GCOV - Varnish Cache


/*-
 * Copyright (c) 2006 Verdens Gang AS
 * Copyright (c) 2006-2011 Varnish Software AS
 * All rights reserved.
 *
 * Author: Poul-Henning Kamp <phk@phk.freebsd.dk>
 *
 * SPDX-License-Identifier: BSD-2-Clause
 *
 * 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.
 *
 * A classic bucketed hash
 */

#include "config.h"

#include <stdio.h>
#include <stdlib.h>

#include "cache/cache_varnishd.h"
#include "cache/cache_objhead.h"
#include "common/heritage.h"

#include "hash/hash_slinger.h"

static struct VSC_lck *lck_hcl;

/*--------------------------------------------------------------------*/

struct hcl_hd {
        unsigned                magic;
#define HCL_HEAD_MAGIC          0x0f327016
        VTAILQ_HEAD(, objhead)  head;
        struct lock             mtx;
};

static unsigned                 hcl_nhash = 16383;
static struct hcl_hd            *hcl_head;

/*--------------------------------------------------------------------
 * The ->init method allows the management process to pass arguments
 */

static void v_matchproto_(hash_init_f)
hcl_init(int ac, char * const *av)
{
        int i;
        unsigned u;

        if (ac == 0)
                return;
        if (ac > 1)
                ARGV_ERR("(-hclassic) too many arguments\n");
        i = sscanf(av[0], "%u", &u);
        if (i <= 0 || u == 0)
                return;
        if (u > 2 && !(u & (u - 1))) {
                fprintf(stderr,
                    "NOTE:\n"
                    "\tA power of two number of hash buckets is "
                    "marginally less efficient\n"
                    "\twith systematic URLs.  Reducing by one"
                    " hash bucket.\n");
                u--;
        }
        hcl_nhash = u;
        fprintf(stderr, "Classic hash: %u buckets\n", hcl_nhash);
}

/*--------------------------------------------------------------------
 * The ->start method is called during cache process start and allows
 * initialization to happen before the first lookup.
 */

static void v_matchproto_(hash_start_f)
hcl_start(void)
{
        unsigned u;

        lck_hcl = Lck_CreateClass(NULL, "hcl");
        hcl_head = calloc(hcl_nhash, sizeof *hcl_head);
        XXXAN(hcl_head);

        for (u = 0; u < hcl_nhash; u++) {
                VTAILQ_INIT(&hcl_head[u].head);
                Lck_New(&hcl_head[u].mtx, lck_hcl);
                hcl_head[u].magic = HCL_HEAD_MAGIC;
        }
}

/*--------------------------------------------------------------------
 * Lookup and possibly insert element.
 * If nobj != NULL and the lookup does not find key, nobj is inserted.
 * If nobj == NULL and the lookup does not find key, NULL is returned.
 * A reference to the returned object is held.
 * We use a two-pass algorithm to handle inserts as they are quite
 * rare and collisions even rarer.
 */

static struct objhead * v_matchproto_(hash_lookup_f)
hcl_lookup(struct worker *wrk, const void *digest, struct objhead **noh)
{
        struct objhead *oh;
        struct hcl_hd *hp;
        unsigned u1, hdigest;
        int i;

        CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);
        AN(digest);
        if (noh != NULL)
                CHECK_OBJ_NOTNULL(*noh, OBJHEAD_MAGIC);

        assert(sizeof oh->digest >= sizeof hdigest);
        memcpy(&hdigest, digest, sizeof hdigest);
        u1 = hdigest % hcl_nhash;
        hp = &hcl_head[u1];

        Lck_Lock(&hp->mtx);
        VTAILQ_FOREACH(oh, &hp->head, hoh_list) {
                CHECK_OBJ_NOTNULL(oh, OBJHEAD_MAGIC);
                i = memcmp(oh->digest, digest, sizeof oh->digest);
                if (i < 0)
                        continue;
                if (i > 0)
                        break;
                oh->refcnt++;
                Lck_Unlock(&hp->mtx);
                Lck_Lock(&oh->mtx);
                return (oh);
        }

        if (noh == NULL) {
                Lck_Unlock(&hp->mtx);
                return (NULL);
        }

        if (oh != NULL)
                VTAILQ_INSERT_BEFORE(oh, *noh, hoh_list);
        else
                VTAILQ_INSERT_TAIL(&hp->head, *noh, hoh_list);

        oh = *noh;
        *noh = NULL;
        memcpy(oh->digest, digest, sizeof oh->digest);

        oh->hoh_head = hp;

        Lck_Unlock(&hp->mtx);
        Lck_Lock(&oh->mtx);
        return (oh);
}

/*--------------------------------------------------------------------
 * Dereference and if no references are left, free.
 */

static int v_matchproto_(hash_deref_f)
hcl_deref(struct worker *wrk, struct objhead *oh)
{
        struct hcl_hd *hp;
        int ret;

        CHECK_OBJ_NOTNULL(oh, OBJHEAD_MAGIC);
        Lck_AssertHeld(&oh->mtx);
        Lck_Unlock(&oh->mtx);

        CAST_OBJ_NOTNULL(hp, oh->hoh_head, HCL_HEAD_MAGIC);
        assert(oh->refcnt > 0);
        Lck_Lock(&hp->mtx);
        if (--oh->refcnt == 0) {
                VTAILQ_REMOVE(&hp->head, oh, hoh_list);
                ret = 0;
        } else
                ret = 1;
        Lck_Unlock(&hp->mtx);
        if (!ret)
                HSH_DeleteObjHead(wrk, oh);
        return (ret);
}

/*--------------------------------------------------------------------*/

const struct hash_slinger hcl_slinger = {
        .magic  =       SLINGER_MAGIC,
        .name   =       "classic",
        .init   =       hcl_init,
        .start  =       hcl_start,
        .lookup =       hcl_lookup,
        .deref  =       hcl_deref,
};

		varnish-cache/bin/varnishd/hash/hash_classic.c
0		/*-
1		* Copyright (c) 2006 Verdens Gang AS
2		* Copyright (c) 2006-2011 Varnish Software AS
3		* All rights reserved.
4		*
5		* Author: Poul-Henning Kamp <phk@phk.freebsd.dk>
6		*
7		* SPDX-License-Identifier: BSD-2-Clause
8		*
9		* Redistribution and use in source and binary forms, with or without
10		* modification, are permitted provided that the following conditions
11		* are met:
12		* 1. Redistributions of source code must retain the above copyright
13		* notice, this list of conditions and the following disclaimer.
14		* 2. Redistributions in binary form must reproduce the above copyright
15		* notice, this list of conditions and the following disclaimer in the
16		* documentation and/or other materials provided with the distribution.
17		*
18		* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19		* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20		* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21		* ARE DISCLAIMED. IN NO EVENT SHALL AUTHOR OR CONTRIBUTORS BE LIABLE
22		* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23		* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24		* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25		* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26		* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27		* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28		* SUCH DAMAGE.
29		*
30		* A classic bucketed hash
31		*/
32
33		#include "config.h"
34
35		#include <stdio.h>
36		#include <stdlib.h>
37
38		#include "cache/cache_varnishd.h"
39		#include "cache/cache_objhead.h"
40		#include "common/heritage.h"
41
42		#include "hash/hash_slinger.h"
43
44		static struct VSC_lck *lck_hcl;
45
46		/--------------------------------------------------------------------/
47
48		struct hcl_hd {
49		unsigned magic;
50		#define HCL_HEAD_MAGIC 0x0f327016
51		VTAILQ_HEAD(, objhead) head;
52		struct lock mtx;
53		};
54
55		static unsigned hcl_nhash = 16383;
56		static struct hcl_hd *hcl_head;
57
58		/*--------------------------------------------------------------------
59		* The ->init method allows the management process to pass arguments
60		*/
61
62		static void v_matchproto_(hash_init_f)
63	40	hcl_init(int ac, char * const *av)
64		{
65		int i;
66		unsigned u;
67
68	40	if (ac == 0)
69	0	return;
70	40	if (ac > 1)
71	0	ARGV_ERR("(-hclassic) too many arguments\n");
72	40	i = sscanf(av[0], "%u", &u);
73	40	if (i <= 0 \|\| u == 0)
74	0	return;
75	40	if (u > 2 && !(u & (u - 1))) {
76	0	fprintf(stderr,
77		"NOTE:\n"
78		"\tA power of two number of hash buckets is "
79		"marginally less efficient\n"
80		"\twith systematic URLs. Reducing by one"
81		" hash bucket.\n");
82	0	u--;
83	0	}
84	40	hcl_nhash = u;
85	40	fprintf(stderr, "Classic hash: %u buckets\n", hcl_nhash);
86	40	}
87
88		/*--------------------------------------------------------------------
89		* The ->start method is called during cache process start and allows
90		* initialization to happen before the first lookup.
91		*/
92
93		static void v_matchproto_(hash_start_f)
94	40	hcl_start(void)
95		{
96		unsigned u;
97
98	40	lck_hcl = Lck_CreateClass(NULL, "hcl");
99	40	hcl_head = calloc(hcl_nhash, sizeof *hcl_head);
100	40	XXXAN(hcl_head);
101
102	480	for (u = 0; u < hcl_nhash; u++) {
103	440	VTAILQ_INIT(&hcl_head[u].head);
104	440	Lck_New(&hcl_head[u].mtx, lck_hcl);
105	440	hcl_head[u].magic = HCL_HEAD_MAGIC;
106	440	}
107	40	}
108
109		/*--------------------------------------------------------------------
110		* Lookup and possibly insert element.
111		* If nobj != NULL and the lookup does not find key, nobj is inserted.
112		* If nobj == NULL and the lookup does not find key, NULL is returned.
113		* A reference to the returned object is held.
114		* We use a two-pass algorithm to handle inserts as they are quite
115		* rare and collisions even rarer.
116		*/
117
118		static struct objhead * v_matchproto_(hash_lookup_f)
119	160	hcl_lookup(struct worker wrk, const void digest, struct objhead **noh)
120		{
121		struct objhead *oh;
122		struct hcl_hd *hp;
123		unsigned u1, hdigest;
124		int i;
125
126	160	CHECK_OBJ_NOTNULL(wrk, WORKER_MAGIC);
127	160	AN(digest);
128	160	if (noh != NULL)
129	160	CHECK_OBJ_NOTNULL(*noh, OBJHEAD_MAGIC);
130
131	160	assert(sizeof oh->digest >= sizeof hdigest);
132	160	memcpy(&hdigest, digest, sizeof hdigest);
133	160	u1 = hdigest % hcl_nhash;
134	160	hp = &hcl_head[u1];
135
136	160	Lck_Lock(&hp->mtx);
137	160	VTAILQ_FOREACH(oh, &hp->head, hoh_list) {
138	80	CHECK_OBJ_NOTNULL(oh, OBJHEAD_MAGIC);
139	80	i = memcmp(oh->digest, digest, sizeof oh->digest);
140	80	if (i < 0)
141	0	continue;
142	80	if (i > 0)
143	0	break;
144	80	oh->refcnt++;
145	80	Lck_Unlock(&hp->mtx);
146	80	Lck_Lock(&oh->mtx);
147	80	return (oh);
148		}
149
150	80	if (noh == NULL) {
151	0	Lck_Unlock(&hp->mtx);
152	0	return (NULL);
153		}
154
155	80	if (oh != NULL)
156	0	VTAILQ_INSERT_BEFORE(oh, *noh, hoh_list);
157		else
158	80	VTAILQ_INSERT_TAIL(&hp->head, *noh, hoh_list);
159
160	80	oh = *noh;
161	80	*noh = NULL;
162	80	memcpy(oh->digest, digest, sizeof oh->digest);
163
164	80	oh->hoh_head = hp;
165
166	80	Lck_Unlock(&hp->mtx);
167	80	Lck_Lock(&oh->mtx);
168	80	return (oh);
169	160	}
170
171		/*--------------------------------------------------------------------
172		* Dereference and if no references are left, free.
173		*/
174
175		static int v_matchproto_(hash_deref_f)
176	80	hcl_deref(struct worker wrk, struct objhead oh)
177		{
178		struct hcl_hd *hp;
179		int ret;
180
181	80	CHECK_OBJ_NOTNULL(oh, OBJHEAD_MAGIC);
182	80	Lck_AssertHeld(&oh->mtx);
183	80	Lck_Unlock(&oh->mtx);
184
185	80	CAST_OBJ_NOTNULL(hp, oh->hoh_head, HCL_HEAD_MAGIC);
186	80	assert(oh->refcnt > 0);
187	80	Lck_Lock(&hp->mtx);
188	80	if (--oh->refcnt == 0) {
189	0	VTAILQ_REMOVE(&hp->head, oh, hoh_list);
190	0	ret = 0;
191	0	} else
192	80	ret = 1;
193	80	Lck_Unlock(&hp->mtx);
194	80	if (!ret)
195	0	HSH_DeleteObjHead(wrk, oh);
196	80	return (ret);
197		}
198
199		/--------------------------------------------------------------------/
200
201		const struct hash_slinger hcl_slinger = {
202		.magic = SLINGER_MAGIC,
203		.name = "classic",
204		.init = hcl_init,
205		.start = hcl_start,
206		.lookup = hcl_lookup,
207		.deref = hcl_deref,
208		};