+        const TBucket& bucket = GetBucketForKey(key);
+        TGuard<TLock> guard(bucket.Mutex);
+        return bucket.GetUnsafe(key);
+    }
+
+    bool Get(const K& key, V& result) const {
+        const TBucket& bucket = GetBucketForKey(key);
+        TGuard<TLock> guard(bucket.Mutex);
+        if (bucket.HasUnsafe(key)) {
+            result = bucket.GetUnsafe(key);
+            return true;
+        }
+        return false;
+    }
+
+    V Remove(const K& key) {
+        TBucket& bucket = GetBucketForKey(key);
+        TGuard<TLock> guard(bucket.Mutex);
+        return bucket.RemoveUnsafe(key);
+    }
+
+    bool Has(const K& key) const {
+        const TBucket& bucket = GetBucketForKey(key);
+        TGuard<TLock> guard(bucket.Mutex);
+        return bucket.HasUnsafe(key);
+    }
+};