commit e6625113c98c281b0a649598d7daa347c28915e9 Author: Isis Lovecruft isis@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() {