diff options
Diffstat (limited to 'daemon/utmpd/friend.cpp')
-rw-r--r-- | daemon/utmpd/friend.cpp | 350 |
1 files changed, 350 insertions, 0 deletions
diff --git a/daemon/utmpd/friend.cpp b/daemon/utmpd/friend.cpp new file mode 100644 index 00000000..e62a7198 --- /dev/null +++ b/daemon/utmpd/friend.cpp @@ -0,0 +1,350 @@ +#define NDEBUG +#include <algorithm> +#include <cassert> + +// for some constant and type +#include "bbs.h" + +/* for each login of user, + * input: my index, friend[MAX_FRIEND] of uid, reject[MAX_REJECT] of uid, + * for all my relation, + * output: his index, his uid, relation to me, relation to him + */ +/* 除了 user 及 utmp 之外, 全部的 ref index 都是雙向的, 確保 insert & delete O(1) */ +/* 當沒有人 refer 時則 resource recycle */ + +typedef int Uid; +typedef int Idx; + + +struct Relation { + Uid him; + short him_offset; + + Relation(Uid _him, short _him_offset=-1) :him(_him),him_offset(_him_offset) {} +}; + +template<class T> +struct freelist { + static const int KEEP = 64; + static T* list[8][KEEP]; // 2^0~2^7 + static int tail[8]; + +#define IS_2xxN(a) (a && (a&(a-1))==0) + static T* alloc(int n) { + assert(n>0); + if(n<256 && IS_2xxN(n) && sizeof(T)*n<65536) { + int t=n; + int slot; + for(slot=0; t>1; t/=2) + slot++; + assert(0<=slot && slot<8); + if(tail[slot]) { + return list[slot][--tail[slot]]; + } + } + return (T*)malloc(sizeof(T)*n); + } + static void free(T* p, int n) { + assert(n>0); + if(n<256 && IS_2xxN(n) && sizeof(T)*n<65536) { + int t=n; + int slot; + for(slot=0; t>1; t/=2) + slot++; + assert(0<=slot && slot<8); + if(tail[slot]<KEEP) { + list[slot][tail[slot]++]=p; + return; + } + } + ::free(p); + } +}; + +template<class T> T* freelist<T>::list[8][KEEP]; +template<class T> int freelist<T>::tail[8]={0}; + +template<class T,int MIN_ROOM = 8, class S = int> +struct myvector { + // 大致上想要 STL vector, 但 STL 的 capacity 只會增加不會縮小 + // (後來發現, 以 online friend 來說, capacity 不會縮小其實沒什麼影響) + // 此外, pointer 在 64bit 機器上要 8bytes, basic overhead 8*3 bytes, + // 但我的資料量沒那麼大, 改用 S(int or short) 存 size & capacity 比較省 + T *base; + S room, n; + + myvector() :base(0),room(0),n(0) {} + ~myvector() { + clear(); + } + S append(T data) { + if(room<n+1) + resizefor(n+1); + base[n++]=data; + return n-1; + } + void pop_back() { + assert(n>0); + n--; + resizefor(n); + } + void clear() { + n=0; + resizefor(n); + } + /* + T& operator[](int idx) { + return base[idx]; + } + */ + + void resizefor(S size) { + assert(size>=n); + if(size==0) { + if(base) freelist<T>::free(base, room); + base=0; + room=0; + } else { + S origroom=room; + if(room==0) + room=MIN_ROOM; + while(room<size) room=S(room*2); + if(size<MIN_ROOM) size=MIN_ROOM; + while(room/2>size) room=S(room/2); + if(room!=origroom || base==0) { + //base=(T*)realloc(base, sizeof(T)*room); + T* tmp=freelist<T>::alloc(room); + assert(tmp); + if(n>0) + memcpy(tmp, base, sizeof(T)*n); + if(base!=0) + freelist<T>::free(base, origroom); + base=tmp; + } + assert(base); + } + } +}; + +template<class R,class B> +struct RelationList: public myvector<Relation, 8, short> { + RelationList() :myvector<Relation, 8, short>() {} + void add(Uid me, Uid him) { + RelationList<B,R>& bl=R::backlist(him); + short me_offset=append(Relation(him)); + short him_offset=bl.append(Relation(me,me_offset)); + + setbackoffset(me_offset,him_offset); + assert(bl.base[him_offset].him==me); + assert(bl.base[him_offset].him_offset==me_offset); + } + void deleteall(Uid me) { + for(int i=0; i<n; i++) { + RelationList<B,R>& bl=R::backlist(base[i].him); + assert(bl.base[base[i].him_offset].him==me); + assert(bl.base[base[i].him_offset].him_offset==i); + bl.delete_half(base[i].him_offset); + //try_recycle(base[i].him); // dirty + } + clear(); + } + private: + void setbackoffset(short which,short offset) { + assert(0<=which && which<n); + base[which].him_offset=offset; + } + void delete_half(short offset) { + assert(0<=offset && offset<n); + if(offset<n-1) { + base[offset]=base[n-1]; + R::backlist(base[offset].him).setbackoffset(base[offset].him_offset,offset); + } + pop_back(); + } + friend class RelationList<B,R>; +}; + +struct Like; +struct Likeby; +struct Hate; +struct Hateby; +struct Like: public Relation { + Like(Uid _him, short _him_offset=-1) :Relation(_him,_him_offset) {} + static RelationList<Likeby,Like>& backlist(Uid him); +}; +struct Likeby: public Relation { + Likeby(Uid _him, short _him_offset=-1) :Relation(_him,_him_offset) {} + static RelationList<Like,Likeby>& backlist(Uid him); +}; +struct Hate: public Relation { + Hate(Uid _him, short _him_offset=-1) :Relation(_him,_him_offset) {} + static RelationList<Hateby,Hate>& backlist(Uid him); +}; +struct Hateby: public Relation { + Hateby(Uid _him, short _him_offset=-1) :Relation(_him,_him_offset) {} + static RelationList<Hate,Hateby>& backlist(Uid him); +}; + + +struct Utmp { + Utmp() { + for(int i=0; i<USHM_SIZE; i++) + utmp[i]=-1; + } + /* + Uid& operator[](int idx) { + return utmp[idx]; + } + */ + public: + Uid utmp[USHM_SIZE]; +}; +static Utmp utmp; + +struct BBSUser { + Uid me; + int online; + /* assume utmplist is short, so just use plain vector and linear search */ + myvector<int,2> utmplist; + + RelationList<Like,Likeby> like; + RelationList<Hate,Hateby> hate; + RelationList<Likeby,Like> likeby; + RelationList<Hateby,Hate> hateby; + + BBSUser() :me(-1),online(0),utmplist(),like(),hate(),likeby(),hateby() {} + BBSUser(Uid uid) :me(uid),online(0),utmplist(),like(),hate(),likeby(),hateby() {} + + void login(int utmpidx, const Uid likehim[MAX_FRIEND], const Uid hatehim[MAX_REJECT]) { + if(online>0) { + /* multiple login 的話, 以最後一次的 like/hate 為準 */ + like.deleteall(me); + hate.deleteall(me); + } + utmp.utmp[utmpidx]=me; + utmplist.append(utmpidx); + online++; + assert(online==utmplist.n); + for(int i=0; i<MAX_FRIEND && likehim[i]; i++) + like.add(me, likehim[i]); + for(int i=0; i<MAX_REJECT && hatehim[i]; i++) + hate.add(me, hatehim[i]); + } + + void logout(int utmpidx) { + assert(utmp.utmp[utmpidx]==me); + assert(online==utmplist.n); + for(int i=0; i<utmplist.n; i++) + if(utmplist.base[i]==utmpidx) { + utmplist.base[i]=utmplist.base[utmplist.n-1]; + utmplist.pop_back(); + break; + } + utmp.utmp[utmpidx]=-1; + online--; + assert(online==utmplist.n); + if(online==0) { + like.deleteall(me); + hate.deleteall(me); + } + } + bool isfree() const { + return online==0 && like.n==0 && hate.n==0 && likeby.n==0 && hateby.n==0; + } +}; + +struct UserList { + BBSUser users[MAX_USERS]; + + UserList() { + for(int i=0; i<MAX_USERS; i++) + users[i].me=i; + } + void login(Uid uid, Idx idx, const Uid likehim[MAX_FRIEND], const Uid hatehim[MAX_REJECT]) { + assert(uid<MAX_USERS); + assert(idx<USHM_SIZE); + /* 由於不會收到 logout event, 因此 logout 只發生在 utmp override */ + if(utmp.utmp[idx]!=-1) users[utmp.utmp[idx]].logout(idx); + users[uid].login(idx, likehim, hatehim); + } +}; + +struct UserList userlist; +RelationList<Likeby,Like>& Like::backlist(Uid him) { return userlist.users[him].likeby; } +RelationList<Like,Likeby>& Likeby::backlist(Uid him) { return userlist.users[him].like; } +RelationList<Hateby,Hate>& Hate::backlist(Uid him) { return userlist.users[him].hateby; } +RelationList<Hate,Hateby>& Hateby::backlist(Uid him) { return userlist.users[him].hate; } + +struct Result { + Uid who; + int bits; + Result(Uid _who, int _bits) :who(_who),bits(_bits) {} + bool operator<(const Result& b) const { + return who<b.who; + } +}; + +int reverse_friend_stat(int stat) +{ + int stat1 = 0; + if (stat & IFH) stat1 |= HFM; + if (stat & IRH) stat1 |= HRM; + if (stat & HFM) stat1 |= IFH; + if (stat & HRM) stat1 |= IRH; + return stat1; +} + +extern "C" void utmplogin(int uid, int index, const int like[MAX_FRIEND], const int hate[MAX_REJECT]) +{ + /* login */ + userlist.login(uid, index, like, hate); +} + +extern "C" int genfriendlist(int uid, int index, ocfs_t *fs, int maxfs) +{ + /* collect data */ + BBSUser& u=userlist.users[uid]; + myvector<Result,64,short> work; + for(int i=0; i<u.like.n; i++) work.append(Result(u.like.base[i].him, IFH)); + for(int i=0; i<u.hate.n; i++) work.append(Result(u.hate.base[i].him, IRH)); + for(int i=0; i<u.likeby.n; i++) work.append(Result(u.likeby.base[i].him, HFM)); + for(int i=0; i<u.hateby.n; i++) work.append(Result(u.hateby.base[i].him, HRM)); + + /* sort */ + std::sort(work.base, work.base+work.n); + /* merge */ + if(work.n>0) { + int newn=1; + for(int i=1; i<work.n; i++) + if(work.base[i].who==work.base[newn-1].who) { + work.base[newn-1].bits|=work.base[i].bits; + } else { + work.base[newn++]=work.base[i]; + } + work.n=newn; + } + /* fill */ + int nfs=0; + for(int i=0; i<work.n && nfs<maxfs; i++) { + BBSUser& h=userlist.users[work.base[i].who]; + for(int j=0; j<h.utmplist.n && nfs<maxfs; j++) { + int rstat=reverse_friend_stat(work.base[i].bits); + if(h.utmplist.base[j]==index) continue; + fs[nfs].index=h.utmplist.base[j]; + fs[nfs].uid=h.me; + fs[nfs].friendstat=(work.base[i].bits<<24)|h.utmplist.base[j]; + fs[nfs].rfriendstat=(rstat<<24)|index; + nfs++; + } + } + return nfs; +} + +extern "C" void utmplogoutall(void) +{ + for(int i=0; i<USHM_SIZE; i++) + if(utmp.utmp[i]!=-1) + userlist.users[utmp.utmp[i]].logout(i); +} + |