MvccUtil.java

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// to you under the Apache License, Version 2.0 (the
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//   http://www.apache.org/licenses/LICENSE-2.0
//
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package org.apache.doris.datasource.mvcc;

import org.apache.doris.analysis.TableScanParams;
import org.apache.doris.analysis.TableSnapshot;
import org.apache.doris.catalog.TableIf;
import org.apache.doris.nereids.StatementContext;
import org.apache.doris.qe.ConnectContext;

import java.util.Optional;

public class MvccUtil {
    /**
     * get Snapshot From StatementContext
     *
     * @param tableIf
     * @return MvccSnapshot
     */
    public static Optional<MvccSnapshot> getSnapshotFromContext(TableIf tableIf) {
        return getSnapshotFromContext(tableIf, null, null);
    }

    /** Return a validated statement snapshot for metadata paths without relation identity. */
    public static Optional<MvccSnapshot> getSnapshotForTableMetadataFromContext(TableIf tableIf) {
        ConnectContext connectContext = ConnectContext.get();
        if (connectContext == null || connectContext.getStatementContext() == null) {
            return Optional.empty();
        }
        return connectContext.getStatementContext().getSnapshotForTableMetadata(tableIf);
    }

    public static Optional<MvccSnapshot> getSnapshotFromContext(TableIf tableIf,
            TableSnapshot tableSnapshot, TableScanParams scanParams) {
        ConnectContext connectContext = ConnectContext.get();
        if (connectContext == null) {
            return Optional.empty();
        }
        StatementContext statementContext = connectContext.getStatementContext();
        if (statementContext == null) {
            return Optional.empty();
        }
        if (tableSnapshot == null && scanParams == null) {
            return statementContext.getSnapshot(tableIf);
        }
        return statementContext.getSnapshot(tableIf, Optional.ofNullable(tableSnapshot),
                Optional.ofNullable(scanParams));
    }
}