nrnbbs.cpp

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#include <../../nrnconf.h>
// bug in the osx 10.2 environment
#if defined(__POWERPC__) && defined(__APPLE__)
#undef HAVE_LOCKF
#endif
 
#include <stdio.h>
#include <fcntl.h>
#include <ctype.h>
#include <signal.h>
#include <unistd.h>
#include <stdlib.h>
#include <string.h>
 
#include <sys/stat.h>
 
#include <OS/list.h>
#include <OS/string.h>
#include "nrnbbs.h"
 
#if !defined(HAVE_LOCKF)
#include <sys/file.h>
#endif
 
#define HISTORY 0
 
#define NRNBBSTMP     "nrnbbs"
#define NOTIFY        "notify"
#define NRNBBS        "nrnbbs"
#define LOCKFILE      "lock"
#define TMPFILE       "temp"
#define NOTIFY_SIGNAL SIGUSR1
 
class NrnBBSCallbackItem {
  public:
    NrnBBSCallbackItem(const char*, NrnBBSCallback);
    virtual ~NrnBBSCallbackItem();
    bool equal(const char*);
    void execute();
 
  private:
    CopyString s_;
    NrnBBSCallback cb_;
};
 
static const char* fname(const char* name);
 
static void history(const char* s1, const char* s2, const char* s3) {
#if HISTORY
    FILE* f;
    if ((f = fopen(fname("history"), "a")) != (FILE*) 0) {
        fprintf(f, "%5d %s  |%s| |%s|\n", getpid(), s1, s2, s3);
        fclose(f);
    }
#endif
}
 
static void history(const char* s1) {
    history(s1, "", "");
}
static void history(const char* s1, const char* s2) {
    history(s1, s2, "");
}
static void history(const char* s1, int i) {
    char buf[20];
    sprintf(buf, "%d", i);
    history(s1, buf, "");
}
 
declarePtrList(NrnBBSCallbackList, NrnBBSCallbackItem)
implementPtrList(NrnBBSCallbackList, NrnBBSCallbackItem)
 
static NrnBBSCallbackList* cblist_;
static FILE* lockfile_;
 
static void get_lock() {
#if !defined(HAVE_LOCKF)
    while (flock(fileno(lockfile_), LOCK_EX) != 0) {
#else
    while (lockf(fileno(lockfile_), F_LOCK, 0) != 0) {
#endif
        history("lockf returned non zero");
    }
    // printf("got lock for %d\n", getpid());
}
 
static void release_lock() {
#if !defined(HAVE_LOCKF)
    flock(fileno(lockfile_), LOCK_UN);
#else
    lockf(fileno(lockfile_), F_ULOCK, 0);
#endif
    // printf("released lock for %d\n", getpid());
}
 
static const char* nrnbbsdir() {
    static char* d;
    if (!d) {
        char buf[256];
        char* tmpdir;
        tmpdir = getenv("TMPDIR");
        if (!tmpdir) {
            tmpdir = "/tmp";
        }
        sprintf(buf, "%s/%s_%s", tmpdir, getenv("USER"), NRNBBSTMP);
        d = new char[strlen(buf) + 1];
        strcpy(d, buf);
        mkdir(d, 0777);
    }
    return d;
}
 
static const char* fname(const char* name) {
    static char buf[2][256];
    static int i = 0;
    i = (i + 1) % 2;
    sprintf(buf[i], "%s/%s", nrnbbsdir(), name);
    return buf[i];
}
 
static bool connected_;
 
bool nrnbbs_connect() {
    if (!lockfile_) {
        const char* lfile = fname(LOCKFILE);
        lockfile_ = fopen(lfile, "w");
        if (!lockfile_) {
            connected_ = false;
            return connected_;
        }
    }
    connected_ = true;
    history("connect");
    return connected_;
}
 
void nrnbbs_disconnect() {
    connected_ = false;
    history("disconnect");
    if (cblist_) {
        get_lock();
        int pid = getpid();
        FILE* f = fopen(fname(NOTIFY), "r");
        if (f) {
            char buf[256];
            int id;
            FILE* f2 = fopen(fname(TMPFILE), "w");
            if (!f2) {
                fprintf(stderr, "can't open %s\n", fname(TMPFILE));
            }
            while (fgets(buf, 256, f)) {
                buf[strlen(buf) - 1] = '\0';
                fscanf(f, "%d\n", &id);
                if (id != pid) {
                    fprintf(f2, "%s\n%d\n", buf, id);
                }
            }
            fclose(f2);
            fclose(f);
            rename(fname(TMPFILE), fname(NOTIFY));
        }
        release_lock();
        for (long i = 0; i < cblist_->count(); ++i) {
            delete cblist_->item(i);
        }
        delete cblist_;
        cblist_ = nil;
    }
    if (lockfile_) {
        fclose(lockfile_);
        lockfile_ = (FILE*) 0;
    }
}
 
bool nrnbbs_connected() {
    return connected_;
}
 
 
void nrnbbs_wait(bool* pflag) {
    bool f = false;
    bool* pf;
    pf = (pflag) ? pflag : &f;
    while (!(*pf) && nrnbbs_connected()) {
        f = true;  // once only if no arg
        pause();
    }
}
 
void nrnbbs_post(const char* key) {
    nrnbbs_post_string(key, "");
}
 
void nrnbbs_post_int(const char* key, int ival) {
    char buf[30];
    sprintf(buf, "%d", ival);
    nrnbbs_post_string(key, buf);
}
 
void nrnbbs_post_string(const char* key, const char* sval) {
    history("post", key, sval);
    get_lock();
    FILE* f = fopen(fname(NRNBBS), "a");
    fprintf(f, "%s\n%s\n", key, sval);
    FILE* f2 = fopen(fname(NOTIFY), "r");
    char name[256];
    int i, n, id[10];
    n = 0;
    if (f2) {
        while (fgets(name, 256, f2) && n < 10) {
            name[strlen(name) - 1] = '\0';
            fscanf(f2, "%d\n", &i);
            if (strcmp(name, key) == 0) {
                id[n++] = i;
                fprintf(f, "nrnbbs_notifying %s\n\n", key);
            }
        }
        fclose(f2);
    }
    fclose(f);
    release_lock();
    for (i = 0; i < n; ++i) {
        history("  notify", id[i]);
        kill(id[i], NOTIFY_SIGNAL);
    }
}
 
 
bool nrnbbs_take(const char* key) {
    char buf[256];
    return nrnbbs_take_string(key, buf);
}
 
bool nrnbbs_take_int(const char* key, int* ipval) {
    char buf[256];
    bool b = nrnbbs_take_string(key, buf);
    if (b) {
        b = (sscanf(buf, "%d\n", ipval) == 1) ? true : false;
    }
    return b;
}
 
bool nrnbbs_take_string(const char* key, char* sval) {
    history("take", key);
    get_lock();
    bool b = false;
    FILE* f = fopen(fname(NRNBBS), "r");
    if (f != (FILE*) 0) {
        char name[256], val[256];
        FILE* f2 = fopen(fname(TMPFILE), "w");
        while (fgets(name, 256, f)) {
            name[strlen(name) - 1] = '\0';
            if (name[0] == '\0') {
                continue;
            }
            fgets(val, 256, f);
            val[strlen(val) - 1] = '\0';
            if (!b && strcmp(name, key) == 0) {
                history("  found", val);
                b = true;
                strcpy(sval, val);
                continue;
            }
            fprintf(f2, "%s\n%s\n", name, val);
        }
        fclose(f2);
        fclose(f);
        if (b) {
            rename(fname(TMPFILE), fname(NRNBBS));
        }
    } else {
        b = false;
    }
    release_lock();
    return b;
}
 
 
bool nrnbbs_look(const char* key) {
    history("look", key);
    get_lock();
    bool b = false;
    FILE* f = fopen(fname(NRNBBS), "r");
    if (f != (FILE*) 0) {
        char name[256], val[256];
        while (fgets(name, 256, f)) {
            name[strlen(name) - 1] = '\0';
            fgets(val, 256, f);
            if (strcmp(name, key) == 0) {
                history("  found");
                b = true;
                break;
            }
        }
        fclose(f);
    } else {
        b = false;
    }
    release_lock();
    return b;
}
 
 
void nrnbbs_exec(const char* cmd) {
    history("exec", cmd);
    char buf[256];
    sprintf(buf, "%s&", cmd);
    system(buf);
}
 
 
static RETSIGTYPE nrnbbs_handler(int) {
    long i;
#if defined(SIGNAL_CAST)
    signal(NOTIFY_SIGNAL, (SIGNAL_CAST) nrnbbs_handler);
#else
    signal(NOTIFY_SIGNAL, nrnbbs_handler);
#endif
    for (i = 0; i < cblist_->count(); ++i) {
        cblist_->item(i)->execute();
    }
}
 
void nrnbbs_notify(const char* key, NrnBBSCallback cb) {
    history("nrnbbs_notify", key);
    if (!cblist_) {
        cblist_ = new NrnBBSCallbackList();
    }
    cblist_->append(new NrnBBSCallbackItem(key, cb));
    get_lock();
    FILE* f = fopen(fname(NOTIFY), "a");
    if (!f) {
        fprintf(stderr, "can't open %s\n", fname(NOTIFY));
        return;
    }
    fprintf(f, "%s\n%d\n", key, getpid());
    fclose(f);
    release_lock();
#if defined(SIGNAL_CAST)
    signal(NOTIFY_SIGNAL, (SIGNAL_CAST) nrnbbs_handler);
#else
    signal(NOTIFY_SIGNAL, nrnbbs_handler);
#endif
}
 
NrnBBSCallbackItem::NrnBBSCallbackItem(const char* s, NrnBBSCallback cb) {
    cb_ = cb;
    s_ = s;
}
 
NrnBBSCallbackItem::~NrnBBSCallbackItem() {}
 
bool NrnBBSCallbackItem::equal(const char* s) {
    return (strcmp(s_.string(), s) == 0) ? true : false;
}
 
void NrnBBSCallbackItem::execute() {
    char buf[256];
    sprintf(buf, "nrnbbs_notifying %s", s_.string());
    if (nrnbbs_take(buf)) {
        (*cb_)(s_.string());
    }
}