rework the vmod interface for setting flags

README.rst

@@ -65,26 +65,31 @@ missing error handling in varnish-cache. Notice that the VMOD has no
 known way to check for this condition, so please address any blame
 appropriately.
 
-.. _vmod_pesi.serial:
+.. _vmod_pesi.set:
 
-VOID serial(BOOL serial=0)
---------------------------
+VOID set(ENUM {serial} parameter, [BOOL bool])
+----------------------------------------------
 
-Activates serial mode if the argument is ``true``.
+To be called from ``vcl_deliver {}`` only.
 
-To be called from vcl_deliver {} only, the default argument is
-``false``.
+Set per (sub)request parameters for pesi which are documented
+below. Parameters may require one or more of the other additional
+arguments as documented below. Failure to provide them triggers a VCL
+error.
 
-In serial mode, no new threads will be started from this request and
-all ESI subrequests at the next level only will be processed by the
-current thread.
+* ``serial``, requires *bool* argument
 
-In other words, the setting only affects include processing for the
-current response body.
+  Activates serial mode if *bool* is ``true``.
 
-It is strongly recommended to _not_ use serial mode from ESI level 0
-because the ESI level 0 thread is responsible for sending available
-data to the client.
+  In serial mode, no new threads will be started from this request, so
+  all ESI subrequests at the next level will be processed by the
+  current thread. In other words, the setting only affects include
+  processing for the current response body.
+
+  It is strongly recommended to _not_ use serial mode from ESI level 0
+  because the ESI level 0 thread is responsible for sending available
+  data to the client and thus should be running concurrently to other
+  parallel ESI threads.
 
 .. _vmod_pesi.version:
 

src/Makefile.am

@@ -9,6 +9,7 @@ vmod_LTLIBRARIES = libvmod_pesi.la
 
 libvmod_pesi_la_SOURCES = \
 	vdp_pesi.c \
+	tbl_set_parameter.h \
 	foreign/qdef.h \
 	foreign/from_cache_esi_deliver.h \
 	foreign/from_cache_esi_deliver.c

src/tbl_set_parameter.h

+VMODENUM(serial, PF_CFG_SERIAL)
+#undef VMODENUM

src/tests/serial.vtc

@@ -49,7 +49,7 @@ varnish v1 -arg "-p debug=+syncvsl" -vcl+backend {
 
 	sub vcl_deliver {
 		pesi.activate();
-		pesi.serial(true);
+		pesi.set(serial, true);
 	}
 } -start
 
@@ -264,7 +264,7 @@ varnish v1 -vcl+backend {
 	sub vcl_deliver {
 		pesi.activate();
 		if (std.integer(req.http.Serial-Level, -1) >= req.esi_level) {
-			pesi.serial(true);
+			pesi.set(serial, true);
 		}
 	}
 }

src/vdp_pesi.c

@@ -2966,20 +2966,37 @@ vmod_activate(VRT_CTX)
 		req->filter_list = filters;
 }
 
+static unsigned
+vmod_set_param_flag(VCL_ENUM e)
+{
+#define VMODENUM(p,f) if (e == VENUM(p)) return(f);
+#include "tbl_set_parameter.h"
+       WRONG("illegal enum");
+}
+
 VCL_VOID
-vmod_serial(VRT_CTX, VCL_BOOL b)
+vmod_set(VRT_CTX, struct VARGS(set) *args)
 {
 	struct vmod_priv *priv_task;
-	unsigned vclflags;
+	unsigned f, vclflags;
 
 	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
 
 	if (ctx->method != VCL_MET_DELIVER) {
-		VRT_fail(ctx, "pesi.serial() may only be called "
+		VRT_fail(ctx, "pesi.set() may only be called "
 		    "from vcl_deliver{}");
 		return;
 	}
 
+	/* as of now, all parameters require a bool parameter */
+	if (args->valid_bool == 0) {
+		VRT_fail(ctx, "pesi.set(%s) requires a bool "
+		    "parameter", args->parameter);
+		return;
+	}
+
+	/* get current flags from priv_task */
+
 	priv_task = VRT_priv_task(ctx, priv_task_id_cfg);
 
 	if (priv_task == NULL) {
@@ -2998,11 +3015,15 @@ vmod_serial(VRT_CTX, VCL_BOOL b)
 		assert(priv_task->len == 1);
 	}
 
-	AZ(vclflags & ~PF_MASK_CFG);
+	/* set by args */
 
-	vclflags &= ~PF_CFG_SERIAL;
-	if (b)
-		vclflags |= PF_CFG_SERIAL;
+	f = vmod_set_param_flag(args->parameter);
+
+	vclflags &= ~f;
+	if (args->bool)
+		vclflags |= f;
+
+	AZ(vclflags & ~PF_MASK_CFG);
 
 	priv_task->priv = (void *)(uintptr_t)vclflags;
 }

src/vdp_pesi.vcc

@@ -54,23 +54,28 @@ missing error handling in varnish-cache. Notice that the VMOD has no
 known way to check for this condition, so please address any blame
 appropriately.
 
-$Function VOID serial(BOOL serial=0)
+$Function VOID set(ENUM { serial } parameter, [BOOL bool])
 
-Activates serial mode if the argument is ``true``.
+To be called from ``vcl_deliver {}`` only.
 
-To be called from vcl_deliver {} only, the default argument is
-``false``.
+Set per (sub)request parameters for pesi which are documented
+below. Parameters may require one or more of the other additional
+arguments as documented below. Failure to provide them triggers a VCL
+error.
 
-In serial mode, no new threads will be started from this request and
-all ESI subrequests at the next level only will be processed by the
-current thread.
+* ``serial``, requires *bool* argument
 
-In other words, the setting only affects include processing for the
-current response body.
+  Activates serial mode if *bool* is ``true``.
 
-It is strongly recommended to _not_ use serial mode from ESI level 0
-because the ESI level 0 thread is responsible for sending available
-data to the client.
+  In serial mode, no new threads will be started from this request, so
+  all ESI subrequests at the next level will be processed by the
+  current thread. In other words, the setting only affects include
+  processing for the current response body.
+
+  It is strongly recommended to _not_ use serial mode from ESI level 0
+  because the ESI level 0 thread is responsible for sending available
+  data to the client and thus should be running concurrently to other
+  parallel ESI threads.
 
 $Function STRING version()