Introduce VCL_STRANDS, and use it for string compare.

VCL_STRANDS is an alternative to VCL_STRING_LIST which uses a
struct instead of varargs.

This means that multiple VCL_STRANDS can be passed to a function,
and string-compare really needed that to not waste workspace.

Add <, >, <=, >= string comparisons while here anyway.

The struct and a const char *[N] array are built on the stack and
they are only valid for the duration of the function call.

bin/varnishd/cache/cache_vrt.c

@@ -156,6 +156,64 @@ VRT_GetHdr(VRT_CTX, const struct gethdr_s *hs)
 	return (p);
 }
 
+/*--------------------------------------------------------------------
+ * Build STRANDS from what is essentially a STRING_LIST
+ */
+
+VCL_STRANDS
+VRT_BundleStrands(int n, struct strands *s, char const **d, const char *f, ...)
+{
+	va_list ap;
+
+	s->n = n;
+	s->p = d;
+	*d++ = f;
+	va_start(ap, f);
+	while(--n)
+		*d++ = va_arg(ap, const char *);
+	assert(va_arg(ap, const char *) == vrt_magic_string_end);
+	va_end(ap);
+	return (s);
+}
+
+/*--------------------------------------------------------------------
+ * Compare two STRANDS
+ */
+
+int
+VRT_CompareStrands(VCL_STRANDS a, VCL_STRANDS b)
+{
+	const char *pa = NULL, *pb = NULL;
+	int na = 0, nb = 0;
+
+	while (1) {
+		if (pa != NULL && *pa == '\0')
+			pa = NULL;
+		if (pb != NULL && *pb == '\0')
+			pb = NULL;
+		if (pa == NULL && na < a->n)
+			pa = a->p[na++];
+		else if (pb == NULL && nb < b->n)
+			pb = b->p[nb++];
+		else if (pa == NULL && pb == NULL)
+			return (0);
+		else if (pa == NULL)
+			return (-1);
+		else if (pb == NULL)
+			return (1);
+		else if (*pa == '\0')
+			pa = NULL;
+		else if (*pb == '\0')
+			pb = NULL;
+		else if (*pa != *pb)
+			return (*pa - *pb);
+		else {
+			pa++;
+			pb++;
+		}
+	}
+}
+
 /*--------------------------------------------------------------------
  * Collapse a STRING_LIST in the space provided, or return NULL
  */
@@ -341,7 +399,7 @@ VRT_r_now(VRT_CTX)
 
 /*--------------------------------------------------------------------*/
 
-char *
+VCL_STRING v_matchproto_()
 VRT_IP_string(VRT_CTX, VCL_IP ip)
 {
 	char *p;
@@ -361,7 +419,7 @@ VRT_IP_string(VRT_CTX, VCL_IP ip)
 	return (p);
 }
 
-char *
+VCL_STRING v_matchproto_()
 VRT_INT_string(VRT_CTX, long num)
 {
 
@@ -369,7 +427,7 @@ VRT_INT_string(VRT_CTX, long num)
 	return (WS_Printf(ctx->ws, "%ld", num));
 }
 
-char *
+VCL_STRING v_matchproto_()
 VRT_REAL_string(VRT_CTX, double num)
 {
 
@@ -377,7 +435,7 @@ VRT_REAL_string(VRT_CTX, double num)
 	return (WS_Printf(ctx->ws, "%.3f", num));
 }
 
-char *
+VCL_STRING v_matchproto_()
 VRT_TIME_string(VRT_CTX, double t)
 {
 	char *p;
@@ -389,7 +447,7 @@ VRT_TIME_string(VRT_CTX, double t)
 	return (p);
 }
 
-const char * v_matchproto_()
+VCL_STRING v_matchproto_()
 VRT_BACKEND_string(VCL_BACKEND d)
 {
 	if (d == NULL)
@@ -398,7 +456,7 @@ VRT_BACKEND_string(VCL_BACKEND d)
 	return (d->vcl_name);
 }
 
-const char *
+VCL_STRING v_matchproto_()
 VRT_BOOL_string(unsigned val)
 {
 

bin/varnishtest/tests/a00015.vtc

@@ -12,7 +12,7 @@ server s1 {
 	txresp -hdr "Content-Type: text/plain" -body response
 } -start
 
-varnish v1 -vcl+backend {} -start
+varnish v1 -vcl+backend {} -start -cliok "param.set debug +syncvsl"
 
 client c1 {
 	txreq -req POST -hdr "Content-Type: text/plain" -body request

bin/varnishtest/tests/v00002.vtc

+varnishtest "Test VCL STRINGS/STRANDS comparisons"
+
+server s1 {
+	rxreq
+	txresp
+} -start
+
+varnish v1 -vcl+backend {
+	sub vcl_deliver {
+		set resp.http.test = req.http.test;
+
+		set resp.http.eq =
+		    req.http.foo == req.http.bar;
+
+		set resp.http.neq =
+		    req.http.foo != req.http.bar;
+
+		set resp.http.lt =
+		    req.http.foo < req.http.bar;
+
+		set resp.http.le =
+		    req.http.foo <= req.http.bar;
+
+		set resp.http.gt =
+		    req.http.foo > req.http.bar;
+
+		set resp.http.ge =
+		    req.http.foo >= req.http.bar;
+	}
+} -start
+
+client c1 {
+	txreq -hdr "foo: 1" -hdr "bar: 1" -hdr "test: 1"
+	rxresp
+	expect resp.http.eq == true
+	expect resp.http.neq == false
+	expect resp.http.lt == false
+	expect resp.http.le == true
+	expect resp.http.gt == false
+	expect resp.http.ge == true
+
+	txreq -hdr "foo: 1" -hdr "bar: 2" -hdr "test: 2"
+	rxresp
+	expect resp.http.eq == false
+	expect resp.http.neq == true
+	expect resp.http.lt == true
+	expect resp.http.le == true
+	expect resp.http.gt == false
+	expect resp.http.ge == false
+
+	txreq -hdr "foo: 2" -hdr "bar: 1" -hdr "test: 3"
+	rxresp
+	expect resp.http.eq == false
+	expect resp.http.neq == true
+	expect resp.http.lt == false
+	expect resp.http.le == false
+	expect resp.http.gt == true
+	expect resp.http.ge == true
+
+	txreq -hdr "foo: 1" -hdr "bar: 11" -hdr "test: 4"
+	rxresp
+	expect resp.http.eq == false
+	expect resp.http.neq == true
+	expect resp.http.lt == true
+	expect resp.http.le == true
+	expect resp.http.gt == false
+	expect resp.http.ge == false
+
+	txreq -hdr "foo: 11" -hdr "bar: 1" -hdr "test: 5"
+	rxresp
+	expect resp.http.eq == false
+	expect resp.http.neq == true
+	expect resp.http.lt == false
+	expect resp.http.le == false
+	expect resp.http.gt == true
+	expect resp.http.ge == true
+
+	txreq -hdr "foo:" -hdr "bar:" -hdr "test: 6"
+	rxresp
+	expect resp.http.eq == true
+	expect resp.http.neq == false
+	expect resp.http.lt == false
+	expect resp.http.le == true
+	expect resp.http.gt == false
+	expect resp.http.ge == true
+
+	txreq -hdr "foo:" -hdr "bar: 1" -hdr "test: 7"
+	rxresp
+	expect resp.http.eq == false
+	expect resp.http.neq == true
+	expect resp.http.lt == true
+	expect resp.http.le == true
+	expect resp.http.gt == false
+	expect resp.http.ge == false
+
+} -run
+
+varnish v1 -vsl_catchup -vcl+backend {
+	sub vcl_deliver {
+		set resp.http.test = req.http.test;
+
+		set resp.http.eq =
+		    req.http.foo + " " == req.http.bar + " ";
+
+		set resp.http.neq =
+		    req.http.foo + " " != req.http.bar + " ";
+
+		set resp.http.lt =
+		    req.http.foo + " " < req.http.bar + " ";
+
+		set resp.http.le =
+		    req.http.foo + " " <= req.http.bar + " ";
+
+		set resp.http.gt =
+		    req.http.foo + " " > req.http.bar + " ";
+
+		set resp.http.ge =
+		    req.http.foo + " " >= req.http.bar + " ";
+	}
+}
+
+client c1 -run
+
+varnish v1 -vsl_catchup -vcl+backend {
+	sub vcl_deliver {
+		set resp.http.test = req.http.test;
+
+		set resp.http.eq =
+		    req.http.foo == req.http.bar + req.http.not;
+
+		set resp.http.neq =
+		    req.http.foo != req.http.bar + req.http.not;
+
+		set resp.http.lt =
+		    req.http.foo < req.http.bar + req.http.not;
+
+		set resp.http.le =
+		    req.http.foo <= req.http.bar + req.http.not;
+
+		set resp.http.gt =
+		    req.http.foo > req.http.bar + req.http.not;
+
+		set resp.http.ge =
+		    req.http.foo >= req.http.bar + req.http.not;
+	}
+}
+
+client c1 -run
+
+varnish v1 -vsl_catchup -vcl+backend {
+	sub vcl_deliver {
+		set resp.http.test = req.http.test;
+
+		set resp.http.eq =
+		    req.http.not + req.http.foo == req.http.bar + req.http.not;
+
+		set resp.http.neq =
+		    req.http.not + req.http.foo != req.http.bar + req.http.not;
+
+		set resp.http.lt =
+		    req.http.not + req.http.foo < req.http.bar + req.http.not;
+
+		set resp.http.le =
+		    req.http.not + req.http.foo <= req.http.bar + req.http.not;
+
+		set resp.http.gt =
+		    req.http.not + req.http.foo > req.http.bar + req.http.not;
+
+		set resp.http.ge =
+		    req.http.not + req.http.foo >= req.http.bar + req.http.not;
+	}
+}
+
+client c1 -run

include/vrt.h

@@ -61,6 +61,7 @@
  *	VRT_r_beresp_storage_hint() removed - under discussion #2509
  *	VRT_l_beresp_storage_hint() removed - under discussion #2509
  *	VRT_blob() added
+ *	VCL_STRANDS added
  * 6.1 (2017-09-15 aka 5.2)
  *	http_CollectHdrSep added
  *	VRT_purge modified (may fail a transaction, signature changed)
@@ -114,6 +115,11 @@ struct vsb;
 struct vsl_log;
 struct ws;
 
+struct strands {
+	int		n;
+	const char	**p;
+};
+
 /***********************************************************************
  * This is the central definition of the mapping from VCL types to
  * C-types.  The python scripts read these from here.
@@ -136,6 +142,7 @@ typedef const struct suckaddr *			VCL_IP;
 typedef const struct vrt_backend_probe *	VCL_PROBE;
 typedef double					VCL_REAL;
 typedef const struct stevedore *		VCL_STEVEDORE;
+typedef const struct strands *			VCL_STRANDS;
 typedef const char *				VCL_STRING;
 typedef double					VCL_TIME;
 typedef struct vcl *				VCL_VCL;
@@ -421,14 +428,19 @@ VCL_STEVEDORE VRT_stevedore(const char *nm);
 
 /* Convert things to string */
 
-char *VRT_IP_string(VRT_CTX, VCL_IP);
-char *VRT_INT_string(VRT_CTX, VCL_INT);
-char *VRT_REAL_string(VRT_CTX, VCL_REAL);
-char *VRT_TIME_string(VRT_CTX, VCL_TIME);
-const char *VRT_BOOL_string(VCL_BOOL);
-const char *VRT_BACKEND_string(VCL_BACKEND);
-const char *VRT_STEVEDORE_string(VCL_STEVEDORE);
-const char *VRT_CollectString(VRT_CTX, const char *p, ...);
+VCL_STRANDS VRT_BundleStrands(int, struct strands *, char const **,
+    const char *f, ...);
+int VRT_CompareStrands(VCL_STRANDS a, VCL_STRANDS b);
+
+VCL_STRING VRT_BACKEND_string(VCL_BACKEND);
+VCL_STRING VRT_BOOL_string(VCL_BOOL);
+VCL_STRING VRT_CollectString(VRT_CTX, const char *p, ...);
+VCL_STRING VRT_INT_string(VRT_CTX, VCL_INT);
+VCL_STRING VRT_IP_string(VRT_CTX, VCL_IP);
+VCL_STRING VRT_REAL_string(VRT_CTX, VCL_REAL);
+VCL_STRING VRT_STEVEDORE_string(VCL_STEVEDORE);
+VCL_STRING VRT_STRANDS_string(VCL_STRANDS);
+VCL_STRING VRT_TIME_string(VRT_CTX, VCL_TIME);
 
 #ifdef va_start	// XXX: hackish
 void *VRT_VSC_Alloc(const char *, size_t, size_t, const unsigned char *, size_t,

lib/libvcc/vcc_types.c

@@ -131,7 +131,11 @@ const struct type STEVEDORE[1] = {{
 const struct type STRING[1] = {{
 	.magic =		TYPE_MAGIC,
 	.name =			"STRING",
-	.tostring =		"",
+}};
+
+const struct type STRANDS[1] = {{
+	.magic =		TYPE_MAGIC,
+	.name =			"STRANDS",
 }};
 
 const struct type STRINGS[1] = {{