+ (NSArray *)systemLogDictionariesForAppName:(NSString *)appName {
aslmsg q = asl_new(ASL_TYPE_QUERY);
asl_set_query(q, ASL_KEY_SENDER, [appName cStringUsingEncoding:NSASCIIStringEncoding], ASL_QUERY_OP_EQUAL);
aslresponse r = asl_search(NULL, q);
aslmsg m;
uint32_t i;
const char *key, *val;
NSMutableArray *systemLogDictionaries = [NSMutableArray array];
while (NULL != (m = aslresponse_next(r)))
{
NSMutableDictionary *dictionary = [NSMutableDictionary dictionary];
for (i = 0; (NULL != (key = asl_key(m, i))); i++)
{
val = asl_get(m, key);
NSString *stringKey = [NSString stringWithCString:key encoding:NSUTF8StringEncoding];
NSString *stringVal = [NSString stringWithCString:val encoding:NSUTF8StringEncoding];
[dictionary setObject:stringVal forKey:stringKey];
}
[systemLogDictionaries addObject:dictionary];
}
aslresponse_free(r);
return systemLogDictionaries;
}
以上代码将获取苹果系统日志。问题是,从 Apple 系统日志 (ASL) 中提取所有日志大约需要 8 秒。有什么方法可以优化 asl_set_query 以更快地获取数据或我缺少的任何其他方式。
注意:我们能否创建一个带时间戳的 ASL 查询,这样我们就可以处理更少的数据。这将解决我认为的问题。
最佳答案
ASL 支持几种不同的日志记录级别,因此您可以指定限制性更强的级别。
例如,您可以添加另一个查询(根据手册页,它们通过逻辑 AND
连接):
// ...
asl_set_query(q, ASL_KEY_SENDER, [appName cStringUsingEncoding:NSASCIIStringEncoding], ASL_QUERY_OP_EQUAL);
// 3 is error messages
asl_set_query(q, ASL_KEY_LEVEL, "3", ASL_QUERY_OP_LESS_EQUAL | ASL_QUERY_OP_NUMERIC);
//-- Check for time --//
/* A dumped entry with your code looks like:
ASLMessageID = 1825403;
"CFLog Local Time" = "2013-07-20 08:33:12.943";
"CFLog Thread" = 951f;
Facility = "com.apple.Safari";
GID = 20;
Host = "XXX.local";
Level = 4;
Message = "CFPropertyListCreateFromXMLData(): Old-style plist parser: missing semicolon in dictionary on line 3. Parsing will be abandoned. Break on _CFPropertyListMissingSemicolon to debug.";
PID = 183;
ReadUID = 501;
Sender = Safari;
Time = 1374305592;
TimeNanoSec = 943173000;
UID = 501;
Time is a Unix timestamp, so you can use it in your query with ASL_KEY_TIME and one of these operators: ASL_QUERY_OP_EQUAL, ASL_QUERY_OP_GREATER, ASL_QUERY_OP_GREATER_EQUAL, ASL_QUERY_OP_LESS, ASL_QUERY_OP_LESS_EQUAL, ASL_QUERY_OP_NOT_EQUAL
The code below, generates a unix timestamp for yesterday and dumps all messages that occurred yesterday or later.
(Nevermind the dirty/hacky way I generate the timestamp, that was just for testing purposes)
*/
NSDate *yesterday = [NSDate dateWithTimeIntervalSinceNow: -(60.0f*60.0f*24.0f)];
NSString *theDate = [NSString stringWithFormat:@"%d", (int)[yesterday timeIntervalSince1970]];
asl_set_query(q, ASL_KEY_TIME, [theDate cStringUsingEncoding:NSASCIIStringEncoding], ASL_QUERY_OP_GREATER_EQUAL | ASL_QUERY_OP_NUMERIC);
aslresponse r = asl_search(NULL, q);
//...
有关不同错误级别的更多信息,请查看:http://www.cocoanetics.com/2011/03/accessing-the-ios-system-log/
请注意,根据您设置的级别和您的日志消息的级别,进一步过滤可能无效(即,如果为您的应用实际记录的所有消息都属于同一级别)
进一步注意,与调试级别查询不同,我还没有在任何生产代码中使用时间戳查询,但在测试中它似乎工作得很好并且正在做它应该做的事情。
关于ios - 优化苹果系统日志,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/17702662/