ClickHouse/src/Analyzer/TableNode.h

#pragma once

#include <Storages/IStorage_fwd.h>
#include <Storages/TableLockHolder.h>
#include <Storages/StorageSnapshot.h>

#include <Interpreters/Context_fwd.h>
#include <Interpreters/StorageID.h>

#include <Analyzer/IQueryTreeNode.h>

namespace DB
{

/** Table node represents table in query tree.
  * Example: SELECT a FROM test_table.
  * test_table - is identifier, that during query analysis pass must be resolved into table node.
  *
  * During construction table node:
  * 1. Lock storage for share. Later lock can be moved out of node using `moveTableLock` method.
  * 2. Take storage snapshot.
  */
class TableNode;
using TableNodePtr = std::shared_ptr<TableNode>;

class TableNode : public IQueryTreeNode
{
public:
    /// Construct table node with storage and context
    explicit TableNode(StoragePtr storage_, ContextPtr context);

    /// Get storage
    const StoragePtr & getStorage() const
    {
        return storage;
    }

    /// Get storage id
    const StorageID & getStorageID() const
    {
        return storage_id;
    }

    /// Get storage snapshot
    const StorageSnapshotPtr & getStorageSnapshot() const
    {
        return storage_snapshot;
    }

    /// Get table lock
    const TableLockHolder & getTableLock() const
    {
        return table_lock;
    }

    /** Move table lock out of table node.
      * After using this method table node state becomes invalid.
      */
    TableLockHolder && moveTableLock()
    {
        return std::move(table_lock);
    }

    QueryTreeNodeType getNodeType() const override
    {
        return QueryTreeNodeType::TABLE;
    }

    String getName() const override;

    void dumpTreeImpl(WriteBuffer & buffer, FormatState & format_state, size_t indent) const override;

    bool isEqualImpl(const IQueryTreeNode & rhs) const override;

    void updateTreeHashImpl(HashState & state) const override;

protected:
    ASTPtr toASTImpl() const override;

    QueryTreeNodePtr cloneImpl() const override;

private:
    TableNode();

    StoragePtr storage;
    StorageID storage_id;
    TableLockHolder table_lock;
    StorageSnapshotPtr storage_snapshot;
};

}