ns3_config/
config_lib_rust_config_lib_source.rs

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use fidl::unpersist;
use fidl_cf_sc_internal_ns3config::Config as FidlConfig;
use fuchsia_inspect::Node;
use fuchsia_runtime::{take_startup_handle, HandleInfo, HandleType};
#[derive(Debug)]
pub struct Config {
    pub debug_logs: bool,
    pub num_threads: u8,
    pub suspend_enabled: bool,
}
impl Config {
    pub fn take_from_startup_handle() -> Self {
        let config_vmo: zx::Vmo =
            take_startup_handle(HandleInfo::new(HandleType::ComponentConfigVmo, 0))
                .expect("Config VMO handle must be provided and cannot already have been taken.")
                .into();
        let config_size =
            config_vmo.get_content_size().expect("must be able to read config vmo content size");
        assert_ne!(config_size, 0, "config vmo must be non-empty");
        let config_bytes =
            config_vmo.read_to_vec(0, config_size).expect("must be able to read config vmo");
        let checksum_length = u16::from_le_bytes([config_bytes[0], config_bytes[1]]) as usize;
        let fidl_start = 2 + checksum_length;
        let observed_checksum = &config_bytes[2..fidl_start];
        let expected_checksum = vec![
            0x84, 0xa6, 0x75, 0x14, 0x99, 0xda, 0x46, 0x39, 0x09, 0x0e, 0x6c, 0x5f, 0x3b, 0xd9,
            0x82, 0x86, 0xcf, 0x80, 0xf9, 0x61, 0x9b, 0xcd, 0xbd, 0x1b, 0xeb, 0xb1, 0xf9, 0x3e,
            0xc3, 0xbf, 0x45, 0x16,
        ];
        assert_eq!(
            observed_checksum, expected_checksum,
            "checksum from config VMO does not match expected checksum"
        );
        let fidl_config: FidlConfig = unpersist(&config_bytes[fidl_start..])
            .expect("must be able to parse bytes as config FIDL");
        Self {
            debug_logs: fidl_config.debug_logs,
            num_threads: fidl_config.num_threads,
            suspend_enabled: fidl_config.suspend_enabled,
        }
    }
    pub fn record_inspect(&self, inspector_node: &Node) {
        inspector_node.record_bool("debug_logs", self.debug_logs);
        inspector_node.record_uint("num_threads", self.num_threads as u64);
        inspector_node.record_bool("suspend_enabled", self.suspend_enabled);
    }
}