Remove Interners struct.

This commit is contained in:
Stephen Chung 2022-08-14 14:32:16 +08:00
parent f7d910fa55
commit b75ea94908
2 changed files with 44 additions and 46 deletions

View File

@ -43,22 +43,17 @@ const NEVER_ENDS: &str = "`Token`";
/// Unroll `switch` ranges no larger than this.
const SMALL_SWITCH_RANGE: usize = 16;
#[derive(Debug, Default, Clone)]
pub struct InternedStrings<'e> {
pub main: StringsInterner<'e>,
#[cfg(not(feature = "no_object"))]
pub getters: StringsInterner<'e>,
#[cfg(not(feature = "no_object"))]
pub setters: StringsInterner<'e>,
}
const NUM_INTERNERS: usize = if cfg!(feature = "no_object") { 1 } else { 3 };
/// _(internals)_ A type that encapsulates the current state of the parser.
/// Exported under the `internals` feature only.
pub struct ParseState<'e> {
/// Input stream buffer containing the next character to read.
pub tokenizer_control: TokenizerControl,
/// Controls whether parsing of an expression should stop given the next token.
pub expr_filter: fn(&Token) -> bool,
/// String interners.
interned_strings: InternedStrings<'e>,
interned_strings: [StringsInterner<'e>; NUM_INTERNERS],
/// External [scope][Scope] with constants.
pub scope: &'e Scope<'e>,
/// Global runtime state.
@ -67,8 +62,6 @@ pub struct ParseState<'e> {
pub stack: Scope<'e>,
/// Size of the local variables stack upon entry of the current block scope.
pub block_stack_len: usize,
/// Controls whether parsing of an expression should stop given the next token.
pub expr_filter: fn(&Token) -> bool,
/// Tracks a list of external variables (variables that are not explicitly declared in the scope).
#[cfg(not(feature = "no_closure"))]
pub external_vars: Vec<crate::ast::Ident>,
@ -118,7 +111,7 @@ impl<'e> ParseState<'e> {
pub fn new(
engine: &Engine,
scope: &'e Scope,
interners: InternedStrings<'e>,
interned_strings: [StringsInterner<'e>; NUM_INTERNERS],
tokenizer_control: TokenizerControl,
) -> Self {
Self {
@ -128,7 +121,7 @@ impl<'e> ParseState<'e> {
external_vars: Vec::new(),
#[cfg(not(feature = "no_closure"))]
allow_capture: true,
interned_strings: interners,
interned_strings,
scope,
global: GlobalRuntimeState::new(engine),
stack: Scope::new(),
@ -250,40 +243,35 @@ impl<'e> ParseState<'e> {
/// Get an interned string, creating one if it is not yet interned.
#[inline(always)]
#[allow(dead_code)]
#[must_use]
pub fn get_interned_string(
&mut self,
text: impl AsRef<str> + Into<ImmutableString>,
) -> ImmutableString {
self.interned_strings.main.get(text)
self.interned_strings[0].get(text)
}
/// Get an interned property getter, creating one if it is not yet interned.
#[cfg(not(feature = "no_object"))]
#[inline(always)]
#[allow(dead_code)]
#[must_use]
pub fn get_interned_getter(
&mut self,
text: impl AsRef<str> + Into<ImmutableString>,
) -> ImmutableString {
self.interned_strings
.getters
self.interned_strings[1]
.get_with_mapper(|s| crate::engine::make_getter(s.as_ref()).into(), text)
}
/// Get an interned property setter, creating one if it is not yet interned.
#[cfg(not(feature = "no_object"))]
#[inline(always)]
#[allow(dead_code)]
#[must_use]
pub fn get_interned_setter(
&mut self,
text: impl AsRef<str> + Into<ImmutableString>,
) -> ImmutableString {
self.interned_strings
.setters
self.interned_strings[2]
.get_with_mapper(|s| crate::engine::make_setter(s.as_ref()).into(), text)
}
}
@ -1384,12 +1372,13 @@ impl Engine {
// | ...
#[cfg(not(feature = "no_function"))]
Token::Pipe | Token::Or if settings.options.contains(LangOptions::ANON_FN) => {
let interners = std::mem::take(&mut state.interned_strings);
// Build new parse state
let interned_strings = std::mem::take(&mut state.interned_strings);
let mut new_state = ParseState::new(
self,
state.scope,
interners,
interned_strings,
state.tokenizer_control.clone(),
);
@ -1435,6 +1424,7 @@ impl Engine {
let result = self.parse_anon_fn(input, &mut new_state, lib, new_settings);
// Restore parse state
state.interned_strings = new_state.interned_strings;
let (expr, func) = result?;
@ -3259,12 +3249,13 @@ impl Engine {
match input.next().expect(NEVER_ENDS) {
(Token::Fn, pos) => {
let interners = std::mem::take(&mut state.interned_strings);
// Build new parse state
let interned_strings = std::mem::take(&mut state.interned_strings);
let mut new_state = ParseState::new(
self,
state.scope,
interners,
interned_strings,
state.tokenizer_control.clone(),
);
@ -3314,6 +3305,7 @@ impl Engine {
comments,
);
// Restore parse state
state.interned_strings = new_state.interned_strings;
let func = func?;

View File

@ -5,6 +5,7 @@ use crate::ImmutableString;
use std::prelude::v1::*;
use std::{
collections::BTreeMap,
fmt,
hash::{Hash, Hasher},
marker::PhantomData,
ops::AddAssign,
@ -20,10 +21,12 @@ pub const MAX_STRING_LEN: usize = 24;
/// Exported under the `internals` feature only.
///
/// Normal identifiers, property getters and setters are interned separately.
#[derive(Debug, Clone, Hash)]
#[derive(Clone, Hash)]
pub struct StringsInterner<'a> {
/// Maximum capacity.
max: usize,
/// Maximum number of strings interned.
pub capacity: usize,
/// Maximum string length.
pub max_string_len: usize,
/// Normal strings.
strings: BTreeMap<u64, ImmutableString>,
/// Take care of the lifetime parameter.
@ -37,24 +40,26 @@ impl Default for StringsInterner<'_> {
}
}
impl fmt::Debug for StringsInterner<'_> {
#[inline]
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
f.debug_list().entries(self.strings.values()).finish()
}
}
impl StringsInterner<'_> {
/// Create a new [`StringsInterner`].
#[inline(always)]
#[must_use]
pub fn new() -> Self {
Self::new_with_capacity(MAX_INTERNED_STRINGS)
}
/// Create a new [`StringsInterner`] with maximum capacity.
#[inline]
#[must_use]
pub fn new_with_capacity(capacity: usize) -> Self {
Self {
max: capacity,
capacity: MAX_INTERNED_STRINGS,
max_string_len: MAX_STRING_LEN,
strings: BTreeMap::new(),
dummy: PhantomData,
}
}
/// Get an identifier from a text string, adding it to the interner if necessary.
#[inline(always)]
#[must_use]
@ -72,12 +77,9 @@ impl StringsInterner<'_> {
) -> ImmutableString {
let key = text.as_ref();
// Do not intern numbers
if key.bytes().all(|c| c == b'.' || (c >= b'0' && c <= b'9')) {
return text.into();
}
if key.len() > MAX_STRING_LEN {
// Do not intern long strings or numbers
if key.len() > MAX_STRING_LEN || key.bytes().all(|c| c == b'.' || (c >= b'0' && c <= b'9'))
{
return mapper(text);
}
@ -98,11 +100,15 @@ impl StringsInterner<'_> {
self.strings.insert(key, value.clone());
// If the interner is over capacity, remove the longest entry
if self.strings.len() > self.max {
if self.strings.len() > self.capacity {
// Leave some buffer to grow when shrinking the cache.
// We leave at least two entries, one for the empty string, and one for the string
// that has just been inserted.
let max = if self.max < 5 { 2 } else { self.max - 3 };
let max = if self.capacity < 5 {
2
} else {
self.capacity - 3
};
while self.strings.len() > max {
let (_, n) = self.strings.iter().fold((0, 0), |(x, n), (&k, v)| {
@ -127,7 +133,7 @@ impl StringsInterner<'_> {
self.strings.len()
}
/// Number of strings interned.
/// Are there no interned strings?
#[inline(always)]
#[must_use]
pub fn is_empty(&self) -> bool {
@ -135,7 +141,7 @@ impl StringsInterner<'_> {
}
/// Clear all interned strings.
#[inline]
#[inline(always)]
pub fn clear(&mut self) {
self.strings.clear();
}