diff options
Diffstat (limited to 'tvix/nix-compat/src/nar/reader/mod.rs')
| -rw-r--r-- | tvix/nix-compat/src/nar/reader/mod.rs | 162 |
1 files changed, 81 insertions, 81 deletions
diff --git a/tvix/nix-compat/src/nar/reader/mod.rs b/tvix/nix-compat/src/nar/reader/mod.rs index 75463a6450..9e9237ead3 100644 --- a/tvix/nix-compat/src/nar/reader/mod.rs +++ b/tvix/nix-compat/src/nar/reader/mod.rs @@ -10,9 +10,15 @@ use std::io::{ Read, Write, }; +#[cfg(not(debug_assertions))] +use std::marker::PhantomData; + // Required reading for understanding this module. use crate::nar::wire; +#[cfg(feature = "async")] +pub mod r#async; + mod read; #[cfg(test)] mod test; @@ -27,25 +33,15 @@ struct ArchiveReader<'a, 'r> { /// * An error is encountered at any point /// * A file or directory reader is dropped before being read entirely. /// All of these checks vanish in release mode. - #[cfg(debug_assertions)] status: ArchiveReaderStatus<'a>, } -macro_rules! poison { - ($it:expr) => { - #[cfg(debug_assertions)] - { - $it.status.poison(); - } - }; -} - macro_rules! try_or_poison { ($it:expr, $ex:expr) => { match $ex { Ok(x) => x, Err(e) => { - poison!($it); + $it.status.poison(); return Err(e.into()); } } @@ -56,11 +52,7 @@ pub fn open<'a, 'r>(reader: &'a mut Reader<'r>) -> io::Result<Node<'a, 'r>> { read::token(reader, &wire::TOK_NAR)?; Node::new(ArchiveReader { inner: reader, - #[cfg(debug_assertions)] - status: ArchiveReaderStatus::StackTop { - poisoned: false, - ready: true, - }, + status: ArchiveReaderStatus::top(), }) } @@ -80,7 +72,6 @@ impl<'a, 'r> Node<'a, 'r> { /// /// Reading the terminating [wire::TOK_PAR] is done immediately for [Node::Symlink], /// but is otherwise left to [DirReader] or [FileReader]. - #[allow(unused_mut)] // due to debug_assertions code fn new(mut reader: ArchiveReader<'a, 'r>) -> io::Result<Self> { Ok(match read::tag(reader.inner)? { wire::Node::Sym => { @@ -88,15 +79,12 @@ impl<'a, 'r> Node<'a, 'r> { try_or_poison!(reader, read::bytes(reader.inner, wire::MAX_TARGET_LEN)); if target.is_empty() || target.contains(&0) { - poison!(reader); + reader.status.poison(); return Err(InvalidData.into()); } try_or_poison!(reader, read::token(reader.inner, &wire::TOK_PAR)); - #[cfg(debug_assertions)] - { - reader.status.ready_parent(); // Immediately allow reading from parent again - } + reader.status.ready_parent(); // Immediately allow reading from parent again Node::Symlink { target } } @@ -131,17 +119,13 @@ pub struct FileReader<'a, 'r> { impl<'a, 'r> FileReader<'a, 'r> { /// Instantiate a new reader, starting after [wire::TOK_REG] or [wire::TOK_EXE]. /// We handle the terminating [wire::TOK_PAR] on semantic EOF. - #[allow(unused_mut)] // due to debug_assertions code fn new(mut reader: ArchiveReader<'a, 'r>, len: u64) -> io::Result<Self> { // For zero-length files, we have to read the terminating TOK_PAR // immediately, since FileReader::read may never be called; we've // already reached semantic EOF by definition. if len == 0 { read::token(reader.inner, &wire::TOK_PAR)?; - #[cfg(debug_assertions)] - { - reader.status.ready_parent(); - } + reader.status.ready_parent(); } Ok(Self { @@ -175,7 +159,7 @@ impl FileReader<'_, '_> { let mut buf = try_or_poison!(self.reader, self.reader.inner.fill_buf()); if buf.is_empty() { - poison!(self.reader); + self.reader.status.poison(); return Err(UnexpectedEof.into()); } @@ -237,7 +221,7 @@ impl Read for FileReader<'_, '_> { self.len -= n as u64; if n == 0 { - poison!(self.reader); + self.reader.status.poison(); return Err(UnexpectedEof.into()); } @@ -260,18 +244,15 @@ impl FileReader<'_, '_> { try_or_poison!(self.reader, self.reader.inner.read_exact(&mut buf[pad..])); if buf != [0; 8] { - poison!(self.reader); + self.reader.status.poison(); return Err(InvalidData.into()); } } try_or_poison!(self.reader, read::token(self.reader.inner, &wire::TOK_PAR)); - #[cfg(debug_assertions)] - { - // Done with reading this file, allow going back up the chain of readers - self.reader.status.ready_parent(); - } + // Done with reading this file, allow going back up the chain of readers + self.reader.status.ready_parent(); Ok(()) } @@ -283,11 +264,11 @@ pub struct DirReader<'a, 'r> { reader: ArchiveReader<'a, 'r>, /// Previous directory entry name. /// We have to hang onto this to enforce name monotonicity. - prev_name: Option<Vec<u8>>, + prev_name: Vec<u8>, } pub struct Entry<'a, 'r> { - pub name: Vec<u8>, + pub name: &'a [u8], pub node: Node<'a, 'r>, } @@ -295,7 +276,7 @@ impl<'a, 'r> DirReader<'a, 'r> { fn new(reader: ArchiveReader<'a, 'r>) -> Self { Self { reader, - prev_name: None, + prev_name: vec![], } } @@ -314,23 +295,21 @@ impl<'a, 'r> DirReader<'a, 'r> { // COME FROM the previous iteration: if we've already read an entry, // read its terminating TOK_PAR here. - if self.prev_name.is_some() { + if !self.prev_name.is_empty() { try_or_poison!(self.reader, read::token(self.reader.inner, &wire::TOK_PAR)); } // Determine if there are more entries to follow if let wire::Entry::None = try_or_poison!(self.reader, read::tag(self.reader.inner)) { // We've reached the end of this directory. - #[cfg(debug_assertions)] - { - self.reader.status.ready_parent(); - } + self.reader.status.ready_parent(); return Ok(None); } + let mut name = [0; wire::MAX_NAME_LEN + 1]; let name = try_or_poison!( self.reader, - read::bytes(self.reader.inner, wire::MAX_NAME_LEN) + read::bytes_buf(self.reader.inner, &mut name, wire::MAX_NAME_LEN) ); if name.is_empty() @@ -339,29 +318,23 @@ impl<'a, 'r> DirReader<'a, 'r> { || name == b"." || name == b".." { - poison!(self.reader); + self.reader.status.poison(); return Err(InvalidData.into()); } // Enforce strict monotonicity of directory entry names. - match &mut self.prev_name { - None => { - self.prev_name = Some(name.clone()); - } - Some(prev_name) => { - if *prev_name >= name { - poison!(self.reader); - return Err(InvalidData.into()); - } - - name[..].clone_into(prev_name); - } + if &self.prev_name[..] >= name { + self.reader.status.poison(); + return Err(InvalidData.into()); } + self.prev_name.clear(); + self.prev_name.extend_from_slice(name); + try_or_poison!(self.reader, read::token(self.reader.inner, &wire::TOK_NOD)); Ok(Some(Entry { - name, + name: &self.prev_name, // Don't need to worry about poisoning here: Node::new will do it for us if needed node: Node::new(self.reader.child())?, })) @@ -373,12 +346,12 @@ impl<'a, 'r> DirReader<'a, 'r> { /// so we can check they are abandoned when an error occurs /// * Make sure only the most recently created object is read from, and is fully exhausted /// before anything it was created from is used again. -#[cfg(debug_assertions)] enum ArchiveReaderStatus<'a> { - StackTop { - poisoned: bool, - ready: bool, - }, + #[cfg(not(debug_assertions))] + None(PhantomData<&'a ()>), + #[cfg(debug_assertions)] + StackTop { poisoned: bool, ready: bool }, + #[cfg(debug_assertions)] StackChild { poisoned: &'a mut bool, parent_ready: &'a mut bool, @@ -386,12 +359,28 @@ enum ArchiveReaderStatus<'a> { }, } -#[cfg(debug_assertions)] impl ArchiveReaderStatus<'_> { + fn top() -> Self { + #[cfg(debug_assertions)] + { + ArchiveReaderStatus::StackTop { + poisoned: false, + ready: true, + } + } + + #[cfg(not(debug_assertions))] + ArchiveReaderStatus::None(PhantomData) + } + /// Poison all the objects sharing the same reader, to be used when an error occurs fn poison(&mut self) { match self { + #[cfg(not(debug_assertions))] + ArchiveReaderStatus::None(_) => {} + #[cfg(debug_assertions)] ArchiveReaderStatus::StackTop { poisoned: x, .. } => *x = true, + #[cfg(debug_assertions)] ArchiveReaderStatus::StackChild { poisoned: x, .. } => **x = true, } } @@ -399,10 +388,14 @@ impl ArchiveReaderStatus<'_> { /// Mark the parent as ready, allowing it to be used again and preventing this reference to the reader being used again. fn ready_parent(&mut self) { match self { - Self::StackTop { ready, .. } => { + #[cfg(not(debug_assertions))] + ArchiveReaderStatus::None(_) => {} + #[cfg(debug_assertions)] + ArchiveReaderStatus::StackTop { ready, .. } => { *ready = false; } - Self::StackChild { + #[cfg(debug_assertions)] + ArchiveReaderStatus::StackChild { ready, parent_ready, .. @@ -415,15 +408,23 @@ impl ArchiveReaderStatus<'_> { fn poisoned(&self) -> bool { match self { - Self::StackTop { poisoned, .. } => *poisoned, - Self::StackChild { poisoned, .. } => **poisoned, + #[cfg(not(debug_assertions))] + ArchiveReaderStatus::None(_) => false, + #[cfg(debug_assertions)] + ArchiveReaderStatus::StackTop { poisoned, .. } => *poisoned, + #[cfg(debug_assertions)] + ArchiveReaderStatus::StackChild { poisoned, .. } => **poisoned, } } fn ready(&self) -> bool { match self { - Self::StackTop { ready, .. } => *ready, - Self::StackChild { ready, .. } => *ready, + #[cfg(not(debug_assertions))] + ArchiveReaderStatus::None(_) => true, + #[cfg(debug_assertions)] + ArchiveReaderStatus::StackTop { ready, .. } => *ready, + #[cfg(debug_assertions)] + ArchiveReaderStatus::StackChild { ready, .. } => *ready, } } } @@ -434,6 +435,8 @@ impl<'a, 'r> ArchiveReader<'a, 'r> { fn child(&mut self) -> ArchiveReader<'_, 'r> { ArchiveReader { inner: self.inner, + #[cfg(not(debug_assertions))] + status: ArchiveReaderStatus::None(PhantomData), #[cfg(debug_assertions)] status: match &mut self.status { ArchiveReaderStatus::StackTop { poisoned, ready } => { @@ -462,16 +465,13 @@ impl<'a, 'r> ArchiveReader<'a, 'r> { /// Only does anything when debug assertions are on. #[inline(always)] fn check_correct(&self) { - #[cfg(debug_assertions)] - { - debug_assert!( - !self.status.poisoned(), - "Archive reader used after it was meant to be abandoned!" - ); - debug_assert!( - self.status.ready(), - "Non-ready archive reader used! (Should've been reading from something else)" - ) - } + assert!( + !self.status.poisoned(), + "Archive reader used after it was meant to be abandoned!" + ); + assert!( + self.status.ready(), + "Non-ready archive reader used! (Should've been reading from something else)" + ); } } |