rhai/src/api/limits.rs
2021-12-06 20:52:47 +08:00

247 lines
8.1 KiB
Rust

//! Settings for [`Engine`]'s limitations.
#![cfg(not(feature = "unchecked"))]
use crate::Engine;
use std::num::{NonZeroU64, NonZeroUsize};
#[cfg(feature = "no_std")]
use std::prelude::v1::*;
/// A type containing all the limits imposed by the [`Engine`].
///
/// Not available under `unchecked`.
#[derive(Debug, Clone, Eq, PartialEq, Hash)]
pub struct Limits {
/// Maximum levels of call-stack to prevent infinite recursion.
///
/// Set to zero to effectively disable function calls.
///
/// Not available under `no_function`.
#[cfg(not(feature = "no_function"))]
pub max_call_stack_depth: usize,
/// Maximum depth of statements/expressions at global level.
pub max_expr_depth: Option<NonZeroUsize>,
/// Maximum depth of statements/expressions in functions.
///
/// Not available under `no_function`.
#[cfg(not(feature = "no_function"))]
pub max_function_expr_depth: Option<NonZeroUsize>,
/// Maximum number of operations allowed to run.
pub max_operations: Option<std::num::NonZeroU64>,
/// Maximum number of [modules][crate::Module] allowed to load.
///
/// Set to zero to effectively disable loading any [module][crate::Module].
///
/// Not available under `no_module`.
#[cfg(not(feature = "no_module"))]
pub max_modules: usize,
/// Maximum length of a [string][crate::ImmutableString].
pub max_string_size: Option<NonZeroUsize>,
/// Maximum length of an [array][crate::Array].
///
/// Not available under `no_index`.
#[cfg(not(feature = "no_index"))]
pub max_array_size: Option<NonZeroUsize>,
/// Maximum number of properties in an [object map][crate::Map].
///
/// Not available under `no_object`.
#[cfg(not(feature = "no_object"))]
pub max_map_size: Option<NonZeroUsize>,
}
impl Limits {
/// Create a new [`Limits`] with default values.
///
/// Not available under `unchecked`.
#[inline]
pub const fn new() -> Self {
Self {
#[cfg(not(feature = "no_function"))]
max_call_stack_depth: crate::engine::MAX_CALL_STACK_DEPTH,
max_expr_depth: NonZeroUsize::new(crate::engine::MAX_EXPR_DEPTH),
#[cfg(not(feature = "no_function"))]
max_function_expr_depth: NonZeroUsize::new(crate::engine::MAX_FUNCTION_EXPR_DEPTH),
max_operations: None,
#[cfg(not(feature = "no_module"))]
max_modules: usize::MAX,
max_string_size: None,
#[cfg(not(feature = "no_index"))]
max_array_size: None,
#[cfg(not(feature = "no_object"))]
max_map_size: None,
}
}
}
impl Default for Limits {
#[inline(always)]
fn default() -> Self {
Self::new()
}
}
impl Engine {
/// Set the maximum levels of function calls allowed for a script in order to avoid
/// infinite recursion and stack overflows.
///
/// Not available under `unchecked` or `no_function`.
#[cfg(not(feature = "no_function"))]
#[inline(always)]
pub fn set_max_call_levels(&mut self, levels: usize) -> &mut Self {
self.limits.max_call_stack_depth = levels;
self
}
/// The maximum levels of function calls allowed for a script.
///
/// Not available under `unchecked` or `no_function`.
#[cfg(not(feature = "no_function"))]
#[inline(always)]
#[must_use]
pub const fn max_call_levels(&self) -> usize {
self.limits.max_call_stack_depth
}
/// Set the maximum number of operations allowed for a script to run to avoid
/// consuming too much resources (0 for unlimited).
///
/// Not available under `unchecked`.
#[inline(always)]
pub fn set_max_operations(&mut self, operations: u64) -> &mut Self {
self.limits.max_operations = NonZeroU64::new(operations);
self
}
/// The maximum number of operations allowed for a script to run (0 for unlimited).
///
/// Not available under `unchecked`.
#[inline]
#[must_use]
pub const fn max_operations(&self) -> u64 {
if let Some(n) = self.limits.max_operations {
n.get()
} else {
0
}
}
/// Set the maximum number of imported [modules][crate::Module] allowed for a script.
///
/// Not available under `unchecked` or `no_module`.
#[cfg(not(feature = "no_module"))]
#[inline(always)]
pub fn set_max_modules(&mut self, modules: usize) -> &mut Self {
self.limits.max_modules = modules;
self
}
/// The maximum number of imported [modules][crate::Module] allowed for a script.
///
/// Not available under `unchecked` or `no_module`.
#[cfg(not(feature = "no_module"))]
#[inline(always)]
#[must_use]
pub const fn max_modules(&self) -> usize {
self.limits.max_modules
}
/// Set the depth limits for expressions (0 for unlimited).
///
/// Not available under `unchecked`.
#[inline(always)]
pub fn set_max_expr_depths(
&mut self,
max_expr_depth: usize,
#[cfg(not(feature = "no_function"))] max_function_expr_depth: usize,
) -> &mut Self {
self.limits.max_expr_depth = NonZeroUsize::new(max_expr_depth);
#[cfg(not(feature = "no_function"))]
{
self.limits.max_function_expr_depth = NonZeroUsize::new(max_function_expr_depth);
}
self
}
/// The depth limit for expressions (0 for unlimited).
///
/// Not available under `unchecked`.
#[inline]
#[must_use]
pub const fn max_expr_depth(&self) -> usize {
if let Some(n) = self.limits.max_expr_depth {
n.get()
} else {
0
}
}
/// The depth limit for expressions in functions (0 for unlimited).
///
/// Not available under `unchecked` or `no_function`.
#[cfg(not(feature = "no_function"))]
#[inline]
#[must_use]
pub const fn max_function_expr_depth(&self) -> usize {
if let Some(n) = self.limits.max_function_expr_depth {
n.get()
} else {
0
}
}
/// Set the maximum length of [strings][crate::ImmutableString] (0 for unlimited).
///
/// Not available under `unchecked`.
#[inline(always)]
pub fn set_max_string_size(&mut self, max_size: usize) -> &mut Self {
self.limits.max_string_size = NonZeroUsize::new(max_size);
self
}
/// The maximum length of [strings][crate::ImmutableString] (0 for unlimited).
///
/// Not available under `unchecked`.
#[inline]
#[must_use]
pub const fn max_string_size(&self) -> usize {
if let Some(n) = self.limits.max_string_size {
n.get()
} else {
0
}
}
/// Set the maximum length of [arrays][crate::Array] (0 for unlimited).
///
/// Not available under `unchecked` or `no_index`.
#[cfg(not(feature = "no_index"))]
#[inline(always)]
pub fn set_max_array_size(&mut self, max_size: usize) -> &mut Self {
self.limits.max_array_size = NonZeroUsize::new(max_size);
self
}
/// The maximum length of [arrays][crate::Array] (0 for unlimited).
///
/// Not available under `unchecked` or `no_index`.
#[cfg(not(feature = "no_index"))]
#[inline]
#[must_use]
pub const fn max_array_size(&self) -> usize {
if let Some(n) = self.limits.max_array_size {
n.get()
} else {
0
}
}
/// Set the maximum size of [object maps][crate::Map] (0 for unlimited).
///
/// Not available under `unchecked` or `no_object`.
#[cfg(not(feature = "no_object"))]
#[inline(always)]
pub fn set_max_map_size(&mut self, max_size: usize) -> &mut Self {
self.limits.max_map_size = NonZeroUsize::new(max_size);
self
}
/// The maximum size of [object maps][crate::Map] (0 for unlimited).
///
/// Not available under `unchecked` or `no_object`.
#[cfg(not(feature = "no_object"))]
#[inline]
#[must_use]
pub const fn max_map_size(&self) -> usize {
if let Some(n) = self.limits.max_map_size {
n.get()
} else {
0
}
}
}