Struct EncodedDepInfo

pub struct EncodedDepInfo {
    pub files: Vec<(DepInfoPathType, PathBuf, Option<(u64, String)>)>,
    pub env: Vec<(String, Option<String>)>,
}

Same as RustcDepInfo except avoids absolute paths as much as possible to allow moving around the target directory.

This is also stored in an optimized format to make parsing it fast because Cargo will read it for crates on all future compilations.

Currently the format looks like:

+--------+---------+------------+------------+---------------+---------------+
| marker | version | # of files | file paths | # of env vars | env var pairs |
+--------+---------+------------+------------+---------------+---------------+

Each field represents

• Marker — A magic marker to ensure that older Cargoes, which only recognize format v0 (prior to checksum support in f4ca7390), do not proceed with parsing newer formats. Since EncodedDepInfo is merely an optimization, and to avoid adding complexity, Cargo recognizes only one version of CURRENT_ENCODED_DEP_INFO_VERSION. The current layout looks like this

  +----------------------------+
  | [0x01 0x00 0x00 0x00 0xff] |
  +----------------------------+

  These bytes will be interpreted as “one file tracked and an invalid DepInfoPathType variant with 255” by older Cargoes, causing them to stop parsing. This could prevent problematic parsing as noted in rust-lang/cargo#14712.

• Version — The current format version.

• Number of files/envs — A u32 representing the number of things.

• File paths — Zero or more paths of files the dep-info file depends on. Each path is encoded as the following:

  +-----------+-------------+------------+---------------+-----------+-------+
  | path type | len of path | path bytes | cksum exists? | file size | cksum |
  +-----------+-------------+------------+---------------+-----------+-------+

• Env var pairs — Zero or more env vars the dep-info file depends on. Each env key-value pair is encoded as the following:

  +------------+-----------+---------------+--------------+-------------+
  | len of key | key bytes | value exists? | len of value | value bytes |
  +------------+-----------+---------------+--------------+-------------+

Fields

files: Vec<(DepInfoPathType, PathBuf, Option<(u64, String)>)>

env: Vec<(String, Option<String>)>

Implementations

impl EncodedDepInfo

pub fn parse(bytes: &[u8]) -> Option<EncodedDepInfo>

pub fn serialize(&self) -> CargoResult<Vec<u8>>

Trait Implementations

impl Debug for EncodedDepInfo

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for EncodedDepInfo

fn default() -> EncodedDepInfo

Returns the “default value” for a type.

impl PartialEq for EncodedDepInfo

fn eq(&self, other: &EncodedDepInfo) -> bool

Tests for self and other values to be equal, and is used by ==.

fn ne(&self, other: &Rhs) -> bool

Tests for !=. The default implementation is almost always sufficient, and should not be overridden without very good reason.

impl Eq for EncodedDepInfo

impl StructuralPartialEq for EncodedDepInfo

Layout

Note: Most layout information is completely unstable and may even differ between compilations. The only exception is types with certain repr(...) attributes. Please see the Rust Reference's “Type Layout” chapter for details on type layout guarantees.

Size: 48 bytes