Set timeouts for HTTP requests

[TomAugspurger]

xref #603 (comment)

Investigate whether it's possible for the current remote IO implementation to hang indefinitely. https://curl.se/libcurl/c/CURLOPT_TIMEOUT.html describes the option we probably want. We can add that as an option in libcurl.cpp next to the other CURLOPTs.

We'd need to figure out a good default value for this parameter and a way to configure it.

There's an interaction with #603: timeout errors raised by libcurl is one of the non-completed HTTP request / response errors that should be retried automatically (along with things like closed sockets).

[TomAugspurger]

A quick test on top of #603

diff --git a/cpp/src/shim/libcurl.cpp b/cpp/src/shim/libcurl.cpp
index 825c38a..d2912d1 100644
--- a/cpp/src/shim/libcurl.cpp
+++ b/cpp/src/shim/libcurl.cpp
@@ -110,6 +110,7 @@ CurlHandle::CurlHandle(LibCurl::UniqueHandlePtr handle,
 
   // Make curl_easy_perform() fail when receiving HTTP code errors.
   setopt(CURLOPT_FAILONERROR, 1L);
+  setopt(CURLOPT_TIMEOUT, 5L);
 }
 
 CurlHandle::~CurlHandle() noexcept { LibCurl::instance().retain_handle(std::move(_handle)); }
diff --git a/python/kvikio/tests/test_http_io.py b/python/kvikio/tests/test_http_io.py
index b084f81..2998baf 100644
--- a/python/kvikio/tests/test_http_io.py
+++ b/python/kvikio/tests/test_http_io.py
@@ -3,6 +3,7 @@
 
 
 import http
+import time
 from http.server import SimpleHTTPRequestHandler
 from typing import Literal
 
@@ -68,6 +69,7 @@ class HTTP500Handler(SimpleHTTPRequestHandler):
                 return super().do_HEAD()
 
     def do_GET(self) -> None:
+        time.sleep(10)
         return self._do_with_error_count("GET")
 
     def do_HEAD(self) -> None:

The HTTP server sleeps for 10 seconds before responding to GET requests. kvikio is configured to time out after 5s.

The first GET request time out, and isn't retried:

127.0.0.1 - - [04/Feb/2025 14:40:50] "HEAD /a HTTP/1.1" 200 -
FAILED

=============================================================================================================================================== FAILURES ===============================================================================================================================================
_____________________________________________________________________________________________________________________________________ test_retry_http_500_ok[cupy] _____________________________________________________________________________________________________________________________________
python/kvikio/tests/test_http_io.py:178: in test_retry_http_500_ok
    f.read(b)
python/kvikio/kvikio/remote_file.py:182: in read
    return self.pread(buf, size, file_offset).get()
python/kvikio/kvikio/cufile.py:54: in get
    return self._handle.get()
future.pyx:33: in kvikio._lib.future.IOFuture.get
    ???
E   RuntimeError: curl_easy_perform() error near /home/coder/kvikio/cpp/src/remote_handle.cpp:353(Operation timed out after 5002 milliseconds with 0 bytes received)
======================================================================================================================================= short test summary info ========================================================================================================================================
FAILED python/kvikio/tests/test_http_io.py::test_retry_http_500_ok[cupy] - RuntimeError: curl_easy_perform() error near /home/coder/kvikio/cpp/src/remote_handle.cpp:353(Operation timed out after 5002 milliseconds with 0 bytes received)
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! stopping after 1 failures !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!