Fix interner max.

Author: schungx

CHANGELOG.md

@@ -9,6 +9,11 @@ Deprecated API's
 
 * The plugin macros `export_fn`, `register_exported_fn!`, `set_exported_fn!` and `set_exported_global_fn!` are deprecated because they do not add value over existing direct API's.
 
+New features
+------------
+
+* New options `Engine::set_max_strings_interned` and `Engine::max_strings_interned` are added to limit the maximum number of strings interned in the `Engine`'s string interner.
+
 Enhancements
 ------------
 

src/api/mod.rs

@@ -63,7 +63,7 @@ impl Engine {
                 guard.set_max(max);
             }
         } else {
-            self.interned_strings = Some(StringsInterner::new(self.max_strings_interned()).into());
+            self.interned_strings = Some(StringsInterner::new(max).into());
         }
         self
     }

src/eval/cache.rs

@@ -26,7 +26,7 @@ pub struct FnResolutionCache {
     /// Hash map containing cached functions.
     pub dict: StraightHashMap<Option<FnResolutionCacheEntry>>,
     /// Bloom filter to avoid caching "one-hit wonders".
-    pub filter: BloomFilterU64,
+    pub bloom_filter: BloomFilterU64,
 }
 
 impl FnResolutionCache {
@@ -35,7 +35,7 @@ impl FnResolutionCache {
     #[allow(dead_code)]
     pub fn clear(&mut self) {
         self.dict.clear();
-        self.filter.clear();
+        self.bloom_filter.clear();
     }
 }
 

src/func/call.rs

@@ -222,7 +222,7 @@ impl Engine {
                             func: f.clone(),
                             source: s.cloned(),
                         };
-                        return if cache.filter.is_absent_and_set(hash) {
+                        return if cache.bloom_filter.is_absent_and_set(hash) {
                             // Do not cache "one-hit wonders"
                             *local_entry = Some(new_entry);
                             local_entry.as_ref()
@@ -298,7 +298,7 @@ impl Engine {
                                     }),
                             });
 
-                        return if cache.filter.is_absent_and_set(hash) {
+                        return if cache.bloom_filter.is_absent_and_set(hash) {
                             // Do not cache "one-hit wonders"
                             *local_entry = builtin;
                             local_entry.as_ref()

src/func/script.rs

@@ -238,7 +238,7 @@ impl Engine {
             // Then check sub-modules
             || self.global_sub_modules.values().any(|m| m.contains_qualified_fn(hash_script));
 
-        if !res && !cache.filter.is_absent_and_set(hash_script) {
+        if !res && !cache.bloom_filter.is_absent_and_set(hash_script) {
             // Do not cache "one-hit wonders"
             cache.dict.insert(hash_script, None);
         }

src/types/interner.rs

@@ -16,7 +16,7 @@ use std::{
 };
 
 /// Maximum length of strings interned.
-pub const MAX_STRING_LEN: usize = 24;
+pub const MAX_STRING_LEN: usize = 32;
 
 /// _(internals)_ A cache for interned strings.
 /// Exported under the `internals` feature only.
@@ -61,6 +61,7 @@ impl StringsInterner {
     #[inline(always)]
     pub fn set_max(&mut self, max: usize) {
         self.max_strings_interned = max;
+        self.throttle_cache(None);
     }
     /// The maximum number of strings to be interned.
     #[inline(always)]
@@ -105,14 +106,14 @@ impl StringsInterner {
         };
 
         // Throttle the cache upon exit
-        self.throttle_cache(hash);
+        self.throttle_cache(Some(hash));
 
         result
     }
 
     /// If the interner is over capacity, remove the longest entry that has the lowest count
     #[inline]
-    fn throttle_cache(&mut self, skip_hash: u64) {
+    fn throttle_cache(&mut self, skip_hash: Option<u64>) {
         if self.max() == 0 {
             self.clear();
             return;
@@ -130,7 +131,7 @@ impl StringsInterner {
             let mut index = 0;
 
             for (&k, v) in &self.cache {
-                if k != skip_hash
+                if skip_hash.map_or(true, |hash| k != hash)
                     && (v.strong_count() < min_count
                         || (v.strong_count() == min_count && v.len() > max_len))
                 {