From 965868783e21e37f2eef83ec0c1bd02c3e49fcb3 Mon Sep 17 00:00:00 2001
From: Paweł Redman <pawel.redman@gmail.com>
Date: Thu, 6 Apr 2017 16:17:58 +0200
Subject: Implement on-the-fly reloading of lists.

---
 src/database.c |  1 -
 src/lists.c    | 36 ++++++++++++++++++++++++++++++++++--
 src/main.c     |  8 +++++++-
 src/shared.h   |  1 +
 4 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/src/database.c b/src/database.c
index c42cfb6..996a2c5 100644
--- a/src/database.c
+++ b/src/database.c
@@ -91,4 +91,3 @@ void db_destroy(void)
 
 	pthread_mutex_unlock(&database_mutex);
 }
-
diff --git a/src/lists.c b/src/lists.c
index 00e29ba..98ba866 100644
--- a/src/lists.c
+++ b/src/lists.c
@@ -33,6 +33,7 @@ typedef struct {
 } entry_t;
 
 static entry_t *entry_list;
+static pthread_mutex_t entry_list_mutex = PTHREAD_MUTEX_INITIALIZER;
 static size_t total_entries;
 
 static int parse_entry(lexer_state_t *lexer, vstr_t *token, entry_type_t type)
@@ -75,7 +76,8 @@ static int parse_entry(lexer_state_t *lexer, vstr_t *token, entry_type_t type)
 	return 0;
 }
 
-// FIXME: Make this MT-safe (lock the list before adding shit to it)
+// NOTE: This function is not MT-safe. It's to be called only once during
+//       initialization. Use lists_reload to reload the lists on-the-fly.
 int lists_load(const char *file, size_t depth)
 {
 	int error = 1, rv;
@@ -127,7 +129,33 @@ out:
 
 void lists_destroy(void)
 {
-	// TODO...
+	entry_t *entry, *next;
+
+	for (entry = entry_list; entry; entry = next){
+		next = entry->list.next;
+
+		free(entry->pattern);
+		free(entry);
+	}
+
+	entry_list = NULL;
+	total_entries = 0;
+}
+
+int lists_reload(const char *file)
+{
+	int ret;
+
+	pthread_mutex_lock(&entry_list_mutex);
+	lists_destroy();
+	ret = lists_load(file, 0);
+	if (!ret)
+		lists_destroy();
+	pthread_mutex_unlock(&entry_list_mutex);
+
+	// FIXME: invalidate all cached results
+
+	return ret;
 }
 
 int lists_test(const char *revdns, const char *whois)
@@ -135,6 +163,8 @@ int lists_test(const char *revdns, const char *whois)
 	entry_t *entry;
 	int total = 0;
 
+	pthread_mutex_lock(&entry_list_mutex);
+
 	eli_for(entry, entry_list, list) {
 		// TODO: regexps
 		if (entry->type == ENTRY_REVDNS &&
@@ -149,5 +179,7 @@ int lists_test(const char *revdns, const char *whois)
 		total += entry->niceness;
 	}
 
+	pthread_mutex_unlock(&entry_list_mutex);
+
 	return total;
 }
diff --git a/src/main.c b/src/main.c
index e5d5d6a..c10ec68 100644
--- a/src/main.c
+++ b/src/main.c
@@ -148,7 +148,13 @@ int handle_signals(void)
 
 	if (signals_reload) {
 		signals_reload = false;
-		DEBUG("reload the lists (not yet implemented)\n");
+		eprintf("reloading the lists...\n");
+
+		// Don't initiate an exit if the lists failed to reload.
+		// It's better to continue operating with empty lists instead
+		// having to be restarted (with an empty revDNS/WHOIS cache).
+		if (lists_reload("schachts.list"))
+			eprintf("error: couldn't reload the lists\n");
 	}
 
 	return 0;
diff --git a/src/shared.h b/src/shared.h
index 77c9d3f..13fd791 100644
--- a/src/shared.h
+++ b/src/shared.h
@@ -158,5 +158,6 @@ void lexer_perror_eg(lexer_state_t *ls, const char *expected);
 // lists.c
 
 int lists_load(const char *file, size_t depth);
+int lists_reload(const char *file);
 void lists_destroy(void);
 int lists_test(const char *revdns, const char *whois);
-- 
cgit