Convenience code ... allow a pool to be used as a client.

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/sqlclient/trunk@38248 72102866-910b-0410-8b05-ffd578937521

SQLClient.h

@@ -1411,6 +1411,16 @@ SQLCLIENT_PRIVATE
  * <p>All clients in the pool share the same cache object, so query results
  * cached by one client will be available to other clients in the pool.
  * </p>
+ * <p>As a convenience, an SQLClientPool instance acts as a proxy for the
+ * clients it contains, so you may (where it makes sense) send the same
+ * messages to a pool that you would send to an individual client, and the
+ * pool will temporarily allocate one of its clients to handle it.<br />
+ * In this case the client will be returned to the pool immediately
+ * after the message has been handled (and subsequent messages may go
+ * to a different client), so you can't change settings or send any other
+ * method which would be required to be followed up by another message to
+ * the same client.
+ * </p>
  */
 @interface	SQLClientPool : NSObject
 {

SQLClientPool.m

@@ -29,6 +29,7 @@
 #import	<Foundation/NSAutoreleasePool.h>
 #import	<Foundation/NSDebug.h>
 #import	<Foundation/NSException.h>
+#import	<Foundation/NSInvocation.h>
 #import	<Foundation/NSLock.h>
 #import	<Foundation/NSString.h>
 
@@ -541,3 +542,60 @@
 
 @end
 
+@implementation SQLClientPool (Proxying)
+
+static BOOL
+selIsBad(SEL aSelector)
+{
+  const char    *n = sel_getName(aSelector);
+
+  if (strncmp(n, "set", 3) == 0)
+    {
+      return YES;
+    }
+  if (strncmp(n, "backend", 7) == 0)
+    {
+      return YES;
+    }
+  if (strcmp(n, "begin") == 0)
+    {
+      return YES;
+    }
+  return NO;
+}
+
+- (void) forwardInvocation: (NSInvocation*)anInvocation
+{
+  SQLClient     *db;
+
+  db = [self provideClient];
+  [anInvocation invokeWithTarget: db];
+  [self swallowClient: db];
+}
+
+- (NSMethodSignature*) methodSignatureForSelector: (SEL)aSelector
+{
+  NSMethodSignature     *methodSig;
+
+  methodSig = [super methodSignatureForSelector: aSelector];
+  if (nil == methodSig && 0 != c && NO == selIsBad(aSelector))
+    {
+      methodSig = [c[0] methodSignatureForSelector: aSelector];
+    }
+  return methodSig;
+}
+
+- (BOOL) respondsToSelector: (SEL)aSelector
+{
+  BOOL  result;
+
+  result = [super respondsToSelector: aSelector];
+  if (NO == result && 0 != c && NO == selIsBad(aSelector))
+    {
+      result = [c[0] respondsToSelector: aSelector];
+    }
+  return result;
+}
+
+@end
+