cloud-hypervisor/option_parser/src/lib.rs

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// Copyright © 2020 Intel Corporation
//
// SPDX-License-Identifier: Apache-2.0
//
use std::collections::HashMap;
use std::fmt;
use std::num::ParseIntError;
use std::str::FromStr;
#[derive(Default)]
pub struct OptionParser {
options: HashMap<String, OptionParserValue>,
}
struct OptionParserValue {
value: Option<String>,
requires_value: bool,
}
#[derive(Debug)]
pub enum OptionParserError {
UnknownOption(String),
InvalidSyntax(String),
Conversion(String, String),
}
impl fmt::Display for OptionParserError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match self {
OptionParserError::UnknownOption(s) => write!(f, "unknown option: {}", s),
OptionParserError::InvalidSyntax(s) => write!(f, "invalid syntax:{}", s),
OptionParserError::Conversion(field, value) => {
write!(f, "unable to convert {} for {}", value, field)
}
}
}
}
type OptionParserResult<T> = std::result::Result<T, OptionParserError>;
fn split_commas(s: &str) -> OptionParserResult<Vec<String>> {
let mut list: Vec<String> = Vec::new();
let mut opened_brackets = 0;
let mut in_quotes = false;
let mut current = String::new();
for c in s.trim().chars() {
match c {
'[' => {
opened_brackets += 1;
current.push('[');
}
']' => {
opened_brackets -= 1;
if opened_brackets < 0 {
return Err(OptionParserError::InvalidSyntax(s.to_owned()));
}
current.push(']');
}
'"' => in_quotes = !in_quotes,
',' => {
if opened_brackets > 0 || in_quotes {
current.push(',')
} else {
list.push(current);
current = String::new();
}
}
c => current.push(c),
}
}
list.push(current);
if opened_brackets != 0 || in_quotes {
return Err(OptionParserError::InvalidSyntax(s.to_owned()));
}
Ok(list)
}
impl OptionParser {
pub fn new() -> Self {
Self {
options: HashMap::new(),
}
}
pub fn parse(&mut self, input: &str) -> OptionParserResult<()> {
if input.trim().is_empty() {
return Ok(());
}
for option in split_commas(input)?.iter() {
let parts: Vec<&str> = option.splitn(2, '=').collect();
match self.options.get_mut(parts[0]) {
None => return Err(OptionParserError::UnknownOption(parts[0].to_owned())),
Some(value) => {
if value.requires_value {
if parts.len() != 2 {
return Err(OptionParserError::InvalidSyntax((*option).to_owned()));
}
value.value = Some(parts[1].trim().to_owned());
} else {
value.value = Some(String::new());
}
}
}
}
Ok(())
}
pub fn add(&mut self, option: &str) -> &mut Self {
self.options.insert(
option.to_owned(),
OptionParserValue {
value: None,
requires_value: true,
},
);
self
}
pub fn add_valueless(&mut self, option: &str) -> &mut Self {
self.options.insert(
option.to_owned(),
OptionParserValue {
value: None,
requires_value: false,
},
);
self
}
pub fn get(&self, option: &str) -> Option<String> {
self.options
.get(option)
.and_then(|v| v.value.clone())
.and_then(|s| if s.is_empty() { None } else { Some(s) })
}
pub fn is_set(&self, option: &str) -> bool {
self.options
.get(option)
.and_then(|v| v.value.as_ref())
.is_some()
}
pub fn convert<T: FromStr>(&self, option: &str) -> OptionParserResult<Option<T>> {
match self.get(option) {
None => Ok(None),
Some(v) => Ok(Some(v.parse().map_err(|_| {
OptionParserError::Conversion(option.to_owned(), v.to_owned())
})?)),
}
}
}
pub struct Toggle(pub bool);
pub enum ToggleParseError {
InvalidValue(String),
}
impl FromStr for Toggle {
type Err = ToggleParseError;
fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
match s.to_lowercase().as_str() {
"" => Ok(Toggle(false)),
"on" => Ok(Toggle(true)),
"off" => Ok(Toggle(false)),
"true" => Ok(Toggle(true)),
"false" => Ok(Toggle(false)),
_ => Err(ToggleParseError::InvalidValue(s.to_owned())),
}
}
}
pub struct ByteSized(pub u64);
#[derive(Debug)]
pub enum ByteSizedParseError {
InvalidValue(String),
}
impl FromStr for ByteSized {
type Err = ByteSizedParseError;
fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
Ok(ByteSized({
let s = s.trim();
let shift = if s.ends_with('K') {
10
} else if s.ends_with('M') {
20
} else if s.ends_with('G') {
30
} else {
0
};
let s = s.trim_end_matches(|c| c == 'K' || c == 'M' || c == 'G');
s.parse::<u64>()
.map_err(|_| ByteSizedParseError::InvalidValue(s.to_owned()))?
<< shift
}))
}
}
pub struct IntegerList(pub Vec<u64>);
pub enum IntegerListParseError {
InvalidValue(String),
}
impl FromStr for IntegerList {
type Err = IntegerListParseError;
fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
let mut integer_list = Vec::new();
let ranges_list: Vec<&str> = s
.trim()
.trim_matches(|c| c == '[' || c == ']')
.split(',')
.collect();
for range in ranges_list.iter() {
let items: Vec<&str> = range.split('-').collect();
if items.len() > 2 {
return Err(IntegerListParseError::InvalidValue((*range).to_string()));
}
let start_range = items[0]
.parse::<u64>()
.map_err(|_| IntegerListParseError::InvalidValue(items[0].to_owned()))?;
integer_list.push(start_range);
if items.len() == 2 {
let end_range = items[1]
.parse::<u64>()
.map_err(|_| IntegerListParseError::InvalidValue(items[1].to_owned()))?;
if start_range >= end_range {
return Err(IntegerListParseError::InvalidValue((*range).to_string()));
}
for i in start_range..end_range {
integer_list.push(i + 1);
}
}
}
Ok(IntegerList(integer_list))
}
}
pub trait TupleValue {
fn parse_value(input: &str) -> Result<Self, TupleError>
where
Self: Sized;
}
impl TupleValue for u64 {
fn parse_value(input: &str) -> Result<Self, TupleError> {
input.parse::<u64>().map_err(TupleError::InvalidInteger)
}
}
impl TupleValue for Vec<u8> {
fn parse_value(input: &str) -> Result<Self, TupleError> {
Ok(IntegerList::from_str(input)
.map_err(TupleError::InvalidIntegerList)?
.0
.iter()
.map(|v| *v as u8)
.collect())
}
}
impl TupleValue for Vec<u64> {
fn parse_value(input: &str) -> Result<Self, TupleError> {
Ok(IntegerList::from_str(input)
.map_err(TupleError::InvalidIntegerList)?
.0)
}
}
pub struct Tuple<S, T>(pub Vec<(S, T)>);
pub enum TupleError {
InvalidValue(String),
SplitOutsideBrackets(OptionParserError),
InvalidIntegerList(IntegerListParseError),
InvalidInteger(ParseIntError),
}
impl<S: FromStr, T: TupleValue> FromStr for Tuple<S, T> {
type Err = TupleError;
fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
let mut list: Vec<(S, T)> = Vec::new();
let body = s
.trim()
.strip_prefix('[')
.and_then(|s| s.strip_suffix(']'))
.ok_or_else(|| TupleError::InvalidValue(s.to_string()))?;
let tuples_list = split_commas(body).map_err(TupleError::SplitOutsideBrackets)?;
for tuple in tuples_list.iter() {
let items: Vec<&str> = tuple.split('@').collect();
if items.len() != 2 {
return Err(TupleError::InvalidValue((*tuple).to_string()));
}
let item1 = items[0]
.parse::<S>()
.map_err(|_| TupleError::InvalidValue(items[0].to_owned()))?;
let item2 = TupleValue::parse_value(items[1])?;
list.push((item1, item2));
}
Ok(Tuple(list))
}
}
#[derive(Default)]
pub struct StringList(pub Vec<String>);
pub enum StringListParseError {
InvalidValue(String),
}
impl FromStr for StringList {
type Err = StringListParseError;
fn from_str(s: &str) -> std::result::Result<Self, Self::Err> {
let string_list: Vec<String> = s
.trim()
.trim_matches(|c| c == '[' || c == ']')
.split(',')
.map(|e| e.to_owned())
.collect();
Ok(StringList(string_list))
}
}
#[cfg(test)]
mod tests {
use super::*;
#[test]
fn test_option_parser() {
let mut parser = OptionParser::new();
parser
.add("size")
.add("mergeable")
.add("hotplug_method")
.add("hotplug_size")
.add("topology")
.add("cmdline");
assert!(parser.parse("size=128M,hanging_param").is_err());
assert!(parser.parse("size=128M,too_many_equals=foo=bar").is_err());
assert!(parser.parse("size=128M,file=/dev/shm").is_err());
assert!(parser.parse("size=128M").is_ok());
assert_eq!(parser.get("size"), Some("128M".to_owned()));
assert!(!parser.is_set("mergeable"));
assert!(parser.is_set("size"));
assert!(parser.parse("size=128M,mergeable=on").is_ok());
assert_eq!(parser.get("size"), Some("128M".to_owned()));
assert_eq!(parser.get("mergeable"), Some("on".to_owned()));
assert!(parser
.parse("size=128M,mergeable=on,topology=[1,2]")
.is_ok());
assert_eq!(parser.get("size"), Some("128M".to_owned()));
assert_eq!(parser.get("mergeable"), Some("on".to_owned()));
assert_eq!(parser.get("topology"), Some("[1,2]".to_owned()));
assert!(parser
.parse("size=128M,mergeable=on,topology=[[1,2],[3,4]]")
.is_ok());
assert_eq!(parser.get("size"), Some("128M".to_owned()));
assert_eq!(parser.get("mergeable"), Some("on".to_owned()));
assert_eq!(parser.get("topology"), Some("[[1,2],[3,4]]".to_owned()));
assert!(parser.parse("topology=[").is_err());
assert!(parser.parse("topology=[[[]]]]").is_err());
assert!(parser.parse("cmdline=\"console=ttyS0,9600n8\"").is_ok());
assert_eq!(
parser.get("cmdline"),
Some("console=ttyS0,9600n8".to_owned())
);
assert!(parser.parse("cmdline=\"").is_err());
assert!(parser.parse("cmdline=\"\"\"").is_err());
}
}