[Phase 2] Performance Optimizations

[SBFRF]

Overview

Implement performance optimizations for the murgtools/getdata module.

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2.1 Cache Server Detection

Move server detection from getnc() to module-level with caching. Currently re-runs socket operations on every call.

Problem: Every getnc() call runs socket operations to detect FRF vs external network.

Solution: Cache at module load with thread-safe implementation.

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2.2 Convert Lookup Tables to Dictionaries

Replace 144-line if-elif chain in _waveGaugeURLlookup() with O(1) dictionary lookup.

Methods to update:

• _waveGaugeURLlookup() (~144 lines)
• _wlGageURLlookup() (~56 lines)

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2.3 Add Dataset Caching with TTL

Add simple cache for getnc() results (5-minute TTL default) to avoid redundant network calls.

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2.4 Consolidate Try-Except Fallback Pattern

Create helper function for the 40+ duplicate FRF/CHL server fallback patterns:

def _fetch_with_fallback(self, primary_url, fallback_url, error_message=None):
    """Fetch dataset with automatic fallback from FRF to CHL server."""
    try:
        return nc.Dataset(primary_url)
    except IOError:
        try:
            return nc.Dataset(fallback_url)
        except IOError:
            if error_message:
                print(error_message)
            return None

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Files to Modify

• murgtools/getdata/getDataFRF.py

Acceptance Criteria

• 2.1 Server detection cached at module level
• 2.2 Lookup tables converted to dictionaries
• 2.3 Dataset caching with TTL implemented
• 2.4 Fallback pattern consolidated into helper
• All existing tests pass

[SBFRF]

All tasks completed:

• 2.1 Cache Server Detection (PR Add data caching system with disk persistence (Issue #50 Task 2.1) #58)
• 2.2 Convert Lookup Tables to Dictionaries (PR Convert gauge URL lookups to O(1) dictionary lookups (#50) #59)
• 2.3 Add Dataset Caching with TTL (PR Add data caching system with disk persistence (Issue #50 Task 2.1) #58)
• 2.4 Consolidate Try-Except Fallback Pattern (PR Add network fallback helper functions (#50 Task 2.4) #60)