org.opentripplanner.graph_builder.module.ned.DegreeGridNEDTileSource Maven / Gradle / Ivy

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package org.opentripplanner.graph_builder.module.ned;

import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.InputStream;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.List;
import org.jets3t.service.S3Service;
import org.jets3t.service.S3ServiceException;
import org.jets3t.service.ServiceException;
import org.jets3t.service.impl.rest.httpclient.RestS3Service;
import org.jets3t.service.model.S3Object;
import org.jets3t.service.security.AWSCredentials;
import org.locationtech.jts.geom.Coordinate;
import org.opentripplanner.common.model.P2;
import org.opentripplanner.graph_builder.services.ned.NEDTileSource;
import org.opentripplanner.routing.graph.Graph;
import org.opentripplanner.routing.graph.Vertex;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

/**
 * Download one-degree-wide, 1/3 arcsecond NED tiles from S3 (or get them from a directory of files
 * organized as USGS organizes them when you ship them a hard drive).
 *
 * @author novalis
 */
public class DegreeGridNEDTileSource implements NEDTileSource {

  private static final Logger log = LoggerFactory.getLogger(DegreeGridNEDTileSource.class);

  private File cacheDirectory;

  public String awsAccessKey;

  public String awsSecretKey;

  public String awsBucketName;

  private List nedTiles;

  @Override
  public void fetchData(Graph graph, File cacheDirectory) {
    this.cacheDirectory = cacheDirectory;

    HashSet> tiles = new HashSet<>();

    for (Vertex v : graph.getVertices()) {
      Coordinate coord = v.getCoordinate();
      tiles.add(new P2<>((int) coord.x, (int) coord.y));
    }

    List paths = new ArrayList<>();
    for (P2 tile : tiles) {
      int x = tile.first - 1;
      int y = tile.second + 1;
      File tilePath = getPathToTile(x, y);
      if (tilePath != null) {
        paths.add(tilePath);
      }
    }
    if (paths.size() == 0) {
      throw new RuntimeException("No elevation tiles were able to be downloaded!");
    }
    nedTiles = paths;
  }

  @Override
  public List getNEDTiles() {
    return nedTiles;
  }

  private String formatLatLon(int x, int y) {
    String northSouth, eastWest;
    if (y < 0) {
      northSouth = "s";
      y = -y;
    } else {
      northSouth = "n";
    }
    if (x < 0) {
      eastWest = "w";
      x = -x;
    } else {
      eastWest = "e";
    }
    return String.format("%s%d%s%03d", northSouth, y, eastWest, x);
  }

  private File getPathToTile(int x, int y) {
    File path = new File(cacheDirectory, formatLatLon(x, y) + ".tiff");
    if (path.exists()) {
      return path;
    } else {
      path.getParentFile().mkdirs();

      if (awsAccessKey == null || awsSecretKey == null) {
        throw new RuntimeException(
          "Cannot download NED tiles from S3: awsAccessKey or awsSecretKey properties are not set"
        );
      }
      log.info("Downloading NED degree tile {}", path);
      // download the file from S3.
      AWSCredentials awsCredentials = new AWSCredentials(awsAccessKey, awsSecretKey);
      String key = formatLatLon(x, y) + ".tiff";
      try {
        S3Service s3Service = new RestS3Service(awsCredentials);
        S3Object object = s3Service.getObject(awsBucketName, key);

        InputStream istream = object.getDataInputStream();
        FileOutputStream ostream = new FileOutputStream(path);

        byte[] buffer = new byte[4096];
        while (true) {
          int read = istream.read(buffer);
          if (read == -1) {
            break;
          }
          ostream.write(buffer, 0, read);
        }
        ostream.close();
        istream.close();
      } catch (S3ServiceException e) {
        // Check if the error code is a NoSuchKey code which indicates that the file was not found in the S3
        // bucket. If this is the cause, allow execution to continue, but add an annotation about the missing
        // file.
        //
        // Note: The IAM policy for the provided credentials must allow both s3:GetObject and s3:ListBucket for
        // the target bucket. If just GetObject is provided, the S3ServiceException will instead indicate a
        // forbidden access error.
        if (e.getS3ErrorCode().equals("NoSuchKey")) {
          log.error(
            String.format("Elevation tile %s missing from s3bucket. Proceeding without tile!", key)
          );
          return null;
        }
        // Some other error occurred.
        path.deleteOnExit();
        throw new RuntimeException(e);
      } catch (ServiceException | IOException e) {
        path.deleteOnExit();
        throw new RuntimeException(e);
      }
      return path;
    }
  }
}