Module analog_signal_cache 

Analog signal cache with fast min/max queries using Blocked RMQ + Binary Search

Complexity

• Construction: O(N + N/B · log(N/B))

• Time queries: O(log N) for binary search + O(1) for min/max

• Memory: O(N + N/B · log(N/B)) where B is the block size

Per-sample storage (N samples):

• timestamps: Vec<u64> = 8N bytes
• values: Vec<f64> = 8N bytes

Sparse table storage (B = 64 default block size):

• MinMax struct = 24 bytes (8 + 8 + 1 + padding)
• num_blocks = ⌈N/B⌉
• num_levels = 1 + ⌊log₂(num_blocks)⌋
• Sparse table = num_blocks × num_levels × 24 bytes

Total ≈ 16N + (N/64) × (1 + log₂(N/64)) × 24 bytes

Examples

1M Samples ~ 21.3 MB 100M Samples ~ 2.39 GB

Structs

AnalogCacheEntry

Wrapper for analog cache with reference counting and lazy initialization.

AnalogSignalCache

Cache entry for a single analog signal.

CacheQueryResult

MinMax 🔒

SignalRMQ 🔒

Constants

NAN_HIGHIMP

Quiet NaN representing high-impedance (Z) values in analog signals.

NAN_UNDEF

Quiet NaN representing undefined (X) values in analog signals.

Functions

is_nan_highimp

Check NaN payload to determine if it represents HighImp.