text: /*-
   * Copyright (c) 2013-2015 Varnish Software AS
   * All rights reserved.
   *
   * Author: Poul-Henning Kamp <phk@FreeBSD.org>
   *
   * 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.
   *
   * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
   * ANY EXPRESS 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 AUTHOR OR 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.
   */
  
  #include "config.h"
  
  #include <stdlib.h>
  #include <string.h>
  
  #include "cache/cache.h"
  
  #include "vdir.h"
  
  #include "vcc_if.h"
  
  struct vmod_directors_hash {
  	unsigned				magic;
  #define VMOD_DIRECTORS_HASH_MAGIC		0xc08dd611
  	struct vdir				*vd;
  };
  
  static void v_matchproto_(vdi_destroy_f)
  vmod_hash_destroy(VCL_BACKEND dir)
  {
  	struct vmod_directors_hash *rr;
  
  	CAST_OBJ_NOTNULL(rr, dir->priv, VMOD_DIRECTORS_HASH_MAGIC);
  	vdir_delete(&rr->vd);
  	FREE_OBJ(rr);
  }
  
  static const struct vdi_methods vmod_hash_methods[1] = {{
  	.magic =		VDI_METHODS_MAGIC,
  	.type =			"hash",
  	.destroy =		vmod_hash_destroy
  }};
  
  
  VCL_VOID v_matchproto_()
  vmod_hash__init(VRT_CTX, struct vmod_directors_hash **rrp,
      const char *vcl_name)
  {
  	struct vmod_directors_hash *rr;
  
  	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
  	AN(rrp);
  	AZ(*rrp);
  	ALLOC_OBJ(rr, VMOD_DIRECTORS_HASH_MAGIC);
  	AN(rr);
  	*rrp = rr;
  	vdir_new(ctx, &rr->vd, vcl_name, vmod_hash_methods, rr);
  }
  
  VCL_VOID v_matchproto_()
  vmod_hash__fini(struct vmod_directors_hash **rrp)
  {
  	struct vmod_directors_hash *rr;
  
  	TAKE_OBJ_NOTNULL(rr, rrp, VMOD_DIRECTORS_HASH_MAGIC);
  	VRT_DelDirector(&rr->vd->dir);
  }
  
  VCL_VOID v_matchproto_()
  vmod_hash_add_backend(VRT_CTX,
      struct vmod_directors_hash *rr, VCL_BACKEND be, double w)
  {
  
  	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
  	CHECK_OBJ_NOTNULL(rr, VMOD_DIRECTORS_HASH_MAGIC);
  	vdir_add_backend(ctx, rr->vd, be, w);
  }
  
  VCL_VOID v_matchproto_()
  vmod_hash_remove_backend(VRT_CTX,
      struct vmod_directors_hash *rr, VCL_BACKEND be)
  {
  
  	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
  	CHECK_OBJ_NOTNULL(rr, VMOD_DIRECTORS_HASH_MAGIC);
  	vdir_remove_backend(ctx, rr->vd, be, NULL);
  }
  
  VCL_BACKEND v_matchproto_()
  vmod_hash_backend(VRT_CTX, struct vmod_directors_hash *rr, VCL_STRANDS s)
  {
  	VCL_BACKEND be;
  	double r;
  
  	CHECK_OBJ_NOTNULL(ctx, VRT_CTX_MAGIC);
  	CHECK_OBJ_ORNULL(ctx->bo, BUSYOBJ_MAGIC);
  	CHECK_OBJ_NOTNULL(rr, VMOD_DIRECTORS_HASH_MAGIC);
  	AN(s);
  
  	r = VRT_HashStrands32(s);
  	r = scalbn(r, -32);
  	assert(r >= 0 && r <= 1.0);
  	be = vdir_pick_be(ctx, rr->vd, r);
  	return (be);
  }
  