garmintools.adapters.garmin.MetadataGarminAdapter.java Source code

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Here is the source code for garmintools.adapters.garmin.MetadataGarminAdapter.java

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/**
 *    Copyright 2016 Iron City Software LLC
 *
 *  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 garmintools.adapters.garmin;

import static garmintools.encoding.SixBitAsciiEncoding.SIMPLE_ENCODING;
import garmintools.Proto;
import garmintools.encoding.LittleEndianByteArrayDataOutput;
import garmintools.encoding.SixBitAsciiEncoding;
import garmintools.sections.DataLengthSection;
import garmintools.sections.Ids;
import garmintools.util.StringUtil;
import garmintools.wrappers.TableOfContentsEntry;

import java.nio.ByteBuffer;

import com.google.common.base.Charsets;
import com.google.common.base.Preconditions;
import com.google.common.io.ByteArrayDataOutput;
import com.google.common.io.ByteStreams;

public class MetadataGarminAdapter implements GarminAdapter<Proto.Metadata> {
    /** Metadata does not have a TOC entry, so use a pseudo one for consistency. */
    public static final TableOfContentsEntry METADATA_TOC_ENTRY = TableOfContentsEntry.newBuilder()
            .setSectionNumber(Ids.METADATA_SECTION).setFileOffset(0).setItemLength(1).setItemQuantity(512)
            .setActualLength(512).build();
    private static final int DEFAULT_PREAMBLE_LENGTH = 128;
    private static final int PART_NUMBER_LENGTH = 16;
    private static final int COVERAGE_REGION_LENGTH = 30;
    private static final int COVERAGE_REGION_PAD_LENGTH = 25;
    private static final int COPYRIGHT_LINE_LENGTH = 25;
    private static final int TRAILING_ZERO_BYTE_LENGTH = 272;

    @Override
    public Proto.Metadata read(DataLengthSection dataLengthSection, TableOfContentsEntry entry,
            ByteBuffer byteBuffer) {
        Proto.Metadata.Builder builder = Proto.Metadata.newBuilder();
        int preambleLength = byteBuffer.get() & 0xff;
        byteBuffer.position(preambleLength + 1);

        builder.setCycleNumber(byteBuffer.getShort());
        builder.setEffectiveDate(readDate(byteBuffer));
        builder.setExpiresDate(readDate(byteBuffer));
        builder.setAeronauticalDataSnapshotDate(readDate(byteBuffer));

        builder.setUnknownData1(byteBuffer.get());
        builder.setUnknownData2(byteBuffer.getShort());
        builder.setUnknownData3(byteBuffer.get());

        byte partNumberBytes[] = new byte[SixBitAsciiEncoding.getEncodedSize(PART_NUMBER_LENGTH)];
        byteBuffer.get(partNumberBytes);
        builder.setPartNumber(SIMPLE_ENCODING.decode(partNumberBytes).trim());

        byte coverageRegionBytes[] = new byte[COVERAGE_REGION_LENGTH];
        byteBuffer.get(coverageRegionBytes);
        builder.setCoverageRegion(new String(coverageRegionBytes, Charsets.US_ASCII).trim());

        byte copyrightLineBytes[] = new byte[COPYRIGHT_LINE_LENGTH];
        byteBuffer.get(copyrightLineBytes);
        builder.setCopyrightLine1(new String(copyrightLineBytes, Charsets.US_ASCII).trim());
        byteBuffer.get(copyrightLineBytes);
        builder.setCopyrightLine2(new String(copyrightLineBytes, Charsets.US_ASCII).trim());

        builder.setUnknownData4(byteBuffer.get());

        while (byteBuffer.hasRemaining()) {
            Preconditions.checkState(byteBuffer.get() == 0);
        }

        return builder.build();
    }

    @Override
    public GarminOutput write(Proto.Metadata data) {
        ByteArrayDataOutput output = new LittleEndianByteArrayDataOutput(ByteStreams.newDataOutput());
        writePreamble(output);
        writeMetadata(data, output);
        return new GarminOutput(output.toByteArray());
    }

    private void writePreamble(ByteArrayDataOutput output) {
        output.write(DEFAULT_PREAMBLE_LENGTH);
        for (int i = 0; i < DEFAULT_PREAMBLE_LENGTH; ++i) {
            output.write(i);
        }
    }

    private void writeMetadata(Proto.Metadata data, ByteArrayDataOutput output) {
        output.writeShort(data.getCycleNumber());
        writeDate(output, data.getEffectiveDate());
        writeDate(output, data.getExpiresDate());
        writeDate(output, data.getAeronauticalDataSnapshotDate());
        output.write(data.getUnknownData1());
        output.writeShort(data.getUnknownData2());
        output.write(data.getUnknownData3());
        output.write(SIMPLE_ENCODING.encode(StringUtil.pad(data.getPartNumber(), PART_NUMBER_LENGTH)));
        writeStringAndPadWithSpace(output, StringUtil.pad(data.getCoverageRegion(), COVERAGE_REGION_PAD_LENGTH),
                COVERAGE_REGION_LENGTH);
        writeStringAndPadWithSpace(output, data.getCopyrightLine1(), COPYRIGHT_LINE_LENGTH);
        writeStringAndPadWithSpace(output, data.getCopyrightLine2(), COPYRIGHT_LINE_LENGTH);
        output.write(data.getUnknownData4());
        for (int i = 0; i < TRAILING_ZERO_BYTE_LENGTH; ++i) {
            output.write(0);
        }
    }

    private void writeStringAndPadWithSpace(ByteArrayDataOutput output, String string, int paddedLength) {
        byte b[] = string.getBytes(Charsets.US_ASCII);
        output.write(b);
        output.write(0);
        Preconditions.checkArgument(b.length + 1 <= paddedLength);
        for (int i = b.length + 1; i < paddedLength; ++i) {
            output.write(32);
        }
    }

    private void writeDate(ByteArrayDataOutput output, Proto.Date date) {
        output.write(date.getMonth());
        output.write(date.getDay());
        output.writeShort(date.getYear());
    }

    private Proto.Date readDate(ByteBuffer byteBuffer) {
        return Proto.Date.newBuilder().setMonth(byteBuffer.get()).setDay(byteBuffer.get())
                .setYear(byteBuffer.getShort()).build();
    }
}