seiso.moe
1use anyhow::{Context, Result};
2use hex;
3use sha2::{Digest, Sha256};
4use std::fs::{File};
5use std::io::{BufReader, Read};
6use std::path::Path;
7
8const HASH_BUFFER_SIZE: usize = 8192;
9
10pub fn calculate_image_hash(path: &Path) -> Result<String> {
11 let file = File::open(path)
12 .with_context(|| format!("Failed to open image file for hashing: {}", path.display()))?;
13 let mut reader = BufReader::with_capacity(HASH_BUFFER_SIZE, file);
14 let mut hasher = Sha256::new();
15 let mut buffer = [0u8; HASH_BUFFER_SIZE];
16
17 loop {
18 let bytes_read = reader.read(&mut buffer).with_context(|| {
19 format!("Failed to read image file for hashing: {}", path.display())
20 })?;
21 if bytes_read == 0 {
22 break;
23 }
24 hasher.update(&buffer[..bytes_read]);
25 }
26
27 let hash_bytes = hasher.finalize();
28 Ok(hex::encode(hash_bytes))
29}