config_lib/
config_lib_rust_config_lib_source.rs

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use fidl::unpersist;
use fidl_cf_sc_internal_configlib::Config as FidlConfig;
use fuchsia_inspect::{ArrayProperty, Node};
use fuchsia_runtime::{take_startup_handle, HandleInfo, HandleType};
#[derive(Debug)]
pub struct Config {
    pub echo_bool: bool,
    pub echo_num: u64,
    pub echo_string: String,
    pub echo_string_vector: Vec<String>,
}
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![
            0x1e, 0x2c, 0x8c, 0x11, 0x78, 0x21, 0x1b, 0xf4, 0x53, 0xba, 0x24, 0x7c, 0x85, 0xfa,
            0x38, 0x87, 0xf2, 0xcc, 0x60, 0x5d, 0xdb, 0xba, 0x3d, 0xe6, 0x07, 0x44, 0xa1, 0x0e,
            0x17, 0xa6, 0x12, 0x97,
        ];
        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 {
            echo_bool: fidl_config.echo_bool,
            echo_num: fidl_config.echo_num,
            echo_string: fidl_config.echo_string,
            echo_string_vector: fidl_config.echo_string_vector,
        }
    }
    pub fn record_inspect(&self, inspector_node: &Node) {
        inspector_node.record_bool("echo_bool", self.echo_bool);
        inspector_node.record_uint("echo_num", self.echo_num);
        inspector_node.record_string("echo_string", &self.echo_string);
        let arr =
            inspector_node.create_string_array("echo_string_vector", self.echo_string_vector.len());
        for i in 0..self.echo_string_vector.len() {
            arr.set(i, &self.echo_string_vector[i]);
        }
        inspector_node.record(arr);
    }
}