io.warp10.script.functions.GEOUNPACK.java Source code

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Here is the source code for io.warp10.script.functions.GEOUNPACK.java

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//
//   Copyright 2016  Cityzen Data
//
//   Licensed under the Apache License, Version 2.0 (the "License");
//   you may not use this file except in compliance with the License.
//   You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
//   Unless required by applicable law or agreed to in writing, software
//   distributed under the License is distributed on an "AS IS" BASIS,
//   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//   See the License for the specific language governing permissions and
//   limitations under the License.
//

package io.warp10.script.functions;

import io.warp10.continuum.gts.GTSDecoder;
import io.warp10.continuum.gts.GTSWrapperHelper;
import io.warp10.continuum.store.thrift.data.GTSWrapper;
import io.warp10.crypto.OrderPreservingBase64;
import io.warp10.script.NamedWarpScriptFunction;
import io.warp10.script.WarpScriptException;
import io.warp10.script.WarpScriptStack;
import io.warp10.script.WarpScriptStackFunction;

import org.apache.thrift.TDeserializer;
import org.apache.thrift.TException;
import org.apache.thrift.protocol.TCompactProtocol;

import com.geoxp.GeoXPLib;
import com.geoxp.GeoXPLib.GeoXPShape;
import com.google.common.base.Charsets;

/**
 * Unpack a GeoXPShape
 * 
 * We relay on GTSWrappers for this, this is kinda weird but hey, it works!
 * 
 */
public class GEOUNPACK extends NamedWarpScriptFunction implements WarpScriptStackFunction {

    public GEOUNPACK(String name) {
        super(name);
    }

    @Override
    public Object apply(WarpScriptStack stack) throws WarpScriptException {

        Object o = stack.pop();

        if (!(o instanceof String)) {
            throw new WarpScriptException(getName() + " expects a packed shape on top of the stack.");
        }

        byte[] serialized = OrderPreservingBase64.decode(o.toString().getBytes(Charsets.US_ASCII));

        TDeserializer deserializer = new TDeserializer(new TCompactProtocol.Factory());

        GTSWrapper wrapper = new GTSWrapper();

        try {
            deserializer.deserialize(wrapper, serialized);
        } catch (TException te) {
            throw new WarpScriptException(te);
        }

        GTSDecoder decoder = GTSWrapperHelper.fromGTSWrapperToGTSDecoder(wrapper);

        long[] cells = new long[(int) wrapper.getCount()];

        int idx = 0;

        while (idx < cells.length && decoder.next()) {
            long cell = decoder.getTimestamp();
            Object value = decoder.getValue();

            if (!Boolean.TRUE.equals(value)) {
                throw new WarpScriptException(getName() + " invalid GeoXPShape.");
            }

            cells[idx++] = cell;
        }

        if (idx != cells.length) {
            throw new WarpScriptException(getName() + " invalid GeoXPShape.");
        }

        GeoXPShape shape = GeoXPLib.fromCells(cells, false);

        stack.push(shape);

        return stack;
    }
}