Implement HTTP share listing endpoint.

docs/proposed/http-storage-node-protocol.rst

@@ -630,8 +630,8 @@ Reading
 ``GET /v1/immutable/:storage_index/shares``
 !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
 
-Retrieve a list indicating all shares available for the indicated storage index.
-For example::
+Retrieve a list (semantically, a set) indicating all shares available for the
+indicated storage index. For example::
 
   [1, 5]
 

src/allmydata/storage/http_client.py

@@ -136,6 +136,7 @@ class UploadProgress(object):
     """
     Progress of immutable upload, per the server.
     """
+
     # True when upload has finished.
     finished = attr.ib(type=bool)
     # Remaining ranges to upload.
@@ -221,7 +222,7 @@ class StorageClientImmutables(object):
             headers=Headers(
                 {
                     "content-range": [
-                        ContentRange("bytes", offset, offset+len(data)).to_header()
+                        ContentRange("bytes", offset, offset + len(data)).to_header()
                     ]
                 }
             ),
@@ -268,11 +269,7 @@ class StorageClientImmutables(object):
             "GET",
             url,
             headers=Headers(
-                {
-                    "range": [
-                        Range("bytes", [(offset, offset + length)]).to_header()
-                    ]
-                }
+                {"range": [Range("bytes", [(offset, offset + length)]).to_header()]}
             ),
         )
         if response.code == http.PARTIAL_CONTENT:
@@ -282,3 +279,23 @@ class StorageClientImmutables(object):
             raise ClientException(
                 response.code,
             )
+
+    @inlineCallbacks
+    def list_shares(self, storage_index):  # type: (bytes,) -> Deferred[Set[int]]
+        """
+        Return the set of shares for a given storage index.
+        """
+        url = self._client._url(
+            "/v1/immutable/{}/shares".format(_encode_si(storage_index))
+        )
+        response = yield self._client._request(
+            "GET",
+            url,
+        )
+        if response.code == http.OK:
+            body = yield response.content()
+            returnValue(set(loads(body)))
+        else:
+            raise ClientException(
+                response.code,
+            )

src/allmydata/storage/http_server.py

@@ -255,6 +255,22 @@ class HTTPServer(object):
             required.append({"begin": start, "end": end})
         return self._cbor(request, {"required": required})
 
+    @_authorized_route(
+        _app,
+        set(),
+        "/v1/immutable/<string:storage_index>/shares",
+        methods=["GET"],
+    )
+    def list_shares(self, request, authorization, storage_index):
+        """
+        List shares for the given storage index.
+        """
+        storage_index = si_a2b(storage_index.encode("ascii"))
+
+        # TODO in future ticket, handle KeyError as 404
+        share_numbers = list(self._storage_server.get_buckets(storage_index).keys())
+        return self._cbor(request, share_numbers)
+
     @_authorized_route(
         _app,
         set(),

src/allmydata/test/test_storage_http.py

@@ -382,6 +382,37 @@ class ImmutableHTTPAPITests(SyncTestCase):
             )
             self.assertEqual(downloaded, expected_data[offset : offset + length])
 
+    def test_list_shares(self):
+        """
+        Once a share is finished uploading, it's possible to list it.
+        """
+        im_client = StorageClientImmutables(self.http.client)
+        upload_secret = urandom(32)
+        lease_secret = urandom(32)
+        storage_index = b"".join(bytes([i]) for i in range(16))
+        result_of(
+            im_client.create(
+                storage_index, {1, 2, 3}, 10, upload_secret, lease_secret, lease_secret
+            )
+        )
+
+        # Initially there are no shares:
+        self.assertEqual(result_of(im_client.list_shares(storage_index)), set())
+
+        # Upload shares 1 and 3:
+        for share_number in [1, 3]:
+            progress = result_of(im_client.write_share_chunk(
+                    storage_index,
+                    share_number,
+                    upload_secret,
+                    0,
+                    b"0123456789",
+            ))
+            self.assertTrue(progress.finished)
+
+        # Now shares 1 and 3 exist:
+        self.assertEqual(result_of(im_client.list_shares(storage_index)), {1, 3})
+
     def test_multiple_shares_uploaded_to_different_place(self):
         """
         If a storage index has multiple shares, uploads to different shares are