uuid

I need to store a 128 bits long UUID in a variable. Is there a 128-bit datatype in C++? I do not need arithmetic operations, I just want to easily store and read the value very fast. A new feature from C++11 would be fine, too. GCC and Clang support __int128 Patrik Beck Checkout boost's implementation : #include <boost/multiprecision/cpp_int.hpp> using namespace boost::multiprecision; int128_t v = 1; This is better than strings and arrays, especially if you need to do arithmetic operations with it. Although GCC does provide __int128 , it is supported only for targets (processors) which have an

How would I create a java.util.UUID from a string with no dashes? "5231b533ba17478798a3f2df37de2aD7" => #uuid "5231b533-ba17-4787-98a3-f2df37de2aD7" Clojure's #uuid tagged literal is a pass-through to java.util.UUID/fromString . And, fromString splits it by the "-" and converts it into two Long values. (The format for UUID is standardized to 8-4-4-4-12 hex digits, but the "-" are really only there for validation and visual identification.) The straight forward solution is to reinsert the "-" and use java.util.UUID/fromString . (defn uuid-from-string [data] (java.util.UUID/fromString (clojure

Mysql5.6基于GTID全局事务的复制 什么是 GTID ？   GTID(Global Transaction Identifiers)是全局事务标识 当使用GTIDS时，在主上提交的每一个事务都会被识别和跟踪，并且运用到所有从MySQL，而且配置主从或者主从切换时不再需要指定 master_log_files和master_log_pos；由于GTID-base复制是完全基于事务的，所以能很简单的决定主从复制的一致性； 官方建议Binlog采用Row格式 MySQL 5.1.12 开始，可以用以下三种模式来实现： 基于SQL语句的复制(statement-based replication, SBR)， 基于行的复制(row-based replication, RBR)， 混合模式复制(mixed-based replication, MBR)。 相应地，binlog的格式也有三种：STATEMENT，ROW，MIXED。 MBR 模式中，SBR 模式是默认的。 基于混合模式的复制：它是根据事件的类型实时的改变binlog的格式。当设置为混合模式时，默认为基于语句的格式，但在特定的情况下它会自动的转变为基于行的模式。 SBR 的优点： 历史悠久，技术成熟 binlog文件较小 binlog中包含了所有数据 库更改信息，可以据此来审核数据库的安全等情况

What is the best way to programmatically generate a GUID or UUID in C++ without relying on a platform-specific tool? I am trying to make unique identifiers for objects in a simulation, but can't rely on Microsoft's implementation as the project is cross-platform. Notes: Since this is for a simulator, I don't really need cryptographic randomness. It would be best if this is a 32 bit number. Anonymous If you can afford to use Boost, then there is a UUID library that should do the trick. It's very straightforward to use - check the documentation and this answer . on linux: man uuid on win: check

For a number of reasons^, I'd like to use a UUID as a primary key in some of my Django models. If I do so, will I still be able to use outside apps like "contrib.comments", "django-voting" or "django-tagging" which use generic relations via ContentType? Using "django-voting" as an example, the Vote model looks like this: class Vote(models.Model): user = models.ForeignKey(User) content_type = models.ForeignKey(ContentType) object_id = models.PositiveIntegerField() object = generic.GenericForeignKey('content_type', 'object_id') vote = models.SmallIntegerField(choices=SCORES) This app seems to be

I have been experimenting with using UUIDs as database keys. I want to take up the least amount of bytes as possible, while still keeping the UUID representation human readable. I think that I have gotten it down to 22 bytes using base64 and removing some trailing "==" that seem to be unnecessary to store for my purposes. Are there any flaws with this approach? Basically my test code does a bunch of conversions to get the UUID down to a 22 byte String, then converts it back into a UUID. import java.io.IOException; import java.util.UUID; public class UUIDTest { public static void main(String[]