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https://github.com/RGBCube/uutils-coreutils
synced 2025-07-29 12:07:46 +00:00
dd: move dd_out() function up to module level
Move the `dd_out()` function out of the `impl Output` and up to the module level, renaming it to `dd_copy()`. This change aligns it with the pattern set by `std::io::copy()`, which similarly takes an input reader and an output writer. This does not change the behavior of `dd`, just the code organization to make it more closely match the idioms in the Rust standard library.
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1 changed files with 94 additions and 95 deletions
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@ -138,7 +138,7 @@ impl Read for Source {
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///
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///
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/// Use the [`Input::new_stdin`] or [`Input::new_file`] functions to
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/// Use the [`Input::new_stdin`] or [`Input::new_file`] functions to
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/// construct a new instance of this struct. Then pass the instance to
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/// construct a new instance of this struct. Then pass the instance to
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/// the [`Output::dd_out`] function to execute the main copy operation
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/// the [`dd_copy`] function to execute the main copy operation
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/// for `dd`.
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/// for `dd`.
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struct Input<'a> {
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struct Input<'a> {
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/// The source from which bytes will be read.
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/// The source from which bytes will be read.
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@ -449,7 +449,7 @@ impl Write for Dest {
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///
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///
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/// Use the [`Output::new_stdout`] or [`Output::new_file`] functions
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/// Use the [`Output::new_stdout`] or [`Output::new_file`] functions
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/// to construct a new instance of this struct. Then use the
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/// to construct a new instance of this struct. Then use the
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/// [`Output::dd_out`] function to execute the main copy operation for
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/// [`dd_copy`] function to execute the main copy operation for
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/// `dd`.
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/// `dd`.
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struct Output<'a> {
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struct Output<'a> {
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/// The destination to which bytes will be written.
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/// The destination to which bytes will be written.
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@ -579,102 +579,101 @@ impl<'a> Output<'a> {
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Ok(())
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Ok(())
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}
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}
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}
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}
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}
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/// Copy the given input data to this output, consuming both.
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/// Copy the given input data to this output, consuming both.
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///
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///
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/// This method contains the main loop for the `dd` program. Bytes
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/// This method contains the main loop for the `dd` program. Bytes
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/// are read in blocks from `i` and written in blocks to this
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/// are read in blocks from `i` and written in blocks to this
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/// output. Read/write statistics are reported to stderr as
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/// output. Read/write statistics are reported to stderr as
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/// configured by the `status` command-line argument.
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/// configured by the `status` command-line argument.
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///
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///
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/// # Errors
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/// # Errors
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///
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///
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/// If there is a problem reading from the input or writing to
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/// If there is a problem reading from the input or writing to
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/// this output.
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/// this output.
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fn dd_out(mut self, mut i: Input) -> std::io::Result<()> {
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fn dd_copy(mut i: Input, mut o: Output) -> std::io::Result<()> {
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// The read and write statistics.
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// The read and write statistics.
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//
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// These objects are counters, initialized to zero. After each
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// iteration of the main loop, each will be incremented by the
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// number of blocks read and written, respectively.
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let mut rstat = ReadStat::default();
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let mut wstat = WriteStat::default();
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// The time at which the main loop starts executing.
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//
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// When `status=progress` is given on the command-line, the
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// `dd` program reports its progress every second or so. Part
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// of its report includes the throughput in bytes per second,
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// which requires knowing how long the process has been
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// running.
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let start = time::Instant::now();
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// A good buffer size for reading.
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//
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// This is an educated guess about a good buffer size based on
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// the input and output block sizes.
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let bsize = calc_bsize(i.settings.ibs, o.settings.obs);
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// Start a thread that reports transfer progress.
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//
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// The `dd` program reports its progress after every block is written,
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// at most every 1 second, and only if `status=progress` is given on
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// the command-line or a SIGUSR1 signal is received. We
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// perform this reporting in a new thread so as not to take
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// any CPU time away from the actual reading and writing of
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// data. We send a `ProgUpdate` from the transmitter `prog_tx`
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// to the receives `rx`, and the receiver prints the transfer
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// information.
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let (prog_tx, rx) = mpsc::channel();
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let output_thread = thread::spawn(gen_prog_updater(rx, i.settings.status));
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let mut progress_as_secs = 0;
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// Optimization: if no blocks are to be written, then don't
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// bother allocating any buffers.
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if let Some(Num::Blocks(0) | Num::Bytes(0)) = i.settings.count {
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return finalize(&mut o, rstat, wstat, start, &prog_tx, output_thread);
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};
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// Create a common buffer with a capacity of the block size.
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// This is the max size needed.
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let mut buf = vec![BUF_INIT_BYTE; bsize];
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// The main read/write loop.
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//
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// Each iteration reads blocks from the input and writes
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// blocks to this output. Read/write statistics are updated on
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// each iteration and cumulative statistics are reported to
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// the progress reporting thread.
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while below_count_limit(&i.settings.count, &rstat, &wstat) {
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// Read a block from the input then write the block to the output.
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//
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//
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// These objects are counters, initialized to zero. After each
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// As an optimization, make an educated guess about the
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// iteration of the main loop, each will be incremented by the
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// best buffer size for reading based on the number of
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// number of blocks read and written, respectively.
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// blocks already read and the number of blocks remaining.
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let mut rstat = ReadStat::default();
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let loop_bsize = calc_loop_bsize(&i.settings.count, &rstat, &wstat, i.settings.ibs, bsize);
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let mut wstat = WriteStat::default();
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let rstat_update = read_helper(&mut i, &mut buf, loop_bsize)?;
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if rstat_update.is_empty() {
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// The time at which the main loop starts executing.
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break;
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//
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}
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// When `status=progress` is given on the command-line, the
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let wstat_update = o.write_blocks(&buf)?;
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// `dd` program reports its progress every second or so. Part
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// of its report includes the throughput in bytes per second,
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// Update the read/write stats and inform the progress thread once per second.
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// which requires knowing how long the process has been
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//
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// running.
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// If the receiver is disconnected, `send()` returns an
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let start = time::Instant::now();
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// error. Since it is just reporting progress and is not
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// crucial to the operation of `dd`, let's just ignore the
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// A good buffer size for reading.
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// error.
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//
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rstat += rstat_update;
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// This is an educated guess about a good buffer size based on
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wstat += wstat_update;
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// the input and output block sizes.
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let prog_update = ProgUpdate::new(rstat, wstat, start.elapsed(), false);
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let bsize = calc_bsize(i.settings.ibs, self.settings.obs);
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if prog_update.duration.as_secs() >= progress_as_secs {
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progress_as_secs = prog_update.duration.as_secs() + 1;
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// Start a thread that reports transfer progress.
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prog_tx.send(prog_update).unwrap_or(());
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//
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// The `dd` program reports its progress after every block is written,
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// at most every 1 second, and only if `status=progress` is given on
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// the command-line or a SIGUSR1 signal is received. We
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// perform this reporting in a new thread so as not to take
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// any CPU time away from the actual reading and writing of
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// data. We send a `ProgUpdate` from the transmitter `prog_tx`
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// to the receives `rx`, and the receiver prints the transfer
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// information.
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let (prog_tx, rx) = mpsc::channel();
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let output_thread = thread::spawn(gen_prog_updater(rx, i.settings.status));
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let mut progress_as_secs = 0;
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// Optimization: if no blocks are to be written, then don't
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// bother allocating any buffers.
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if let Some(Num::Blocks(0) | Num::Bytes(0)) = i.settings.count {
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return finalize(&mut self, rstat, wstat, start, &prog_tx, output_thread);
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};
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// Create a common buffer with a capacity of the block size.
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// This is the max size needed.
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let mut buf = vec![BUF_INIT_BYTE; bsize];
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// The main read/write loop.
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//
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// Each iteration reads blocks from the input and writes
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// blocks to this output. Read/write statistics are updated on
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// each iteration and cumulative statistics are reported to
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// the progress reporting thread.
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while below_count_limit(&i.settings.count, &rstat, &wstat) {
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// Read a block from the input then write the block to the output.
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//
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// As an optimization, make an educated guess about the
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// best buffer size for reading based on the number of
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// blocks already read and the number of blocks remaining.
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let loop_bsize =
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calc_loop_bsize(&i.settings.count, &rstat, &wstat, i.settings.ibs, bsize);
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let rstat_update = read_helper(&mut i, &mut buf, loop_bsize)?;
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if rstat_update.is_empty() {
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break;
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}
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let wstat_update = self.write_blocks(&buf)?;
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// Update the read/write stats and inform the progress thread once per second.
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//
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// If the receiver is disconnected, `send()` returns an
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// error. Since it is just reporting progress and is not
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// crucial to the operation of `dd`, let's just ignore the
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// error.
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rstat += rstat_update;
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wstat += wstat_update;
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let prog_update = ProgUpdate::new(rstat, wstat, start.elapsed(), false);
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if prog_update.duration.as_secs() >= progress_as_secs {
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progress_as_secs = prog_update.duration.as_secs() + 1;
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prog_tx.send(prog_update).unwrap_or(());
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}
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}
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}
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finalize(&mut self, rstat, wstat, start, &prog_tx, output_thread)
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}
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}
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finalize(&mut o, rstat, wstat, start, &prog_tx, output_thread)
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}
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}
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/// Flush output, print final stats, and join with the progress thread.
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/// Flush output, print final stats, and join with the progress thread.
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@ -925,7 +924,7 @@ pub fn uumain(args: impl uucore::Args) -> UResult<()> {
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}
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}
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None => Output::new_stdout(&settings)?,
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None => Output::new_stdout(&settings)?,
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};
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};
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o.dd_out(i).map_err_context(|| "IO error".to_string())
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dd_copy(i, o).map_err_context(|| "IO error".to_string())
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}
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}
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pub fn uu_app() -> Command {
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pub fn uu_app() -> Command {
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