fix: free memory blocks when they're not needed

src/config.rs

@@ -34,5 +34,9 @@ pub fn get_memory(key: impl AsRef<str>) -> Result<Option<Memory>, Error> {
 /// let my_config = config::get("my_config")?.unwrap_or(0u32);
 /// ```
 pub fn get(key: impl AsRef<str>) -> Result<Option<String>, Error> {
-    Ok(get_memory(key)?.map(|x| x.to_string().expect("Config value is not a valid string")))
+    Ok(get_memory(key)?.map(|x| {
+        let s = x.to_string().expect("Config value is not a valid string");
+        x.free();
+        s
+    }))
 }

src/http.rs

@@ -44,6 +44,8 @@ pub fn request<T: ToMemory>(
     };
     let data = body.as_ref().map(|x| x.offset()).unwrap_or(0);
     let offs = unsafe { extism::http_request(req.offset(), data) };
+    req.free();
+    body.map(|x| x.free());
     let status = unsafe { extism::http_status_code() };
     let len = unsafe { extism::length_unsafe(offs) };
     Ok(HttpResponse {

src/macros.rs

@@ -3,7 +3,8 @@ macro_rules! log {
     ($lvl:expr, $($arg:tt)+) => {{
         let fmt = format!($($arg)+);
         let memory = $crate::Memory::from_bytes(&fmt).unwrap();
-        memory.log($lvl)
+        memory.log($lvl);
+        memory.free()
     }}
 }
 

src/var.rs

@@ -32,7 +32,11 @@ pub fn get_memory(key: impl AsRef<str>) -> Result<Option<Memory>, Error> {
 /// let my_var = var::get("my_var")?.unwrap_or(0u32);
 /// ```
 pub fn get<T: FromBytesOwned>(key: impl AsRef<str>) -> Result<Option<T>, Error> {
-    match get_memory(key)?.map(|x| x.to_vec()) {
+    match get_memory(key)?.map(|x| {
+        let res = x.to_vec();
+        x.free();
+        res
+    }) {
         Some(v) => Ok(Some(T::from_bytes(&v)?)),
         None => Ok(None),
     }
@@ -56,6 +60,8 @@ pub fn set(key: impl AsRef<str>, val: impl ToMemory) -> Result<(), Error> {
     let val = val.to_memory()?;
     let key = Memory::from_bytes(key.as_ref().as_bytes())?;
     unsafe { extism::var_set(key.offset(), val.offset()) }
+    key.free();
+    val.free();
     Ok(())
 }
 
@@ -74,5 +80,6 @@ pub fn set(key: impl AsRef<str>, val: impl ToMemory) -> Result<(), Error> {
 pub fn remove(key: impl AsRef<str>) -> Result<(), Error> {
     let key = Memory::from_bytes(key.as_ref().as_bytes())?;
     unsafe { extism::var_set(key.offset(), 0) };
+    key.free();
     Ok(())
 }