perf: cache username syscalls, precompute filter paths, eliminate hot-loop allocations

- Cache username via OnceCell on Process (syscall runs once per instance)
- Precompute slash-suffixed file/dir paths in Filter at construction
- Fix filter exclusion loop to call username() once, not per-excluded-name
- FD name comparison: parse filter string to int instead of int to string
- Precompute parsed IpAddr for host matching (structural equality vs to_string)
- FdName::as_display returns Cow<str> (zero-alloc for static variants)
- Add Process::new() constructor, keep username_cache private

Author: MenkeTechnologies

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "lsofrs"
-version = "4.7.1"
+version = "4.8.0"
 edition = "2024"
 authors = ["Jacob Menke"]
 description = "Modern, high-performance lsof implementation in Rust"

src/csv_out.rs

@@ -46,16 +46,7 @@ mod tests {
     use super::*;
 
     fn make_proc(pid: i32, cmd: &str, files: Vec<OpenFile>) -> Process {
-        Process {
-            pid,
-            ppid: 1,
-            pgid: pid,
-            uid: 0,
-            command: cmd.to_string(),
-            files,
-            sel_flags: 0,
-            sel_state: 0,
-        }
+        Process::new(pid, 1, pid, 0, cmd.to_string(), files)
     }
 
     fn make_file(fd: i32, ft: FileType, name: &str) -> OpenFile {

src/darwin.rs

@@ -968,16 +968,14 @@ fn process_pid(pid: pid_t) -> Option<Process> {
         }
     }
 
-    Some(Process {
+    Some(Process::new(
         pid,
-        ppid: tai.pbsd.pbi_ppid as i32,
-        pgid: tai.pbsd.pbi_pgid as i32,
-        uid: tai.pbsd.pbi_uid,
-        command: cmd,
+        tai.pbsd.pbi_ppid as i32,
+        tai.pbsd.pbi_pgid as i32,
+        tai.pbsd.pbi_uid,
+        cmd,
         files,
-        sel_flags: 0,
-        sel_state: 0,
-    })
+    ))
 }
 
 /// Gather all process information from the system

src/delta.rs

@@ -134,13 +134,13 @@ mod tests {
     use super::*;
 
     fn make_proc(pid: i32, cmd: &str, files: Vec<(&str, &str)>) -> Process {
-        Process {
+        Process::new(
             pid,
-            ppid: 1,
-            pgid: 1,
-            uid: 501,
-            command: cmd.to_string(),
-            files: files
+            1,
+            1,
+            501,
+            cmd.to_string(),
+            files
                 .into_iter()
                 .map(|(fd, name)| OpenFile {
                     fd: FdName::Number(fd.parse().unwrap()),
@@ -150,9 +150,7 @@ mod tests {
                     ..Default::default()
                 })
                 .collect(),
-            sel_flags: 0,
-            sel_state: 0,
-        }
+        )
     }
 
     #[test]
@@ -514,16 +512,7 @@ mod tests {
     }
 
     fn proc_with_open_files(pid: i32, cmd: &str, files: Vec<OpenFile>) -> Process {
-        Process {
-            pid,
-            ppid: 1,
-            pgid: 1,
-            uid: 501,
-            command: cmd.to_string(),
-            files,
-            sel_flags: 0,
-            sel_state: 0,
-        }
+        Process::new(pid, 1, 1, 501, cmd.to_string(), files)
     }
 
     #[test]