Refactor file range processing and update logging in mrd

[suni72]

Key changes:

• Enhanced File Range Processing:
  • The _cat_file method now explicitly returns empty bytes when start >= end >= 0 to prevent invalid HTTP range requests.
  • The logic for start and end parameters in _cat_file and _process_limits_to_offset_and_length has been refined to correctly handle 0 values and negative indices.
  • Invalid ranges (e.g., start > end) are now gracefully handled by returning an empty range instead of raising ValueError in _process_limits_to_offset_and_length.
  • Negative start offsets are clamped to 0 if they would result in an offset before the beginning of the file in _process_limits_to_offset_and_length.
• Multi-Range Download Refactoring:
  • The multi-range download logic has been extracted into a new download_ranges function in gcsfs/zb_hns_utils.py.
  • This new function includes improved logging for short reads and validates the number of requested ranges against MRD_MAX_RANGES (1000).
• Zonal Bucket Merge Restrictions:
  • A new _merge method has been added to extended_gcsfs.py which explicitly raises a NotImplementedError if an attempt is made to merge objects in a Zonal Bucket, as server-side compose is not supported for them. For standard buckets, it delegates to the parent class's _merge implementation.
• Improved Logging:
  • Warning messages in _fetch_range_split, _cat_file, and _get_file now include the relevant file path for better debugging.
• Test Updates:
  • Unit tests for _process_limits_to_offset_and_length have been updated to reflect the new behavior, and new tests for _merge and download_ranges have been added.

[ankitaluthra1]

/gcbrun

[codecov]

Codecov Report

❌ Patch coverage is 97.29730% with 1 line in your changes missing coverage. Please review.
✅ Project coverage is 76.30%. Comparing base (fee3945) to head (97e0423).
⚠️ Report is 2 commits behind head on main.

Files with missing lines	Patch %	Lines
gcsfs/core.py	80.00%	1 Missing ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main     #790      +/-   ##
==========================================
+ Coverage   75.84%   76.30%   +0.46%     
==========================================
  Files          14       14              
  Lines        2645     2663      +18     
==========================================
+ Hits         2006     2032      +26     
+ Misses        639      631       -8     

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[ankitaluthra1]

/gcbrun