1 /*
2 +----------------------------------------------------------------------+
3 | Zend OPcache |
4 +----------------------------------------------------------------------+
5 | Copyright (c) 1998-2017 The PHP Group |
6 +----------------------------------------------------------------------+
7 | This source file is subject to version 3.01 of the PHP license, |
8 | that is bundled with this package in the file LICENSE, and is |
9 | available through the world-wide-web at the following url: |
10 | http://www.php.net/license/3_01.txt |
11 | If you did not receive a copy of the PHP license and are unable to |
12 | obtain it through the world-wide-web, please send a note to |
13 | license@php.net so we can mail you a copy immediately. |
14 +----------------------------------------------------------------------+
15 | Authors: Andi Gutmans <andi@zend.com> |
16 | Zeev Suraski <zeev@zend.com> |
17 | Stanislav Malyshev <stas@zend.com> |
18 | Dmitry Stogov <dmitry@zend.com> |
19 +----------------------------------------------------------------------+
20 */
21
22 #ifndef ZEND_ACCELERATOR_HASH_H
23 #define ZEND_ACCELERATOR_HASH_H
24
25 #include "zend.h"
26
27 /*
28 zend_accel_hash - is a hash table allocated in shared memory and
29 distributed across simultaneously running processes. The hash tables have
30 fixed sizen selected during construction by zend_accel_hash_init(). All the
31 hash entries are preallocated in the 'hash_entries' array. 'num_entries' is
32 initialized by zero and grows when new data is added.
33 zend_accel_hash_update() just takes the next entry from 'hash_entries'
34 array and puts it into appropriate place of 'hash_table'.
35 Hash collisions are resolved by separate chaining with linked lists,
36 however, entries are still taken from the same 'hash_entries' array.
37 'key' and 'data' passed to zend_accel_hash_update() must be already
38 allocated in shared memory. Few keys may be resolved to the same data.
39 using 'indirect' entries, that point to other entries ('data' is actually
40 a pointer to another zend_accel_hash_entry).
41 zend_accel_hash_update() requires exclusive lock, however,
42 zend_accel_hash_find() does not.
43 */
44
45 typedef struct _zend_accel_hash_entry zend_accel_hash_entry;
46
47 struct _zend_accel_hash_entry {
48 zend_ulong hash_value;
49 char *key;
50 uint32_t key_length;
51 zend_accel_hash_entry *next;
52 void *data;
53 zend_bool indirect;
54 };
55
56 typedef struct _zend_accel_hash {
57 zend_accel_hash_entry **hash_table;
58 zend_accel_hash_entry *hash_entries;
59 uint32_t num_entries;
60 uint32_t max_num_entries;
61 uint32_t num_direct_entries;
62 } zend_accel_hash;
63
64 void zend_accel_hash_init(zend_accel_hash *accel_hash, uint32_t hash_size);
65 void zend_accel_hash_clean(zend_accel_hash *accel_hash);
66
67 zend_accel_hash_entry* zend_accel_hash_update(
68 zend_accel_hash *accel_hash,
69 char *key,
70 uint32_t key_length,
71 zend_bool indirect,
72 void *data);
73
74 void* zend_accel_hash_find(
75 zend_accel_hash *accel_hash,
76 zend_string *key);
77
78 zend_accel_hash_entry* zend_accel_hash_find_entry(
79 zend_accel_hash *accel_hash,
80 zend_string *key);
81
82 void* zend_accel_hash_str_find(
83 zend_accel_hash *accel_hash,
84 char *key,
85 uint32_t key_length);
86
87 zend_accel_hash_entry* zend_accel_hash_str_find_entry(
88 zend_accel_hash *accel_hash,
89 char *key,
90 uint32_t key_length);
91
92 int zend_accel_hash_unlink(
93 zend_accel_hash *accel_hash,
94 char *key,
95 uint32_t key_length);
96
zend_accel_hash_is_full(zend_accel_hash * accel_hash)97 static inline zend_bool zend_accel_hash_is_full(zend_accel_hash *accel_hash)
98 {
99 if (accel_hash->num_entries == accel_hash->max_num_entries) {
100 return 1;
101 } else {
102 return 0;
103 }
104 }
105
106 #endif /* ZEND_ACCELERATOR_HASH_H */
107
