ssb: Proof of concept to try to stay connected to a handful of peers. #130

src/ssb.connections.c

@@ -2,6 +2,7 @@
 
 #include "log.h"
 #include "mem.h"
+#include "ssb.db.h"
 #include "ssb.h"
 #include "util.js.h"
 
@@ -51,15 +52,19 @@ static void _tf_ssb_connections_changed_callback(tf_ssb_t* ssb, tf_ssb_change_t
 	}
 }
 
-static bool _tf_ssb_connections_get_next_connection(tf_ssb_connections_t* connections, char* host, size_t host_size, int* port, char* key, size_t key_size)
+static bool _tf_ssb_connections_get_next_connection(
+	tf_ssb_connections_t* connections, char* host, size_t host_size, int* port, char* key, size_t key_size, bool* out_stay_connected)
 {
 	bool result = false;
 	sqlite3_stmt* statement;
 	sqlite3* db = tf_ssb_acquire_db_reader(connections->ssb);
+
+	tf_ssb_db_get_global_setting_bool(db, "stay_connected", out_stay_connected);
+
 	if (sqlite3_prepare_v2(db, "SELECT host, port, key FROM connections WHERE last_attempt IS NULL OR (strftime('%s', 'now') - last_attempt > ?1) ORDER BY last_attempt LIMIT 1",
 			-1, &statement, NULL) == SQLITE_OK)
 	{
-		if (sqlite3_bind_int(statement, 1, 60000) == SQLITE_OK && sqlite3_step(statement) == SQLITE_ROW)
+		if (sqlite3_bind_int(statement, 1, *out_stay_connected ? 15 : 60000) == SQLITE_OK && sqlite3_step(statement) == SQLITE_ROW)
 		{
 			tf_string_set(host, host_size, (const char*)sqlite3_column_text(statement, 0));
 			*port = sqlite3_column_int(statement, 1);
@@ -80,6 +85,8 @@ typedef struct _tf_ssb_connections_get_next_t
 {
 	tf_ssb_connections_t* connections;
 	bool ready;
+	bool stay_connected;
+	bool full;
 	char host[256];
 	int port;
 	char key[k_id_base64_len];
@@ -92,7 +99,7 @@ static void _tf_ssb_connections_get_next_work(tf_ssb_t* ssb, void* user_data)
 	{
 		return;
 	}
-	next->ready = _tf_ssb_connections_get_next_connection(next->connections, next->host, sizeof(next->host), &next->port, next->key, sizeof(next->key));
+	next->ready = _tf_ssb_connections_get_next_connection(next->connections, next->host, sizeof(next->host), &next->port, next->key, sizeof(next->key), &next->stay_connected);
 }
 
 static void _tf_ssb_connections_get_next_after_work(tf_ssb_t* ssb, int status, void* user_data)
@@ -100,12 +107,20 @@ static void _tf_ssb_connections_get_next_after_work(tf_ssb_t* ssb, int status, v
 	tf_ssb_connections_get_next_t* next = user_data;
 	if (next->ready)
 	{
+		/*
+		** Might be a duplicate connection or otherwise discarded by
+		** tf_ssb_connect() before we otherwise set attempted, so do it
+		** here.
+		*/
+		tf_ssb_connections_set_attempted(next->connections, next->host, next->port, next->key);
+
 		uint8_t key_bin[k_id_bin_len];
 		if (tf_ssb_id_str_to_bin(key_bin, next->key))
 		{
 			tf_ssb_connect(ssb, next->host, next->port, key_bin, k_tf_ssb_connect_flag_do_not_store, NULL, NULL);
 		}
 	}
+	uv_timer_set_repeat(&next->connections->timer, next->stay_connected ? (next->full ? 2000 : 200) : (next->full ? 10000 : 2000));
 	tf_free(next);
 }
 
@@ -124,6 +139,7 @@ static void _tf_ssb_connections_timer(uv_timer_t* timer)
 		tf_ssb_connections_get_next_t* next = tf_malloc(sizeof(tf_ssb_connections_get_next_t));
 		*next = (tf_ssb_connections_get_next_t) {
 			.connections = connections,
+			.full = count + 1 == tf_countof(active),
 		};
 		tf_ssb_run_work(connections->ssb, _tf_ssb_connections_get_next_work, _tf_ssb_connections_get_next_after_work, next);
 	}

src/util.js.c

@@ -400,6 +400,10 @@ static const setting_t k_settings[] = {
 	{ .name = "autologin", .type = "boolean", .description = "Whether mobile autologin is supported.", .default_value = { .kind = k_kind_bool, .bool_value = TF_IS_MOBILE != 0 } },
 	{ .name = "broadcast", .type = "boolean", .description = "Send network discovery broadcasts.", .default_value = { .kind = k_kind_bool, .bool_value = true } },
 	{ .name = "discovery", .type = "boolean", .description = "Receive network discovery broadcasts.", .default_value = { .kind = k_kind_bool, .bool_value = true } },
+	{ .name = "stay_connected",
+		.type = "boolean",
+		.description = "Whether to attempt to keep several peer connections open.",
+		.default_value = { .kind = k_kind_bool, .bool_value = false } },
 };
 
 static const setting_t* _util_get_setting(const char* name, tf_setting_kind_t kind)