caching_ext: allow caching of bincode-enabled types

Summary: Add `bincode::Encode` and `bincode::Decode<()>` as trait bounds on cacheable types.  This will allow us to switch to a bincode-backed cache.

Reviewed By: RajivTS

Differential Revision: D72465913

fbshipit-source-id: 6b68bf9554c5b3bb2e6261afca37ddf1fbe4605e

Author: markbt

cachelib/rust/src/abomonation_cache.rs

@@ -26,7 +26,7 @@ use crate::lrucache::VolatileLruCachePool;
 /// Will attempt to fetch and decode a cached item
 pub fn get_cached<T>(cache_pool: &VolatileLruCachePool, cache_key: &str) -> Result<Option<T>>
 where
-    T: abomonation::Abomonation + Clone + Send + 'static,
+    T: abomonation::Abomonation + Clone,
 {
     let cache_handle = cache_pool.get_handle(cache_key)?;
     let cache_data: Option<Vec<u8>> = match cache_handle {
@@ -60,7 +60,7 @@ pub fn set_cached<T>(
     ttl: Option<Duration>,
 ) -> Result<bool>
 where
-    T: abomonation::Abomonation + Clone + Send + 'static,
+    T: abomonation::Abomonation,
 {
     let handle = cache_pool.allocate_with_ttl(cache_key, abomonation::measure(entry), ttl)?;
     let mut handle = handle.ok_or_else(|| Error::msg("can not allocate cachelib handle"))?;

cachelib/rust/src/bincode_cache.rs

@@ -62,7 +62,7 @@ const CONFIG: bincode::config::Configuration<
 /// Will attempt to fetch and decode a cached item
 pub fn get_cached<T>(cache_pool: &VolatileLruCachePool, cache_key: &str) -> Result<Option<T>>
 where
-    T: bincode::Decode<()> + Clone + Send + 'static,
+    T: bincode::Decode<()>,
 {
     if let Some(cache_handle) = cache_pool.get_handle(cache_key)? {
         let reader = cache_handle.get_reader()?;
@@ -115,7 +115,7 @@ pub fn set_cached<T>(
     ttl: Option<Duration>,
 ) -> Result<bool>
 where
-    T: bincode::Encode + Clone + Send + 'static,
+    T: bincode::Encode,
 {
     let size = encoded_size(entry, CONFIG)?;
     let handle = cache_pool.allocate_with_ttl(cache_key, size, ttl)?;