[tor-commits] [tor/release-0.3.3] rust: Implement more memory-efficient protover datatype.
nickm at torproject.org
nickm at torproject.org
Tue Apr 3 23:16:05 UTC 2018
commit e6625113c98c281b0a649598d7daa347c28915e9
Author: Isis Lovecruft <isis at torproject.org>
Date: Wed Mar 21 00:43:55 2018 +0000
rust: Implement more memory-efficient protover datatype.
* ADD new protover::protoset module.
* ADD new protover::protoset::ProtoSet class for holding protover versions.
* REMOVE protover::Versions type implementation and its method
`from_version_string()`, and instead implement this behaviour in a more
rust-like manner as `impl FromStr for ProtoSet`.
* MOVE the `find_range()` utility function from protover::protover to
protover::protoset since it's only used internally in the
implementation of ProtoSet.
* REMOVE the `contract_protocol_list()` function from protover::protover and
instead refactor it (reusing nearly the entire thing, with minor superficial,
i.e. non-behavioural, changes) into a more rusty
`impl ToString for ProtoSet`.
* REMOVE the `expand_version_range()` function from protover::protover and
instead refactor it into a more rusty implementation of
`impl Into<Vec<Version>> for ProtoSet` using the new error types in
protover::errors.
* FIXES part of #24031: https://bugs.torproject.org/24031.
---
src/rust/protover/lib.rs | 1 +
src/rust/protover/protoset.rs | 634 ++++++++++++++++++++++++++++++++++++++++++
src/rust/protover/protover.rs | 215 +-------------
3 files changed, 641 insertions(+), 209 deletions(-)
diff --git a/src/rust/protover/lib.rs b/src/rust/protover/lib.rs
index 371d1ae58..483260bca 100644
--- a/src/rust/protover/lib.rs
+++ b/src/rust/protover/lib.rs
@@ -31,6 +31,7 @@ extern crate tor_allocate;
extern crate tor_util;
pub mod errors;
+pub mod protoset;
mod protover;
pub mod ffi;
diff --git a/src/rust/protover/protoset.rs b/src/rust/protover/protoset.rs
new file mode 100644
index 000000000..f94e6299c
--- /dev/null
+++ b/src/rust/protover/protoset.rs
@@ -0,0 +1,634 @@
+// Copyright (c) 2018, The Tor Project, Inc.
+// Copyright (c) 2018, isis agora lovecruft
+// See LICENSE for licensing information
+
+//! Sets for lazily storing ordered, non-overlapping ranges of integers.
+
+use std::slice;
+use std::str::FromStr;
+use std::u32;
+
+use protover::MAX_PROTOCOLS_TO_EXPAND;
+use errors::ProtoverError;
+
+/// A single version number.
+pub type Version = u32;
+
+/// A `ProtoSet` stores an ordered `Vec<T>` of `(low, high)` pairs of ranges of
+/// non-overlapping protocol versions.
+///
+/// # Examples
+///
+/// ```
+/// use std::str::FromStr;
+///
+/// use protover::errors::ProtoverError;
+/// use protover::protoset::ProtoSet;
+/// use protover::protoset::Version;
+///
+/// # fn do_test() -> Result<ProtoSet, ProtoverError> {
+/// let protoset: ProtoSet = ProtoSet::from_str("3-5,8")?;
+///
+/// // We could also equivalently call:
+/// let protoset: ProtoSet = "3-5,8".parse()?;
+///
+/// assert!(protoset.contains(&4));
+/// assert!(!protoset.contains(&7));
+///
+/// let expanded: Vec<Version> = protoset.clone().into();
+///
+/// assert_eq!(&expanded[..], &[3, 4, 5, 8]);
+///
+/// let contracted: String = protoset.clone().to_string();
+///
+/// assert_eq!(contracted, "3-5,8".to_string());
+/// # Ok(protoset)
+/// # }
+/// # fn main() { do_test(); } // wrap the test so we can use the ? operator
+#[derive(Clone, Debug, Eq, PartialEq, Hash)]
+pub struct ProtoSet {
+ pub(crate) pairs: Vec<(Version, Version)>,
+}
+
+impl Default for ProtoSet {
+ fn default() -> Self {
+ let pairs: Vec<(Version, Version)> = Vec::new();
+
+ ProtoSet{ pairs }
+ }
+}
+
+impl<'a> ProtoSet {
+ /// Create a new `ProtoSet` from a slice of `(low, high)` pairs.
+ ///
+ /// # Inputs
+ ///
+ /// We do not assume the input pairs are deduplicated or ordered.
+ pub fn from_slice(low_high_pairs: &'a [(Version, Version)]) -> Result<Self, ProtoverError> {
+ let mut pairs: Vec<(Version, Version)> = Vec::with_capacity(low_high_pairs.len());
+
+ for &(low, high) in low_high_pairs {
+ pairs.push((low, high));
+ }
+ // Sort the pairs without reallocation and remove all duplicate pairs.
+ pairs.sort_unstable();
+ pairs.dedup();
+
+ ProtoSet{ pairs }.is_ok()
+ }
+}
+
+/// Expand this `ProtoSet` to a `Vec` of all its `Version`s.
+///
+/// # Examples
+///
+/// ```
+/// use std::str::FromStr;
+/// use protover::protoset::ProtoSet;
+/// use protover::protoset::Version;
+/// # use protover::errors::ProtoverError;
+///
+/// # fn do_test() -> Result<Vec<Version>, ProtoverError> {
+/// let protoset: ProtoSet = ProtoSet::from_str("3-5,21")?;
+/// let versions: Vec<Version> = protoset.into();
+///
+/// assert_eq!(&versions[..], &[3, 4, 5, 21]);
+/// #
+/// # Ok(versions)
+/// # }
+/// # fn main() { do_test(); } // wrap the test so we can use the ? operator
+/// ```
+impl Into<Vec<Version>> for ProtoSet {
+ fn into(self) -> Vec<Version> {
+ let mut versions: Vec<Version> = Vec::new();
+
+ for &(low, high) in self.iter() {
+ versions.extend(low..high + 1);
+ }
+ versions
+ }
+}
+
+impl ProtoSet {
+ /// Get an iterator over the `(low, high)` `pairs` in this `ProtoSet`.
+ pub fn iter(&self) -> slice::Iter<(Version, Version)> {
+ self.pairs.iter()
+ }
+
+ /// Expand this `ProtoSet` into a `Vec` of all its `Version`s.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// # use protover::errors::ProtoverError;
+ /// use protover::protoset::ProtoSet;
+ ///
+ /// # fn do_test() -> Result<bool, ProtoverError> {
+ /// let protoset: ProtoSet = "3-5,9".parse()?;
+ ///
+ /// assert_eq!(protoset.expand(), vec![3, 4, 5, 9]);
+ ///
+ /// let protoset: ProtoSet = "1,3,5-7".parse()?;
+ ///
+ /// assert_eq!(protoset.expand(), vec![1, 3, 5, 6, 7]);
+ /// #
+ /// # Ok(true)
+ /// # }
+ /// # fn main() { do_test(); } // wrap the test so we can use the ? operator
+ /// ```
+ pub fn expand(self) -> Vec<Version> {
+ self.into()
+ }
+
+ pub fn len(&self) -> usize {
+ let mut length: usize = 0;
+
+ for &(low, high) in self.iter() {
+ length += (high as usize - low as usize) + 1;
+ }
+
+ length
+ }
+
+ /// Check that this `ProtoSet` is well-formed.
+ ///
+ /// This is automatically called in `ProtoSet::from_str()`.
+ ///
+ /// # Errors
+ ///
+ /// * `ProtoverError::LowGreaterThanHigh`: if its `pairs` were not
+ /// well-formed, i.e. a `low` in a `(low, high)` was higher than the
+ /// previous `high`,
+ /// * `ProtoverError::Overlap`: if one or more of the `pairs` are
+ /// overlapping,
+ /// * `ProtoverError::ExceedsMax`: if the number of versions when expanded
+ /// would exceed `MAX_PROTOCOLS_TO_EXPAND`, and
+ ///
+ /// # Returns
+ ///
+ /// A `Result` whose `Ok` is this `Protoset`, and whose `Err` is one of the
+ /// errors enumerated in the Errors section above.
+ fn is_ok(self) -> Result<ProtoSet, ProtoverError> {
+ let mut last_high: Version = 0;
+
+ for &(low, high) in self.iter() {
+ if low == u32::MAX || high == u32::MAX {
+ return Err(ProtoverError::ExceedsMax);
+ }
+ if low < last_high {
+ return Err(ProtoverError::Overlap);
+ } else if low > high {
+ return Err(ProtoverError::LowGreaterThanHigh);
+ }
+ last_high = high;
+ }
+
+ if self.len() > MAX_PROTOCOLS_TO_EXPAND {
+ return Err(ProtoverError::ExceedsMax);
+ }
+
+ Ok(self)
+ }
+
+ /// Determine if this `ProtoSet` contains no `Version`s.
+ ///
+ /// # Returns
+ ///
+ /// * `true` if this `ProtoSet`'s length is zero, and
+ /// * `false` otherwise.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use protover::protoset::ProtoSet;
+ ///
+ /// let protoset: ProtoSet = ProtoSet::default();
+ ///
+ /// assert!(protoset.is_empty());
+ /// ```
+ pub fn is_empty(&self) -> bool {
+ self.pairs.len() == 0
+ }
+
+ /// Determine if `version` is included within this `ProtoSet`.
+ ///
+ /// # Inputs
+ ///
+ /// * `version`: a `Version`.
+ ///
+ /// # Returns
+ ///
+ /// `true` if the `version` is contained within this set; `false` otherwise.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// # use protover::errors::ProtoverError;
+ /// use protover::protoset::ProtoSet;
+ ///
+ /// # fn do_test() -> Result<ProtoSet, ProtoverError> {
+ /// let protoset: ProtoSet = ProtoSet::from_slice(&[(0, 5), (7, 9), (13, 14)])?;
+ ///
+ /// assert!(protoset.contains(&5));
+ /// assert!(!protoset.contains(&10));
+ /// #
+ /// # Ok(protoset)
+ /// # }
+ /// # fn main() { do_test(); } // wrap the test so we can use the ? operator
+ /// ```
+ pub fn contains(&self, version: &Version) -> bool {
+ for &(low, high) in self.iter() {
+ if low <= *version && *version <= high {
+ return true;
+ }
+ }
+ false
+ }
+
+ /// Retain only the `Version`s in this `ProtoSet` for which the predicate
+ /// `F` returns `true`.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// # use protover::errors::ProtoverError;
+ /// use protover::protoset::ProtoSet;
+ ///
+ /// # fn do_test() -> Result<bool, ProtoverError> {
+ /// let mut protoset: ProtoSet = "1,3-5,9".parse()?;
+ ///
+ /// // Keep only versions less than or equal to 8:
+ /// protoset.retain(|x| x <= &8);
+ ///
+ /// assert_eq!(protoset.expand(), vec![1, 3, 4, 5]);
+ /// #
+ /// # Ok(true)
+ /// # }
+ /// # fn main() { do_test(); } // wrap the test so we can use the ? operator
+ /// ```
+ // XXX we could probably do something more efficient here. —isis
+ pub fn retain<F>(&mut self, f: F)
+ where F: FnMut(&Version) -> bool
+ {
+ let mut expanded: Vec<Version> = self.clone().expand();
+ expanded.retain(f);
+ *self = expanded.into();
+ }
+}
+
+impl FromStr for ProtoSet {
+ type Err = ProtoverError;
+
+ /// Parse the unique version numbers supported by a subprotocol from a string.
+ ///
+ /// # Inputs
+ ///
+ /// * `version_string`, a string comprised of "[0-9,-]"
+ ///
+ /// # Returns
+ ///
+ /// A `Result` whose `Ok` value is a `ProtoSet` holding all of the unique
+ /// version numbers.
+ ///
+ /// The returned `Result`'s `Err` value is an `ProtoverError` appropriate to
+ /// the error.
+ ///
+ /// # Errors
+ ///
+ /// This function will error if:
+ ///
+ /// * the `version_string` is an equals (`"="`) sign,
+ /// * the expansion of a version range produces an error (see
+ /// `expand_version_range`),
+ /// * any single version number is not parseable as an `u32` in radix 10, or
+ /// * there are greater than 2^16 version numbers to expand.
+ ///
+ /// # Examples
+ ///
+ /// ```
+ /// use std::str::FromStr;
+ ///
+ /// use protover::errors::ProtoverError;
+ /// use protover::protoset::ProtoSet;
+ ///
+ /// # fn do_test() -> Result<ProtoSet, ProtoverError> {
+ /// let protoset: ProtoSet = ProtoSet::from_str("2-5,8")?;
+ ///
+ /// assert!(protoset.contains(&5));
+ /// assert!(!protoset.contains(&10));
+ ///
+ /// // We can also equivalently call `ProtoSet::from_str` by doing:
+ /// let protoset: ProtoSet = "4-6,12".parse()?;
+ ///
+ /// // There are lots of ways to get an `Err` from this function. Here are
+ /// // a few:
+ /// assert_eq!(Err(ProtoverError::Unparseable), ProtoSet::from_str("="));
+ /// assert_eq!(Err(ProtoverError::Unparseable), ProtoSet::from_str("-"));
+ /// assert_eq!(Err(ProtoverError::Unparseable), ProtoSet::from_str("not_an_int"));
+ /// assert_eq!(Err(ProtoverError::Unparseable), ProtoSet::from_str("3-"));
+ /// assert_eq!(Err(ProtoverError::Unparseable), ProtoSet::from_str("1-,4"));
+ /// assert_eq!(Err(ProtoverError::ExceedsMax), ProtoSet::from_str("1-70000"));
+ ///
+ /// // Things which would get parsed into an _empty_ `ProtoSet` are,
+ /// // however, legal, and result in an empty `ProtoSet`:
+ /// assert_eq!(Ok(ProtoSet::default()), ProtoSet::from_str(""));
+ /// assert_eq!(Ok(ProtoSet::default()), ProtoSet::from_str(",,,"));
+ /// #
+ /// # Ok(protoset)
+ /// # }
+ /// # fn main() { do_test(); } // wrap the test so we can use the ? operator
+ /// ```
+ fn from_str(version_string: &str) -> Result<Self, Self::Err> {
+ let mut pairs: Vec<(Version, Version)> = Vec::new();
+ let pieces: ::std::str::Split<char> = version_string.trim().split(',');
+
+ for piece in pieces {
+ let p: &str = piece.trim();
+
+ if p.is_empty() {
+ continue;
+ } else if p.contains('-') {
+ let mut pair = p.split('-');
+
+ let low = pair.next().ok_or(ProtoverError::Unparseable)?;
+ let high = pair.next().ok_or(ProtoverError::Unparseable)?;
+
+ let lo: Version = low.parse().or(Err(ProtoverError::Unparseable))?;
+ let hi: Version = high.parse().or(Err(ProtoverError::Unparseable))?;
+
+ if lo == u32::MAX || hi == u32::MAX {
+ return Err(ProtoverError::ExceedsMax);
+ }
+ pairs.push((lo, hi));
+ } else {
+ let v: u32 = p.parse().or(Err(ProtoverError::Unparseable))?;
+
+ if v == u32::MAX {
+ return Err(ProtoverError::ExceedsMax);
+ }
+ pairs.push((v, v));
+ }
+ }
+ // If we were passed in an empty string, or a bunch of whitespace, or
+ // simply a comma, or a pile of commas, then return an empty ProtoSet.
+ if pairs.len() == 0 {
+ return Ok(ProtoSet::default());
+ }
+ ProtoSet::from_slice(&pairs[..])
+ }
+}
+
+impl ToString for ProtoSet {
+ /// Contracts a `ProtoSet` of versions into a string.
+ ///
+ /// # Returns
+ ///
+ /// A `String` representation of this `ProtoSet` in ascending order.
+ fn to_string(&self) -> String {
+ let mut final_output: Vec<String> = Vec::new();
+
+ for &(lo, hi) in self.iter() {
+ if lo != hi {
+ debug_assert!(lo < hi);
+ final_output.push(format!("{}-{}", lo, hi));
+ } else {
+ final_output.push(format!("{}", lo));
+ }
+ }
+ final_output.join(",")
+ }
+}
+
+/// Checks to see if there is a continuous range of integers, starting at the
+/// first in the list. Returns the last integer in the range if a range exists.
+///
+/// # Inputs
+///
+/// `list`, an ordered vector of `u32` integers of "[0-9,-]" representing the
+/// supported versions for a single protocol.
+///
+/// # Returns
+///
+/// A `bool` indicating whether the list contains a range, starting at the first
+/// in the list, a`Version` of the last integer in the range, and a `usize` of
+/// the index of that version.
+///
+/// For example, if given vec![1, 2, 3, 5], find_range will return true,
+/// as there is a continuous range, and 3, which is the last number in the
+/// continuous range, and 2 which is the index of 3.
+fn find_range(list: &Vec<Version>) -> (bool, Version, usize) {
+ if list.len() == 0 {
+ return (false, 0, 0);
+ }
+
+ let mut index: usize = 0;
+ let mut iterable = list.iter().peekable();
+ let mut range_end = match iterable.next() {
+ Some(n) => *n,
+ None => return (false, 0, 0),
+ };
+
+ let mut has_range = false;
+
+ while iterable.peek().is_some() {
+ let n = *iterable.next().unwrap();
+ if n != range_end + 1 {
+ break;
+ }
+
+ has_range = true;
+ range_end = n;
+ index += 1;
+ }
+
+ (has_range, range_end, index)
+}
+
+impl From<Vec<Version>> for ProtoSet {
+ fn from(mut v: Vec<Version>) -> ProtoSet {
+ let mut version_pairs: Vec<(Version, Version)> = Vec::new();
+
+ v.sort_unstable();
+ v.dedup();
+
+ 'vector: while !v.is_empty() {
+ let (has_range, end, index): (bool, Version, usize) = find_range(&v);
+
+ if has_range {
+ let first: Version = match v.first() {
+ Some(x) => *x,
+ None => continue,
+ };
+ let last: Version = match v.get(index) {
+ Some(x) => *x,
+ None => continue,
+ };
+ debug_assert!(last == end, format!("last = {}, end = {}", last, end));
+
+ version_pairs.push((first, last));
+ v = v.split_off(index + 1);
+
+ if v.len() == 0 {
+ break 'vector;
+ }
+ } else {
+ let last: Version = match v.get(index) {
+ Some(x) => *x,
+ None => continue,
+ };
+ version_pairs.push((last, last));
+ v.remove(index);
+ }
+ }
+ ProtoSet::from_slice(&version_pairs[..]).unwrap_or(ProtoSet::default())
+ }
+}
+
+#[cfg(test)]
+mod test {
+ use super::*;
+
+ #[test]
+ fn test_find_range() {
+ assert_eq!((false, 0, 0), find_range(&vec![]));
+ assert_eq!((false, 1, 0), find_range(&vec![1]));
+ assert_eq!((true, 2, 1), find_range(&vec![1, 2]));
+ assert_eq!((true, 3, 2), find_range(&vec![1, 2, 3]));
+ assert_eq!((true, 3, 2), find_range(&vec![1, 2, 3, 5]));
+ }
+
+ macro_rules! assert_contains_each {
+ ($protoset:expr, $versions:expr) => (
+ for version in $versions {
+ assert!($protoset.contains(version));
+ }
+ )
+ }
+
+ macro_rules! test_protoset_contains_versions {
+ ($list:expr, $str:expr) => (
+ let versions: &[Version] = $list;
+ let protoset: Result<ProtoSet, ProtoverError> = ProtoSet::from_str($str);
+
+ assert!(protoset.is_ok());
+ let p = protoset.unwrap();
+ assert_contains_each!(p, versions);
+ )
+ }
+
+ #[test]
+ fn test_versions_from_str() {
+ test_protoset_contains_versions!(&[], "");
+ test_protoset_contains_versions!(&[1], "1");
+ test_protoset_contains_versions!(&[1, 2], "1,2");
+ test_protoset_contains_versions!(&[1, 2, 3], "1-3");
+ test_protoset_contains_versions!(&[0, 1], "0-1");
+ test_protoset_contains_versions!(&[1, 2, 5], "1-2,5");
+ test_protoset_contains_versions!(&[1, 3, 4, 5], "1,3-5");
+ test_protoset_contains_versions!(&[42, 55, 56, 57, 58], "42,55-58");
+ }
+
+ #[test]
+ fn test_versions_from_str_ab() {
+ assert_eq!(Err(ProtoverError::Unparseable), ProtoSet::from_str("a,b"));
+ }
+
+ #[test]
+ fn test_versions_from_str_negative_1() {
+ assert_eq!(Err(ProtoverError::Unparseable), ProtoSet::from_str("-1"));
+ }
+
+ #[test]
+ fn test_versions_from_str_1exclam() {
+ assert_eq!(Err(ProtoverError::Unparseable), ProtoSet::from_str("1,!"));
+ }
+
+ #[test]
+ fn test_versions_from_str_percent_equal() {
+ assert_eq!(Err(ProtoverError::Unparseable), ProtoSet::from_str("%="));
+ }
+
+ #[test]
+ fn test_versions_from_str_overlap() {
+ assert_eq!(Err(ProtoverError::Overlap), ProtoSet::from_str("1-3,2-4"));
+ }
+
+ #[test]
+ fn test_versions_from_slice_overlap() {
+ assert_eq!(Err(ProtoverError::Overlap), ProtoSet::from_slice(&[(1, 3), (2, 4)]));
+ }
+
+ #[test]
+ fn test_versions_from_str_max() {
+ assert_eq!(Err(ProtoverError::ExceedsMax), ProtoSet::from_str("4294967295"));
+ }
+
+ #[test]
+ fn test_versions_from_slice_max() {
+ assert_eq!(Err(ProtoverError::ExceedsMax), ProtoSet::from_slice(&[(4294967295, 4294967295)]));
+ }
+
+ #[test]
+ fn test_protoset_contains() {
+ let protoset: ProtoSet = ProtoSet::from_slice(&[(0, 5), (7, 9), (13, 14)]).unwrap();
+
+ for x in 0..6 { assert!(protoset.contains(&x), format!("should contain {}", x)); }
+ for x in 7..10 { assert!(protoset.contains(&x), format!("should contain {}", x)); }
+ for x in 13..15 { assert!(protoset.contains(&x), format!("should contain {}", x)); }
+
+ for x in [6, 10, 11, 12, 15, 42, 43, 44, 45, 1234584].iter() {
+ assert!(!protoset.contains(&x), format!("should not contain {}", x));
+ }
+ }
+
+ #[test]
+ fn test_protoset_contains_0_3() {
+ let protoset: ProtoSet = ProtoSet::from_slice(&[(0, 3)]).unwrap();
+
+ for x in 0..4 { assert!(protoset.contains(&x), format!("should contain {}", x)); }
+ }
+
+ macro_rules! assert_protoset_from_vec_contains_all {
+ ($($x:expr),*) => (
+ let vec: Vec<Version> = vec!($($x),*);
+ let protoset: ProtoSet = vec.clone().into();
+
+ for x in vec.iter() {
+ assert!(protoset.contains(&x));
+ }
+ )
+ }
+
+ #[test]
+ fn test_protoset_from_vec_123() {
+ assert_protoset_from_vec_contains_all!(1, 2, 3);
+ }
+
+ #[test]
+ fn test_protoset_from_vec_0_315() {
+ assert_protoset_from_vec_contains_all!(0, 1, 2, 3, 15);
+ }
+
+ #[test]
+ fn test_protoset_from_vec_unordered() {
+ let v: Vec<Version> = vec!(2, 3, 8, 4, 3, 9, 7, 2);
+ let ps: ProtoSet = v.into();
+
+ assert_eq!(ps.to_string(), "2-4,7-9");
+ }
+
+ #[test]
+ fn test_protoset_into_vec() {
+ let ps: ProtoSet = "1-13,42,9001,4294967294".parse().unwrap();
+ let v: Vec<Version> = ps.into();
+
+ assert!(v.contains(&7));
+ assert!(v.contains(&9001));
+ assert!(v.contains(&4294967294));
+ }
+}
+
+#[cfg(all(test, feature = "bench"))]
+mod bench {
+ use super::*;
+}
diff --git a/src/rust/protover/protover.rs b/src/rust/protover/protover.rs
index 8ce182cf1..d74ca00c1 100644
--- a/src/rust/protover/protover.rs
+++ b/src/rust/protover/protover.rs
@@ -14,6 +14,7 @@ use std::u32;
use tor_util::strings::NUL_BYTE;
use errors::ProtoverError;
+use protoset::Version;
/// The first version of Tor that included "proto" entries in its descriptors.
/// Authorities should use this to decide whether to guess proto lines.
@@ -26,7 +27,7 @@ const FIRST_TOR_VERSION_TO_ADVERTISE_PROTOCOLS: &'static str = "0.2.9.3-alpha";
/// before concluding that someone is trying to DoS us
///
/// C_RUST_COUPLED: src/or/protover.c `MAX_PROTOCOLS_TO_EXPAND`
-const MAX_PROTOCOLS_TO_EXPAND: usize = (1<<16);
+pub(crate) const MAX_PROTOCOLS_TO_EXPAND: usize = (1<<16);
/// Currently supported protocols and their versions, as a byte-slice.
///
@@ -159,70 +160,6 @@ impl SupportedProtocols {
}
}
-type Version = u32;
-
-/// Set of versions for a protocol.
-#[derive(Debug, PartialEq, Eq)]
-pub struct Versions(HashSet<Version>);
-
-impl Versions {
- /// Get the unique version numbers supported by a subprotocol.
- ///
- /// # Inputs
- ///
- /// * `version_string`, a string comprised of "[0-9,-]"
- ///
- /// # Returns
- ///
- /// A `Result` whose `Ok` value is a `HashSet<u32>` holding all of the unique
- /// version numbers. If there were ranges in the `version_string`, then these
- /// are expanded, i.e. `"1-3"` would expand to `HashSet<u32>::new([1, 2, 3])`.
- /// The returned HashSet is *unordered*.
- ///
- /// The returned `Result`'s `Err` value is an `&'static str` with a description
- /// of the error.
- ///
- /// # Errors
- ///
- /// This function will error if:
- ///
- /// * the `version_string` is empty or contains an equals (`"="`) sign,
- /// * the expansion of a version range produces an error (see
- /// `expand_version_range`),
- /// * any single version number is not parseable as an `u32` in radix 10, or
- /// * there are greater than 2^16 version numbers to expand.
- ///
- fn from_version_string(
- version_string: &str,
- ) -> Result<Self, &'static str> {
- let mut versions = HashSet::<Version>::new();
-
- for piece in version_string.split(",") {
- if piece.contains("-") {
- for p in expand_version_range(piece)? {
- versions.insert(p);
- }
- } else if piece == "" {
- continue;
- } else {
- let v = u32::from_str(piece).or(
- Err("invalid protocol entry"),
- )?;
- if v == u32::MAX {
- return Err("invalid protocol entry");
- }
- versions.insert(v);
- }
-
- if versions.len() > MAX_PROTOCOLS_TO_EXPAND {
- return Err("Too many versions to expand");
- }
- }
- Ok(Versions(versions))
- }
-}
-
-
/// Parse the subprotocol type and its version numbers.
///
/// # Inputs
@@ -409,149 +346,6 @@ pub fn protover_string_supports_protocol_or_later(
supported_versions.0.iter().any(|v| v >= &vers)
}
-/// Fully expand a version range. For example, 1-3 expands to 1,2,3
-/// Helper for Versions::from_version_string
-///
-/// # Inputs
-///
-/// `range`, a string comprised of "[0-9,-]"
-///
-/// # Returns
-///
-/// A `Result` whose `Ok` value a vector of unsigned integers representing the
-/// expanded range of supported versions by a single protocol.
-/// Otherwise, the `Err` value of this `Result` is a description of the error
-///
-/// # Errors
-///
-/// This function will error if:
-///
-/// * the specified range is empty
-/// * the version range does not contain both a valid lower and upper bound.
-///
-fn expand_version_range(range: &str) -> Result<Range<u32>, &'static str> {
- if range.is_empty() {
- return Err("version string empty");
- }
-
- let mut parts = range.split("-");
-
- let lower_string = parts.next().ok_or(
- "cannot parse protocol range lower bound",
- )?;
-
- let lower = u32::from_str_radix(lower_string, 10).or(Err(
- "cannot parse protocol range lower bound",
- ))?;
-
- let higher_string = parts.next().ok_or(
- "cannot parse protocol range upper bound",
- )?;
-
- let higher = u32::from_str_radix(higher_string, 10).or(Err(
- "cannot parse protocol range upper bound",
- ))?;
-
- if lower == u32::MAX || higher == u32::MAX {
- return Err("protocol range value out of range");
- }
-
- if lower > higher {
- return Err("protocol range is badly formed");
- }
-
- // We can use inclusive range syntax when it becomes stable.
- let result = lower..higher + 1;
-
- if result.len() > MAX_PROTOCOLS_TO_EXPAND {
- Err("Too many protocols in expanded range")
- } else {
- Ok(result)
- }
-}
-
-/// Checks to see if there is a continuous range of integers, starting at the
-/// first in the list. Returns the last integer in the range if a range exists.
-/// Helper for compute_vote
-///
-/// # Inputs
-///
-/// `list`, an ordered vector of `u32` integers of "[0-9,-]" representing the
-/// supported versions for a single protocol.
-///
-/// # Returns
-///
-/// A `bool` indicating whether the list contains a range, starting at the
-/// first in the list, and an `u32` of the last integer in the range.
-///
-/// For example, if given vec![1, 2, 3, 5], find_range will return true,
-/// as there is a continuous range, and 3, which is the last number in the
-/// continuous range.
-///
-fn find_range(list: &Vec<u32>) -> (bool, u32) {
- if list.len() == 0 {
- return (false, 0);
- }
-
- let mut iterable = list.iter().peekable();
- let mut range_end = match iterable.next() {
- Some(n) => *n,
- None => return (false, 0),
- };
-
- let mut has_range = false;
-
- while iterable.peek().is_some() {
- let n = *iterable.next().unwrap();
- if n != range_end + 1 {
- break;
- }
-
- has_range = true;
- range_end = n;
- }
-
- (has_range, range_end)
-}
-
-/// Contracts a HashSet representation of supported versions into a string.
-/// Helper for compute_vote
-///
-/// # Inputs
-///
-/// `supported_set`, a set of integers of "[0-9,-]" representing the
-/// supported versions for a single protocol.
-///
-/// # Returns
-///
-/// A `String` representation of this set in ascending order.
-///
-fn contract_protocol_list<'a>(supported_set: &'a HashSet<Version>) -> String {
- let mut supported: Vec<Version> =
- supported_set.iter().map(|x| *x).collect();
- supported.sort();
-
- let mut final_output: Vec<String> = Vec::new();
-
- while supported.len() != 0 {
- let (has_range, end) = find_range(&supported);
- let current = supported.remove(0);
-
- if has_range {
- final_output.push(format!(
- "{}-{}",
- current.to_string(),
- &end.to_string(),
- ));
- supported.retain(|&x| x > end);
- } else {
- final_output.push(current.to_string());
- }
- }
-
- final_output.join(",")
-}
-
/// Parses a protocol list without validating the protocol names
///
/// # Inputs
@@ -790,7 +584,10 @@ pub fn compute_for_old_tor(version: &str) -> &'static [u8] {
#[cfg(test)]
mod test {
- use super::Version;
+ use std::str::FromStr;
+ use std::string::ToString;
+
+ use super::*;
#[test]
fn test_versions_from_version_string() {
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