Thomas K Ales [MSE]
104 lines
3.9 KiB
Python
Executable File
104 lines
3.9 KiB
Python
Executable File
"""Burst sizing and row-splitting, exercised without any instrument."""
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import pytest
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from core.scope_burst import (
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frame_means_block, normalize_row, rows_per_burst, split_row_counts,
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)
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SPF = 8
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# ── rows_per_burst ───────────────────────────────────────────────────────────
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def test_rows_per_burst_rounds_down():
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# 9.7 rows' worth of capacity is 9 rows: a partial row is unusable.
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assert rows_per_burst(97, 10, SPF, rows_remaining=100) == 9
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assert rows_per_burst(100, 10, SPF, rows_remaining=100) == 10
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def test_rows_per_burst_clamped_by_rows_remaining():
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assert rows_per_burst(1000, 10, SPF, rows_remaining=3) == 3
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def test_rows_per_burst_clamped_by_memory_budget():
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# Budget holds 4 rows of 10 frames × 8 samples; the scope would hold 100.
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assert rows_per_burst(1000, 10, SPF, rows_remaining=100,
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memory_budget=4 * 10 * SPF) == 4
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def test_rows_per_burst_headroom_reserves_slack_per_row():
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assert rows_per_burst(100, 10, SPF, rows_remaining=100, headroom=0) == 10
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assert rows_per_burst(100, 10, SPF, rows_remaining=100, headroom=2) == 8
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def test_rows_per_burst_never_returns_zero():
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"""A row too big for any budget still goes, or the scan cannot progress."""
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assert rows_per_burst(5, 10, SPF, rows_remaining=100) == 1
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assert rows_per_burst(1000, 10, SPF, rows_remaining=100,
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memory_budget=1) == 1
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def test_rows_per_burst_rejects_degenerate_geometry():
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with pytest.raises(ValueError):
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rows_per_burst(100, 0, SPF, rows_remaining=1)
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# ── split_row_counts ─────────────────────────────────────────────────────────
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def test_split_row_counts_differences_the_cumulative_counter():
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assert split_row_counts([4, 8, 12]) == [4, 4, 4]
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assert split_row_counts([4, 7, 12]) == [4, 3, 5]
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assert split_row_counts([]) == []
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def test_split_row_counts_rejects_a_counter_that_went_backwards():
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# Only happens if the acquisition restarted mid-burst, which would
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# misattribute every later row.
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with pytest.raises(RuntimeError, match="backwards"):
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split_row_counts([8, 4])
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# ── normalize_row ────────────────────────────────────────────────────────────
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def test_normalize_row_passes_an_exact_row_through():
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buf = bytes(range(4 * SPF))
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assert bytes(normalize_row(buf, 0, 4, 4, SPF)) == buf
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def test_normalize_row_pads_a_short_row():
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buf = bytes(range(3 * SPF))
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out = bytes(normalize_row(buf, 0, 3, 4, SPF))
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assert len(out) == 4 * SPF
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assert out[:3 * SPF] == buf
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assert out[3 * SPF:] == bytes(SPF)
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def test_normalize_row_truncates_a_long_row():
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buf = bytes(range(6 * SPF))
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out = bytes(normalize_row(buf, 0, 6, 4, SPF))
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assert out == buf[:4 * SPF]
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def test_normalize_row_reads_at_an_offset():
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buf = bytes(range(8 * SPF))
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out = bytes(normalize_row(buf, 2 * SPF, 4, 4, SPF))
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assert out == buf[2 * SPF:6 * SPF]
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def test_normalize_row_pads_a_buffer_that_ends_early():
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"""Defensive: a truncated transfer must not shorten the row on disk."""
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out = bytes(normalize_row(bytes(2 * SPF), 0, 4, 4, SPF))
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assert len(out) == 4 * SPF
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# ── frame_means_block ────────────────────────────────────────────────────────
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def test_frame_means_block_is_per_frame():
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buf = bytes([1] * SPF + [3] * SPF)
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assert frame_means_block(buf, 0, 2, SPF) == [1.0, 3.0]
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def test_frame_means_block_reads_signed_samples_at_an_offset():
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buf = bytes([0] * SPF) + bytes([0xFF] * SPF) # 0xFF == -1 as int8
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assert frame_means_block(buf, SPF, 1, SPF) == [-1.0]
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