module util import os import io import crypto.md5 import crypto.sha256 const reader_buf_size = 1_000_000 const prefixes = ['B', 'KB', 'MB', 'GB'] // Dummy struct to work around the fact that you can only share structs, maps & // arrays pub struct Dummy { x int } // exit_with_message exits the program with a given status code after having // first printed a specific message to STDERR [noreturn] pub fn exit_with_message(code int, msg string) { eprintln(msg) exit(code) } // reader_to_file writes the contents of a BufferedReader to a file pub fn reader_to_file(mut reader io.BufferedReader, length int, path string) ? { mut file := os.create(path) ? defer { file.close() } mut buf := []byte{len: util.reader_buf_size} mut bytes_left := length // Repeat as long as the stream still has data for bytes_left > 0 { // TODO check if just breaking here is safe bytes_read := reader.read(mut buf) or { break } bytes_left -= bytes_read mut to_write := bytes_read for to_write > 0 { // TODO don't just loop infinitely here bytes_written := file.write(buf[bytes_read - to_write..bytes_read]) or { continue } to_write = to_write - bytes_written } } } // hash_file returns the md5 & sha256 hash of a given file // TODO actually implement sha256 pub fn hash_file(path &string) ?(string, string) { file := os.open(path) or { return error('Failed to open file.') } mut md5sum := md5.new() mut sha256sum := sha256.new() buf_size := int(1_000_000) mut buf := []byte{len: buf_size} mut bytes_left := os.file_size(path) for bytes_left > 0 { // TODO check if just breaking here is safe bytes_read := file.read(mut buf) or { return error('Failed to read from file.') } bytes_left -= u64(bytes_read) // For now we'll assume that this always works md5sum.write(buf[..bytes_read]) or { return error('Failed to update md5 checksum. This should never happen.') } sha256sum.write(buf[..bytes_read]) or { return error('Failed to update sha256 checksum. This should never happen.') } } return md5sum.checksum().hex(), sha256sum.checksum().hex() } // pretty_bytes converts a byte count to human-readable version pub fn pretty_bytes(bytes int) string { mut i := 0 mut n := f32(bytes) for n >= 1024 { i++ n /= 1024 } return '${n:.2}${util.prefixes[i]}' }