RGBCube/uutils-coreutils
1
Fork 0
mirror of https://github.com/RGBCube/uutils-coreutils synced 2025-07-29 12:07:46 +00:00
Code Issues Activity

truncate: create TruncateMode::to_size() method

Browse source 
Create a method that computes the final target size in bytes for the
file to truncate, given the reference file size and the parameter to the
`TruncateMode`.
This commit is contained in:
Jeffrey Finkelstein 2021-05-21 21:09:33 -04:00
parent 544ae87575
commit c6d4d0c07d
1 changed files with 27 additions and 10 deletions
Download patch file Download diff file Expand all files Collapse all files

37
src/uu/truncate/src/truncate.rs
View file

@ -27,6 +27,32 @@ enum TruncateMode {
RoundUp(u64),
}
impl TruncateMode {
/// Compute a target size in bytes for this truncate mode.
///
/// `fsize` is the size of the reference file, in bytes.
///
/// # Examples
///
/// ```rust,ignore
/// let mode = TruncateMode::Extend(5);
/// let fsize = 10;
/// assert_eq!(mode.to_size(fsize), 15);
/// ```
fn to_size(&self, fsize: u64) -> u64 {
match self {
TruncateMode::Absolute(modsize) => *modsize,
TruncateMode::Reference(_) => fsize,
TruncateMode::Extend(modsize) => fsize + modsize,
TruncateMode::Reduce(modsize) => fsize - modsize,
TruncateMode::AtMost(modsize) => fsize.min(*modsize),
TruncateMode::AtLeast(modsize) => fsize.max(*modsize),
TruncateMode::RoundDown(modsize) => fsize - fsize % modsize,
TruncateMode::RoundUp(modsize) => fsize + fsize % modsize,
}
}
}
static ABOUT: &str = "Shrink or extend the size of each file to the specified size.";
static VERSION: &str = env!("CARGO_PKG_VERSION");
@ -176,16 +202,7 @@ fn truncate(
}
},
};
let tsize: u64 = match mode {
TruncateMode::Absolute(modsize) => modsize,
TruncateMode::Reference(_) => fsize,
TruncateMode::Extend(modsize) => fsize + modsize,
TruncateMode::Reduce(modsize) => fsize - modsize,
TruncateMode::AtMost(modsize) => fsize.min(modsize),
TruncateMode::AtLeast(modsize) => fsize.max(modsize),
TruncateMode::RoundDown(modsize) => fsize - fsize % modsize,
TruncateMode::RoundUp(modsize) => fsize + fsize % modsize,
};
let tsize = mode.to_size(fsize);
match file.set_len(tsize) {
Ok(_) => {}
Err(f) => crash!(1, "{}", f.to_string()),