bench.wasm : same as "bench" but runs in the browser (#89)

examples/bench.wasm/emscripten.cpp

@@ -0,0 +1,80 @@
+#include "whisper.h"
+
+#include <emscripten.h>
+#include <emscripten/bind.h>
+
+#include <cmath>
+#include <string>
+#include <thread>
+#include <vector>
+
+constexpr int N_THREAD = 8;
+
+// TODO: get rid of this vector of contexts - bad idea in the first place
+std::vector<struct whisper_context *> g_contexts(4, nullptr);
+
+std::thread g_worker;
+
+void bench_main(size_t index) {
+    const int n_threads = std::min(N_THREAD, (int) std::thread::hardware_concurrency());
+
+    // whisper context
+    auto & ctx = g_contexts[index];
+
+    fprintf(stderr, "%s: running benchmark with %d threads - please wait...\n", __func__, n_threads);
+
+    if (int ret = whisper_set_mel(ctx, nullptr, 0, WHISPER_N_MEL)) {
+        fprintf(stderr, "error: failed to set mel: %d\n", ret);
+        return;
+    }
+
+    if (int ret = whisper_encode(ctx, 0, n_threads) != 0) {
+        fprintf(stderr, "error: failed to encode model: %d\n", ret);
+        return;
+    }
+
+    whisper_print_timings(ctx);
+
+    fprintf(stderr, "\n");
+    fprintf(stderr, "If you wish, you can submit these results here:\n");
+    fprintf(stderr, "\n");
+    fprintf(stderr, "  https://github.com/ggerganov/whisper.cpp/issues/89\n");
+    fprintf(stderr, "\n");
+    fprintf(stderr, "Please include the following information:\n");
+    fprintf(stderr, "\n");
+    fprintf(stderr, "  - CPU model\n");
+    fprintf(stderr, "  - Operating system\n");
+    fprintf(stderr, "  - Browser\n");
+    fprintf(stderr, "\n");
+}
+
+EMSCRIPTEN_BINDINGS(bench) {
+    emscripten::function("init", emscripten::optional_override([](const std::string & path_model) {
+        for (size_t i = 0; i < g_contexts.size(); ++i) {
+            if (g_contexts[i] == nullptr) {
+                g_contexts[i] = whisper_init(path_model.c_str());
+                if (g_contexts[i] != nullptr) {
+                    if (g_worker.joinable()) {
+                        g_worker.join();
+                    }
+                    g_worker = std::thread([i]() {
+                        bench_main(i);
+                    });
+
+                    return i + 1;
+                } else {
+                    return (size_t) 0;
+                }
+            }
+        }
+
+        return (size_t) 0;
+    }));
+
+    emscripten::function("free", emscripten::optional_override([](size_t index) {
+        if (index < g_contexts.size()) {
+            whisper_free(g_contexts[index]);
+            g_contexts[index] = nullptr;
+        }
+    }));
+}