From c73ff3ce1bca44cfe6e57ca99c3b4a644bed9151 Mon Sep 17 00:00:00 2001
From: ed <s@ocv.me>
Date: Thu, 28 Apr 2022 22:46:53 +0200
Subject: [PATCH] avoid sqlite deadlock on windows

---
 copyparty/u2idx.py | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/copyparty/u2idx.py b/copyparty/u2idx.py
index 566bb146..fbc784ea 100644
--- a/copyparty/u2idx.py
+++ b/copyparty/u2idx.py
@@ -21,6 +21,12 @@ except:
     HAVE_SQLITE3 = False
 
 
+try:
+    from pathlib import Path
+except:
+    pass
+
+
 class U2idx(object):
     def __init__(self, conn):
         self.log_func = conn.log_func
@@ -76,7 +82,22 @@ class U2idx(object):
         if not bos.path.exists(db_path):
             return None
 
-        cur = sqlite3.connect(db_path, 2).cursor()
+        cur = None
+        if ANYWIN:
+            uri = ""
+            try:
+                uri = "{}?mode=ro&nolock=1".format(Path(db_path).as_uri())
+                cur = sqlite3.connect(uri, 2, uri=True).cursor()
+                self.log("ro: {}".format(db_path))
+            except:
+                self.log("could not open read-only: {}\n{}".format(uri, min_ex()))
+
+        if not cur:
+            # on windows, this steals the write-lock from up2k.deferred_init --
+            # seen on win 10.0.17763.2686, py 3.10.4, sqlite 3.37.2
+            cur = sqlite3.connect(db_path, 2).cursor()
+            self.log("opened {}".format(db_path))
+
         self.cur[ptop] = cur
         return cur