C++实现一致性hash算法

#include <stdint.h> #include <iostream> #include <unistd.h> #include <stdlib.h> #include <pthread.h> #include "ConsistentHashing.h" uint32_t getcrc(const char* buffer, size_t size); Obj2node::Obj2node(int cache, int vnum) { pthread_rwlock_init(&m_key2vnode_lock, NULL); m_CacheNum = cache; m_virtualNum = vnum; m_is_active = false; } Obj2node::~Obj2node() { } void Obj2node::AddNode(std::string ip) { pthread_rwlock_wrlock(&m_key2vnode_lock); m_is_active = false; for(int i=0;i<m_virtualNum;i++) { virtualnode* tmpvnode=new virtualnode(ip); tmpvnode->VId = i; std::string ipNum = ip+"#"+transToString(i); int key = getcrc(ipNum.c_str(), ipNum.size()) % m_CacheNum; std::map<int,virtualnode*>::iterator iter = m_key2vnode.find(key); if(iter!= m_key2vnode.end()) { if(iter->second->Id == 0) { if(iter->second->VId < tmpvnode->VId) { delete tmpvnode; continue; } else if(iter->second->VId == tmpvnode->VId) { if((iter->second->m_ip).compare(ip) <= 0) { delete tmpvnode; continue; } } } delete iter->second; } m_key2vnode[key] = tmpvnode; } pthread_rwlock_unlock(&m_key2vnode_lock); } bool Obj2node::Active() { pthread_rwlock_wrlock(&m_key2vnode_lock); if(m_key2vnode.size()==0) { return false; } int pre_key = m_CacheNum+1; int now_key; int first_key = m_key2vnode.begin()->first; for(std::map<int,virtualnode*>::iterator iter = m_key2vnode.begin();iter!=m_key2vnode.end();iter++) { if(iter->second == NULL || iter->second->Id != 0) { continue; } now_key = iter->first; if(pre_key == m_CacheNum+1) { pre_key = now_key; continue; } int tmpVid = m_key2vnode[pre_key]->VId; std::string tmpIp = m_key2vnode[pre_key]->m_ip; for(int i=pre_key+1,j=1; i<now_key; i++,j++) { virtualnode* tmpvnode = new virtualnode(); tmpvnode->VId = tmpVid; tmpvnode->Id = j; tmpvnode->m_ip = tmpIp; std::map<int,virtualnode*>::iterator previter = m_key2vnode.find(i); if(previter != m_key2vnode.end()) { if(previter->second!=NULL) delete previter->second; } m_key2vnode[i] = tmpvnode; } pre_key = now_key; } int tmpVid = m_key2vnode[pre_key]->VId; std::string tmpIp = m_key2vnode[pre_key]->m_ip; int j=1; for(int i=pre_key+1;i<m_CacheNum;i++,j++) { virtualnode* tmpvnode = new virtualnode(); tmpvnode->VId = tmpVid; tmpvnode->Id = j; tmpvnode->m_ip = tmpIp; std::map<int,virtualnode*>::iterator previter = m_key2vnode.find(i); if(previter != m_key2vnode.end() && previter->second != NULL) { delete previter->second; } m_key2vnode[i] = tmpvnode; } for(int i=0;i<first_key;i++,j++) { virtualnode* tmpvnode = new virtualnode(); tmpvnode->VId = tmpVid; tmpvnode->Id = j; tmpvnode->m_ip = tmpIp; std::map<int,virtualnode*>::iterator previter = m_key2vnode.find(i); if(previter != m_key2vnode.end() && previter->second != NULL) { delete previter->second; } m_key2vnode[i] = tmpvnode; } m_is_active = true; pthread_rwlock_unlock(&m_key2vnode_lock); return true; } std::string Obj2node::Get(std::string obj) { std::string res; pthread_rwlock_rdlock(&m_key2vnode_lock); if(m_is_active) { res = m_key2vnode[getcrc(obj.c_str(),obj.size()) % m_CacheNum]->m_ip; } else { std::cout << "Obj2node is not actived" << std::endl; exit(0); } pthread_rwlock_unlock(&m_key2vnode_lock); return res; } void Obj2node::Delete(std::string ip) { pthread_rwlock_wrlock(&m_key2vnode_lock); m_is_active = false; for(int i=0;i<m_virtualNum;i++) { std::string ipNum = ip+"#"+transToString(i); int key = getcrc(ipNum.c_str(), ipNum.size()) % m_CacheNum; std::map<int,virtualnode*>::iterator previter = m_key2vnode.find(key); if(previter==m_key2vnode.end() || previter->second == NULL) { continue; } if(previter->second->m_ip != ip) { continue; } delete previter->second; m_key2vnode[key] = NULL; } pthread_rwlock_unlock(&m_key2vnode_lock); } void Obj2node::Debug() { pthread_rwlock_rdlock(&m_key2vnode_lock); std::cout<<"CacheNum:"<<m_CacheNum<<"virtualNum:"<<m_virtualNum<<std::endl; std::cout<<"real cache num:"<<m_key2vnode.size()<<std::endl; std::cout<<"is actived ?"<<m_is_active<<std::endl; if(!m_is_active) return; std::map<std::string, int> count; for(int i=0;i<m_CacheNum;i++) { std::map<std::string, int>::iterator iter = count.find(m_key2vnode[i]->m_ip); if(iter==count.end()) count[m_key2vnode[i]->m_ip]=1; else { int tmpnum = iter->second; count[m_key2vnode[i]->m_ip]=tmpnum+1; } std::cout<< "" << i << ":\t\t" <<m_key2vnode[i]->m_ip<< "\t" << m_key2vnode[i]->Id<< "\t" << m_key2vnode[i]->VId<<std::endl; } std::cout << "==================count==================" << std::endl; std::map<std::string,int>::iterator iter_count = count.begin(); for(;iter_count!=count.end();iter_count++) { std::cout << iter_count->first << "\t" << iter_count->second << std::endl; } //std::cout<<count<<std::endl; pthread_rwlock_unlock(&m_key2vnode_lock); } uint32_t getcrc(const char* buffer, size_t size) { if(size==0) return 0; static const uint32_t crc32tab[256] = { 0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419, 0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4, 0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07, 0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de, 0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856, 0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9, 0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4, 0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b, 0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3, 0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a, 0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599, 0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924, 0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190, 0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f, 0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e, 0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01, 0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed, 0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950, 0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3, 0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2, 0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a, 0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5, 0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010, 0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f, 0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17, 0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6, 0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615, 0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8, 0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344, 0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb, 0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a, 0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5, 0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1, 0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c, 0x36034af6, 0x4104