The protobuf library 0.3.0 memory usage is about 300KB higher than 0.28.0

[zzzzzzzzzy9]

I'm using the open source repository containerd/rust-extensions. When I use protobuf 0.28.0, the memory cost is about 900KB. But when I use protobuf 0.3.0 or 0.4.0, the momory usage is abot 1200KB.
I used the valgrind memory capture tool to collect the memory of the process, and the result is as follows:

1. for 0.3.0 or 0.4.0
2. for 0.28.0

By analyzing the results, I found that the function file_descriptor takes up about 300KB of heap memory. This function is in the end of file /src/descriptor.rs. This function was not available in version 0.28.0.

Also, I found that the Message struct in 0.28.0 became the current MessageFull struct, and when I removed the related dependencies of the messageFull struct in the containerd/rust-extensions project (which of course caused the rust-extensions project to not work properly) I noticed that the memory dropped by about 400KB.

I cannot use Message struct in 0.3.0 because of PartialEq.

The differences between 0.28.0(/src/message.rs) and 0.3.0(/src/message.rs and /src/messagedyn.rs):

1. 0.28.0
   pub trait Message: fmt::Debug + Clear + Any + Send + Sync { .....
2. 0.3.0
   pub trait Message: Default + Clone + Send + Sync + Sized + PartialEq + 'static {
pub trait MessageDyn: Any + fmt::Debug + fmt::Display + Send + Sync + 'static {
   We can see that in 0.3.0 static is used in both the Message struct and the MessageDyn struct, but not in 0.28.0

I wonder what the modification of the Message struct and the addition of file_descriptor functions are? Does it really need to be defined as static? This results in an unusually large memory overhead.

[zzzzzzzzzy9]

@stepancheg

[stepancheg]

Version 0.3 is prehistoric. Current version is 3.x.

[zzzzzzzzzy9]

Oh, I'm sorry. It is 2.28.0/2.27.1 and 3.3.0/3.4.0. @stepancheg