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JSimpleDB classes supporting command line interfaces.

There is a newer version: 3.6.1


/*
 * Copyright (C) 2015 Archie L. Cobbs. All rights reserved.
 */

package org.jsimpledb.cli.cmd;

import java.io.PrintWriter;
import java.util.Map;

import org.jsimpledb.SessionMode;
import org.jsimpledb.cli.CliSession;
import org.jsimpledb.kv.KVTransaction;
import org.jsimpledb.parse.ParseException;
import org.jsimpledb.util.ParseContext;

@Command(modes = { SessionMode.KEY_VALUE })
public class KVRemoveCommand extends AbstractKVCommand {

    public KVRemoveCommand() {
        super("kvremove -range:range key:bytes maxKey:bytes?");
    }

    @Override
    public String getHelpSummary() {
        return "Deletes one, or a range, of raw database key/value pairs";
    }

    @Override
    public String getHelpDetail() {
        return "Deletes a single raw database key/value pair, or a range of key/value pairs. If `-range' is not given,"
          + " the specified key/value pair is deleted. Otherwise, `key' is the minimum key (inclusive) and `maxKey'"
          + " is the maximum key (exclusive) if given, otherwise there is no maximum key. `key' and `maxKey' may be given"
          + " as hexadecimal strings or C-style doubly-quoted strings."
          + "\n\nWARNING: this command can corrupt a JSimpleDB database.";
    }

    @Override
    public CliSession.Action getAction(CliSession session, ParseContext ctx, boolean complete, Map params) {
        final boolean range = params.containsKey("range");
        final byte[] key = (byte[])params.get("key");
        final byte[] maxKey = (byte[])params.get("maxKey");
        if (maxKey != null && !range)
            throw new ParseException(ctx, "`-range' must be specified to delete a range of keys");
        return new CliSession.TransactionalAction() {
            @Override
            public void run(CliSession session) throws Exception {
                final PrintWriter writer = session.getWriter();
                final KVTransaction kvt = session.getKVTransaction();
                if (!range)
                    kvt.remove(key);
                else
                    kvt.removeRange(key, maxKey);
            }
        };
    }
}