api: make URL transforms more generic

gwdatafind_server/api/v1.py

@@ -251,6 +251,11 @@ def find_latest_url(ext, site, tag, urltype=None):
 
 # -- URL matcher --------------------------------------------------------------
 
+URL_TRANSFORM = {
+    "file": _file_url,
+    "gsiftp": _gsiftp_url,
+}
+
 
 def _get_latest_segment(seglist, duration):
     """Get segment for latest file of the given duration in a segment list
@@ -303,15 +308,18 @@ def _find_urls(
                 gps += cdur
 
     # convert paths to URLs for various schemes
+    urltypes = set(URL_TRANSFORM.keys())
+    if urltype:
+        urltypes &= {urltype}
     allurls = {}
     for lfn in lfns:
         allurls[lfn] = []
         for path in lfns[lfn]:
-            # build file:// and gsiftp:// URL for each LFN
-            allurls[lfn].extend((
-                _file_url(path),
-                _gsiftp_url(path),
-            ))
+            # build URL for each urltype
+            allurls[lfn].extend(
+                URL_TRANSFORM[_urlt](path)
+                for _urlt in sorted(urltypes)
+            )
 
     # filter URLs for each LFN and return
     urls = []