com.sap.hana.datalake.files.directaccess.gcs.GcsSignedUrl Maven / Gradle / Ivy

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An implementation of org.apache.hadoop.fs.FileSystem targeting SAP HANA Data Lake Files.

There is a newer version: 3.0.27

// © 2023 SAP SE or an SAP affiliate company. All rights reserved.
package com.sap.hana.datalake.files.directaccess.gcs;

import java.time.Instant;
import java.time.ZoneOffset;
import java.time.format.DateTimeFormatter;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

import com.sap.hana.datalake.files.HdlfsFileSystemCapabilities.DirectAccessSignedUrl;
import com.sap.hana.datalake.files.directaccess.BaseSignedUrl;

/* package-private */ class GcsSignedUrl extends BaseSignedUrl {

  private static final Pattern URL_DATE_PARAMETER_PATTERN = Pattern.compile("^https?://.+(?:\\?|\\?.+&)X-Goog-Date=(\\d{8}T\\d{6}Z)(&.*|#.*|$)");
  private static final Pattern URL_EXPIRES_PARAMETER_PATTERN = Pattern.compile("^https?://.+(?:\\?|\\?.+&)X-Goog-Expires=(\\d+)(&.*|#.*|$)");
  private static final DateTimeFormatter DATE_FORMATTER = DateTimeFormatter.ofPattern("yyyyMMdd'T'HHmmss'Z'").withZone(ZoneOffset.UTC);

  private final long expirationTimeSeconds;

  public static GcsSignedUrl from(final DirectAccessSignedUrl directAccessSignedUrl,
      final int expirationSafetyMargin) {
    return new GcsSignedUrl(directAccessSignedUrl, expirationSafetyMargin);
  }

  /* package-private */ GcsSignedUrl(final DirectAccessSignedUrl directAccessSignedUrl, final int expirationSafetyMarginSeconds) {
    super(directAccessSignedUrl, expirationSafetyMarginSeconds);
    this.expirationTimeSeconds = this.getExpirationTimeFromSignedUrl(this.url);
  }

  public long getExpirationTimeSeconds() {
    return this.expirationTimeSeconds;
  }

  @Override
  public boolean isExpired() {
    return this.expirationTimeSeconds < System.currentTimeMillis();
  }

  private long getExpirationTimeFromSignedUrl(final String signedUrl) {
    final Matcher creationDateMatcher = URL_DATE_PARAMETER_PATTERN.matcher(signedUrl);
    final Matcher expirationTimeMatcher = URL_EXPIRES_PARAMETER_PATTERN.matcher(signedUrl);

    if (!creationDateMatcher.matches()) {
      throw new IllegalArgumentException("Signed URL does not contain a creation date");
    }

    if (!expirationTimeMatcher.matches()) {
      throw new IllegalArgumentException("Signed URL does not contain an expiration time");
    }

    final String creationDate = creationDateMatcher.group(1);
    final long expirationTime = Long.parseLong(expirationTimeMatcher.group(1));
    final long signedUrlValiditySeconds;

    // do not apply safety margin if that means the URL would not be valid for at least one second
    if (expirationTime - this.expirationSafetyMarginSeconds > 1) {
      signedUrlValiditySeconds = expirationTime - this.expirationSafetyMarginSeconds;
    } else {
      signedUrlValiditySeconds = expirationTime;
    }

    final Instant creationInstant = Instant.from(DATE_FORMATTER.parse(creationDate));
    final Instant expirationInstant = creationInstant.plusSeconds(signedUrlValiditySeconds);

    return expirationInstant.toEpochMilli();
  }

}

// © 2023 SAP SE or an SAP affiliate company. All rights reserved.