PaimonTableCacheValue.java

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package org.apache.doris.datasource.paimon;

import org.apache.doris.datasource.NameMapping;
import org.apache.doris.datasource.metacache.MetaCacheSizeEstimate;
import org.apache.doris.datasource.metacache.MetaCacheSizeEstimator;

import org.apache.paimon.table.Table;

import java.util.Objects;
import java.util.concurrent.atomic.AtomicLong;

/**
 * Cache value for a Paimon table handle. Snapshot projections use a separate cache entry; the
 * only post-admission growth of this value is the lazily built store graph and RowType lookup
 * maps of the table itself, which the publication estimate reserves up front.
 */
public class PaimonTableCacheValue {
    private static final AtomicLong NEXT_GENERATION = new AtomicLong();

    private final Table paimonTable;
    private final long generation;
    private volatile long retainedTablePayloadBytes;
    private volatile MetaCacheSizeEstimate sizeEstimate;

    public PaimonTableCacheValue(Table paimonTable) {
        this.paimonTable = paimonTable;
        this.generation = NEXT_GENERATION.incrementAndGet();
    }

    public PaimonTableCacheValue(Table paimonTable, PaimonSnapshotCacheValue ignoredFence) {
        this(paimonTable);
        Objects.requireNonNull(ignoredFence, "latestSnapshotFence can not be null");
    }

    public Table getPaimonTable() {
        return paimonTable;
    }

    public long getGeneration() {
        return generation;
    }

    long getRetainedTablePayloadBytes() {
        return retainedTablePayloadBytes;
    }

    /**
     * Compute the retained weight once before the value is published to a weight-bounded cache.
     * Never opens the table store; failures fail closed as an incomplete estimate.
     */
    synchronized MetaCacheSizeEstimate prepareForCachePublication(NameMapping key) {
        if (sizeEstimate == null) {
            sizeEstimate = MetaCacheSizeEstimator.estimateSafely("paimon_table_preparation_failed",
                    () -> {
                        retainedTablePayloadBytes =
                                PaimonCacheSizeEstimator.retainedTablePayloadBytes(paimonTable);
                        return PaimonCacheSizeEstimator.estimateTableEntry(key, this);
                    });
        }
        return sizeEstimate;
    }

    public MetaCacheSizeEstimate getSizeEstimate() {
        return sizeEstimate == null
                ? MetaCacheSizeEstimate.incomplete("not_prepared") : sizeEstimate;
    }
}