From e39ddaefb20546a2c8f35fd6fcd47fcfd9d654d0 Mon Sep 17 00:00:00 2001
From: Nicolas Stalder <n@stalder.io>
Date: Wed, 29 Apr 2020 23:34:49 +0200
Subject: [PATCH] Reliability > efficiency

---
 src/fs.rs   | 14 +++++++++++---
 src/path.rs | 42 +++++++++++++++++++++++++++++++++++-------
 2 files changed, 46 insertions(+), 10 deletions(-)

diff --git a/src/fs.rs b/src/fs.rs
index 75d36016..9d0f4583 100644
--- a/src/fs.rs
+++ b/src/fs.rs
@@ -154,7 +154,7 @@ pub struct Filesystem<'a, Storage: driver::Storage> {
 }
 
 /// Regular file vs directory
-#[derive(Clone,Copy,Debug,Eq,Hash,PartialEq)]
+#[derive(Clone,Copy,Debug,Eq,Hash,PartialEq,ufmt::derive::uDebug,serde::Serialize,serde::Deserialize)]
 pub enum FileType {
     File,
     Dir,
@@ -173,7 +173,7 @@ impl FileType {
 }
 
 /// File type (regular vs directory) and size of a file.
-#[derive(Clone,Debug,Eq,PartialEq)]
+#[derive(Clone,Debug,Eq,PartialEq,ufmt::derive::uDebug,serde::Serialize,serde::Deserialize)]
 pub struct Metadata {
     file_type: FileType,
     size: usize,
@@ -960,7 +960,7 @@ impl<S: driver::Storage> io::Write for File<'_, '_, S>
     fn flush(&self) -> Result<()> { Ok(()) }
 }
 
-#[derive(Clone,Debug,PartialEq)]
+#[derive(Clone,Debug,PartialEq,Eq, ufmt::derive::uDebug,serde::Serialize,serde::Deserialize)]
 pub struct DirEntry {
     file_name: PathBuf,
     metadata: Metadata,
@@ -995,6 +995,14 @@ impl DirEntry {
         &self.path
     }
 
+    #[cfg(feature = "dir-entry-path")]
+    #[doc(hidden)]
+    // This is used in `crypto-service` to "namespace" paths
+    // by mutating a DirEntry in-place.
+    pub unsafe fn path_buf_mut(&mut self) -> &mut PathBuf {
+        &mut self.path
+    }
+
 }
 
 pub struct ReadDirAllocation {
diff --git a/src/path.rs b/src/path.rs
index d298a7eb..711315dc 100644
--- a/src/path.rs
+++ b/src/path.rs
@@ -1,6 +1,6 @@
 //! Paths
 
-use core::{convert::TryFrom, fmt, marker::PhantomData, mem::MaybeUninit, ops, ptr, slice, str};
+use core::{convert::TryFrom, fmt, marker::PhantomData, ops, ptr, slice, str};
 
 use cstr_core::CStr;
 use cty::{c_char, size_t};
@@ -76,6 +76,11 @@ impl Path {
     pub fn exists<S: crate::driver::Storage>(&self, fs: &crate::fs::Filesystem<S>) -> bool {
         fs.metadata(self).is_ok()
     }
+
+    // helpful for debugging wither the trailing nul is indeed a trailing nul.
+    pub fn as_str_ref_with_trailing_nul(&self) -> &str {
+        unsafe { str::from_utf8_unchecked(self.inner.to_bytes_with_nul()) }
+    }
 }
 
 impl AsRef<str> for Path {
@@ -87,7 +92,8 @@ impl AsRef<str> for Path {
 
 impl fmt::Debug for Path {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        write!(f, "{:?}", self.as_ref())
+        // helpful for debugging wither the trailing nul is indeed a trailing nul.
+        write!(f, "p{:?}", self.as_str_ref_with_trailing_nul())
     }
 }
 
@@ -245,12 +251,14 @@ impl PathBuf {
 
 impl From<&Path> for PathBuf {
     fn from(path: &Path) -> Self {
-        let mut buf = MaybeUninit::<[c_char; consts::PATH_MAX_PLUS_ONE]>::uninit();
         let bytes = path.as_ref().as_bytes();
+
+        let mut buf = [0; consts::PATH_MAX_PLUS_ONE];
         let len = bytes.len();
-        unsafe { ptr::copy_nonoverlapping(bytes.as_ptr(), buf.as_mut_ptr().cast(), len) }
+        assert!(len <= consts::PATH_MAX);
+        unsafe { ptr::copy_nonoverlapping(bytes.as_ptr(), buf.as_mut_ptr().cast(), len + 1) }
         Self {
-            buf: unsafe { buf.assume_init() },
+            buf,
             len: len + 1,
         }
     }
@@ -262,7 +270,7 @@ impl From<&[u8]> for PathBuf {
         let mut buf = [0; consts::PATH_MAX_PLUS_ONE];
         let len = bytes.len();
         assert!(len <= consts::PATH_MAX);
-        assert!(bytes.iter().position(|x| *x == 0).is_none());
+        assert!(bytes.is_ascii());
         unsafe { ptr::copy_nonoverlapping(bytes.as_ptr(), buf.as_mut_ptr().cast(), len) }
         Self {
             buf,
@@ -349,12 +357,32 @@ impl fmt::Display for PathBuf {
 impl core::cmp::PartialEq for PathBuf {
     fn eq(&self, other: &Self) -> bool {
         // from cstr_core
-        self == other
+        self.as_ref() == other.as_ref()
+
+        // // use cortex_m_semihosting::hprintln;
+        // // hprintln!("inside PathBuf PartialEq");
+        // // hprintln!("self.len {}, other.len {}", self.len, other.len).ok();
+        // // hprintln!("self..len {:?}, other..len {:?}", &self.buf[..self.len], &other.buf[..other.len]).ok();
+        // self.len == other.len && self.buf[..self.len - 1] == other.buf[..other.len - 1]
     }
 }
 
 impl core::cmp::Eq for PathBuf {}
 
+// use core::cmp::Ordering;
+
+// impl Ord for PathBuf {
+//     fn cmp(&self, other: &Self) -> Ordering {
+//         self.len.cmp(&other.len)
+//     }
+// }
+
+// impl PartialOrd for PathBuf {
+//     fn partial_cmp(&self, other: &Self) -> Option<Ordering> {
+//         Some(self.cmp(other))
+//     }
+// }
+
 /// Errors that arise from converting byte buffers into paths
 #[derive(Clone, Copy, Debug)]
 pub enum Error {