chore(sampling): pr review feedback

Author: bantonsson

libdd-sampling/src/bounded_byte_cache.rs

@@ -16,8 +16,12 @@ use std::num::NonZeroUsize;
 /// Default maximum entry count.
 pub const DEFAULT_MAX_ENTRIES: usize = 256;
 
-/// Default maximum tracked byte size (256 KiB).
-pub const DEFAULT_MAX_BYTES: usize = 256 * 1024;
+/// Default maximum tracked byte size (64 KiB).
+///
+/// Under normal use (short keys such as service or resource names), the entry count cap binds
+/// first. This byte budget acts as a safety valve against memory exhaustion from unexpectedly
+/// large keys due to misconfiguration or adversarial input.
+pub const DEFAULT_MAX_BYTES: usize = 256 * 256;
 
 /// LRU cache bounded by both entry count and total tracked byte size.
 ///
@@ -57,7 +61,6 @@ where
 
     /// Insert `key -> value`. Entries larger than `max_bytes` are dropped silently. Otherwise
     /// LRU entries are evicted until the new entry fits.
-    #[inline]
     pub fn put(&mut self, key: K, value: V) {
         let entry_bytes = Self::entry_size(&key);
 
@@ -91,6 +94,7 @@ where
     }
 
     #[cfg(test)]
+    #[inline]
     pub fn current_bytes(&self) -> usize {
         self.current_bytes
     }

libdd-sampling/src/glob_matcher.rs

@@ -43,7 +43,7 @@ pub struct GlobMatcher {
     pattern_is_star: bool,
     /// Shared LRU cache of matched subjects, keyed on raw bytes (ASCII path) or lowercased
     /// UTF-8 (Unicode path). Only consulted for wildcard patterns. Bounded by byte size to
-    /// cap memory under arbitrary key sizes.
+    /// cap memory under arbitrarily large attribute values.
     cache: Arc<Mutex<BoundedByteCache<Vec<u8>, bool>>>,
 }
 
@@ -60,15 +60,12 @@ impl GlobMatcher {
     /// Creates a new GlobMatcher with the given pattern.
     pub fn new(pattern: &str) -> Self {
         let pattern_lower = pattern.to_lowercase();
-        let pattern_is_ascii = pattern_lower.is_ascii();
-        let pattern_has_wildcards = pattern_lower.contains('*') || pattern_lower.contains('?');
-        // Any non-empty run of only `*` matches everything (e.g. `*`, `**`, `***`).
-        let pattern_is_star = !pattern_lower.is_empty() && pattern_lower.bytes().all(|b| b == b'*');
         GlobMatcher {
+            pattern_is_ascii: pattern_lower.is_ascii(),
+            pattern_has_wildcards: pattern_lower.contains('*') || pattern_lower.contains('?'),
+            // Any non-empty run of only `*` matches everything (e.g. `*`, `**`, `***`).
+            pattern_is_star: !pattern_lower.is_empty() && pattern_lower.bytes().all(|b| b == b'*'),
             pattern_lower,
-            pattern_is_ascii,
-            pattern_has_wildcards,
-            pattern_is_star,
             cache: Arc::new(Mutex::new(BoundedByteCache::new(
                 DEFAULT_MAX_ENTRIES,
                 DEFAULT_MAX_BYTES,