From cb3c7afadeda386f2fc6c7a1a9dc7363ee610f79 Mon Sep 17 00:00:00 2001
From: Cory McWilliams <cory@unprompted.com>
Date: Sun, 16 Jun 2024 08:07:02 -0400
Subject: [PATCH] Move ssb.getPrivateKey's DB work off the main thread.

---
 src/ssb.js.c | 50 +++++++++++++++++++++++++++++++++++++++++++-------
 1 file changed, 43 insertions(+), 7 deletions(-)

diff --git a/src/ssb.js.c b/src/ssb.js.c
index e8a54797..c7e9e63d 100644
--- a/src/ssb.js.c
+++ b/src/ssb.js.c
@@ -390,17 +390,53 @@ static JSValue _tf_ssb_getIdentities(JSContext* context, JSValueConst this_val,
 	return result;
 }
 
+typedef struct _get_private_key_t
+{
+	JSContext* context;
+	JSValue promise[2];
+	char id[k_id_base64_len];
+	uint8_t private_key[crypto_sign_SECRETKEYBYTES];
+	bool got_private_key;
+	char user[];
+} get_private_key_t;
+
+static void _tf_ssb_get_private_key_work(tf_ssb_t* ssb, void* user_data)
+{
+	get_private_key_t* work = user_data;
+	work->got_private_key = tf_ssb_db_identity_get_private_key(ssb, work->user, work->id, work->private_key, sizeof(work->private_key));
+}
+
+static void _tf_ssb_get_private_key_after_work(tf_ssb_t* ssb, int status, void* user_data)
+{
+	get_private_key_t* work = user_data;
+	JSValue result = JS_UNDEFINED;
+	JSContext* context = work->context;
+	if (work->got_private_key)
+	{
+		result = tf_util_new_uint8_array(context, work->private_key, sizeof(work->private_key) / 2);
+	}
+	JSValue error = JS_Call(context, work->promise[0], JS_UNDEFINED, 1, &result);
+	JS_FreeValue(context, result);
+	tf_util_report_error(context, error);
+	JS_FreeValue(context, error);
+	JS_FreeValue(context, work->promise[0]);
+	JS_FreeValue(context, work->promise[1]);
+	tf_free(work);
+}
+
 static JSValue _tf_ssb_getPrivateKey(JSContext* context, JSValueConst this_val, int argc, JSValueConst* argv)
 {
-	JSValue result = JS_UNDEFINED;
 	tf_ssb_t* ssb = JS_GetOpaque(this_val, _tf_ssb_classId);
-	const char* user = JS_ToCString(context, argv[0]);
+	size_t user_length = 0;
+	const char* user = JS_ToCStringLen(context, &user_length, argv[0]);
 	const char* id = JS_ToCString(context, argv[1]);
-	uint8_t private_key[crypto_sign_SECRETKEYBYTES];
-	if (tf_ssb_db_identity_get_private_key(ssb, user, id, private_key, sizeof(private_key)))
-	{
-		result = tf_util_new_uint8_array(context, private_key, sizeof(private_key) / 2);
-	}
+	get_private_key_t* work = tf_malloc(sizeof(get_private_key_t) + user_length + 1);
+	*work = (get_private_key_t) { .context = context };
+	memcpy(work->user, user, user_length + 1);
+	snprintf(work->id, sizeof(work->id), "%s", id);
+	JSValue result = JS_NewPromiseCapability(context, work->promise);
+	tf_ssb_run_work(ssb, _tf_ssb_get_private_key_work, _tf_ssb_get_private_key_after_work, work);
+
 	JS_FreeCString(context, user);
 	JS_FreeCString(context, id);
 	return result;