1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146

// This file is part of dpdk-unix. It is subject to the license terms in the COPYRIGHT file found in the top-level directory of this distribution and at https://raw.githubusercontent.com/lemonrock/dpdk-unix/master/COPYRIGHT. No part of dpdk-unix, including this file, may be copied, modified, propagated, or distributed except according to the terms contained in the COPYRIGHT file.
// Copyright © 2016-2017 The developers of dpdk-unix. See the COPYRIGHT file in the top-level directory of this distribution and at https://raw.githubusercontent.com/lemonrock/dpdk-unix/master/COPYRIGHT.


quick_error!
{
	/// List parse error.
	#[derive(Debug)]
	pub enum ListParseError
	{
		/// An IO error.
		IoError(err: io::Error)
		{
			cause(err)
			from()
		}
		
		/// Contains an empty index or range.
		ContainsAnEmptyIndexOrRange
		{
		}
		
		/// Could not parse index.
		CouldNotParseIndex(description: &'static str, unparsable_index: String, cause: ParseIntError)
		{
			display("Could not parse {} index '{}' because '{}'", description, unparsable_index, cause)
			cause(cause)
		}
		
		/// Contains mis-sorted indices.
		ContainsMisSortedIndices(first: u16, next_minimum_index_expected: u16)
		{
			display("Did not expect '{}' when minimum expectation is '{}'", first, next_minimum_index_expected)
		}
		
		/// Range is not an ascending range with more than one element.
		RangeIsNotAnAscendingRangeWithMoreThanOneElement(first: u16, second: u16)
		{
			display("range is not an ascending range with more than one element; it is '{}-{}'!", first, second)
		}
	}
}

impl ListParseError
{
	/// Parses a Linux list string used for cpu sets, core masks and NUMA nodes such as "2,4-31,32-63" and "1,2,10-20,100-2000:2/25" (see <https://www.kernel.org/doc/html/latest/admin-guide/kernel-parameters.html> for an awful description of this mad syntax).
	///
	/// Returns a BTreeSet with the zero-based indices found in the string. For example, "2,4-31,32-63" would return a set with all values between 0 to 63 except 0, 1 and 3.
	pub fn parse_linux_list_string<Mapper: Fn(u16) -> R, R: Ord>(linux_list_string: &str, mapper: Mapper) -> Result<BTreeSet<R>, ListParseError>
	{
		#[inline(always)]
		fn parse_index(index_string: &str, description: &'static str) -> Result<u16, ListParseError>
		{
			match index_string.parse()
			{
				Ok(index) => Ok(index),
				Err(error) => Err(ListParseError::CouldNotParseIndex(description, index_string.to_owned(), error)),
			}
		}
		
		let mut result = BTreeSet::new();
		
		use self::ListParseError::*;
		
		// Prevents mis-sorted strings
		let mut next_minimum_index_expected = 0;
		for index_or_range in linux_list_string.split(',')
		{
			if index_or_range.is_empty()
			{
				return Err(ContainsAnEmptyIndexOrRange);
			}
			
			let mut range_iterator = index_or_range.splitn(2, '-');
			
			let first =
			{
				let index = parse_index(range_iterator.next().unwrap(), "first")?;
				if index < next_minimum_index_expected
				{
					return Err(ContainsMisSortedIndices(index, next_minimum_index_expected));
				}
				index
			};
			
			if let Some(second) = range_iterator.last()
			{
				// There is a weird, but rare, syntax used of `100-2000:2/25` for some ranges.
				let mut range_or_range_with_groups = second.splitn(2, ':');
				
				let second =
				{
					let index = parse_index(range_or_range_with_groups.next().unwrap(), "second")?;
					if first >= index
					{
						return Err(RangeIsNotAnAscendingRangeWithMoreThanOneElement(first, index));
					}
					index
				};
				
				match range_or_range_with_groups.last()
				{
					None =>
					{
						for index in first .. (second + 1)
						{
							result.insert(mapper(index));
						}
						
						next_minimum_index_expected = second;
					}
					
					Some(weird_but_rare_group_syntax) =>
					{
						let mut weird_but_rare_group_syntax = weird_but_rare_group_syntax.splitn(2, '/');
						let used_size = parse_index(weird_but_rare_group_syntax.next().unwrap(), "used_size")?;
						let group_size = parse_index(weird_but_rare_group_syntax.last().expect("a group does not have group_size"), "group_size")?;
						
						assert_ne!(used_size, 0, "used_size is zero");
						assert_ne!(group_size, 0, "group_size is zero");
						
						let mut base_cpu_index = first;
						while base_cpu_index < second
						{
							for cpu_index_increment in 0 .. used_size
							{
								let cpu_index = base_cpu_index + cpu_index_increment;
								result.insert(mapper(cpu_index));
							}
							
							base_cpu_index += group_size;
						}
					}
				}
			}
			else
			{
				let sole = first;
				result.insert(mapper(sole));
				next_minimum_index_expected = sole;
			}
		}
		
		Ok(result)
	}
}