nautilus_test_kit/
files.rs

1// -------------------------------------------------------------------------------------------------
2//  Copyright (C) 2015-2025 Nautech Systems Pty Ltd. All rights reserved.
3//  https://nautechsystems.io
4//
5//  Licensed under the GNU Lesser General Public License Version 3.0 (the "License");
6//  You may not use this file except in compliance with the License.
7//  You may obtain a copy of the License at https://www.gnu.org/licenses/lgpl-3.0.en.html
8//
9//  Unless required by applicable law or agreed to in writing, software
10//  distributed under the License is distributed on an "AS IS" BASIS,
11//  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12//  See the License for the specific language governing permissions and
13//  limitations under the License.
14// -------------------------------------------------------------------------------------------------
15
16use std::{
17    fs::{File, OpenOptions},
18    io::{BufReader, BufWriter, Read, copy},
19    path::Path,
20};
21
22use reqwest::blocking::Client;
23use ring::digest;
24use serde_json::Value;
25
26/// Ensures that a file exists at the specified path by downloading it if necessary.
27///
28/// If the file already exists, it checks the integrity of the file using a SHA-256 checksum
29/// from the optional `checksums` file. If the checksum is valid, the function exits early. If
30/// the checksum is invalid or missing, the function updates the checksums file with the correct
31/// hash for the existing file without redownloading it.
32///
33/// If the file does not exist, it downloads the file from the specified `url` and updates the
34/// checksums file (if provided) with the calculated SHA-256 checksum of the downloaded file.
35pub fn ensure_file_exists_or_download_http(
36    filepath: &Path,
37    url: &str,
38    checksums: Option<&Path>,
39) -> anyhow::Result<()> {
40    if filepath.exists() {
41        println!("File already exists: {}", filepath.display());
42
43        if let Some(checksums_file) = checksums {
44            if verify_sha256_checksum(filepath, checksums_file)? {
45                println!("File is valid");
46                return Ok(());
47            } else {
48                let new_checksum = calculate_sha256(filepath)?;
49                println!("Adding checksum for existing file: {new_checksum}");
50                update_sha256_checksums(filepath, checksums_file, &new_checksum)?;
51                return Ok(());
52            }
53        }
54        return Ok(());
55    }
56
57    download_file(filepath, url)?;
58
59    if let Some(checksums_file) = checksums {
60        let new_checksum = calculate_sha256(filepath)?;
61        update_sha256_checksums(filepath, checksums_file, &new_checksum)?;
62    }
63
64    Ok(())
65}
66
67fn download_file(filepath: &Path, url: &str) -> anyhow::Result<()> {
68    println!("Downloading file from {url} to {}", filepath.display());
69
70    if let Some(parent) = filepath.parent() {
71        std::fs::create_dir_all(parent)?;
72    }
73
74    let mut response = Client::new().get(url).send()?;
75    if !response.status().is_success() {
76        anyhow::bail!("Failed to download file: HTTP {}", response.status());
77    }
78
79    let mut out = File::create(filepath)?;
80    copy(&mut response, &mut out)?;
81
82    println!("File downloaded to {}", filepath.display());
83    Ok(())
84}
85
86fn calculate_sha256(filepath: &Path) -> anyhow::Result<String> {
87    let mut file = File::open(filepath)?;
88    let mut context = digest::Context::new(&digest::SHA256);
89    let mut buffer = [0; 4096];
90
91    loop {
92        let count = file.read(&mut buffer)?;
93        if count == 0 {
94            break;
95        }
96        context.update(&buffer[..count]);
97    }
98
99    let digest = context.finish();
100    Ok(hex::encode(digest.as_ref()))
101}
102
103fn verify_sha256_checksum(filepath: &Path, checksums: &Path) -> anyhow::Result<bool> {
104    let file = File::open(checksums)?;
105    let reader = BufReader::new(file);
106    let checksums: Value = serde_json::from_reader(reader)?;
107
108    let filename = filepath.file_name().unwrap().to_str().unwrap();
109    if let Some(expected_checksum) = checksums.get(filename) {
110        let expected_checksum_str = expected_checksum.as_str().unwrap();
111        let expected_hash = expected_checksum_str
112            .strip_prefix("sha256:")
113            .unwrap_or(expected_checksum_str);
114        let calculated_checksum = calculate_sha256(filepath)?;
115        if expected_hash == calculated_checksum {
116            return Ok(true);
117        }
118    }
119
120    Ok(false)
121}
122
123fn update_sha256_checksums(
124    filepath: &Path,
125    checksums_file: &Path,
126    new_checksum: &str,
127) -> anyhow::Result<()> {
128    let checksums: Value = if checksums_file.exists() {
129        let file = File::open(checksums_file)?;
130        let reader = BufReader::new(file);
131        serde_json::from_reader(reader)?
132    } else {
133        serde_json::json!({})
134    };
135
136    let mut checksums_map = checksums.as_object().unwrap().clone();
137
138    // Add or update the checksum
139    let filename = filepath.file_name().unwrap().to_str().unwrap().to_string();
140    let prefixed_checksum = format!("sha256:{new_checksum}");
141    checksums_map.insert(filename, Value::String(prefixed_checksum));
142
143    let file = OpenOptions::new()
144        .write(true)
145        .create(true)
146        .truncate(true)
147        .open(checksums_file)?;
148    let writer = BufWriter::new(file);
149    serde_json::to_writer_pretty(writer, &serde_json::Value::Object(checksums_map))?;
150
151    Ok(())
152}
153
154////////////////////////////////////////////////////////////////////////////////
155// Tests
156////////////////////////////////////////////////////////////////////////////////
157#[cfg(test)]
158mod tests {
159    use std::{
160        fs,
161        io::{BufWriter, Write},
162        net::SocketAddr,
163        sync::Arc,
164    };
165
166    use axum::{Router, http::StatusCode, routing::get, serve};
167    use rstest::*;
168    use serde_json::{json, to_writer};
169    use tempfile::TempDir;
170    use tokio::{
171        net::TcpListener,
172        task,
173        time::{Duration, sleep},
174    };
175
176    use super::*;
177
178    async fn setup_test_server(
179        server_content: Option<String>,
180        status_code: StatusCode,
181    ) -> SocketAddr {
182        let server_content = Arc::new(server_content);
183        let server_content_clone = server_content.clone();
184        let app = Router::new().route(
185            "/testfile.txt",
186            get(move || {
187                let server_content = server_content_clone.clone();
188                async move {
189                    let response_body = match &*server_content {
190                        Some(content) => content.clone(),
191                        None => "File not found".to_string(),
192                    };
193                    (status_code, response_body)
194                }
195            }),
196        );
197
198        let listener = TcpListener::bind("127.0.0.1:0").await.unwrap();
199        let addr = listener.local_addr().unwrap();
200        let server = serve(listener, app);
201
202        task::spawn(async move {
203            if let Err(e) = server.await {
204                eprintln!("server error: {e}");
205            }
206        });
207
208        sleep(Duration::from_millis(100)).await;
209
210        addr
211    }
212
213    #[tokio::test]
214    async fn test_file_already_exists() {
215        let temp_dir = TempDir::new().unwrap();
216        let file_path = temp_dir.path().join("testfile.txt");
217        fs::write(&file_path, "Existing file content").unwrap();
218
219        let url = "http://example.com/testfile.txt".to_string();
220        let result = ensure_file_exists_or_download_http(&file_path, &url, None);
221
222        assert!(result.is_ok());
223        let content = fs::read_to_string(&file_path).unwrap();
224        assert_eq!(content, "Existing file content");
225    }
226
227    #[tokio::test]
228    async fn test_download_file_success() {
229        let temp_dir = TempDir::new().unwrap();
230        let filepath = temp_dir.path().join("testfile.txt");
231        let filepath_clone = filepath.clone();
232
233        let server_content = Some("Server file content".to_string());
234        let status_code = StatusCode::OK;
235        let addr = setup_test_server(server_content.clone(), status_code).await;
236        let url = format!("http://{addr}/testfile.txt");
237
238        let result = tokio::task::spawn_blocking(move || {
239            ensure_file_exists_or_download_http(&filepath_clone, &url, None)
240        })
241        .await
242        .unwrap();
243
244        assert!(result.is_ok());
245        let content = fs::read_to_string(&filepath).unwrap();
246        assert_eq!(content, server_content.unwrap());
247    }
248
249    #[tokio::test]
250    async fn test_download_file_not_found() {
251        let temp_dir = TempDir::new().unwrap();
252        let file_path = temp_dir.path().join("testfile.txt");
253
254        let server_content = None;
255        let status_code = StatusCode::NOT_FOUND;
256        let addr = setup_test_server(server_content, status_code).await;
257        let url = format!("http://{addr}/testfile.txt");
258
259        let result = tokio::task::spawn_blocking(move || {
260            ensure_file_exists_or_download_http(&file_path, &url, None)
261        })
262        .await
263        .unwrap();
264
265        assert!(result.is_err());
266        let err_msg = format!("{}", result.unwrap_err());
267        assert!(
268            err_msg.contains("Failed to download file"),
269            "Unexpected error message: {err_msg}"
270        );
271    }
272
273    #[tokio::test]
274    async fn test_network_error() {
275        let temp_dir = TempDir::new().unwrap();
276        let file_path = temp_dir.path().join("testfile.txt");
277
278        // Use an unreachable address to simulate a network error
279        let url = "http://127.0.0.1:0/testfile.txt".to_string();
280
281        let result = tokio::task::spawn_blocking(move || {
282            ensure_file_exists_or_download_http(&file_path, &url, None)
283        })
284        .await
285        .unwrap();
286
287        assert!(result.is_err());
288        let err_msg = format!("{}", result.unwrap_err());
289        assert!(
290            err_msg.contains("error"),
291            "Unexpected error message: {err_msg}"
292        );
293    }
294
295    #[rstest]
296    fn test_calculate_sha256() -> anyhow::Result<()> {
297        let temp_dir = TempDir::new()?;
298        let test_file_path = temp_dir.path().join("test_file.txt");
299        let mut test_file = File::create(&test_file_path)?;
300        let content = b"Hello, world!";
301        test_file.write_all(content)?;
302
303        let expected_hash = "315f5bdb76d078c43b8ac0064e4a0164612b1fce77c869345bfc94c75894edd3";
304        let calculated_hash = calculate_sha256(&test_file_path)?;
305
306        assert_eq!(calculated_hash, expected_hash);
307        Ok(())
308    }
309
310    #[rstest]
311    fn test_verify_sha256_checksum() -> anyhow::Result<()> {
312        let temp_dir = TempDir::new()?;
313        let test_file_path = temp_dir.path().join("test_file.txt");
314        let mut test_file = File::create(&test_file_path)?;
315        let content = b"Hello, world!";
316        test_file.write_all(content)?;
317
318        let calculated_checksum = calculate_sha256(&test_file_path)?;
319
320        // Create checksums.json containing the checksum
321        let checksums_path = temp_dir.path().join("checksums.json");
322        let checksums_data = json!({
323            "test_file.txt": format!("sha256:{}", calculated_checksum)
324        });
325        let checksums_file = File::create(&checksums_path)?;
326        let writer = BufWriter::new(checksums_file);
327        to_writer(writer, &checksums_data)?;
328
329        let is_valid = verify_sha256_checksum(&test_file_path, &checksums_path)?;
330        assert!(is_valid, "The checksum should be valid");
331        Ok(())
332    }
333}
nautilus_test_kit/files.rs

nautilus_test_kit/
files.rs
