SnowFlake

Code

python

def make_snowflake(timestamp_ms, datacenter_id, worker_id, sequence_id, twepoch=twepoch):
    """generate a twitter-snowflake id, based on 
    https://github.com/twitter/snowflake/blob/master/src/main/scala/com/twitter/service/snowflake/IdWorker.scala
    :param: timestamp_ms time since UNIX epoch in milliseconds"""
    sid = ((int(timestamp_ms) - twepoch) % max_timestamp) << datacenter_id_bits << worker_id_bits << sequence_id_bits
    sid += (datacenter_id % max_datacenter_id) << worker_id_bits << sequence_id_bits
    sid += (worker_id % max_worker_id) << sequence_id_bits
    sid += sequence_id % max_sequence_id
    return sid
#snowflake 生成content
t0 = int(time.time() * 1000)
dentialsInfo.strCredentials_content = make_snowflake(t0, 1, 2, 3)

uuid.h

#ifndef __UTIL_UUID_H__
#define __UTIL_UUID_H__
#include <stdint.h>
namespace utils
{
// twitter snowflake算法
// 64       63--------------22---------12---------0
// 符号位   |     41位时间   |10位机器码|12位自增码|
extern uint64_t get_time();
class unique_id_t
{
public:
    unique_id_t();
    ~unique_id_t();
    void set_epoch(uint64_t epoch);
    void set_machine(int32_t machine);
    int64_t generate();
private:
    uint64_t epoch_;
    uint64_t time_;
    int32_t machine_;
    int32_t sequence_;
};
}
#endif // !__UTIL_UUID_H__

#include "uuid.h"
#include <sys/time.h>
#include <unistd.h>
#define EPOCHFILETIME 11644473600000000ULL
namespace utils
{
    uint64_t get_time()
    {
        struct timeval tv;
        gettimeofday(&tv, NULL);
        uint64_t time = tv.tv_usec;
        time /= 1000;
        time += (tv.tv_sec * 1000);
        return time;
    }
    unique_id_t::unique_id_t()
    {
        epoch_ = 0;
        time_ = 0;
        machine_ = 0;
        sequence_ = 0;
    }
    unique_id_t::~unique_id_t()
    {
    }
    void unique_id_t::set_epoch(uint64_t epoch)
    {
        epoch_ = epoch;
    }
    void unique_id_t::set_machine(int32_t machine)
    {
        machine_ = machine;
    }
    int64_t unique_id_t::generate()
    {
        int64_t value = 0;
        uint64_t time = get_time() - epoch_;
        // 保留后41位时间
        value = time << 22;
        // 中间10位是机器ID
        value |= (machine_ & 0x3FF) << 12;
        // 最后12位是sequenceID
        value |= sequence_++ & 0xFFF;
        if (sequence_ == 0x1000)
        {
            sequence_ = 0;
        }
        return value;
    }
}
#include <iostream>
int main()
{
    utils::unique_id_t* u_id_ptr = new utils::unique_id_t();
    u_id_ptr->set_epoch(uint64_t(1367505795100));
    u_id_ptr->set_machine(int32_t(100));
    for (int i = 0; i < 1024; ++i)
    {
        std::cout << u_id_ptr->generate() << std::endl;;
    }
    return 0;
}