Fix --serve-web <file> (#10382)

jprochazk · web-flow · commit d60786950c26 · 2025-06-26T15:36:51.000+02:00
diff --git a/crates/top/rerun/src/commands/entrypoint.rs b/crates/top/rerun/src/commands/entrypoint.rs
@@ -117,13 +117,14 @@ Example: `16GB` or `50%` (of system total)."
 
     #[clap(
         long,
-        default_value = "0B",
+        default_value = None,
         long_help = r"An upper limit on how much memory the gRPC server (`--serve-web`) should use.
 The server buffers log messages for the benefit of late-arriving viewers.
 When this limit is reached, Rerun will drop the oldest data.
-Example: `16GB` or `50%` (of system total)."
+Example: `16GB` or `50%` (of system total).
+Default is `0B`, or `25%` if any of the `--serve-*` flags are set."
     )]
-    server_memory_limit: String,
+    server_memory_limit: Option<String>,
 
     #[clap(
         long,
@@ -163,13 +164,17 @@ When persisted, the state will be stored at the following locations:
     ///
     /// The server will act like a proxy, listening for incoming connections from
     /// logging SDKs, and forwarding it to Rerun viewers.
+    ///
+    /// Using this sets the default `--server-memory-limit` to 25% of available system memory.
     #[clap(long)]
     serve_web: bool,
 
     /// This will host a gRPC server.
     ///
     /// The server will act like a proxy, listening for incoming connections from
     /// logging SDKs, and forwarding it to Rerun viewers.
+    ///
+    /// Using this sets the default `--server-memory-limit` to 25% of available system memory.
     #[clap(long)]
     serve_grpc: bool,
 
@@ -720,7 +725,19 @@ fn run_impl(
     #[cfg(feature = "server")]
     let server_memory_limit = {
         re_log::debug!("Parsing memory limit for gRPC server");
-        re_memory::MemoryLimit::parse(&args.server_memory_limit)
+        let value = match &args.server_memory_limit {
+            Some(v) => v.as_str(),
+            None => {
+                // When spawning just a server, we don't want the memory limit to be 0.
+                if args.serve || args.serve_web || args.serve_grpc {
+                    "25%"
+                } else {
+                    "0B"
+                }
+            }
+        };
+        re_log::debug!("Server memory limit: {value}");
+        re_memory::MemoryLimit::parse(value)
             .map_err(|err| anyhow::format_err!("Bad --server-memory-limit: {err}"))?
     };
 
