refactor(tvix/castore/fs): add InodeData::as_fuse_{entry,file_attr} r/7921

Remove the now unused gen_file_attr (which had a wrong docstring).

Change-Id: Ie86b14d1ad798e6233bc44c43ace3f8b95c67ea9
Reviewed-on: https://cl.tvl.fyi/c/depot/+/11430
Tested-by: BuildkiteCI
Autosubmit: flokli <flokli@flokli.de>
Reviewed-by: Connor Brewster <cbrewster@hey.com>

3 files changed, 46 insertions, 57 deletions

diff --git a/tvix/castore/src/fs/file_attr.rs b/tvix/castore/src/fs/file_attr.rs
index ad41f036a2..2e0e70e3cd 100644
--- a/tvix/castore/src/fs/file_attr.rs
+++ b/tvix/castore/src/fs/file_attr.rs
@@ -1,5 +1,5 @@
 #![allow(clippy::unnecessary_cast)] // libc::S_IFDIR is u32 on Linux and u16 on MacOS
-use super::inodes::{DirectoryInodeData, InodeData};
+
 use fuse_backend_rs::abi::fuse_abi::Attr;
 
 /// The [Attr] describing the root
@@ -27,27 +27,3 @@ pub const ROOT_FILE_ATTR: Attr = Attr {
     #[cfg(target_os = "macos")]
     padding: 0,
 };
-
-/// for given &Node and inode, construct an [Attr]
-pub fn gen_file_attr(inode_data: &InodeData, inode: u64) -> Attr {
-    Attr {
-        ino: inode,
-        // FUTUREWORK: play with this numbers, as it affects read sizes for client applications.
-        blocks: 1024,
-        size: match inode_data {
-            InodeData::Regular(_, size, _) => *size as u64,
-            InodeData::Symlink(target) => target.len() as u64,
-            InodeData::Directory(DirectoryInodeData::Sparse(_, size)) => *size as u64,
-            InodeData::Directory(DirectoryInodeData::Populated(_, ref children)) => {
-                children.len() as u64
-            }
-        },
-        mode: match inode_data {
-            InodeData::Regular(_, _, false) => libc::S_IFREG as u32 | 0o444, // no-executable files
-            InodeData::Regular(_, _, true) => libc::S_IFREG as u32 | 0o555,  // executable files
-            InodeData::Symlink(_) => libc::S_IFLNK as u32 | 0o444,
-            InodeData::Directory(_) => libc::S_IFDIR as u32 | 0o555,
-        },
-        ..Default::default()
-    }
-}
diff --git a/tvix/castore/src/fs/inodes.rs b/tvix/castore/src/fs/inodes.rs
index 9131b703ba..69a75acb6b 100644
--- a/tvix/castore/src/fs/inodes.rs
+++ b/tvix/castore/src/fs/inodes.rs
@@ -1,5 +1,7 @@
 //! This module contains all the data structures used to track information
 //! about inodes, which present tvix-castore nodes in a filesystem.
+use std::time::Duration;
+
 use crate::proto as castorepb;
 use crate::B3Digest;
 
@@ -10,6 +12,41 @@ pub enum InodeData {
     Directory(DirectoryInodeData), // either [DirectoryInodeData:Sparse] or [DirectoryInodeData:Populated]
 }
 
+impl InodeData {
+    pub fn as_fuse_file_attr(&self, inode: u64) -> fuse_backend_rs::abi::fuse_abi::Attr {
+        fuse_backend_rs::abi::fuse_abi::Attr {
+            ino: inode,
+            // FUTUREWORK: play with this numbers, as it affects read sizes for client applications.
+            blocks: 1024,
+            size: match self {
+                InodeData::Regular(_, size, _) => *size,
+                InodeData::Symlink(target) => target.len() as u64,
+                InodeData::Directory(DirectoryInodeData::Sparse(_, size)) => *size,
+                InodeData::Directory(DirectoryInodeData::Populated(_, ref children)) => {
+                    children.len() as u64
+                }
+            },
+            mode: match self {
+                InodeData::Regular(_, _, false) => libc::S_IFREG | 0o444, // no-executable files
+                InodeData::Regular(_, _, true) => libc::S_IFREG | 0o555,  // executable files
+                InodeData::Symlink(_) => libc::S_IFLNK | 0o444,
+                InodeData::Directory(_) => libc::S_IFDIR | 0o555,
+            },
+            ..Default::default()
+        }
+    }
+
+    pub fn as_fuse_entry(&self, inode: u64) -> fuse_backend_rs::api::filesystem::Entry {
+        fuse_backend_rs::api::filesystem::Entry {
+            inode,
+            attr: self.as_fuse_file_attr(inode).into(),
+            attr_timeout: Duration::MAX,
+            entry_timeout: Duration::MAX,
+            ..Default::default()
+        }
+    }
+}
+
 /// This encodes the two different states of [InodeData::Directory].
 /// Either the data still is sparse (we only saw a [castorepb::DirectoryNode],
 /// but didn't fetch the [castorepb::Directory] struct yet, or we processed a
diff --git a/tvix/castore/src/fs/mod.rs b/tvix/castore/src/fs/mod.rs
index 2bf22a33ff..1988a49cfc 100644
--- a/tvix/castore/src/fs/mod.rs
+++ b/tvix/castore/src/fs/mod.rs
@@ -14,7 +14,7 @@ mod tests;
 
 pub use self::root_nodes::RootNodes;
 use self::{
-    file_attr::{gen_file_attr, ROOT_FILE_ATTR},
+    file_attr::ROOT_FILE_ATTR,
     inode_tracker::InodeTracker,
     inodes::{DirectoryInodeData, InodeData},
 };
@@ -328,9 +328,9 @@ where
 
         match self.inode_tracker.read().get(inode) {
             None => Err(io::Error::from_raw_os_error(libc::ENOENT)),
-            Some(node) => {
-                debug!(node = ?node, "found node");
-                Ok((gen_file_attr(&node, inode).into(), Duration::MAX))
+            Some(inode_data) => {
+                debug!(inode_data = ?inode_data, "found node");
+                Ok((inode_data.as_fuse_file_attr(inode).into(), Duration::MAX))
             }
         }
     }
@@ -353,13 +353,7 @@ where
             let (ino, inode_data) = self.name_in_root_to_ino_and_data(name)?;
 
             debug!(inode_data=?&inode_data, ino=ino, "Some");
-            return Ok(fuse_backend_rs::api::filesystem::Entry {
-                inode: ino,
-                attr: gen_file_attr(&inode_data, ino).into(),
-                attr_timeout: Duration::MAX,
-                entry_timeout: Duration::MAX,
-                ..Default::default()
-            });
+            return Ok(inode_data.as_fuse_entry(ino));
         }
         // This is the "lookup for "a" inside inode 42.
         // We already know that inode 42 must be a directory.
@@ -376,13 +370,7 @@ where
 
             // Reply with the file attributes for the child.
             // For child directories, we still have all data we need to reply.
-            Ok(fuse_backend_rs::api::filesystem::Entry {
-                inode: *child_ino,
-                attr: gen_file_attr(&child_inode_data, *child_ino).into(),
-                attr_timeout: Duration::MAX,
-                entry_timeout: Duration::MAX,
-                ..Default::default()
-            })
+            Ok(child_inode_data.as_fuse_entry(*child_ino))
         } else {
             // Child not found, return ENOENT.
             Err(io::Error::from_raw_os_error(libc::ENOENT))
@@ -606,13 +594,7 @@ where
                         type_: ty,
                         name,
                     },
-                    fuse_backend_rs::api::filesystem::Entry {
-                        inode: ino,
-                        attr: gen_file_attr(&inode_data, ino).into(),
-                        attr_timeout: Duration::MAX,
-                        entry_timeout: Duration::MAX,
-                        ..Default::default()
-                    },
+                    inode_data.as_fuse_entry(ino),
                 )?;
                 // If the buffer is full, add_entry will return `Ok(0)`.
                 if written == 0 {
@@ -646,13 +628,7 @@ where
                     },
                     name: child_node.get_name(),
                 },
-                fuse_backend_rs::api::filesystem::Entry {
-                    inode: *ino,
-                    attr: gen_file_attr(&inode_data, *ino).into(),
-                    attr_timeout: Duration::MAX,
-                    entry_timeout: Duration::MAX,
-                    ..Default::default()
-                },
+                inode_data.as_fuse_entry(*ino),
             )?;
             // If the buffer is full, add_entry will return `Ok(0)`.
             if written == 0 {