From aa68be645f80dde5a52dc5a32d74304921e97288 Mon Sep 17 00:00:00 2001
From: Itamar Turner-Trauring <itamar@itamarst.org>
Date: Thu, 10 Feb 2022 13:47:56 -0500
Subject: [PATCH] Return Content-Range in responses.

---
 src/allmydata/storage/http_server.py    | 12 +++++------
 src/allmydata/test/test_storage_http.py | 27 +++++++++++++++++++++++++
 2 files changed, 33 insertions(+), 6 deletions(-)

diff --git a/src/allmydata/storage/http_server.py b/src/allmydata/storage/http_server.py
index 88de18f12..bb4ef6c00 100644
--- a/src/allmydata/storage/http_server.py
+++ b/src/allmydata/storage/http_server.py
@@ -24,6 +24,7 @@ from twisted.web import http
 import attr
 from werkzeug.http import parse_range_header, parse_content_range_header
 from werkzeug.routing import BaseConverter
+from werkzeug.datastructures import ContentRange
 
 # TODO Make sure to use pure Python versions?
 from cbor2 import dumps, loads
@@ -323,11 +324,10 @@ class HTTPServer(object):
 
         # TODO limit memory usage
         data = bucket.read(offset, end - offset)
+
         request.setResponseCode(http.PARTIAL_CONTENT)
-        # TODO set content-range on response. We we need to expand the
-        # BucketReader interface to return share's length.
-        #
-        # request.setHeader(
-        #    "content-range", range_header.make_content_range(share_length).to_header()
-        # )
+        request.setHeader(
+            "content-range",
+            ContentRange("bytes", offset, offset + len(data)).to_header(),
+        )
         return data
diff --git a/src/allmydata/test/test_storage_http.py b/src/allmydata/test/test_storage_http.py
index bbda00bf6..c864f923c 100644
--- a/src/allmydata/test/test_storage_http.py
+++ b/src/allmydata/test/test_storage_http.py
@@ -760,3 +760,30 @@ class ImmutableHTTPAPITests(SyncTestCase):
         )
         self.assertEqual(response.code, http.OK)
         self.assertEqual(result_of(response.content()), uploaded_data)
+
+    def test_validate_content_range_response_to_read(self):
+        """
+        The server responds to ranged reads with an appropriate Content-Range
+        header.
+        """
+        storage_index, _ = self.upload(1, 26)
+
+        def check_range(requested_range, expected_response):
+            headers = Headers()
+            headers.setRawHeaders("range", [requested_range])
+            response = result_of(
+                self.http.client.request(
+                    "GET",
+                    self.http.client.relative_url(
+                        "/v1/immutable/{}/1".format(_encode_si(storage_index))
+                    ),
+                    headers=headers,
+                )
+            )
+            self.assertEqual(
+                response.headers.getRawHeaders("content-range"), [expected_response]
+            )
+
+        check_range("bytes=0-10", "bytes 0-10/*")
+        # Can't go beyond the end of the immutable!
+        check_range("bytes=10-100", "bytes 10-25/*")