zip-rs-wasm/examples/write-large-file.rs
2024-05-15 15:31:17 -07:00

37 lines
1.2 KiB
Rust

//! Write a huge file with lots of zeros, that should compress perfectly.
fn main() -> Result<(), Box<dyn std::error::Error>> {
if !cfg!(feature = "_deflate-any") {
return Err("Please enable one of the deflate features".into());
}
let args: Vec<_> = std::env::args().collect();
if args.len() < 2 {
return Err(format!("Usage: {} <filename>", args[0]).into());
}
#[cfg(feature = "_deflate-any")]
{
let filename = &*args[1];
use std::io::Write;
use zip::write::SimpleFileOptions;
let file = std::fs::File::create(filename)?;
let mut zip = zip::ZipWriter::new(file);
let options = SimpleFileOptions::default()
.compression_method(zip::CompressionMethod::Deflated)
// files over u32::MAX require this flag set.
.large_file(true)
.unix_permissions(0o755);
zip.start_file("huge-file-of-zeroes", options)?;
let content: Vec<_> = std::iter::repeat(0_u8).take(65 * 1024).collect();
let mut bytes_written = 0_u64;
while bytes_written < u32::MAX as u64 {
zip.write_all(&content)?;
bytes_written += content.len() as u64;
}
zip.finish()?;
}
Ok(())
}