From 647ce656f4afd6be1c4306d65e0faff4f7b22070 Mon Sep 17 00:00:00 2001
From: John Kohl <jtkohl@mit.edu>
Date: Wed, 18 Mar 1987 12:47:34 +0000
Subject: Initial revision

---
 server/class.c | 186 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 186 insertions(+)
 create mode 100644 server/class.c

(limited to 'server/class.c')

diff --git a/server/class.c b/server/class.c
new file mode 100644
index 0000000..43246ce
--- /dev/null
+++ b/server/class.c
@@ -0,0 +1,186 @@
+/* Copyright (c) 1987 Massachusetts Institute of Technology */
+
+/*
+ *	$Source$
+ *	$Header$
+ */
+
+#ifndef lint
+static char *rcsid_cm_c = "$Header$";
+#endif lint
+
+#include <zephyr/mit-copyright.h>
+#include <zephyr/zephyr.h>
+#include "zserver.h"
+
+/*
+ * Class manager subsystem.
+ * external functions are:
+ * Code_t cm_register(client, class)
+ * Code_t cm_deregister(client, class)
+ * struct qelem *cm_lookup(class)
+ *	ZClientDesc_t *client;
+ *	char *class;
+ */
+
+/* Private variables */ 
+typedef struct _ZClientList_t {
+    struct	_ZClientList_t *q_forw;
+    struct	_ZClientList_t *q_back;
+    ZClientDesc_t	*client;
+} ZClientList_t;
+
+typedef struct _ZClass_t {
+    struct	_ZClass_t *q_forw;
+    struct	_ZClass_t *q_back;
+    char	*classname;
+    ZClientList_t	*clientlist;
+} ZClass_t;
+
+
+#define	NULLZCT		((ZClass_t *) 0)
+#define	NULLZCDT	((ZClientDesc_t *) 0)
+#define	NULLZCLT	((ZClientList_t *) 0)
+
+#define	EMPTY_CLASS	2000
+
+#define	HSHSIZ		8192
+#define	HSHMUL		243
+
+static ZClass_t *class_bucket[511];
+
+/* private routines */
+static ZClass_t *class_alloc(class)
+char *class;
+{
+    register ZClass_t *ptr;
+    if ((ptr = (ZClass_t *) malloc(sizeof(ZClass_t))) == NULLZCT)
+      return(NULLZCT);
+
+    if ((ptr->classname = strsave(class)) == NULL) {
+	free((char *) ptr);
+	return(NULLZCT);
+    }
+    return(ptr);
+}
+
+static ZClientList_t *client_alloc(client)
+ZClientDesc_t *client;
+{
+    register ZClientList_t *ptr;
+    if ((ptr = (ZClientList_t *) malloc(sizeof(ZClientList_t))) == NULLZCLT)
+      return(NULLZCLT);
+
+    ptr->client = client;
+    return(ptr);
+}
+
+static Code_t insert_client(ptr, client)
+ZClass_t *ptr;
+ZClientDesc_t *client;
+{
+    register ZClientList_t *listp;
+
+    if ((listp = client_alloc(client)) == NULLZCLT)
+      return(ZERR_UNIX);
+    if (ptr->clientlist == NULLZCLT)
+      ptr->clientlist = listp;
+    else
+      insque(listp, ptr->clientlist);
+    return(ZERR_NONE);
+}
+
+static Code_t remove_client(ptr, client)
+ZClass_t *ptr;
+ZClientDesc_t *client;
+{
+    register ZClientList_t *listp = ptr->clientlist; 
+    register ZClientList_t *listp2;
+
+    if (listp->client == client) { /* found him */
+	if (listp->q_forw = listp) { /* this is the only elem on this queue */
+	    ptr->clientlist = NULLZCLT;
+	    free(listp);
+	    return(EMPTY_CLASS);
+	}
+	/* ok, remove him, being careful to reset the pointer to the queue */
+	ptr->clientlist = listp->q_forw;
+	remque(listp);
+	free(listp);
+	return(ZERR_NONE);
+    } else {
+      for (listp2 = listp->q_forw; listp2 != listp; listp2 = listp2->q_forw)
+	/* walk down list, looking for him */
+	if (listp2->client == client) {
+	    reqmue(listp);
+	    free(listp);
+	    return(ZERR_NONE);
+	}
+      return(ZERR_S_BADASSOC);
+  }
+}
+    
+/*  */
+/* public routines */
+Code_t cm_register(client, class)
+ZClientDesc_t *client;
+char *class;
+{
+    register ZClass_t *ptr, *ptr2;
+    int hashval = hash(class);
+
+    if ((ptr = class_bucket[hashval]) == NULLZCT) {
+	/* not registered */
+
+	if ((ptr = class_alloc(class)) == NULLZCT)
+	  return(ZERR_UNIX);
+
+	class_bucket[hashval] = ptr;
+	return(insert_client(ptr, client));
+
+    } else if (!strcmp(ptr->classname, class)) /* match! */
+      return(insert_client(ptr, client));
+    else {
+	for (ptr2 = ptr->q_forw; ptr2 != ptr; ptr2 = ptr2->q_forw) {
+	    /* walk down the list, looking for a match */
+	    if (!strcmp(ptr2->classname, class))
+	      return(insert_client(ptr2, client));
+	}
+	if (ptr2 = ptr) { /* fell off the end, no match */
+	    if ((ptr2 = class_alloc(class)) == NULLZCT)
+	      return(ZERR_UNIX);
+	    insque(ptr2, ptr);		/* insert new class into hash bucket */
+	    return(insert_client(ptr2, client));
+	}
+    }
+}
+
+Code_t cm_deregister(client, class)
+ZClientDesc_t *client;
+char *class;
+{
+    register ZClass_t *ptr, *ptr2;
+    int retval = -1;
+    int hashval = hash(class);
+ 
+    if ((ptr = class_bucket[hashval]) == NULLZCT)
+      /* no such class to deregister */
+      return(ZERR_S_BADASSOC);
+    if (!strcmp(ptr->classname, class)) { /* match! */
+	retval = remove_client(ptr, client);
+	/* handle retval here*/
+	ptr2 = ptr;
+    }
+    else {
+	for (ptr2 = ptr->q_forw; ptr2 != ptr; ptr2 = ptr2->q_forw) {
+	    /* walk down the list, looking for a match */
+	    if (!strcmp(ptr2->classname, class)) {
+		retval = remove_client(ptr2, client);
+		/* handle it here too */
+		break;
+	    }
+	}
+	/* fell off, error */
+	return(ZERR_S_BADASSOC);
+    }
+}
-- 
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