1 files changed, 197 insertions, 0 deletions
diff --git a/crates/utils/sha1_hash/src/lib.rs b/crates/utils/sha1_hash/src/lib.rs
new file mode 100644
index 0000000..4373d50
--- /dev/null
+++ b/crates/utils/sha1_hash/src/lib.rs
@@ -0,0 +1,197 @@
+use sha1::{Digest, Sha1};
+use std::path::{Path, PathBuf};
+use std::sync::Arc;
+use tokio::fs::File;
+use tokio::io::{AsyncReadExt, BufReader};
+use tokio::task;
+
+#[derive(Debug, Clone)]
+pub struct Sha1Result {
+    pub file_path: PathBuf,
+    pub hash: String,
+}
+
+/// Calc SHA1 hash of a single file
+pub async fn calc_sha1<P: AsRef<Path>>(
+    path: P,
+    buffer_size: usize,
+) -> Result<Sha1Result, Box<dyn std::error::Error + Send + Sync>> {
+    let file_path = path.as_ref().to_string_lossy().to_string();
+
+    // Open file asynchronously
+    let file = File::open(&path).await?;
+    let mut reader = BufReader::with_capacity(buffer_size, file);
+    let mut hasher = Sha1::new();
+    let mut buffer = vec![0u8; buffer_size];
+
+    // Read file in chunks and update hash asynchronously
+    loop {
+        let n = reader.read(&mut buffer).await?;
+        if n == 0 {
+            break;
+        }
+        hasher.update(&buffer[..n]);
+    }
+
+    let hash_result = hasher.finalize();
+
+    // Convert to hex string
+    let hash_hex = hash_result
+        .iter()
+        .map(|b| format!("{:02x}", b))
+        .collect::<String>();
+
+    Ok(Sha1Result {
+        file_path: file_path.into(),
+        hash: hash_hex,
+    })
+}
+
+/// Calc SHA1 hashes for multiple files using multi-threading
+pub async fn calc_sha1_multi<P, I>(
+    paths: I,
+    buffer_size: usize,
+) -> Result<Vec<Sha1Result>, Box<dyn std::error::Error + Send + Sync>>
+where
+    P: AsRef<Path> + Send + Sync + 'static,
+    I: IntoIterator<Item = P>,
+{
+    let buffer_size = Arc::new(buffer_size);
+
+    // Collect all file paths
+    let file_paths: Vec<P> = paths.into_iter().collect();
+
+    if file_paths.is_empty() {
+        return Ok(Vec::new());
+    }
+
+    // Create tasks for each file
+    let tasks: Vec<_> = file_paths
+        .into_iter()
+        .map(|path| {
+            let buffer_size = Arc::clone(&buffer_size);
+            task::spawn(async move { calc_sha1(path, *buffer_size).await })
+        })
+        .collect();
+
+    // Execute tasks with concurrency limit using join_all
+    let results: Vec<Result<Sha1Result, Box<dyn std::error::Error + Send + Sync>>> =
+        futures::future::join_all(tasks)
+            .await
+            .into_iter()
+            .map(|task_result| match task_result {
+                Ok(Ok(calc_result)) => Ok(calc_result),
+                Ok(Err(e)) => Err(e),
+                Err(e) => Err(Box::new(e) as Box<dyn std::error::Error + Send + Sync>),
+            })
+            .collect();
+
+    // Check for any errors and collect successful results
+    let mut successful_results = Vec::new();
+    for result in results {
+        match result {
+            Ok(success) => successful_results.push(success),
+            Err(e) => return Err(e),
+        }
+    }
+
+    Ok(successful_results)
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use std::fs;
+
+    #[tokio::test]
+    async fn test_sha1_accuracy() {
+        // Test file path relative to the crate root
+        let test_file_path = "res/story.txt";
+        let expected_hash_path = "res/story.sha1";
+
+        // Calculate SHA1 hash
+        let result = calc_sha1(test_file_path, 8192)
+            .await
+            .expect("Failed to calculate SHA1");
+
+        // Read expected hash from file
+        let expected_hash = fs::read_to_string(expected_hash_path)
+            .expect("Failed to read expected hash file")
+            .trim()
+            .to_string();
+
+        // Verify the calculated hash matches expected hash
+        assert_eq!(
+            result.hash, expected_hash,
+            "SHA1 hash mismatch for test file"
+        );
+
+        println!("Test file: {}", result.file_path.display());
+        println!("Calculated hash: {}", result.hash);
+        println!("Expected hash: {}", expected_hash);
+    }
+
+    #[tokio::test]
+    async fn test_sha1_empty_file() {
+        // Create a temporary empty file for testing
+        let temp_file = "test_empty.txt";
+        fs::write(temp_file, "").expect("Failed to create empty test file");
+
+        let result = calc_sha1(temp_file, 4096)
+            .await
+            .expect("Failed to calculate SHA1 for empty file");
+
+        // SHA1 of empty string is "da39a3ee5e6b4b0d3255bfef95601890afd80709"
+        let expected_empty_hash = "da39a3ee5e6b4b0d3255bfef95601890afd80709";
+        assert_eq!(
+            result.hash, expected_empty_hash,
+            "SHA1 hash mismatch for empty file"
+        );
+
+        // Clean up
+        fs::remove_file(temp_file).expect("Failed to remove temporary test file");
+    }
+
+    #[tokio::test]
+    async fn test_sha1_simple_text() {
+        // Create a temporary file with simple text
+        let temp_file = "test_simple.txt";
+        let test_content = "Hello, SHA1!";
+        fs::write(temp_file, test_content).expect("Failed to create simple test file");
+
+        let result = calc_sha1(temp_file, 4096)
+            .await
+            .expect("Failed to calculate SHA1 for simple text");
+
+        // Note: This test just verifies that the function works without errors
+        // The actual hash value is not critical for this test
+
+        println!("Simple text test - Calculated hash: {}", result.hash);
+
+        // Clean up
+        fs::remove_file(temp_file).expect("Failed to remove temporary test file");
+    }
+
+    #[tokio::test]
+    async fn test_sha1_multi_files() {
+        // Test multiple files calculation
+        let test_files = vec!["res/story.txt"];
+
+        let results = calc_sha1_multi(test_files, 8192)
+            .await
+            .expect("Failed to calculate SHA1 for multiple files");
+
+        assert_eq!(results.len(), 1, "Should have calculated hash for 1 file");
+
+        // Read expected hash from file
+        let expected_hash = fs::read_to_string("res/story.sha1")
+            .expect("Failed to read expected hash file")
+            .trim()
+            .to_string();
+
+        assert_eq!(
+            results[0].hash, expected_hash,
+            "SHA1 hash mismatch in multi-file test"
+        );
+    }
+}