danielcweeks commented on code in PR #16174:
URL: https://github.com/apache/iceberg/pull/16174#discussion_r3237680466


##########
core/src/main/java/org/apache/iceberg/util/LocationUtil.java:
##########
@@ -57,4 +57,59 @@ public static String tableLocation(TableIdentifier 
tableIdentifier, boolean useU
       return tableIdentifier.name();
     }
   }
+
+  /**
+   * Returns true if the location contains a URI scheme (e.g. {@code s3:}, 
{@code hdfs:}, {@code
+   * file:}), per <a 
href="https://datatracker.ietf.org/doc/html/rfc3986#section-3.1";>RFC 3986
+   * section 3.1</a>.
+   */
+  private static boolean hasScheme(String location) {
+    if (location.isEmpty()) {
+      return false;
+    }
+
+    // Early termination for relative locations since most commonly start with 
/
+    if (location.charAt(0) == '/') {
+      return false;
+    }
+
+    for (int i = 0; i < location.length(); i += 1) {
+      char ch = location.charAt(i);
+      if (ch == ':') {
+        return i > 0;
+      }
+
+      if (!Character.isLetterOrDigit(ch) && ch != '+' && ch != '-' && ch != 
'.') {
+        return false;
+      }
+    }
+
+    return false;
+  }
+
+  /**
+   * Resolves a relative location against a table location. If the location 
has a URI scheme, it is
+   * returned as-is. Otherwise, the location is appended to the table location 
without any
+   * additional separator.
+   */
+  public static String resolveLocation(String tableLocation, String location) {
+    if (hasScheme(location)) {
+      return location;
+    }
+
+    return tableLocation + location;
+  }
+
+  /**
+   * Relativizes a location against a table location. If the location starts 
with the table
+   * location, the prefix is removed and the remaining relative portion is 
returned. Otherwise, the
+   * location is returned as-is.
+   */
+  public static String relativizeLocation(String tableLocation, String 
location) {
+    if (location.startsWith(tableLocation)) {

Review Comment:
   I think it's reasonable to add defensive checks if it can be done 
efficiently in the reference implementation, but I'm not convinced there's a 
way to cleanly solve for this in the spec.  This scenario should resolve to an 
absolute path, but I don't think we can provide a concrete solution without 
relying on a separator character.  



-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: [email protected]

For queries about this service, please contact Infrastructure at:
[email protected]


---------------------------------------------------------------------
To unsubscribe, e-mail: [email protected]
For additional commands, e-mail: [email protected]

Reply via email to