update: use cow not ref

aya/src/maps/stack_trace.rs

@@ -1,7 +1,12 @@
 //! A hash map of kernel or user space stack traces.
 //!
 //! See [`StackTraceMap`] for documentation and examples.
-use std::{borrow::Borrow, fs, io, mem, path::Path, str::FromStr};
+use std::{
+    borrow::{Borrow, Cow},
+    fs, io, mem,
+    path::Path,
+    str::FromStr,
+};
 
 use crate::{
     maps::{IterableMap, MapData, MapError, MapIter, MapKeys},
@@ -162,7 +167,7 @@ impl<'a, T: Borrow<MapData>> IntoIterator for &'a StackTraceMap<T> {
 /// A resolver for symbols based on an address obtained from a stack trace.
 pub trait SymbolResolver {
     /// Resolve a symbol for a given address, if possible.
-    fn resolve_symbol(&self, addr: u64) -> Option<&str>;
+    fn resolve_symbol(&self, addr: u64) -> Option<Cow<'_, str>>;
 }
 
 /// A kernel or user space stack trace.

aya/src/util.rs

@@ -1,5 +1,6 @@
 //! Utility functions.
 use std::{
+    borrow::Cow,
     collections::BTreeMap,
     error::Error,
     ffi::{CStr, CString},
@@ -206,8 +207,8 @@ fn parse_cpu_ranges(data: &str) -> Result<Vec<u32>, ()> {
 pub type SimpleSymbolResolver = BTreeMap<u64, String>;
 
 impl SymbolResolver for SimpleSymbolResolver {
-    fn resolve_symbol(&self, addr: u64) -> Option<&str> {
+    fn resolve_symbol(&self, addr: u64) -> Option<Cow<'_, str>> {
-        self.range(..=addr).next_back().map(|(_, s)| s.as_str())
+        self.range(..=addr).next_back().map(|(_, s)| Cow::from(s))
     }
 }
 

xtask/public-api/aya.txt

@@ -804,9 +804,9 @@ pub fn aya::maps::stack_trace::StackTraceMap<T>::borrow_mut(&mut self) -> &mut T
 impl<T> core::convert::From<T> for aya::maps::stack_trace::StackTraceMap<T>
 pub fn aya::maps::stack_trace::StackTraceMap<T>::from(t: T) -> T
 pub trait aya::maps::stack_trace::SymbolResolver
-pub fn aya::maps::stack_trace::SymbolResolver::resolve_symbol(&self, addr: u64) -> core::option::Option<&str>
+pub fn aya::maps::stack_trace::SymbolResolver::resolve_symbol(&self, addr: u64) -> core::option::Option<alloc::borrow::Cow<'_, str>>
 impl aya::maps::stack_trace::SymbolResolver for aya::util::SimpleSymbolResolver
-pub fn aya::util::SimpleSymbolResolver::resolve_symbol(&self, addr: u64) -> core::option::Option<&str>
+pub fn aya::util::SimpleSymbolResolver::resolve_symbol(&self, addr: u64) -> core::option::Option<alloc::borrow::Cow<'_, str>>
 pub enum aya::maps::Map
 pub aya::maps::Map::Array(aya::maps::MapData)
 pub aya::maps::Map::BloomFilter(aya::maps::MapData)