named parameter for .backend and .hash_string

README.rst

@@ -8,7 +8,7 @@ Varnish Consistent Hashing Director Module
 
 :Author: Julian Wiesener
 :Date: 2014-07-16
-:Version: 1.0
+:Version: 1.1
 :Manual section: 3
 
 .. _synopsis:
@@ -147,42 +147,23 @@ Initializes the hash ring. This function must be called after all backends are
 added. The argument is the numbers of replicas the hash ring contains for each
 backend.
 
-INT .hash_string(STRING, ENUM { CRC32, SHA256, RS })
-----------------------------------------------------
+INT .hash_string(STRING string, ENUM { CRC32, SHA256, RS } alg)
+---------------------------------------------------------------
 
 Returns the hash of its first argument using the hash
-algorithm defined.
+algorithm defined, defaults to CRC32.
 
-BACKEND .backend()
-------------------
 
-Returns a backend based on the default hash of the request URL.
+BACKEND .backend(INT nte, BOOL altsrv_p, BOOL healthy, INT hash)
+----------------------------------------------------------------
 
-BACKEND .backend_n(INT, BOOL, BOOL, INT)
-----------------------------
-
-Returns the n-th backend (first parameter) with respect of altsrv_p (second
-parameter) and respect of its healthy state (third parameter) for the given
-hash (last parameter).
-
-BACKEND .backend_by_int(INT)
-----------------------------
-
-Returns a backend based on the value of its parameter. The value should be
-evenly distributet between 0 and MAX_INT to get a good distribution of requests.
-
-BACKEND .backend_by_string(STRING)
-----------------------------------
-
-Returns a backend based on the default hash of its argument.
-DEPRECATED: use .backend_by_int(hash_string()) instead
-
-BACKEND .backend_by_string_hash(STRING, ENUM { CRC32, SHA256, RS })
--------------------------------------------------------------------
+Returns the nth backend with respect of altsrv_p  and respect of its healthy
+state for the given hash. All parameters are optional, the defaults are:
 
-Returns a backend based on the hash of its first argument using the hash
-algorithm defined.
-DEPRECATED: use .backend_by_int(hash_string()) instead
+ nte=0 will pick the first backend under respect of VSLP rules
+ altsrv_p=ture
+ healthy=true
+ hash=0 will use a CRC32 of the request URL
 
 
 LIMITATIONS

src/tests/v01001.vtc

@@ -29,13 +29,13 @@ varnish v1 -vcl+backend {
 
 	sub vcl_recv {
 		if(req.url == "/1") {
-			set req.backend_hint = vd.backend_by_int(1);
+			set req.backend_hint = vd.backend(hash=1);
 		}
 		if(req.url == "/2") {
-			set req.backend_hint = vd.backend_by_int(2147483647);
+			set req.backend_hint = vd.backend(hash=2147483647);
 		}
 		if(req.url == "/3") {
-			set req.backend_hint = vd.backend_by_int(4294967295);
+			set req.backend_hint = vd.backend(hash=4294967295);
 		}
 		return(pass);
 	}

src/tests/v01004.vtc

@@ -32,21 +32,21 @@ varnish v1 -vcl+backend {
 	}
 
 	sub recv_sub {
-		set req.backend_hint = vd.backend_by_string_hash(req.http.X-Hash, RS);
+		set req.backend_hint = vd.backend(hash=vd.hash_string(req.http.X-Hash, RS));
 	}
 
 	sub vcl_recv {
 		if(req.url == "/1") {
-			set req.backend_hint = vd.backend_by_string("/eishoSu2");
+			set req.backend_hint = vd.backend(hash=vd.hash_string("/eishoSu2"));
 		} else if (req.url == "/2") {
-			set req.backend_hint = vd.backend_by_string_hash("/eishoSu2", SHA256);
+			set req.backend_hint = vd.backend(hash=vd.hash_string(alg=SHA256, string="/eishoSu2"));
 		} else if (req.url == "/3") {
 			set req.http.X-Hash = "/oob3dahS";
 			call recv_sub;
 		} else if (req.url == "/null_by_string") {
-			set req.backend_hint = vd.backend_by_string(req.http.NonExistent);
+			set req.backend_hint = vd.backend(hash=vd.hash_string(req.http.NonExistent));
 		} else if (req.url == "/null_by_string_hash") {
-			set req.backend_hint = vd.backend_by_string_hash(req.http.NonExistent, SHA256);
+			set req.backend_hint = vd.backend(hash=vd.hash_string(req.http.NonExistent, SHA256));
 		}
 		return(pass);
 	}

src/tests/v01005.vtc

@@ -40,7 +40,7 @@ varnish v1 -vcl+backend {
 	}
 
 	sub vcl_recv {
-		set req.backend_hint = vd.backend_by_string("/eishoSu2");
+		set req.backend_hint = vd.backend(hash=vd.hash_string("/eishoSu2"));
 		if(req.url == "/2" && req.restarts > 0) {
 			unset req.http.vrstart;
 		}

src/tests/v01006.vtc

@@ -28,7 +28,7 @@ varnish v1 -vcl+backend {
 	}
 
 	sub vcl_recv {
-		set req.backend_hint = vd.backend_by_string("/eishoSu2");
+		set req.backend_hint = vd.backend(hash=vd.hash_string("/eishoSu2"));
 		return(pass);
 	}
 

src/tests/v01007.vtc

@@ -31,7 +31,7 @@ varnish v1 -vcl+backend {
 	}
 
 	sub vcl_recv {
-		set req.backend_hint = vd.backend_by_string("/eishoSu2");
+		set req.backend_hint = vd.backend(hash=vd.hash_string("/eishoSu2"));
 		return(pass);
 	}
 

src/vmod_vslp.c

@@ -136,84 +136,27 @@ vmod_vslp_hash_string(const struct vrt_ctx *ctx, struct vmod_vslp_vslp *vslpd, V
 	return (hash);
 }
 
-VCL_BACKEND __match_proto__(td_vslp_vslp_backend)
-vmod_vslp_backend(const struct vrt_ctx *ctx, struct vmod_vslp_vslp *vslpd)
-{
-	uint32_t hash;
-	VCL_BACKEND be;
-	struct http *http;
-
-	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
-	CHECK_OBJ_NOTNULL(vslpd, VMOD_VSLP_VSLP_MAGIC);
-
-	/* client or backend context ? */
-	if (ctx->http_req) {
-		AN(http = ctx->http_req);
-	} else {
-		AN(ctx->http_bereq);
-		AN(http = ctx->http_bereq);
-	}
-
-	hash = vslpd->vslpd->hash_fp(http->hd[HTTP_HDR_URL].b);
-	be = vslpdir_pick_be(vslpd->vslpd, ctx, hash, 0, true, true);
-
-	return (be);
-}
-
 VCL_BACKEND __match_proto__(td_vslp_vslp_backend_n)
-vmod_vslp_backend_n(const struct vrt_ctx *ctx, struct vmod_vslp_vslp *vslpd, VCL_INT n, VCL_BOOL altsrv_p, VCL_BOOL healthy,  VCL_INT i)
+vmod_vslp_backend(const struct vrt_ctx *ctx, struct vmod_vslp_vslp *vslpd, VCL_INT n, VCL_BOOL altsrv_p, VCL_BOOL healthy,  VCL_INT i)
 {
+	uint32_t hash = (uint32_t) i;
 	VCL_BACKEND be;
 
 	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
 	CHECK_OBJ_NOTNULL(vslpd, VMOD_VSLP_VSLP_MAGIC);
 
-	be = vslpdir_pick_be(vslpd->vslpd, ctx, i, n, altsrv_p, healthy);
-
-	return (be);
-}
-
-VCL_BACKEND __match_proto__(td_vslp_vslp_backend_by_int)
-vmod_vslp_backend_by_int(const struct vrt_ctx *ctx, struct vmod_vslp_vslp *vslpd, VCL_INT i)
-{
-	VCL_BACKEND be;
-
-	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
-	CHECK_OBJ_NOTNULL(vslpd, VMOD_VSLP_VSLP_MAGIC);
-
-	be = vslpdir_pick_be(vslpd->vslpd, ctx, i, 0, true, true);
-
-	return (be);
-}
-
-VCL_BACKEND __match_proto__(td_vslp_vslp_backend_by_string)
-vmod_vslp_backend_by_string(const struct vrt_ctx *ctx, struct vmod_vslp_vslp *vslpd, VCL_STRING s)
-{
-	uint32_t hash;
-	VCL_BACKEND be;
-
-	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
-	CHECK_OBJ_NOTNULL(vslpd, VMOD_VSLP_VSLP_MAGIC);
-
-	hash = vslpd->vslpd->hash_fp(s ? s : "");
-	be = vslpdir_pick_be(vslpd->vslpd, ctx, hash, 0, true, true);
-
-	return (be);
-}
-
-VCL_BACKEND __match_proto__(td_vslp_vslp_backend_by_string_hash)
-vmod_vslp_backend_by_string_hash(const struct vrt_ctx *ctx, struct vmod_vslp_vslp *vslpd, VCL_STRING s, VCL_ENUM hash_m)
-{
-	uint32_t hash;
-	hash_func hash_fp;
-	VCL_BACKEND be;
-
-	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
-	CHECK_OBJ_NOTNULL(vslpd, VMOD_VSLP_VSLP_MAGIC);
-
-	hash_fp = vslp_get_hash_fp(hash_m);
-	hash = hash_fp(s ? s : "");
-	be = vslpdir_pick_be(vslpd->vslpd, ctx, hash, 0, true, true);
+	if(!hash) {
+		/* client or backend context ? */
+		struct http *http;
+		if (ctx->http_req) {
+			AN(http = ctx->http_req);
+		} else {
+			AN(ctx->http_bereq);
+			AN(http = ctx->http_bereq);
+		}
+		hash = vslpd->vslpd->hash_fp(http->hd[HTTP_HDR_URL].b);
+	}
+	be = vslpdir_pick_be(vslpd->vslpd, ctx, hash, n, altsrv_p, healthy);
 
 	return (be);
 }

src/vmod_vslp.vcc

@@ -34,9 +34,5 @@ $Method VOID .set_rampup_ratio(REAL)
 $Method VOID .set_rampup_time(DURATION)
 $Method VOID .set_hash(ENUM { CRC32, SHA256, RS })
 $Method VOID .init_hashcircle(INT)
-$Method INT .hash_string(STRING, ENUM { CRC32, SHA256, RS })
-$Method BACKEND .backend()
-$Method BACKEND .backend_n(INT, BOOL, BOOL, INT)
-$Method BACKEND .backend_by_int(INT)
-$Method BACKEND .backend_by_string(STRING)
-$Method BACKEND .backend_by_string_hash(STRING, ENUM { CRC32, SHA256, RS })
+$Method INT .hash_string(STRING string, ENUM { CRC32, SHA256, RS } alg="CRC32")
+$Method BACKEND .backend(INT nte=0, BOOL altsrv_p=1, BOOL healthy=1, INT hash=0)