Fix vector_read data server size query (#56)

pyproject.toml

@@ -25,6 +25,7 @@ strict = true
 show_error_codes = true
 enable_error_code = ["ignore-without-code", "redundant-expr", "truthy-bool"]
 warn_unreachable = true
+ignore_missing_imports = true
 
 
 [tool.check-manifest]

src/fsspec_xrootd/xrootd.py

@@ -9,24 +9,17 @@
 from functools import partial
 from typing import Any, Callable, Iterable
 
-from fsspec.asyn import (  # type: ignore[import-not-found]
-    AsyncFileSystem,
-    _run_coros_in_chunks,
-    sync_wrapper,
-)
-from fsspec.spec import AbstractBufferedFile  # type: ignore[import-not-found]
-from XRootD import client  # type: ignore[import-not-found]
-from XRootD.client.flags import (  # type: ignore[import-not-found]
+from fsspec.asyn import AsyncFileSystem, _run_coros_in_chunks, sync_wrapper
+from fsspec.spec import AbstractBufferedFile
+from XRootD import client
+from XRootD.client.flags import (
     DirListFlags,
     MkDirFlags,
     OpenFlags,
     QueryCode,
     StatInfoFlags,
 )
-from XRootD.client.responses import (  # type: ignore[import-not-found]
-    HostList,
-    XRootDStatus,
-)
+from XRootD.client.responses import HostList, XRootDStatus
 
 
 class ErrorCodes(IntEnum):
@@ -73,9 +66,11 @@ async def _async_wrap(func: Callable[..., Any], *args: Any) -> Any:
     An asyncio future. Result is set when _handle() is called back.
     """
     future = asyncio.get_running_loop().create_future()
-    status = func(*args, callback=partial(_handle, future))
-    if not status.ok:
-        raise OSError(status.message.strip())
+    submit_status = func(*args, callback=partial(_handle, future))
+    if not submit_status.ok:
+        raise OSError(
+            f"Failed to submit {func!r} request: {submit_status.message.strip()}"
+        )
     return await future
 
 
@@ -149,6 +144,8 @@ class XRootDFileSystem(AsyncFileSystem):  # type: ignore[misc]
     root_marker = "/"
     default_timeout = 60
     async_impl = True
+    default_max_num_chunks = 1024
+    default_max_chunk_size = 2097136
 
     _dataserver_info_cache: dict[str, Any] = defaultdict(dict)
 
@@ -458,7 +455,8 @@ async def _get_file(
             # Close the remote file
             await _async_wrap(remote_file.close, self.timeout)
 
-    async def _get_max_chunk_info(self, file: Any) -> tuple[int, int]:
+    @classmethod
+    async def _get_max_chunk_info(cls, file: Any) -> tuple[int, int]:
         """Queries the XRootD server for info required for pyxrootd vector_read() function.
         Queries for maximum number of chunks and the maximum chunk size allowed by the server.
 
@@ -471,20 +469,31 @@ async def _get_max_chunk_info(self, file: Any) -> tuple[int, int]:
         Tuple of max chunk size and max number of chunks. Both ints.
         """
         data_server = file.get_property("DataServer")
-        if data_server not in XRootDFileSystem._dataserver_info_cache:
+        if data_server == "":
+            return cls.default_max_num_chunks, cls.default_max_chunk_size
+        # Normalize to URL
+        data_server = client.URL(data_server)
+        data_server = f"{data_server.protocol}://{data_server.hostid}/"
+        if data_server not in cls._dataserver_info_cache:
+            fs = client.FileSystem(data_server)
             status, result = await _async_wrap(
-                self._myclient.query, QueryCode.CONFIG, "readv_iov_max readv_ior_max"
+                fs.query, QueryCode.CONFIG, "readv_iov_max readv_ior_max"
             )
             if not status.ok:
                 raise OSError(
                     f"Server query for vector read info failed: {status.message}"
                 )
-            max_num_chunks, max_chunk_size = map(int, result.split(b"\n", 1))
-            XRootDFileSystem._dataserver_info_cache[data_server] = {
-                "max_num_chunks": int(max_num_chunks),
-                "max_chunk_size": int(max_chunk_size),
+            try:
+                max_num_chunks, max_chunk_size = map(int, result.split(b"\n", 1))
+            except ValueError:
+                raise OSError(
+                    f"Server query for vector read info failed: could not parse {result!r}"
+                ) from None
+            cls._dataserver_info_cache[data_server] = {
+                "max_num_chunks": max_num_chunks,
+                "max_chunk_size": max_chunk_size,
             }
-        info = XRootDFileSystem._dataserver_info_cache[data_server]
+        info = cls._dataserver_info_cache[data_server]
         return (info["max_num_chunks"], info["max_chunk_size"])
 
     async def _cat_vector_read(
@@ -649,10 +658,8 @@ def open(
                 **kwargs,
             )
             if compression is not None:
-                from fsspec.compression import compr  # type: ignore[import-not-found]
-                from fsspec.core import (  # type: ignore[import-not-found]
-                    get_compression,
-                )
+                from fsspec.compression import compr
+                from fsspec.core import get_compression
 
                 compression = get_compression(path, compression)
                 compress = compr[compression]
@@ -697,7 +704,7 @@ def __init__(
 
         self._myFile = client.File()
         status, _n = self._myFile.open(
-            fs.protocol + "://" + fs.storage_options["hostid"] + "/" + path,
+            fs.unstrip_protocol(path),
             self.mode,
             timeout=self.timeout,
         )