src/client/backup_writer.rs

   1 use std::collections::HashSet;
   2 use std::os::unix::fs::OpenOptionsExt;
   3 use std::sync::atomic::{AtomicUsize, Ordering};
   4 use std::sync::{Arc, Mutex};
   5
   6 use anyhow::{bail, format_err, Error};
   7 use chrono::{DateTime, Utc};
   8 use futures::*;
   9 use futures::stream::Stream;
  10 use futures::future::AbortHandle;
  11 use serde_json::{json, Value};
  12 use tokio::io::AsyncReadExt;
  13 use tokio::sync::{mpsc, oneshot};
  14
  15 use proxmox::tools::digest_to_hex;
  16
  17 use super::merge_known_chunks::{MergedChunkInfo, MergeKnownChunks};
  18 use crate::backup::*;
  19
  20 use super::{HttpClient, H2Client};
  21
  22 pub struct BackupWriter {
  23     h2: H2Client,
  24     abort: AbortHandle,
  25     verbose: bool,
  26     crypt_config: Option<Arc<CryptConfig>>,
  27 }
  28
  29 impl Drop for BackupWriter {
  30
  31     fn drop(&mut self) {
  32         self.abort.abort();
  33     }
  34 }
  35
  36 pub struct BackupStats {
  37     pub size: u64,
  38     pub csum: [u8; 32],
  39 }
  40
  41 impl BackupWriter {
  42
  43     fn new(h2: H2Client, abort: AbortHandle, crypt_config: Option<Arc<CryptConfig>>, verbose: bool) -> Arc<Self> {
  44         Arc::new(Self { h2, abort, crypt_config, verbose })
  45     }
  46
  47     pub async fn start(
  48         client: HttpClient,
  49         crypt_config: Option<Arc<CryptConfig>>,
  50         datastore: &str,
  51         backup_type: &str,
  52         backup_id: &str,
  53         backup_time: DateTime<Utc>,
  54         debug: bool,
  55     ) -> Result<Arc<BackupWriter>, Error> {
  56
  57         let param = json!({
  58             "backup-type": backup_type,
  59             "backup-id": backup_id,
  60             "backup-time": backup_time.timestamp(),
  61             "store": datastore,
  62             "debug": debug
  63         });
  64
  65         let req = HttpClient::request_builder(
  66             client.server(), "GET", "/api2/json/backup", Some(param)).unwrap();
  67
  68         let (h2, abort) = client.start_h2_connection(req, String::from(PROXMOX_BACKUP_PROTOCOL_ID_V1!())).await?;
  69
  70         Ok(BackupWriter::new(h2, abort, crypt_config, debug))
  71     }
  72
  73     pub async fn get(
  74         &self,
  75         path: &str,
  76         param: Option<Value>,
  77     ) -> Result<Value, Error> {
  78         self.h2.get(path, param).await
  79     }
  80
  81     pub async fn put(
  82         &self,
  83         path: &str,
  84         param: Option<Value>,
  85     ) -> Result<Value, Error> {
  86         self.h2.put(path, param).await
  87     }
  88
  89     pub async fn post(
  90         &self,
  91         path: &str,
  92         param: Option<Value>,
  93     ) -> Result<Value, Error> {
  94         self.h2.post(path, param).await
  95     }
  96
  97     pub async fn upload_post(
  98         &self,
  99         path: &str,
 100         param: Option<Value>,
 101         content_type: &str,
 102         data: Vec<u8>,
 103     ) -> Result<Value, Error> {
 104         self.h2.upload("POST", path, param, content_type, data).await
 105     }
 106
 107     pub async fn send_upload_request(
 108         &self,
 109         method: &str,
 110         path: &str,
 111         param: Option<Value>,
 112         content_type: &str,
 113         data: Vec<u8>,
 114     ) -> Result<h2::client::ResponseFuture, Error> {
 115
 116         let request = H2Client::request_builder("localhost", method, path, param, Some(content_type)).unwrap();
 117         let response_future = self.h2.send_request(request, Some(bytes::Bytes::from(data.clone()))).await?;
 118         Ok(response_future)
 119     }
 120
 121     pub async fn upload_put(
 122         &self,
 123         path: &str,
 124         param: Option<Value>,
 125         content_type: &str,
 126         data: Vec<u8>,
 127     ) -> Result<Value, Error> {
 128         self.h2.upload("PUT", path, param, content_type, data).await
 129     }
 130
 131     pub async fn finish(self: Arc<Self>) -> Result<(), Error> {
 132         let h2 = self.h2.clone();
 133
 134         h2.post("finish", None)
 135             .map_ok(move |_| {
 136                 self.abort.abort();
 137             })
 138             .await
 139     }
 140
 141     pub fn cancel(&self) {
 142         self.abort.abort();
 143     }
 144
 145     pub async fn upload_blob<R: std::io::Read>(
 146         &self,
 147         mut reader: R,
 148         file_name: &str,
 149      ) -> Result<BackupStats, Error> {
 150         let mut raw_data = Vec::new();
 151         // fixme: avoid loading into memory
 152         reader.read_to_end(&mut raw_data)?;
 153
 154         let csum = openssl::sha::sha256(&raw_data);
 155         let param = json!({"encoded-size": raw_data.len(), "file-name": file_name });
 156         let size = raw_data.len() as u64;
 157         let _value = self.h2.upload("POST", "blob", Some(param), "application/octet-stream", raw_data).await?;
 158         Ok(BackupStats { size, csum })
 159     }
 160
 161     pub async fn upload_blob_from_data(
 162         &self,
 163         data: Vec<u8>,
 164         file_name: &str,
 165         compress: bool,
 166         encrypt: bool,
 167     ) -> Result<BackupStats, Error> {
 168         let blob = match (encrypt, &self.crypt_config) {
 169              (false, _) => DataBlob::encode(&data, None, compress)?,
 170              (true, None) => bail!("requested encryption without a crypt config"),
 171              (true, Some(crypt_config)) => DataBlob::encode(&data, Some(crypt_config), compress)?,
 172         };
 173
 174         let raw_data = blob.into_inner();
 175         let size = raw_data.len() as u64;
 176
 177         let csum = openssl::sha::sha256(&raw_data);
 178         let param = json!({"encoded-size": size, "file-name": file_name });
 179         let _value = self.h2.upload("POST", "blob", Some(param), "application/octet-stream", raw_data).await?;
 180         Ok(BackupStats { size, csum })
 181     }
 182
 183     pub async fn upload_blob_from_file<P: AsRef<std::path::Path>>(
 184         &self,
 185         src_path: P,
 186         file_name: &str,
 187         compress: bool,
 188         encrypt: bool,
 189     ) -> Result<BackupStats, Error> {
 190
 191         let src_path = src_path.as_ref();
 192
 193         let mut file = tokio::fs::File::open(src_path)
 194             .await
 195             .map_err(|err| format_err!("unable to open file {:?} - {}", src_path, err))?;
 196
 197         let mut contents = Vec::new();
 198
 199         file.read_to_end(&mut contents)
 200             .await
 201             .map_err(|err| format_err!("unable to read file {:?} - {}", src_path, err))?;
 202
 203         self.upload_blob_from_data(contents, file_name, compress, encrypt).await
 204     }
 205
 206     pub async fn upload_stream(
 207         &self,
 208         previous_manifest: Option<Arc<BackupManifest>>,
 209         archive_name: &str,
 210         stream: impl Stream<Item = Result<bytes::BytesMut, Error>>,
 211         prefix: &str,
 212         fixed_size: Option<u64>,
 213         compress: bool,
 214         encrypt: bool,
 215     ) -> Result<BackupStats, Error> {
 216         let known_chunks = Arc::new(Mutex::new(HashSet::new()));
 217
 218         let mut param = json!({ "archive-name": archive_name });
 219         if let Some(size) = fixed_size {
 220             param["size"] = size.into();
 221         }
 222
 223         if encrypt && self.crypt_config.is_none() {
 224             bail!("requested encryption without a crypt config");
 225         }
 226
 227         let index_path = format!("{}_index", prefix);
 228         let close_path = format!("{}_close", prefix);
 229
 230         if let Some(manifest) = previous_manifest {
 231             // try, but ignore errors
 232             match archive_type(archive_name) {
 233                 Ok(ArchiveType::FixedIndex) => {
 234                     let _ = self.download_previous_fixed_index(archive_name, &manifest, known_chunks.clone()).await;
 235                 }
 236                 Ok(ArchiveType::DynamicIndex) => {
 237                     let _ = self.download_previous_dynamic_index(archive_name, &manifest, known_chunks.clone()).await;
 238                 }
 239                 _ => { /* do nothing */ }
 240             }
 241         }
 242
 243         let wid = self.h2.post(&index_path, Some(param)).await?.as_u64().unwrap();
 244
 245         let (chunk_count, size, duration, speed, csum) =
 246             Self::upload_chunk_info_stream(
 247                 self.h2.clone(),
 248                 wid,
 249                 stream,
 250                 &prefix,
 251                 known_chunks.clone(),
 252                 if encrypt { self.crypt_config.clone() } else { None },
 253                 compress,
 254                 self.verbose,
 255             )
 256             .await?;
 257
 258         println!("{}: Uploaded {} bytes as {} chunks in {} seconds ({} MB/s).", archive_name, size, chunk_count, duration.as_secs(), speed);
 259         if chunk_count > 0 {
 260             println!("{}: Average chunk size was {} bytes.", archive_name, size/chunk_count);
 261             println!("{}: Time per request: {} microseconds.", archive_name, (duration.as_micros())/(chunk_count as u128));
 262         }
 263
 264         let param = json!({
 265             "wid": wid ,
 266             "chunk-count": chunk_count,
 267             "size": size,
 268             "csum": proxmox::tools::digest_to_hex(&csum),
 269         });
 270         let _value = self.h2.post(&close_path, Some(param)).await?;
 271         Ok(BackupStats {
 272             size: size as u64,
 273             csum,
 274         })
 275     }
 276
 277     fn response_queue(verbose: bool) -> (
 278         mpsc::Sender<h2::client::ResponseFuture>,
 279         oneshot::Receiver<Result<(), Error>>
 280     ) {
 281         let (verify_queue_tx, verify_queue_rx) = mpsc::channel(100);
 282         let (verify_result_tx, verify_result_rx) = oneshot::channel();
 283
 284         // FIXME: check if this works as expected as replacement for the combinator below?
 285         // tokio::spawn(async move {
 286         //     let result: Result<(), Error> = (async move {
 287         //         while let Some(response) = verify_queue_rx.recv().await {
 288         //             match H2Client::h2api_response(response.await?).await {
 289         //                 Ok(result) => println!("RESPONSE: {:?}", result),
 290         //                 Err(err) => bail!("pipelined request failed: {}", err),
 291         //             }
 292         //         }
 293         //         Ok(())
 294         //     }).await;
 295         //     let _ignore_closed_channel = verify_result_tx.send(result);
 296         // });
 297         // old code for reference?
 298         tokio::spawn(
 299             verify_queue_rx
 300                 .map(Ok::<_, Error>)
 301                 .try_for_each(move |response: h2::client::ResponseFuture| {
 302                     response
 303                         .map_err(Error::from)
 304                         .and_then(H2Client::h2api_response)
 305                         .map_ok(move |result| if verbose { println!("RESPONSE: {:?}", result) })
 306                         .map_err(|err| format_err!("pipelined request failed: {}", err))
 307                 })
 308                 .map(|result| {
 309                       let _ignore_closed_channel = verify_result_tx.send(result);
 310                 })
 311         );
 312
 313         (verify_queue_tx, verify_result_rx)
 314     }
 315
 316     fn append_chunk_queue(h2: H2Client, wid: u64, path: String, verbose: bool) -> (
 317         mpsc::Sender<(MergedChunkInfo, Option<h2::client::ResponseFuture>)>,
 318         oneshot::Receiver<Result<(), Error>>,
 319     ) {
 320         let (verify_queue_tx, verify_queue_rx) = mpsc::channel(64);
 321         let (verify_result_tx, verify_result_rx) = oneshot::channel();
 322
 323         let h2_2 = h2.clone();
 324
 325         // FIXME: async-block-ify this code!
 326         tokio::spawn(
 327             verify_queue_rx
 328                 .map(Ok::<_, Error>)
 329                 .and_then(move |(merged_chunk_info, response): (MergedChunkInfo, Option<h2::client::ResponseFuture>)| {
 330                     match (response, merged_chunk_info) {
 331                         (Some(response), MergedChunkInfo::Known(list)) => {
 332                             future::Either::Left(
 333                                 response
 334                                     .map_err(Error::from)
 335                                     .and_then(H2Client::h2api_response)
 336                                     .and_then(move |_result| {
 337                                         future::ok(MergedChunkInfo::Known(list))
 338                                     })
 339                             )
 340                         }
 341                         (None, MergedChunkInfo::Known(list)) => {
 342                             future::Either::Right(future::ok(MergedChunkInfo::Known(list)))
 343                         }
 344                         _ => unreachable!(),
 345                     }
 346                 })
 347                 .merge_known_chunks()
 348                 .and_then(move |merged_chunk_info| {
 349                     match merged_chunk_info {
 350                         MergedChunkInfo::Known(chunk_list) => {
 351                             let mut digest_list = vec![];
 352                             let mut offset_list = vec![];
 353                             for (offset, digest) in chunk_list {
 354                                 digest_list.push(digest_to_hex(&digest));
 355                                 offset_list.push(offset);
 356                             }
 357                             if verbose { println!("append chunks list len ({})", digest_list.len()); }
 358                             let param = json!({ "wid": wid, "digest-list": digest_list, "offset-list": offset_list });
 359                             let request = H2Client::request_builder("localhost", "PUT", &path, None, Some("application/json")).unwrap();
 360                             let param_data = bytes::Bytes::from(param.to_string().into_bytes());
 361                             let upload_data = Some(param_data);
 362                             h2_2.send_request(request, upload_data)
 363                                 .and_then(move |response| {
 364                                     response
 365                                         .map_err(Error::from)
 366                                         .and_then(H2Client::h2api_response)
 367                                         .map_ok(|_| ())
 368                                 })
 369                                 .map_err(|err| format_err!("pipelined request failed: {}", err))
 370                         }
 371                         _ => unreachable!(),
 372                     }
 373                 })
 374                 .try_for_each(|_| future::ok(()))
 375                 .map(|result| {
 376                       let _ignore_closed_channel = verify_result_tx.send(result);
 377                 })
 378         );
 379
 380         (verify_queue_tx, verify_result_rx)
 381     }
 382
 383     pub async fn download_previous_fixed_index(
 384         &self,
 385         archive_name: &str,
 386         manifest: &BackupManifest,
 387         known_chunks: Arc<Mutex<HashSet<[u8;32]>>>,
 388     ) -> Result<FixedIndexReader, Error> {
 389
 390         let mut tmpfile = std::fs::OpenOptions::new()
 391             .write(true)
 392             .read(true)
 393             .custom_flags(libc::O_TMPFILE)
 394             .open("/tmp")?;
 395
 396         let param = json!({ "archive-name": archive_name });
 397         self.h2.download("previous", Some(param), &mut tmpfile).await?;
 398
 399         let index = FixedIndexReader::new(tmpfile)
 400             .map_err(|err| format_err!("unable to read fixed index '{}' - {}", archive_name, err))?;
 401         // Note: do not use values stored in index (not trusted) - instead, computed them again
 402         let (csum, size) = index.compute_csum();
 403         manifest.verify_file(archive_name, &csum, size)?;
 404
 405         // add index chunks to known chunks
 406         let mut known_chunks = known_chunks.lock().unwrap();
 407         for i in 0..index.index_count() {
 408             known_chunks.insert(*index.index_digest(i).unwrap());
 409         }
 410
 411         if self.verbose {
 412             println!("{}: known chunks list length is {}", archive_name, index.index_count());
 413         }
 414
 415         Ok(index)
 416     }
 417
 418     pub async fn download_previous_dynamic_index(
 419         &self,
 420         archive_name: &str,
 421         manifest: &BackupManifest,
 422         known_chunks: Arc<Mutex<HashSet<[u8;32]>>>,
 423     ) -> Result<DynamicIndexReader, Error> {
 424
 425         let mut tmpfile = std::fs::OpenOptions::new()
 426             .write(true)
 427             .read(true)
 428             .custom_flags(libc::O_TMPFILE)
 429             .open("/tmp")?;
 430
 431         let param = json!({ "archive-name": archive_name });
 432         self.h2.download("previous", Some(param), &mut tmpfile).await?;
 433
 434         let index = DynamicIndexReader::new(tmpfile)
 435             .map_err(|err| format_err!("unable to read dynmamic index '{}' - {}", archive_name, err))?;
 436         // Note: do not use values stored in index (not trusted) - instead, computed them again
 437         let (csum, size) = index.compute_csum();
 438         manifest.verify_file(archive_name, &csum, size)?;
 439
 440         // add index chunks to known chunks
 441         let mut known_chunks = known_chunks.lock().unwrap();
 442         for i in 0..index.index_count() {
 443             known_chunks.insert(*index.index_digest(i).unwrap());
 444         }
 445
 446         if self.verbose {
 447             println!("{}: known chunks list length is {}", archive_name, index.index_count());
 448         }
 449
 450         Ok(index)
 451     }
 452
 453     /// Download backup manifest (index.json) of last backup
 454     pub async fn download_previous_manifest(&self) -> Result<BackupManifest, Error> {
 455
 456         let mut raw_data = Vec::with_capacity(64 * 1024);
 457
 458         let param = json!({ "archive-name": MANIFEST_BLOB_NAME });
 459         self.h2.download("previous", Some(param), &mut raw_data).await?;
 460
 461         let blob = DataBlob::from_raw(raw_data)?;
 462         blob.verify_crc()?;
 463         let data = blob.decode(self.crypt_config.as_ref().map(Arc::as_ref))?;
 464
 465         let manifest = BackupManifest::from_data(&data[..], self.crypt_config.as_ref().map(Arc::as_ref))?;
 466
 467         Ok(manifest)
 468     }
 469
 470     fn upload_chunk_info_stream(
 471         h2: H2Client,
 472         wid: u64,
 473         stream: impl Stream<Item = Result<bytes::BytesMut, Error>>,
 474         prefix: &str,
 475         known_chunks: Arc<Mutex<HashSet<[u8;32]>>>,
 476         crypt_config: Option<Arc<CryptConfig>>,
 477         compress: bool,
 478         verbose: bool,
 479     ) -> impl Future<Output = Result<(usize, usize, std::time::Duration, usize, [u8; 32]), Error>> {
 480
 481         let repeat = Arc::new(AtomicUsize::new(0));
 482         let repeat2 = repeat.clone();
 483
 484         let stream_len = Arc::new(AtomicUsize::new(0));
 485         let stream_len2 = stream_len.clone();
 486
 487         let append_chunk_path = format!("{}_index", prefix);
 488         let upload_chunk_path = format!("{}_chunk", prefix);
 489         let is_fixed_chunk_size = prefix == "fixed";
 490
 491         let (upload_queue, upload_result) =
 492             Self::append_chunk_queue(h2.clone(), wid, append_chunk_path.to_owned(), verbose);
 493
 494         let start_time = std::time::Instant::now();
 495
 496         let index_csum = Arc::new(Mutex::new(Some(openssl::sha::Sha256::new())));
 497         let index_csum_2 = index_csum.clone();
 498
 499         stream
 500             .and_then(move |data| {
 501
 502                 let chunk_len = data.len();
 503
 504                 repeat.fetch_add(1, Ordering::SeqCst);
 505                 let offset = stream_len.fetch_add(chunk_len, Ordering::SeqCst) as u64;
 506
 507                 let mut chunk_builder = DataChunkBuilder::new(data.as_ref())
 508                     .compress(compress);
 509
 510                 if let Some(ref crypt_config) = crypt_config {
 511                     chunk_builder = chunk_builder.crypt_config(crypt_config);
 512                 }
 513
 514                 let mut known_chunks = known_chunks.lock().unwrap();
 515                 let digest = chunk_builder.digest();
 516
 517                 let mut guard = index_csum.lock().unwrap();
 518                 let csum = guard.as_mut().unwrap();
 519
 520                 let chunk_end = offset + chunk_len as u64;
 521
 522                 if !is_fixed_chunk_size { csum.update(&chunk_end.to_le_bytes()); }
 523                 csum.update(digest);
 524
 525                 let chunk_is_known = known_chunks.contains(digest);
 526                 if chunk_is_known {
 527                     future::ok(MergedChunkInfo::Known(vec![(offset, *digest)]))
 528                 } else {
 529                     known_chunks.insert(*digest);
 530                     future::ready(chunk_builder
 531                         .build()
 532                         .map(move |(chunk, digest)| MergedChunkInfo::New(ChunkInfo {
 533                             chunk,
 534                             digest,
 535                             chunk_len: chunk_len as u64,
 536                             offset,
 537                         }))
 538                     )
 539                 }
 540             })
 541             .merge_known_chunks()
 542             .try_for_each(move |merged_chunk_info| {
 543
 544                 if let MergedChunkInfo::New(chunk_info) = merged_chunk_info {
 545                     let offset = chunk_info.offset;
 546                     let digest = chunk_info.digest;
 547                     let digest_str = digest_to_hex(&digest);
 548
 549                     if verbose {
 550                         println!("upload new chunk {} ({} bytes, offset {})", digest_str,
 551                                  chunk_info.chunk_len, offset);
 552                     }
 553
 554                     let chunk_data = chunk_info.chunk.into_inner();
 555                     let param = json!({
 556                         "wid": wid,
 557                         "digest": digest_str,
 558                         "size": chunk_info.chunk_len,
 559                         "encoded-size": chunk_data.len(),
 560                     });
 561
 562                     let ct = "application/octet-stream";
 563                     let request = H2Client::request_builder("localhost", "POST", &upload_chunk_path, Some(param), Some(ct)).unwrap();
 564                     let upload_data = Some(bytes::Bytes::from(chunk_data));
 565
 566                     let new_info = MergedChunkInfo::Known(vec![(offset, digest)]);
 567
 568                     let mut upload_queue = upload_queue.clone();
 569                     future::Either::Left(h2
 570                         .send_request(request, upload_data)
 571                         .and_then(move |response| async move {
 572                             upload_queue
 573                                 .send((new_info, Some(response)))
 574                                 .await
 575                                 .map_err(|err| format_err!("failed to send to upload queue: {}", err))
 576                         })
 577                     )
 578                 } else {
 579                     let mut upload_queue = upload_queue.clone();
 580                     future::Either::Right(async move {
 581                         upload_queue
 582                             .send((merged_chunk_info, None))
 583                             .await
 584                             .map_err(|err| format_err!("failed to send to upload queue: {}", err))
 585                     })
 586                 }
 587             })
 588             .then(move |result| async move {
 589                 upload_result.await?.and(result)
 590             }.boxed())
 591             .and_then(move |_| {
 592                 let repeat = repeat2.load(Ordering::SeqCst);
 593                 let stream_len = stream_len2.load(Ordering::SeqCst);
 594                 let speed = ((stream_len*1_000_000)/(1024*1024))/(start_time.elapsed().as_micros() as usize);
 595
 596                 let mut guard = index_csum_2.lock().unwrap();
 597                 let csum = guard.take().unwrap().finish();
 598
 599                 futures::future::ok((repeat, stream_len, start_time.elapsed(), speed, csum))
 600             })
 601     }
 602
 603     /// Upload speed test - prints result ot stdout
 604     pub async fn upload_speedtest(&self, verbose: bool) -> Result<usize, Error> {
 605
 606         let mut data = vec![];
 607         // generate pseudo random byte sequence
 608         for i in 0..1024*1024 {
 609             for j in 0..4 {
 610                 let byte = ((i >> (j<<3))&0xff) as u8;
 611                 data.push(byte);
 612             }
 613         }
 614
 615         let item_len = data.len();
 616
 617         let mut repeat = 0;
 618
 619         let (upload_queue, upload_result) = Self::response_queue(verbose);
 620
 621         let start_time = std::time::Instant::now();
 622
 623         loop {
 624             repeat += 1;
 625             if start_time.elapsed().as_secs() >= 5 {
 626                 break;
 627             }
 628
 629             let mut upload_queue = upload_queue.clone();
 630
 631             if verbose { println!("send test data ({} bytes)", data.len()); }
 632             let request = H2Client::request_builder("localhost", "POST", "speedtest", None, None).unwrap();
 633             let request_future = self.h2.send_request(request, Some(bytes::Bytes::from(data.clone()))).await?;
 634
 635             upload_queue.send(request_future).await?;
 636         }
 637
 638         drop(upload_queue); // close queue
 639
 640         let _ = upload_result.await?;
 641
 642         println!("Uploaded {} chunks in {} seconds.", repeat, start_time.elapsed().as_secs());
 643         let speed = ((item_len*1_000_000*(repeat as usize))/(1024*1024))/(start_time.elapsed().as_micros() as usize);
 644         println!("Time per request: {} microseconds.", (start_time.elapsed().as_micros())/(repeat as u128));
 645
 646         Ok(speed)
 647     }
 648 }