session.cpp

Oracle调用接口

#include "Session.h"

Session::Session() {
}

Session::Session(char *data_str,time_t t) {
	init(data_str,t);	
}

Session::~Session() {
}

void Session::init(char *str,time_t t) {
	string key,val;
	int state=0;
	unsigned i;
	for(i=0;i<strlen(str);i++) { // state machine 
		switch(state) {
			case 0: // key cannot start from digit 
				key="";
				val="";
				if(isalpha(str[i]) || str[i]=='_') {
					key+=str[i];
					state=1;
				} 
				break;
			case 1:
				if(isalnum(str[i]) || str[i]=='_') {
					key+=str[i];
					state=1;
				} else if(str[i]=='=') {
					state=2;
				} else if(str[i]=='&') {
					data[key]="";
					state=0;
				} 
				break;
			case 2: // value
				if(str[i]=='\\') {
					state=3;
				} else if(str[i]!='&') {
					val+=str[i];
				} else {
					data[key]=val;
					state=0;
				}
				break;
			case 3: // '&' escaped
				val+=str[i];
				state=2;
				break;
		}
	}
	if(state==2 || state==1) {
		data[key]=val;
	}
	touched=t;
}

string &Session::get(const string &key) {
	return data[key];
}

void Session::set(const string &key,const string &val) {
	data[key]=val;
}

char * Session::to_string() {
	int pos=0;
	static char buf[MAXSESSIZE];
	map<string,string>::const_iterator ci=data.begin();
	while(ci!=data.end()) {
		if(pos>=MAXSESSIZE) return buf;
		const char *key=ci->first.c_str();
		const char *val=ci->second.c_str();
		strcpy(buf+pos,key);
		pos+=strlen(key);
		buf[pos++]='=';
		for(int i=0;i<strlen(val);i++) {
			if(val[i]=='&') {
				buf[pos++]='\\';
			}
			buf[pos++]=val[i];
		}
		buf[pos++]='&';
		ci++;	
	}
	buf[pos]=0;
	return buf;
}	

bool getSession(const char *sid,Session &s) {
	int i;
	int shmid,semid;
	key_t key;
	sessionslist *slist;
	key=ftok(FKEY,PROJ);
	semid=getSemID(key);
	if(semid<0) return -1;
	lockSession(semid);
	shmid=getShmID(key);
	if(shmid<0) return -1;
	slist=(sessionslist *)shmat(shmid,NULL,0);
	for(i=0;i<slist->nsessions;i++) {
		if(!strcmp(sid,slist->s[i].sid)) {
			slist->s[i].touched=time(NULL);
			s.init(slist->s[i].data,slist->s[i].touched);
			shmdt(slist);
			unlockSession(semid);
			return true;
		}
	}
	shmdt(slist);
	unlockSession(semid);
	return false;
}

bool addSession(const char *sid,Session &s) {
	int i,sind;
	int shmid,semid;
	bool ret_val=false;
	key_t key;
	sessionslist *slist;
	key=ftok(FKEY,PROJ);
	semid=getSemID(key);
	if(semid<0) return false;
	if(lockSession(semid)==-1) return false;
	shmid=getShmID(key);
	if(shmid<0) goto unlock;
	slist=(sessionslist *)shmat(shmid,NULL,0);
	if((long)slist==-1) goto unlock;
	for(i=0;i<slist->nsessions;i++) {
		if(!strcmp(sid,slist->s[i].sid)) {
			strcpy(slist->s[i].data,s.to_string());
			slist->s[i].touched=time(NULL);
			ret_val=true;
			goto detach;
		}
	}
	if(slist->nsessions>=MAXSESSIONS) {
		cleanUp(slist);
		if(slist->nsessions>=MAXSESSIONS) {
			goto detach;
		}
	}
	strcpy(slist->s[slist->nsessions].data,s.to_string());
	strcpy(slist->s[slist->nsessions].sid,sid);
	slist->s[slist->nsessions].touched=time(NULL);
	slist->nsessions++;
	ret_val=true;
detach:
	shmdt(slist);
unlock:
	unlockSession(semid);
	return ret_val;
}

bool destroy() {
	int semid,shmid;
	key_t key;
	key=ftok(FKEY,PROJ);
	semid=getSemID(key);
	if(semid>=0) {
		shmid=getShmID(key);
		if(shmid) {
			if(!semctl(semid,0,IPC_RMID,0) && !shmctl(shmid,IPC_RMID,0)) {
				return true;
			}
		}
	}
	return false;
}

bool getInfo(int &nsessions,int &seed,vector <string> &sid,vector <string> &data,vector <time_t> &touched) {
	int i,sind;
	int shmid,semid;
	bool ret_val=false;
	key_t key;
	sessionslist *slist;
	key=ftok(FKEY,PROJ);
	semid=getSemID(key);
	if(semid<0) return false;
	if(lockSession(semid)==-1) return false;
	shmid=getShmID(key);
	if(shmid<0) goto unlock;
	slist=(sessionslist *)shmat(shmid,NULL,0);
	if((long)slist==-1) goto unlock;
	nsessions=slist->nsessions;
	seed=slist->seed;
	for(i=0;i<slist->nsessions;i++) {
		sid.push_back(slist->s[i].sid);
		data.push_back(slist->s[i].data);
		touched.push_back(slist->s[i].touched);
	}
	shmdt(slist);
	ret_val=true;
unlock:
	unlockSession(semid);
	return ret_val;
}


	
bool removeSessions() {
	int i;
	int shmid,semid;
	key_t key;
	sessionslist *slist;
	key=ftok(FKEY,PROJ);
	semid=getSemID(key);
	if(semid<0) return -1;
	lockSession(semid);
	shmid=getShmID(key);
	if(shmid<0) return -1;
	slist=(sessionslist *)shmat(shmid,NULL,0);
	slist->nsessions=0;
	fprintf(stderr,"sessions removed\n");
	shmdt(slist);
	unlockSession(semid);
	return true;
}
	
void cleanUp(sessionslist *slist) {
	int i;
	int shmid,semid;
	key_t key;
	fprintf(stderr,"cleaning up ...\n");
	for(i=0;i<slist->nsessions;i++) {
		if((time(NULL) - slist->s[i].touched)>EXPIRE) {
			memmove(&(slist->s[i]),&(slist->s[i+1]),(slist->nsessions-i-1)*sizeof(session));
			slist->nsessions--;
			i--;
		}
	}
	return;
}

int getSemID(key_t key) {
	int semid;
	if((semid=semget(key,1,0))==-1) {
		if(errno==ENOENT) {
			if((semid=semget(key,1,IPC_CREAT | 0755))==-1) {
				perror("semget");
				return -1;
			} else {
				struct sembuf buf={0,1,0};
				if(semop(semid,&buf,1)==-1) {
					perror("semop");
					return -1;
				}
				return semid;
			}
		} else {
			perror("semget");
			return -1;
		}
	}
	return semid;
}

int getShmID(key_t key) {
	int shmid;
	if((shmid=shmget(key,ALLSIZE,0))==-1) {
		if(errno==ENOENT) {
			if((shmid=shmget(key,ALLSIZE,IPC_CREAT | 0755))==-1) {
				perror("shmget");
				return -1;
			} else {
				sessionslist *slist=(sessionslist *)shmat(shmid,NULL,0);
				slist->nsessions=0;
				shmdt(slist);
				return shmid;
			}
		} else {
			perror("shmget");
			return -1;
		}
	}
	return shmid;
}

int lockSession(int semid) {
	struct sembuf buf={0,-1,0};
	if(semop(semid,&buf,1)==-1) {
		perror("semop");
		return -1;
	}
	return 0;
}

int unlockSession(int semid) {
	struct sembuf buf={0,1,0};
	if(semop(semid,&buf,1)==-1) {
		perror("semop");
		return -1;
	}
	return 0;
}

char *getUniqueId() {
	char symbols[]={'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z','1','2','3','4','5','6','7','8','9','0'};
	static char buf[9];
	int i;
	int shmid,semid;
	key_t key;
	sessionslist *slist;
	key=ftok(FKEY,PROJ);
	semid=getSemID(key);
	if(semid<0) return NULL;
	lockSession(semid);
	shmid=getShmID(key);
	if(shmid<0) return NULL;
	slist=(sessionslist *)shmat(shmid,NULL,0);
	if((long)slist==-1) return NULL;
	srand(slist->seed++);
	for(i=0;i<8;i++) {
		buf[i]=symbols[((int) (36.0*rand()/(RAND_MAX+1.0)))];
	}
	shmdt(slist);
	unlockSession(semid);
	return buf;
}