From 108ad744640172ed7332de599333b1652f4beb0f Mon Sep 17 00:00:00 2001
From: Igor Katson <igor.katson@gmail.com>
Date: Mon, 6 May 2024 23:02:10 +0300
Subject: [PATCH] Fix a bug in experimental mmap storage

---
 .zed/settings.json                             | 18 ++++++++++++++++++
 crates/librqbit/src/storage/filesystem/mmap.rs |  8 +++++---
 2 files changed, 23 insertions(+), 3 deletions(-)
 create mode 100644 .zed/settings.json

diff --git a/.zed/settings.json b/.zed/settings.json
new file mode 100644
index 0000000..8496672
--- /dev/null
+++ b/.zed/settings.json
@@ -0,0 +1,18 @@
+// Folder-specific settings
+//
+// For a full list of overridable settings, and general information on folder-specific settings,
+// see the documentation: https://zed.dev/docs/configuring-zed#folder-specific-settings
+{
+  "lsp": {
+    "rust-analyzer": {
+      "initialization_options": {
+        "check": {
+          "command": "clippy" // rust-analyzer.check.command (default: "check")
+        },
+        "cargo": {
+          "features": ["librqbit/storage_middleware"]
+        }
+      }
+    }
+  }
+}
diff --git a/crates/librqbit/src/storage/filesystem/mmap.rs b/crates/librqbit/src/storage/filesystem/mmap.rs
index e5ef44a..87e4157 100644
--- a/crates/librqbit/src/storage/filesystem/mmap.rs
+++ b/crates/librqbit/src/storage/filesystem/mmap.rs
@@ -25,9 +25,11 @@ impl StorageFactory for MmapFilesystemStorageFactory {
     fn init_storage(&self, meta: &ManagedTorrentInfo) -> anyhow::Result<Self::Storage> {
         let fs_storage = FilesystemStorageFactory::default().init_storage(meta)?;
         let mut mmaps = Vec::new();
-        for file in fs_storage.opened_files.iter() {
-            let mmap = unsafe { MmapOptions::new().map_mut(&*file.file.read()) }
-                .context("error mapping file")?;
+        for (idx, file) in fs_storage.opened_files.iter().enumerate() {
+            let fg = file.file.write();
+            fg.set_len(meta.file_infos[idx].len)
+                .context("mmap storage: error setting length")?;
+            let mmap = unsafe { MmapOptions::new().map_mut(&*fg) }.context("error mapping file")?;
             mmaps.push(RwLock::new(mmap));
         }