Generic hooks (and a demo content filter module).

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@87568 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 120 insertions, 0 deletions

diff --git a/include/ap_generic_hook.h b/include/ap_generic_hook.h
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+/* ====================================================================
+ * The Apache Software License, Version 1.1
+ *
+ * Copyright (c) 2000 The Apache Software Foundation.  All rights
+ * reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in
+ *    the documentation and/or other materials provided with the
+ *    distribution.
+ *
+ * 3. The end-user documentation included with the redistribution,
+ *    if any, must include the following acknowledgment:
+ *       "This product includes software developed by the
+ *        Apache Software Foundation (http://www.apache.org/)."
+ *    Alternately, this acknowledgment may appear in the software itself,
+ *    if and wherever such third-party acknowledgments normally appear.
+ *
+ * 4. The names "Apache" and "Apache Software Foundation" must
+ *    not be used to endorse or promote products derived from this
+ *    software without prior written permission. For written
+ *    permission, please contact apache@apache.org.
+ *
+ * 5. Products derived from this software may not be called "Apache",
+ *    nor may "Apache" appear in their name, without prior written
+ *    permission of the Apache Software Foundation.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
+ * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED.  IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
+ * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
+ * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
+ * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ * ====================================================================
+ *
+ * This software consists of voluntary contributions made by many
+ * individuals on behalf of the Apache Software Foundation.  For more
+ * information on the Apache Software Foundation, please see
+ * <http://www.apache.org/>.
+ */
+
+#ifndef APACHE_AP_GENERIC_HOOK_H
+#define APACHE_AP_GENERIC_HOOK_H
+
+#include "apr_tables.h"
+
+/**
+ * @package Apache hooks functions
+ */
+
+#define AP_DECLARE_GENERIC_HOOK(link,ret,name,args) \
+typedef ret HOOK_##name args;
+
+AP_DECLARE(void) ap_hook_generic(const char *szName,void (*pfn)(void),
+				 const char * const *aszPre,
+				 const char * const *aszSucc,int nOrder);
+
+/**
+ * Hook to a generic hook.
+ *
+ * @param name The name of the hook
+ * @param pfn A pointer to a function that will be called
+ * @param aszPre a NULL-terminated array of strings that name modules whose hooks should precede this one
+ * @param aszSucc a NULL-terminated array of strings that name modules whose hooks should succeed this one
+ * @param nOrder an integer determining order before honouring aszPre and aszSucc (for example HOOK_MIDDLE)
+ */
+
+#define AP_HOOK_GENERIC(name,pfn,aszPre,aszSucc,nOrder) \
+    ((void (*)(const char *,HOOK_##name *,const char * const *, \
+	       const char * const *,int))&ap_hook_generic)(#name,pfn,aszPre, \
+							   aszSucc, nOrder)
+
+apr_array_header_t *ap_generic_hook_get(const char *szName);
+
+/**
+ * Implement a generic hook that runs until one of the functions
+ * returns something other than OK or DECLINE.
+ *
+ * @param ret The type of the return value of the hook
+ * @param name The name of the hook
+ * @param args_decl The declaration of the arguments for the hook
+ * @param args_used The names for the arguments for the hook
+ * @deffunc int AP_IMPLEMENT_EXTERNAL_HOOK_RUN_ALL(link, name, args_decl, args_use)
+ */
+#define AP_IMPLEMENT_GENERIC_HOOK_RUN_ALL(ret,name,args_decl,args_use,ok,decline) \
+AP_DECLARE(ret) ap_run_##name args_decl \
+    { \
+    LINK_##name *pHook; \
+    int n; \
+    ret rv; \
+    apr_array_header_t *pHookArray=ap_generic_hook_get(#name); \
+\
+    if(!pHookArray) \
+	return ok; \
+\
+    pHook=(LINK_##name *)pHookArray->elts; \
+    for(n=0 ; n < pHookArray->nelts ; ++n) \
+	{ \
+	rv=pHook[n].pFunc args_use; \
+\
+	if(rv != ok && rv != decline) \
+	    return rv; \
+	} \
+    return ok; \
+    }
+
+#endif /* def APACHE_AP_GENERIC_HOOK_H */