Subversion Repositories planix.SVN

#include <u.h>
#include <libc.h>
#include <draw.h>
#include <event.h>
#include "plumb.h"

typedef struct EQueue EQueue;

struct EQueue
{
        int             id;
        char            *buf;
        int             nbuf;
        EQueue  *next;
};

static  EQueue  *equeue;
static  Lock            eqlock;

static
int
partial(int id, Event *e, uchar *b, int n)
{
        EQueue *eq, *p;
        int nmore;

        lock(&eqlock);
        for(eq = equeue; eq != nil; eq = eq->next)
                if(eq->id == id)
                        break;
        unlock(&eqlock);
        if(eq == nil)
                return 0;
        /* partial message exists for this id */
        eq->buf = realloc(eq->buf, eq->nbuf+n);
        if(eq->buf == nil)
                drawerror(display, "eplumb: cannot allocate buffer");
        memmove(eq->buf+eq->nbuf, b, n);
        eq->nbuf += n;
        e->v = plumbunpackpartial((char*)eq->buf, eq->nbuf, &nmore);
        if(nmore == 0){ /* no more to read in this message */
                lock(&eqlock);
                if(eq == equeue)
                        equeue = eq->next;
                else{
                        for(p = equeue; p!=nil && p->next!=eq; p = p->next)
                                ;
                        if(p == nil)
                                drawerror(display, "eplumb: bad event queue");
                        p->next = eq->next;
                }
                unlock(&eqlock);
                free(eq->buf);
                free(eq);
        }
        return 1;
}

static
void
addpartial(int id, char *b, int n)
{
        EQueue *eq;

        eq = malloc(sizeof(EQueue));
        if(eq == nil)
                return;
        eq->id = id;
        eq->nbuf = n;
        eq->buf = malloc(n);
        if(eq->buf == nil){
                free(eq);
                return;
        }
        memmove(eq->buf, b, n);
        lock(&eqlock);
        eq->next = equeue;
        equeue = eq;
        unlock(&eqlock);
}

static
int
plumbevent(int id, Event *e, uchar *b, int n)
{
        int nmore;

        if(partial(id, e, b, n) == 0){
                /* no partial message already waiting for this id */
                e->v = plumbunpackpartial((char*)b, n, &nmore);
                if(nmore > 0)   /* incomplete message */
                        addpartial(id, (char*)b, n);
        }
        if(e->v == nil)
                return 0;
        return id;
}

int
eplumb(int key, char *port)
{
        int fd;

        fd = plumbopen(port, OREAD|OCEXEC);
        if(fd < 0)
                return -1;
        return estartfn(key, fd, 8192, plumbevent);
}