From a49e54ea3ce119603156bac190b76ec03524fe4a Mon Sep 17 00:00:00 2001
From: genoa <genoa>
Date: Fri, 26 Jun 1992 13:08:02 +0000
Subject: [PATCH 1/1] Added the cache_commit() and cache_abort() routines,
 along with supporting changes.

---
 server/cache.dc | 63 ++++++++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 57 insertions(+), 6 deletions(-)

diff --git a/server/cache.dc b/server/cache.dc
index 23087adb..6e621b80 100644
--- a/server/cache.dc
+++ b/server/cache.dc
@@ -15,6 +15,7 @@ static char *rcsid_cache_dc = "$Header$";
 #include "mr_server.h"
 EXEC SQL INCLUDE sqlca;
 
+
 extern char *whoami, *strsave();
 extern int ingres_errno, mr_errcode;
 
@@ -47,6 +48,7 @@ struct item {
     int id;
     struct item *next;
     struct item *prev;
+    struct item *trans;		/* keep track of transactions */
 };
 
 static struct item cachehead;
@@ -92,6 +94,7 @@ flush_cache()
     if (cachehead.prev != &cachehead)
       free(cachehead.prev);
     cachehead.next = cachehead.prev = &cachehead;
+    cachehead.trans = (struct item *)NULL;
 }
 
 
@@ -104,7 +107,7 @@ char *name;
 char *type;
 int *id;
 {
-    register struct item *i;
+    register struct item *i, *t;
     EXEC SQL BEGIN DECLARE SECTION;
     char *iname;
     int j, rowcount;
@@ -142,8 +145,7 @@ int *id;
 	break;
     case 'M':
     case 'm':
-	uppercase(iname);
-	EXEC SQL SELECT mach_id INTO :j FROM machine WHERE name=:iname;
+	EXEC SQL SELECT mach_id INTO :j FROM machine WHERE name=uppercase(:iname);
 	break;
     case 'C':
     case 'c':
@@ -185,6 +187,12 @@ int *id;
     i->prev = &cachehead;
     cachehead.next->prev = i;
     cachehead.next = i;
+    /* find the end of the transaction chain & add this item */
+    for (t = &cachehead; t->trans && t != i; t = t->trans);
+    if (t != i) {
+	t->trans = i;
+	i->trans = (struct item *)NULL;
+    }
     return(MR_SUCCESS);
 }
 
@@ -281,6 +289,12 @@ char **name;
     i->prev = &cachehead;
     cachehead.next->prev = i;
     cachehead.next = i;
+    /* find the end of the transaction chain & add this item */
+    for (t = &cachehead; t->trans && t != i; t = t->trans);
+    if (t != i) {
+	t->trans = i;
+	i->trans = (struct item *)NULL;
+    }
     return(MR_SUCCESS);
 }
 
@@ -294,11 +308,16 @@ char *name;
 char *type;
 int id;
 {
-    register struct item *i;
+    register struct item *i, *t;
 
     for (i = cachehead.next; i != &cachehead; i = i->next)
-      if (i->id == id && !strcmp(i->type, type))
-	return(MR_SUCCESS);
+      if (i->id == id && !strcmp(i->type, type)) {
+	  if (strcmp(i->name, name)) {
+	      strcpy(i->name, name);
+	      i->nhash = hashname(name, type);
+	  }
+	  return(MR_SUCCESS);
+      }
     if (cachesize < CACHESIZE) {
 	i = (struct item *) malloc(sizeof(struct item));
 	cachesize++;
@@ -315,6 +334,12 @@ int id;
     i->prev = &cachehead;
     cachehead.next->prev = i;
     cachehead.next = i;
+    /* find the end of the transaction chain & add this item */
+    for (t = &cachehead; t->trans && t != i; t = t->trans);
+    if (t != i) {
+	t->trans = i;
+	i->trans = (struct item *)NULL;
+    }
     return(MR_SUCCESS);
 }
 
@@ -340,3 +365,29 @@ char *type;
 	}
     }
 }
+
+
+/* Called when a transaction is committed to also commit any cache changes.
+ * Just throws away the list of cache changes for this transaction.
+ */
+
+cache_commit()
+{
+    cachehead.trans = (struct item *)NULL;
+}
+
+
+/* Called whan a transaction is aborted to throw away any cache changes
+ * from that transaction.
+ */
+
+cache_abort()
+{
+    register struct item *i, *t;
+
+    for (i = cachehead.trans; i; i = t) {
+	t = i->trans;
+	flush_name(i->name, i->type);
+    }
+    cachehead.trans = (struct item *)NULL;
+}
-- 
2.45.2