Closes the remaining library rows of the final completeness audit
(docs/rewrite/notes/final-Z3.md):
- libghostty-vt: OSC parser storage goes through the caller-supplied C
allocator via a ByteStorage abstraction; ghostty_osc_new reports
GHOSTTY_OUT_OF_MEMORY and failed grows invalidate the OSC like Zig.
Tested with a counting/failing/limiting C allocator.
- shadertoy: sampler parameter rewriting is keyed by full signature so
overloads work; the Metal uniform block keeps std140 strides for
iChannelTime[4] (MSL offsets checked against the upload layout).
- tripwire.zig ported (named trip points, hit counts, verification) and
used to port the previously skipped allocation-failure tests that have
a fallible Rust path; the rest are documented.
- crash: fatal signals capture siginfo + registers and a forked helper
writes a minidump (minidump-writer) as an envelope attachment, like
sentry-native/Breakpad; tests parse it with the minidump crate.
- kitty LoadingImage::debug_dump (debug builds) and the Darwin
Instruments signpost around benchmark runs.
Test Plan:
- cargo test -p ghostty-vt-capi --test c_allocator
- cargo test -p ghostty-crash --test minidump
Adds crates/ghostty-bench, a port of ZIG/src/benchmark and src/synthetic:
the ghostty-bench binary (terminal-stream, terminal-parser,
codepoint-width, grapheme-break, is-symbol, osc-parser, screen-clone
with Zig's CLI) and ghostty-synthetic data generators (+ascii, +utf8,
+osc, plus a Rust-only +sgr mode).
Measured against Ghostty's own ghostty-bench built with Zig 0.15.2
(ReleaseFast) vs --profile production, the hot paths were optimized
without behaviour changes:
- Terminal::print single-lookup fast path for width-1 chars mid-line
- page grapheme allocator: bitmap first-fit instead of a linear scan
(was 38% of utf8 stream time; randomized equivalence test added)
- plain cells skip per-cell work in clear_cells and row cloning
- ASCII fast path + strict hand-written UTF-8 decoder (exhaustive
equivalence test against std)
- parser/OSC parser split into inlined fast and state-change paths
- RenderState allocates grapheme vectors only for grapheme rows
- Page::assert_integrity no-op stub so the production profile builds
terminal-stream is now at parity (ascii 1.08x, utf8 0.97x, SGR 1.04x of
Zig's time). Still slower: screen-clone (~2.6x, zero-filling fresh
cell Vecs vs Zig's lazily-zeroed mmap), osc-parser (1.9x), and the raw
parser on SGR data (1.5x). Full table in docs/rewrite/notes/perf-P1.md.
Test Plan:
- cargo test --workspace (no failures)
- cargo run --profile production -p ghostty-bench -- +terminal-stream
--data=<file> and compare with Zig's ghostty-bench
ddidderr