[perf] Add the start of a benchmark for set operations.

perf/benchmark-set.cc

@@ -0,0 +1,49 @@
+#include "benchmark/benchmark.h"
+
+#include <cstdlib>
+#include "hb.h"
+
+void RandomSet(unsigned size, unsigned max_value, hb_set_t* out) {
+  hb_set_clear(out);
+
+  srand(size * max_value);
+  for (unsigned i = 0; i < size; i++) {
+    while (true) {
+      unsigned next = rand() % max_value;
+      if (hb_set_has (out, next)) continue;
+
+      hb_set_add(out, next);
+      break;
+    }
+  }
+}
+
+static void BM_SetInsert(benchmark::State& state) {
+  unsigned set_size = state.range(0);
+  unsigned max_value = state.range(0) * state.range(1);
+
+  hb_set_t* original = hb_set_create ();
+  RandomSet(set_size, max_value, original);
+  assert(hb_set_get_population(original) == set_size);
+
+  for (auto _ : state) {
+    state.PauseTiming();
+    hb_set_t* data = hb_set_copy(original);
+    state.ResumeTiming();
+
+    hb_set_add(data, rand() % max_value);
+
+    state.PauseTiming();
+    hb_set_destroy(data);
+    state.ResumeTiming();
+  }
+
+  hb_set_destroy(original);
+}
+BENCHMARK(BM_SetInsert)
+    ->ArgsProduct({
+        benchmark::CreateRange(1 << 10, 1 << 16, 8), // Set size
+        benchmark::CreateDenseRange(2, 8, /*step=*/2) // Density
+      });
+
+BENCHMARK_MAIN();

perf/meson.build

@@ -19,3 +19,18 @@ benchmark('perf', executable('perf', 'perf.cc',
   link_with: [libharfbuzz],
   install: false,
 ), workdir: meson.current_source_dir() / '..', timeout: 100)
+
+
+benchmark('benchmark-set', executable('benchmark-set', 'benchmark-set.cc',
+  dependencies: [
+    google_benchmark_dep, freetype_dep,
+
+    # the last two, thread and dl, aren't nice as ttf-parser isn't no_std yet
+    # https://github.com/RazrFalcon/ttf-parser/issues/29
+    ttf_parser_dep, thread_dep, cpp.find_library('dl'),
+  ],
+  cpp_args: ttf_parser_dep.found() ? ['-DHAVE_TTFPARSER'] : [],
+  include_directories: [incconfig, incsrc],
+  link_with: [libharfbuzz],
+  install: false,
+), workdir: meson.current_source_dir() / '..', timeout: 100)