refactor: apply 5-pass audit optimizations across mcp-memory codebase

mcp-stdio/Cargo.toml

@@ -5,3 +5,6 @@ edition = "2024"
 
 [dependencies]
 tokio = { version = "1.53.1", features = ["io-util", "macros"] }
+
+[dev-dependencies]
+tokio = { version = "1.53.1", features = ["rt", "macros"] }

mcp-stdio/src/lib.rs

@@ -15,8 +15,14 @@ pub async fn read_mcp_message<R: tokio::io::AsyncRead + Unpin>(
 
         let trimmed_start = line.trim_start();
         if trimmed_start.starts_with('{') {
-            let trimmed = line.trim();
-            return Some(trimmed.to_string());
+            let mut val = std::mem::take(&mut line);
+            let trimmed_len = val.trim_end().len();
+            val.truncate(trimmed_len);
+            let start = val.len() - val.trim_start().len();
+            if start > 0 {
+                val.drain(..start);
+            }
+            return Some(val);
         }
 
         let line = line.trim_end();
@@ -24,7 +30,7 @@ pub async fn read_mcp_message<R: tokio::io::AsyncRead + Unpin>(
             break;
         }
 
-        if line.len() >= 15 && line[..15].eq_ignore_ascii_case("content-length:") {
+        if line.as_bytes().len() >= 15 && line.as_bytes()[..15].eq_ignore_ascii_case(b"content-length:") {
             length = line[15..].trim().parse().unwrap_or(0);
         }
     }
@@ -35,7 +41,7 @@ pub async fn read_mcp_message<R: tokio::io::AsyncRead + Unpin>(
         return None;
     }
 
-    let mut buffer = Vec::with_capacity(length);
+    let mut buffer = Vec::with_capacity(length.min(64 * 1024));
     if stdin.take(length as u64).read_to_end(&mut buffer).await.is_err() || buffer.len() != length {
         return None;
     }