From d75c76e959d625d502a9c10916ca26d980742a5a Mon Sep 17 00:00:00 2001
From: Oliver Hamlet <git@ortham.net>
Date: Thu, 27 Jun 2024 17:34:22 +0100
Subject: [PATCH] Use boxed slices instead of Vec in FFI conversions

Since they're not meaningfully growable.
---
 ffi/src/helpers.rs | 16 ++++++++++++----
 ffi/src/lib.rs     |  8 ++------
 ffi/src/plugin.rs  | 26 +++++++++++---------------
 3 files changed, 25 insertions(+), 25 deletions(-)

diff --git a/ffi/src/helpers.rs b/ffi/src/helpers.rs
index b721bff..77cfa0b 100644
--- a/ffi/src/helpers.rs
+++ b/ffi/src/helpers.rs
@@ -2,7 +2,7 @@ use std::ffi::{CStr, CString};
 
 use libc::{c_char, size_t};
 
-use esplugin::GameId;
+use esplugin::{GameId, Plugin};
 
 use crate::{constants::*, error::error};
 
@@ -43,9 +43,7 @@ pub fn to_c_string_array(strings: &[String]) -> Result<(*mut *mut c_char, size_t
     let mut c_strings = strings
         .iter()
         .map(|s| to_c_string(s))
-        .collect::<Result<Vec<*mut c_char>, u32>>()?;
-
-    c_strings.shrink_to_fit();
+        .collect::<Result<Box<[*mut c_char]>, u32>>()?;
 
     let pointer = c_strings.as_mut_ptr();
     let size = c_strings.len();
@@ -54,6 +52,16 @@ pub fn to_c_string_array(strings: &[String]) -> Result<(*mut *mut c_char, size_t
     Ok((pointer, size))
 }
 
+pub unsafe fn to_plugin_refs_slice<'a>(
+    array: *const *const Plugin,
+    array_size: usize,
+) -> Option<Box<[&'a Plugin]>> {
+    std::slice::from_raw_parts(array, array_size)
+        .iter()
+        .map(|pointer| pointer.as_ref())
+        .collect()
+}
+
 pub fn map_game_id(game_id: u32) -> Result<GameId, u32> {
     match game_id {
         x if x == ESP_GAME_OBLIVION => Ok(GameId::Oblivion),
diff --git a/ffi/src/lib.rs b/ffi/src/lib.rs
index 40ea8fe..d5e2b03 100644
--- a/ffi/src/lib.rs
+++ b/ffi/src/lib.rs
@@ -18,6 +18,7 @@ use self::error::error;
 use error::handle_error;
 use esplugin::Plugin;
 use esplugin::PluginMetadata;
+use helpers::to_plugin_refs_slice;
 use libc::size_t;
 
 pub use self::common::*;
@@ -40,12 +41,7 @@ pub unsafe extern "C" fn esp_get_plugins_metadata(
         if plugins.is_null() || plugins_metadata.is_null() {
             error(ESP_ERROR_NULL_POINTER, "Null pointer passed")
         } else {
-            let plugins: Option<Vec<&Plugin>> = std::slice::from_raw_parts(plugins, plugins_len)
-                .iter()
-                .map(|pointer| pointer.as_ref())
-                .collect();
-
-            let plugins = match plugins {
+            let plugins = match to_plugin_refs_slice(plugins, plugins_len) {
                 Some(p) => p,
                 None => {
                     return error(
diff --git a/ffi/src/plugin.rs b/ffi/src/plugin.rs
index e835c25..fffbaa1 100644
--- a/ffi/src/plugin.rs
+++ b/ffi/src/plugin.rs
@@ -489,21 +489,17 @@ pub unsafe extern "C" fn esp_plugin_records_overlap_size(
             error(ESP_ERROR_NULL_POINTER, "Null pointer passed")
         } else {
             let plugin = &*plugin_ptr;
-            let other_plugins: Option<Vec<&Plugin>> =
-                std::slice::from_raw_parts(other_plugins_ptr, other_plugins_ptr_count)
-                    .iter()
-                    .map(|pointer| pointer.as_ref())
-                    .collect();
-
-            let other_plugins = match other_plugins {
-                Some(p) => p,
-                None => {
-                    return error(
-                        ESP_ERROR_NULL_POINTER,
-                        "Null pointer passed in plugins array",
-                    )
-                }
-            };
+
+            let other_plugins =
+                match to_plugin_refs_slice(other_plugins_ptr, other_plugins_ptr_count) {
+                    Some(p) => p,
+                    None => {
+                        return error(
+                            ESP_ERROR_NULL_POINTER,
+                            "Null pointer passed in plugins array",
+                        )
+                    }
+                };
 
             match plugin.overlap_size(&other_plugins) {
                 Ok(x) => {