Struct opendal::layers::DtraceLayer

pub struct DtraceLayer {}

Available on Linux and crate feature layers-dtrace only.

Support User Statically-Defined Tracing(aka USDT) on Linux

This layer is an experimental feature, it will be enabled by features = ["layers-dtrace"] in Cargo.toml.

For now we have following probes:

For Accessor

1. ${operation}_start, arguments: path
   1. create_dir
   2. read
   3. write
   4. stat
   5. delete
   6. list
   7. presign
   8. blocking_create_dir
   9. blocking_read
   10. blocking_write
   11. blocking_stat
   12. blocking_delete
   13. blocking_list
2. ${operation}_end, arguments: path
   1. create_dir
   2. read
   3. write
   4. stat
   5. delete
   6. list
   7. presign
   8. blocking_create_dir
   9. blocking_read
   10. blocking_write
   11. blocking_stat
   12. blocking_delete
   13. blocking_list

For Reader

1. reader_read_start, arguments: path
2. reader_read_ok, arguments: path, length
3. reader_read_error, arguments: path
4. reader_seek_start, arguments: path
5. reader_seek_ok, arguments: path, offset
6. reader_seek_error, arguments: path
7. reader_next_start, arguments: path
8. reader_next_ok, arguments: path, length
9. reader_next_error, arguments: path
10. reader_next_end, arguments: path

For BlockingReader

1. blocking_reader_read_start, arguments: path
2. blocking_reader_read_ok, arguments: path, length
3. blocking_reader_read_error, arguments: path
4. blocking_reader_seek_start, arguments: path
5. blocking_reader_seek_ok, arguments: path, offset
6. blocking_reader_seek_error, arguments: path
7. blocking_reader_next_start, arguments: path
8. blocking_reader_next_ok, arguments: path, length
9. blocking_reader_next_error, arguments: path

For Writer

1. writer_write_start, arguments: path
2. writer_write_ok, arguments: path, length
3. writer_write_error, arguments: path
4. writer_poll_abort_start, arguments: path
5. writer_poll_abort_ok, arguments: path
6. writer_poll_abort_error, arguments: path
7. writer_close_start, arguments: path
8. writer_close_ok, arguments: path
9. writer_close_error, arguments: path

For BlockingWriter

1. blocking_writer_write_start, arguments: path
2. blocking_writer_write_ok, arguments: path, length
3. blocking_writer_write_error, arguments: path
4. blocking_writer_close_start, arguments: path
5. blocking_writer_close_ok, arguments: path
6. blocking_writer_close_error, arguments: path

Example:

use anyhow::Result;
use opendal::layers::DTraceLayer;
use opendal::services::Fs;
use opendal::Operator;

#[tokio::main]
async fn main() -> Result<()> {
    let mut builder = Fs::default();

    builder.root("/tmp");

    // `Accessor` provides the low level APIs, we will use `Operator` normally.
    let op: Operator = Operator::new(builder)?
        .layer(DtraceLayer::default())
        .finish();

    let path = "/tmp/test.txt";
    for _ in 1..100000 {
        let bs = vec![0; 64 * 1024 * 1024];
        op.write(path, bs).await?;
        op.read(path).await?;
    }
    Ok(())
}

Then you can use readelf -n target/debug/examples/dtrace to see the probes:

Displaying notes found in: .note.stapsdt
  Owner                Data size        Description
  stapsdt              0x00000039       NT_STAPSDT (SystemTap probe descriptors)
    Provider: opendal
    Name: create_dir_start
    Location: 0x00000000000f8f05, Base: 0x0000000000000000, Semaphore: 0x00000000003649f8
    Arguments: -8@%rax
  stapsdt              0x00000037       NT_STAPSDT (SystemTap probe descriptors)
    Provider: opendal
    Name: create_dir_end
    Location: 0x00000000000f9284, Base: 0x0000000000000000, Semaphore: 0x00000000003649fa
    Arguments: -8@%rax
  stapsdt              0x0000003c       NT_STAPSDT (SystemTap probe descriptors)
    Provider: opendal
    Name: blocking_list_start
    Location: 0x00000000000f9487, Base: 0x0000000000000000, Semaphore: 0x0000000000364a28
    Arguments: -8@%rax
  stapsdt              0x0000003a       NT_STAPSDT (SystemTap probe descriptors)
    Provider: opendal
    Name: blocking_list_end
    Location: 0x00000000000f9546, Base: 0x0000000000000000, Semaphore: 0x0000000000364a2a
    Arguments: -8@%rax
  stapsdt              0x0000003c       NT_STAPSDT (SystemTap probe descriptors)

Trait Implementations

impl Clone for DtraceLayer

fn clone(&self) -> DtraceLayer

Returns a copy of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for DtraceLayer

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for DtraceLayer

fn default() -> DtraceLayer

Returns the “default value” for a type.

impl<A: Access> Layer<A> for DtraceLayer

type LayeredAccess = DTraceAccessor<A>

The layered accessor that returned by this layer.

fn layer(&self, inner: A) -> Self::LayeredAccess

Intercept the operations on the underlying storage.