bep: encode file paths in URI format

We need to ensure that special characters are encoded according to the
URI specification RFC2396.

Change-Id: Ie93cbe11a70f448d2e7bacd0bba5699ec20cac25
PiperOrigin-RevId: 167301074

src/main/java/com/google/devtools/build/lib/buildeventstream/PathConverter.java

@@ -20,8 +20,8 @@
  */
 public interface PathConverter {
   /**
-   * Return the URI corresponding to the given path, if the path can be converted to a URI by this
-   * path converter; return {@link null} otherwise.
+   * Returns a URI according to RFC2396 corresponding to the given path, if the path can be
+   * converted to a URI by this path converter; return {@code null} otherwise.
    */
   String apply(Path path);
 }

src/main/java/com/google/devtools/build/lib/buildeventstream/proto/build_event_stream.proto

@@ -340,7 +340,8 @@ message File {
   string name = 1;
 
   oneof file {
-    // A location where the contents of the file can be found.
+    // A location where the contents of the file can be found. The string is
+    // encoded according to RFC2396.
     string uri = 2;
     // The contents of the file, if they are guaranteed to be short.
     bytes contents = 3;

src/main/java/com/google/devtools/build/lib/buildeventstream/transports/BuildEventTransportFactory.java

@@ -21,6 +21,7 @@
 import com.google.devtools.build.lib.buildeventstream.BuildEventTransport;
 import com.google.devtools.build.lib.buildeventstream.PathConverter;
 import com.google.devtools.build.lib.vfs.Path;
+import java.io.File;
 import java.io.IOException;
 
 /** Factory used to create a Set of BuildEventTransports from BuildEventStreamOptions. */
@@ -101,7 +102,7 @@ protected abstract BuildEventTransport create(BuildEventStreamOptions options,
   private static class NullPathConverter implements PathConverter {
     @Override
     public String apply(Path path) {
-      return "file://" + path;
+      return new File(path.getPathString()).toURI().toString();
     }
   }
 }