Ichthyostega
f46f117eda
Content generated by Knowledge-Technology - collect information with the help of Claude - validate my own measurements with sources from the net - find a suitable form for the presentation - instructed Claude to build a SVG with a logarithmic time scale - instructed Claude to summarise the findings as Asciidoc table
245 lines
10 KiB
Python
245 lines
10 KiB
Python
#!/usr/bin/env python3
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"""Generate the FrOSCon io_uring talk 'time scales' wrapped-log-scale diagram.
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Page: 254 x 142.9 mm (== LibreOffice Impress 16:9 slide, 25.4 x 14.29 cm)
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User unit == 1 mm.
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Structure: four bands, each spanning exactly three decades (1 -> 1000 of its
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unit), all at identical horizontal scale. Each band is a separate Inkscape
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layer so the whole thing can be exported step by step (Export > Page) and
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stacked as transparent overlays in Impress.
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@note Code generated 8/2026 by Claude -- prompted by Ichthyostega
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"""
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import math
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W, H = 254.0, 142.9
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X0, X1 = 34.0, 240.0 # axis: value 1 .. value 1000
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DEC = (X1 - X0) / 3.0 # mm per decade
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AXIS_END = 243.5 # slight overshoot + chevron
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BANDS_Y = [40.0, 75.0, 102.0, 120.0]
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# ---- colours -------------------------------------------------------------
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C_AXIS = "#555555"
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C_MINOR = "#b3b3b3"
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C_MACH = "#14507d"
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C_HUMAN = "#b4530a"
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C_VAL_M = "#4a7ba6"
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C_VAL_H = "#c98342"
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C_MUTED = "#8a8a8a"
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C_TITLE = "#222222"
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# ---- type ----------------------------------------------------------------
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F_NAME, F_VAL, F_BAND, F_TITLE, F_NOTE, F_DISC = 3.8, 3.2, 5.5, 8.0, 3.6, 3.0
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FONT = "DejaVu Sans, Verdana, sans-serif"
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# tier offsets relative to band axis Y
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UP1_NAME, UP1_VAL, UP1_STUB = -10.3, -6.5, -5.0
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UP2_NAME, UP2_VAL, UP2_STUB = -18.3, -14.5, -13.0
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LO1_NAME, LO1_VAL, LO1_STUB = 11.2, 7.5, 5.0
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BRACKET_Y = 4.0
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def X(v):
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return X0 + DEC * math.log10(v)
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def esc(s):
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return (s.replace("&", "&").replace("<", "<").replace(">", ">"))
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def text(x, y, s, size, fill, anchor="middle", weight="normal"):
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return (f'<text x="{x:.2f}" y="{y:.2f}" font-family="{FONT}" '
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f'font-size="{size}" font-weight="{weight}" fill="{fill}" '
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f'text-anchor="{anchor}">{esc(s)}</text>')
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def line(x1, y1, x2, y2, stroke, w, dash=None):
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d = f' stroke-dasharray="{dash}"' if dash else ""
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return (f'<path d="M {x1:.2f},{y1:.2f} L {x2:.2f},{y2:.2f}" '
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f'stroke="{stroke}" stroke-width="{w}" fill="none"{d}/>')
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# ==========================================================================
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# entry data
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# ==========================================================================
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# tier: 'up1' | 'up2' | 'lo1'
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# kind: 'machine' | 'human'
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# span: (v_lo, v_hi) -> draw a bracket instead of a dot
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BANDS = [
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dict(unit="1 ns", ay=BANDS_Y[0], layer="ns", entries=[
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dict(v=1, name="L1 cache", val="1 ns", tier="up1", kind="machine"),
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dict(v=4, name="L2 cache", val="4 ns", tier="up1", kind="machine"),
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dict(v=10, name="full memory barrier", val="10 ns", tier="up2", kind="machine"),
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dict(v=15, name="L3 cache", val="15 ns", tier="up1", kind="machine"),
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dict(v=100, name="DRAM access", val="100 ns", tier="up1", kind="machine"),
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dict(span=(50, 100), name="contended cache line", val="50-100 ns",
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tier="lo1", kind="machine"),
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dict(offscale=True, name="1 clock cycle", val="\u2248 0.3 ns",
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tier="lo1", kind="machine"),
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]),
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dict(unit="1 \u00b5s", ay=BANDS_Y[1], layer="us", entries=[
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dict(v=1, name="system call", val="1 \u00b5s", tier="up1", kind="machine"),
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dict(v=2, name="context switch", val="2 \u00b5s", tier="up2", kind="machine"),
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dict(v=50, name="OS timer slack", val="50 \u00b5s", tier="up1", kind="machine"),
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dict(span=(10, 30), name="thread wake-up", val="10-30 \u00b5s",
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tier="lo1", kind="machine"),
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dict(span=(50, 100), name="SSD read", val="50-100 \u00b5s",
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tier="lo1", kind="machine"),
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]),
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dict(unit="1 ms", ay=BANDS_Y[2], layer="ms", entries=[
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dict(v=10, name="disk seek", val="10 ms", tier="up1", kind="machine"),
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dict(v=40, name="one frame @ 25 fps", val="40 ms", tier="up1", kind="machine"),
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dict(v=10, name="barely noticeable", val="10 ms", tier="lo1", kind="human"),
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dict(v=100, name="UI feels sluggish", val="100 ms", tier="lo1", kind="human"),
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]),
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dict(unit="1 s", ay=BANDS_Y[3], layer="s", entries=[
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dict(v=1, name="\u201cit\u2019s thinking\u2026\u201d", val="1 s",
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tier="lo1", kind="human"),
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dict(v=180, name="another coffee", val="3 min", tier="lo1", kind="human"),
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dict(v=900, name="go do something else", val="\u2248 15 min",
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tier="lo1", kind="human", anchor="end", ax=250.0),
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]),
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]
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# ==========================================================================
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# scaffold
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# ==========================================================================
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def band_axis(ay, unit):
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o = []
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o.append(line(X0, ay, AXIS_END, ay, C_AXIS, 0.6))
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# continuation chevron
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o.append(f'<path d="M {AXIS_END-2.4:.2f},{ay-1.6:.2f} L {AXIS_END:.2f},{ay:.2f} '
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f'L {AXIS_END-2.4:.2f},{ay+1.6:.2f}" stroke="{C_AXIS}" '
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f'stroke-width="0.6" fill="none"/>')
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# ticks
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for d in range(3):
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base = 10 ** d
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for m in range(1, 10):
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v = base * m
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x = X(v)
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if m == 1:
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o.append(line(x, ay - 3.0, x, ay + 3.0, C_AXIS, 0.6))
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else:
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o.append(line(x, ay - 1.6, x, ay + 1.6, C_MINOR, 0.25))
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o.append(line(X(1000), ay - 3.0, X(1000), ay + 3.0, C_AXIS, 0.6))
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o.append(text(32.0, ay + 2.0, unit, F_BAND, C_MUTED, "end", "600"))
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return o
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def scaffold():
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o = []
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o.append(text(10.0, 15.0, "Time scales", F_TITLE, C_TITLE, "start", "600"))
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o.append(text(244.0, 12.5, "each row spans three decades", F_NOTE, C_MUTED, "end"))
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o.append(text(244.0, 17.0, "one row down = \u00d7 1000", F_NOTE, C_MUTED, "end"))
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for b in BANDS:
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o += band_axis(b["ay"], b["unit"])
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o.append(text(10.0, 137.0,
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"Order of magnitude only \u2014 contemporary desktop / laptop x86. "
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"Expect \u00b1 2\u20133\u00d7; the ratios are the point.",
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F_DISC, C_MUTED, "start"))
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return o
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# ==========================================================================
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# entries
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# ==========================================================================
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def render_entry(e, ay):
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kind = e.get("kind", "machine")
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cn = C_MACH if kind == "machine" else C_HUMAN
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cv = C_VAL_M if kind == "machine" else C_VAL_H
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tier = e["tier"]
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anchor = e.get("anchor", "middle")
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o = []
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if tier == "up1":
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ny, vy, sy = ay + UP1_NAME, ay + UP1_VAL, ay + UP1_STUB
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elif tier == "up2":
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ny, vy, sy = ay + UP2_NAME, ay + UP2_VAL, ay + UP2_STUB
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else:
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ny, vy, sy = ay + LO1_NAME, ay + LO1_VAL, ay + LO1_STUB
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if e.get("offscale"):
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# dashed stub running off the left-hand end of the scale
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y = ay + BRACKET_Y + 0.5
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o.append(line(X0, y, 22.5, y, cn, 0.5, dash="1.6,1.2"))
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o.append(f'<path d="M 25.4,{y-1.6:.2f} L 22.0,{y:.2f} L 25.4,{y+1.6:.2f}" '
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f'stroke="{cn}" stroke-width="0.6" fill="none"/>')
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ax = 22.0
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o.append(text(ax, vy, e["val"], F_VAL, cv, "start"))
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o.append(text(ax, ny, e["name"], F_NAME, cn, "start", "600"))
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return o
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if "span" in e:
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x1, x2 = X(e["span"][0]), X(e["span"][1])
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by = ay + BRACKET_Y
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o.append(line(x1, by, x2, by, cn, 0.7))
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o.append(line(x1, by, x1, ay, cn, 0.7))
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o.append(line(x2, by, x2, ay, cn, 0.7))
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ax = e.get("ax", (x1 + x2) / 2.0)
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else:
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x = X(e["v"])
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o.append(f'<circle cx="{x:.2f}" cy="{ay:.2f}" r="1.3" fill="{cn}"/>')
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stub_from = ay - 2.0 if tier.startswith("up") else ay + 2.0
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o.append(line(x, stub_from, x, sy, cn, 0.4))
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ax = e.get("ax", x)
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o.append(text(ax, vy, e["val"], F_VAL, cv, anchor))
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o.append(text(ax, ny, e["name"], F_NAME, cn, anchor, "600"))
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return o
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# ==========================================================================
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# assemble
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# ==========================================================================
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def layer(lid, label, body, display="inline"):
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return (f'<g inkscape:groupmode="layer" id="{lid}" '
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f'inkscape:label="{label}" style="display:{display}">\n '
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+ "\n ".join(body) + "\n</g>")
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def build():
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layers = []
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layers.append(layer("layer-1-scaffold", "1 - scaffold", scaffold()))
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for i, b in enumerate(BANDS):
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if b["layer"] == "ms":
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mach = [x for e in b["entries"] if e["kind"] == "machine"
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for x in render_entry(e, b["ay"])]
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hum = [x for e in b["entries"] if e["kind"] == "human"
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for x in render_entry(e, b["ay"])]
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layers.append(layer("layer-4-ms-machine", "4 - ms band (machine)", mach))
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layers.append(layer("layer-5-ms-human", "5 - ms band (human)", hum))
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elif b["layer"] == "ns":
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body = [x for e in b["entries"] for x in render_entry(e, b["ay"])]
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layers.append(layer("layer-2-ns", "2 - ns band", body))
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elif b["layer"] == "us":
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body = [x for e in b["entries"] for x in render_entry(e, b["ay"])]
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layers.append(layer("layer-3-us", "3 - us band", body))
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else:
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body = [x for e in b["entries"] for x in render_entry(e, b["ay"])]
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layers.append(layer("layer-6-s", "6 - s band (human)", body))
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dim = [f'<rect x="0" y="22" width="{W}" height="67" fill="#ffffff" '
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f'fill-opacity="0.74"/>']
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layers.append(layer("layer-7-dim", "7 - dim ns+us (optional)", dim,
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display="none"))
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return f'''<?xml version="1.0" encoding="UTF-8"?>
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<svg xmlns="http://www.w3.org/2000/svg"
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xmlns:inkscape="http://www.inkscape.org/namespaces/inkscape"
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xmlns:sodipodi="http://sodipodi.sourceforge.net/DTD/sodipodi-0.dtd"
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width="{W}mm" height="{H}mm" viewBox="0 0 {W} {H}" version="1.1">
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<sodipodi:namedview inkscape:document-units="mm" units="mm"/>
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<title>Time scales - ns to minutes, wrapped logarithmic</title>
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{chr(10).join(layers)}
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</svg>
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'''
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if __name__ == "__main__":
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open("/mnt/user-data/outputs/time-scales.svg", "w").write(build())
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print("written")
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