sampler_component_config/
sampler-component-config_rust_config_lib_source.rs

1use fidl::unpersist;
2use fidl_cf_sc_internal_samplercomponentconfig::Config as FidlConfig;
3use fuchsia_inspect::{ArrayProperty, Node};
4use fuchsia_runtime::{take_startup_handle, HandleInfo, HandleType};
5use std::convert::TryInto;
6const EXPECTED_CHECKSUM: &[u8] = &[
7    0xa1, 0xe4, 0xf3, 0xf9, 0xd9, 0x6e, 0x93, 0x5b, 0x56, 0xa0, 0x04, 0xb7, 0xef, 0xdd, 0xfc, 0x93,
8    0x61, 0x8d, 0x11, 0xee, 0x9c, 0xbb, 0x5f, 0x69, 0x31, 0x08, 0x93, 0xfc, 0x8c, 0xfd, 0x84, 0x38,
9];
10#[derive(Debug)]
11pub struct Config {
12    pub minimum_sample_rate_sec: i64,
13    pub project_configs: Vec<String>,
14}
15impl Config {
16    #[doc = r" Take the config startup handle and parse its contents."]
17    #[doc = r""]
18    #[doc = r" # Panics"]
19    #[doc = r""]
20    #[doc = r" If the config startup handle was already taken or if it is not valid."]
21    pub fn take_from_startup_handle() -> Self {
22        let handle_info = HandleInfo::new(HandleType::ComponentConfigVmo, 0);
23        let config_vmo: zx::Vmo =
24            take_startup_handle(handle_info).expect("Config VMO handle must be present.").into();
25        Self::from_vmo(&config_vmo).expect("Config VMO handle must be valid.")
26    }
27    #[doc = r" Parse `Self` from `vmo`."]
28    pub fn from_vmo(vmo: &zx::Vmo) -> Result<Self, Error> {
29        let config_size = vmo.get_content_size().map_err(Error::GettingContentSize)?;
30        let config_bytes = vmo.read_to_vec(0, config_size).map_err(Error::ReadingConfigBytes)?;
31        Self::from_bytes(&config_bytes)
32    }
33    #[doc = r" Parse `Self` from `bytes`."]
34    pub fn from_bytes(bytes: &[u8]) -> Result<Self, Error> {
35        let (checksum_len_bytes, bytes) = bytes.split_at_checked(2).ok_or(Error::TooFewBytes)?;
36        let checksum_len_bytes: [u8; 2] =
37            checksum_len_bytes.try_into().expect("previous call guaranteed 2 element slice");
38        let checksum_length = u16::from_le_bytes(checksum_len_bytes) as usize;
39        let (observed_checksum, bytes) =
40            bytes.split_at_checked(checksum_length).ok_or(Error::TooFewBytes)?;
41        if observed_checksum != EXPECTED_CHECKSUM {
42            return Err(Error::ChecksumMismatch { observed_checksum: observed_checksum.to_vec() });
43        }
44        let fidl_config: FidlConfig = unpersist(bytes).map_err(Error::Unpersist)?;
45        Ok(Self {
46            minimum_sample_rate_sec: fidl_config.minimum_sample_rate_sec,
47            project_configs: fidl_config.project_configs,
48        })
49    }
50    pub fn record_inspect(&self, inspector_node: &Node) {
51        inspector_node.record_int("minimum_sample_rate_sec", self.minimum_sample_rate_sec);
52        let arr = inspector_node.create_string_array("project_configs", self.project_configs.len());
53        for i in 0..self.project_configs.len() {
54            arr.set(i, &self.project_configs[i]);
55        }
56        inspector_node.record(arr);
57    }
58}
59#[derive(Debug)]
60pub enum Error {
61    #[doc = r" Failed to read the content size of the VMO."]
62    GettingContentSize(zx::Status),
63    #[doc = r" Failed to read the content of the VMO."]
64    ReadingConfigBytes(zx::Status),
65    #[doc = r" The VMO was too small for this config library."]
66    TooFewBytes,
67    #[doc = r" The VMO's config ABI checksum did not match this library's."]
68    ChecksumMismatch { observed_checksum: Vec<u8> },
69    #[doc = r" Failed to parse the non-checksum bytes of the VMO as this library's FIDL type."]
70    Unpersist(fidl::Error),
71}
72impl std::fmt::Display for Error {
73    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
74        match self {
75            Self::GettingContentSize(status) => {
76                write!(f, "Failed to get content size: {status}")
77            }
78            Self::ReadingConfigBytes(status) => {
79                write!(f, "Failed to read VMO content: {status}")
80            }
81            Self::TooFewBytes => {
82                write!(f, "VMO content is not large enough for this config library.")
83            }
84            Self::ChecksumMismatch { observed_checksum } => {
85                write!(
86                    f,
87                    "ABI checksum mismatch, expected {:?}, got {:?}",
88                    EXPECTED_CHECKSUM, observed_checksum,
89                )
90            }
91            Self::Unpersist(fidl_error) => {
92                write!(f, "Failed to parse contents of config VMO: {fidl_error}")
93            }
94        }
95    }
96}
97impl std::error::Error for Error {
98    #[allow(unused_parens, reason = "rustfmt errors without parens here")]
99    fn source(&self) -> Option<(&'_ (dyn std::error::Error + 'static))> {
100        match self {
101            Self::GettingContentSize(ref status) | Self::ReadingConfigBytes(ref status) => {
102                Some(status)
103            }
104            Self::TooFewBytes => None,
105            Self::ChecksumMismatch { .. } => None,
106            Self::Unpersist(ref fidl_error) => Some(fidl_error),
107        }
108    }
109    fn description(&self) -> &str {
110        match self {
111            Self::GettingContentSize(_) => "getting content size",
112            Self::ReadingConfigBytes(_) => "reading VMO contents",
113            Self::TooFewBytes => "VMO contents too small",
114            Self::ChecksumMismatch { .. } => "ABI checksum mismatch",
115            Self::Unpersist(_) => "FIDL parsing error",
116        }
117    }
118}
sampler_component_config/sampler-component-config_rust_config_lib_source.rs

sampler_component_config/
sampler-component-config_rust_config_lib_source.rs
