Expose detailed I/O data via magic variable

[Copilot]

Change Description

• My PR includes a link to the issue that I am addressing

Implements iops_detailed_data magic variable to expose per-operation I/O details. Previously only aggregate metrics were available; users can now analyze file paths, syscalls, and per-operation sizes.

Solution Description

Core Changes

• Inject iops_detailed_data into user namespace after each %%iops execution
• Returns pandas.DataFrame when detailed tracing available (strace/fs_usage modes)
• Returns explanatory string when using psutil aggregate-only mode

Data Collection

• Enhanced parse_strace_line and parse_fs_usage_line with collect_detailed parameter
• Extract file paths via strace -y flag (fd-to-path resolution)
• Extract syscall names from both tracers
• Fixed mutual exclusivity bug: histogram and detailed collection now work simultaneously

Schema
DataFrame columns when available:

• path (str): File path accessed
• operation (str): "read" or "write"
• syscall (str): Syscall name (read, write, pread64, etc.)
• size_bytes (int): Bytes transferred

Usage Example

%%iops
with open('test.txt', 'w') as f:
    f.write('data' * 1000)
    
# Next cell:
iops_detailed_data  # Access DataFrame
# Analyze: iops_detailed_data.groupby('path')['size_bytes'].sum()

Code Quality

• I have read the Contribution Guide
• My code follows the code style of this project
• My code builds (or compiles) cleanly without any errors or warnings
• My code contains relevant comments and necessary documentation

Project-Specific Pull Request Checklists

New Feature Checklist

• I have added or updated the docstrings associated with my feature using the NumPy docstring format
• I have updated the tutorial to highlight my new feature (if appropriate)
• I have added unit/End-to-End (E2E) test cases to cover my new feature
• My change includes a breaking change
  • My change includes backwards compatibility and deprecation warnings (if possible)

Documentation Change Checklist

• Any updated docstrings use the NumPy docstring format

Build/CI Change Checklist

• If required or optional dependencies have changed (including version numbers), I have updated the README to reflect this

Test Coverage: 13 new tests, all 133 tests passing. CodeQL: 0 alerts.

Original prompt

---

This section details on the original issue you should resolve

<issue_title>Expose detailed I/O data via magic variable</issue_title>
<issue_description>## Expose detailed I/O data via magic variable

Implementation

After %%iops execution, inject a variable iops_detailed_data into the user's namespace via:

self.shell.user_ns['iops_detailed_data'] = detailed_data

Variable Content

When detailed data is available (strace/fs_usage modes):

• Type: pandas.DataFrame
• Columns:
  • path (str): File path
  • operation (str): "read" or "write"
  • syscall (str, optional): Syscall name if available
  • size_bytes (int): Bytes transferred

When detailed data is NOT available (psutil mode):

• Type: str
• Value: "Detailed I/O data not available: profiling uses psutil mode which only provides aggregate metrics"

Documentation

Add a brief note to README.md showing users can access iops_detailed_data after running %%iops.

Example

%%iops
with open('test.txt', 'w') as f:
    f.write('data')

Next cell:

iops_detailed_data  # Access the DataFrame

Also update readthedocs.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Expose detailed I/O data via magic variable #47

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Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 45.49%. Comparing base (b04ec2e) to head (00b8a88).

Additional details and impacted files

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##             main      #48   +/-   ##
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  Coverage   45.49%   45.49%           
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  Files           4        4           
  Lines         455      455           
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  Hits          207      207           
  Misses        248      248           

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