suneido.database.immudb.TableInfo.java Source code

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Here is the source code for suneido.database.immudb.TableInfo.java

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/* Copyright 2011 (c) Suneido Software Corp. All rights reserved.
 * Licensed under GPLv2.
 */

package suneido.database.immudb;

import java.util.Arrays;

import com.google.common.base.MoreObjects;
import com.google.common.collect.ImmutableList;
import com.google.common.collect.Iterables;

import suneido.database.immudb.Bootstrap.TN;

/**
 * Table stats - nextfield, nrows, totalsize, indexInfo
 * <p>
 * Semi-immutable:
 * loaded => immutable => with => mutable => store => immutable
 * <p>
 * Only mutable within a thread confined transaction.
 * <p>
 * Unlike cSuneido, table and index info is not kept in the system tables
 * since that requires more expensive updates.
 * <p>
 * Index info is stored one after another following the table info
 * in the same record.
 */
class TableInfo extends DbHashTrie.Entry {
    private int adr;
    final int tblnum;
    final int nextfield;
    private int nrows;
    private long totalsize;
    final ImmutableList<IndexInfo> indexInfo;

    TableInfo(int tblnum, int nextfield, int nrows, long totalsize, ImmutableList<IndexInfo> indexInfo) {
        adr = 0;
        this.tblnum = tblnum;
        this.nextfield = nextfield;
        this.nrows = nrows;
        this.totalsize = totalsize;
        this.indexInfo = indexInfo;
    }

    TableInfo(Record rec, int adr) {
        this.adr = adr;
        int i = 0;
        tblnum = rec.getInt(i++);
        nextfield = rec.getInt(i++);
        nrows = rec.getInt(i++);
        totalsize = rec.getLong(i++);
        ImmutableList.Builder<IndexInfo> list = ImmutableList.builder();
        for (; i < rec.size(); i += IndexInfo.NFIELDS)
            list.add(new IndexInfo(rec, i));
        indexInfo = list.build();
    }

    TableInfo(TableInfo ti, ImmutableList<IndexInfo> indexInfo) {
        this(ti.tblnum, ti.nextfield, ti.nrows, ti.totalsize, indexInfo);
    }

    /** When a table is dropped, its table info is replaced by an empty entry */
    static TableInfo empty(int tblnum) {
        return new TableInfo(tblnum, 0, 0, 0, ImmutableList.of());
    }

    @Override
    int key() {
        return tblnum;
    }

    @Override
    int value() {
        return adr;
    }

    int nrows() {
        return nrows;
    }

    long totalsize() {
        return totalsize;
    }

    private boolean stored() {
        return adr != 0;
    }

    TableInfo with(int nr, int size) {
        if (stored())
            return new TableInfo(tblnum, nextfield, nrows + nr, totalsize + size, indexInfo);
        else {
            nrows += nr;
            totalsize += size;
            return this;
        }
    }

    /** @return the address of the stored record */
    int store(Storage stor) {
        if (!stored()) {
            RecordBuilder rb = new RecordBuilder();
            rb.add(tblnum).add(nextfield).add(nrows).add(totalsize);
            for (IndexInfo info : indexInfo)
                info.addToRecord(rb);
            DataRecord r = rb.build();
            r.tblnum(TN.TABLES);
            adr = r.store(stor);
        }
        return adr;
    }

    IndexInfo getIndex(int[] indexColumns) {
        for (IndexInfo ii : indexInfo)
            if (Arrays.equals(ii.columns, indexColumns))
                return ii;
        return null;
    }

    void check() {
        for (IndexInfo ii : indexInfo)
            ii.check();
    }

    @Override
    public String toString() {
        return MoreObjects.toStringHelper(this).add("tblnum", tblnum).add("nextfield", nextfield)
                .add("nrows", nrows).add("totalsize", totalsize).addValue(Iterables.toString(indexInfo)).toString();
    }

}