apple-codesign-quick/src/file_bytes.rs (a74924e) - apple-crates · Git

file_bytes.rs

use crate::error::{CodeSignError, Result};
use memmap2::{Mmap, MmapOptions};
use std::fs;
use std::path::Path;

pub(crate) enum FileBytes {
    Mapped(Mmap),
    Owned(Vec<u8>),
}

impl FileBytes {
    pub(crate) fn as_slice(&self) -> &[u8] {
        match self {
            FileBytes::Mapped(map) => map,
            FileBytes::Owned(bytes) => bytes,
        }
    }
}

/// Map a file read-only, or read it if it can't be mapped (empty files can't).
pub(crate) fn read_file_bytes(path: &Path) -> Result<FileBytes> {
    let file = fs::File::open(path).map_err(CodeSignError::io(path))?;
    let len = file.metadata().map_err(CodeSignError::io(path))?.len();
    if len == 0 {
        return Ok(FileBytes::Owned(Vec::new()));
    }

// Mappings are dropped before we rewrite a file, but someone else changing the bundle while we
    // sign it would break us, as it would break the D version of this.
    let map = unsafe { MmapOptions::new().map(&file) };
    match map {
        Ok(map) => Ok(FileBytes::Mapped(map)),
        Err(_) => fs::read(path)
            .map(FileBytes::Owned)
            .map_err(CodeSignError::io(path)),
    }
}

apple-crates

Refactor and unify a lot of things for another project and implement airdrop support