Eliminate redundant array copies and vectorise marker scanning in binary event processing

[Copilot]

Python processes AcquDAQ events orders of magnitude slower than C++ largely because np.delete(arr, []) was called three times per clean event (allocating three full copies of the event array for nothing), and per-event helper functions used Python for loops with list += range(…) to build index arrays.

Key changes

Acqu.py — skip copies when there is nothing to delete

# Before: always copies, even with an empty index list
eventArray = np.delete(eventArray, scalerIndices)

# After: skip the allocation entirely on the common clean-event path
if len(scalerIndices):
    eventArray = np.delete(eventArray, scalerIndices)

Same guard applied to EPICS and error indices. Also moves the error-path np.delete inside the early-return branch so the copy is only paid when the event is being discarded. ~6× speedup on the hot path (no special markers).

Also replaces np.append([1], …) with np.concatenate(([1], …)) in runFunction to avoid an extra intermediate allocation per buffer.

Mk1Format.py / Mk2Format.py — vectorise CheckErrors and FillScalerArray

Replace for … : list += range(…) with NumPy broadcasting and a fully-vectorised ragged-range built from np.repeat + np.cumsum:

# CheckErrors — before
for errorMark in np.where(dataArray == EReadError)[0]:
    errorIndices += range(errorMark, errorMark + 5)

# CheckErrors — after
errorMarks = np.where(dataArray == EReadError)[0]
if not len(errorMarks):
    return []
return (errorMarks[:, np.newaxis] + np.arange(5, dtype=np.intp)).ravel()

# FillScalerArray — before
for indeces in scalerLocations:
    scalerHeaders += [indeces[0], indeces[0] + 1]
    scalerIndices += range(indeces[0] + 2, indeces[1])

# FillScalerArray — after (ragged range, no Python loop)
counts   = (ends - starts - 2).astype(np.intp)
bases    = np.repeat(starts + 2, counts)
cum      = np.concatenate([[0], np.cumsum(counts[:-1])])
offsets  = np.arange(total, dtype=np.intp) - np.repeat(cum, counts)
scalerIndices = bases + offsets

Mk2Format.py — FillEPICSArray type consistency

Replaces per-buffer epicsIndices += range(…) with append(np.arange(…)) + a single np.concatenate at the end. Empty result now returns np.array([], dtype=np.intp) instead of [] so callers always receive a NumPy array.