4 * The contents of this file are subject to the terms of the
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6 * You may not use this file except in compliance with the License.
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9 * or http://www.opensolaris.org/os/licensing.
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11 * and limitations under the License.
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15 * If applicable, add the following below this CDDL HEADER, with the
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22 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
23 * Use is subject to license terms.
26 #ifndef _SYS_ZAP_LEAF_H
27 #define _SYS_ZAP_LEAF_H
29 #pragma ident "%Z%%M% %I% %E% SMI"
37 #define ZAP_LEAF_MAGIC 0x2AB1EAF
39 /* chunk size = 24 bytes */
40 #define ZAP_LEAF_CHUNKSIZE 24
43 * The amount of space available for chunks is:
44 * block size (1<<l->l_bs) - hash entry size (2) * number of hash
45 * entries - header space (2*chunksize)
47 #define ZAP_LEAF_NUMCHUNKS(l) \
48 (((1<<(l)->l_bs) - 2*ZAP_LEAF_HASH_NUMENTRIES(l)) / \
49 ZAP_LEAF_CHUNKSIZE - 2)
52 * The amount of space within the chunk available for the array is:
53 * chunk size - space for type (1) - space for next pointer (2)
55 #define ZAP_LEAF_ARRAY_BYTES (ZAP_LEAF_CHUNKSIZE - 3)
57 #define ZAP_LEAF_ARRAY_NCHUNKS(bytes) \
58 (((bytes)+ZAP_LEAF_ARRAY_BYTES-1)/ZAP_LEAF_ARRAY_BYTES)
61 * Low water mark: when there are only this many chunks free, start
62 * growing the ptrtbl. Ideally, this should be larger than a
63 * "reasonably-sized" entry. 20 chunks is more than enough for the
64 * largest directory entry (MAXNAMELEN (256) byte name, 8-byte value),
65 * while still being only around 3% for 16k blocks.
67 #define ZAP_LEAF_LOW_WATER (20)
70 * The leaf hash table has block size / 2^5 (32) number of entries,
71 * which should be more than enough for the maximum number of entries,
72 * which is less than block size / CHUNKSIZE (24) / minimum number of
73 * chunks per entry (3).
75 #define ZAP_LEAF_HASH_SHIFT(l) ((l)->l_bs - 5)
76 #define ZAP_LEAF_HASH_NUMENTRIES(l) (1 << ZAP_LEAF_HASH_SHIFT(l))
79 * The chunks start immediately after the hash table. The end of the
80 * hash table is at l_hash + HASH_NUMENTRIES, which we simply cast to a
83 #define ZAP_LEAF_CHUNK(l, idx) \
84 ((zap_leaf_chunk_t *) \
85 ((l)->l_phys->l_hash + ZAP_LEAF_HASH_NUMENTRIES(l)))[idx]
86 #define ZAP_LEAF_ENTRY(l, idx) (&ZAP_LEAF_CHUNK(l, idx).l_entry)
88 typedef enum zap_chunk_type {
90 ZAP_CHUNK_ENTRY = 252,
91 ZAP_CHUNK_ARRAY = 251,
92 ZAP_CHUNK_TYPE_MAX = 250
95 #define ZLF_ENTRIES_CDSORTED (1<<0)
99 * If zap_leaf_phys_t is modified, zap_leaf_byteswap() must be modified.
101 typedef struct zap_leaf_phys {
102 struct zap_leaf_header {
103 uint64_t lh_block_type; /* ZBT_LEAF */
105 uint64_t lh_prefix; /* hash prefix of this leaf */
106 uint32_t lh_magic; /* ZAP_LEAF_MAGIC */
107 uint16_t lh_nfree; /* number free chunks */
108 uint16_t lh_nentries; /* number of entries */
109 uint16_t lh_prefix_len; /* num bits used to id this */
111 /* above is accessable to zap, below is zap_leaf private */
113 uint16_t lh_freelist; /* chunk head of free list */
114 uint8_t lh_flags; /* ZLF_* flags */
116 } l_hdr; /* 2 24-byte chunks */
119 * The header is followed by a hash table with
120 * ZAP_LEAF_HASH_NUMENTRIES(zap) entries. The hash table is
121 * followed by an array of ZAP_LEAF_NUMCHUNKS(zap)
122 * zap_leaf_chunk structures. These structures are accessed
123 * with the ZAP_LEAF_CHUNK() macro.
129 typedef union zap_leaf_chunk {
130 struct zap_leaf_entry {
131 uint8_t le_type; /* always ZAP_CHUNK_ENTRY */
132 uint8_t le_int_size; /* size of ints */
133 uint16_t le_next; /* next entry in hash chain */
134 uint16_t le_name_chunk; /* first chunk of the name */
135 uint16_t le_name_length; /* bytes in name, incl null */
136 uint16_t le_value_chunk; /* first chunk of the value */
137 uint16_t le_value_length; /* value length in ints */
138 uint32_t le_cd; /* collision differentiator */
139 uint64_t le_hash; /* hash value of the name */
141 struct zap_leaf_array {
142 uint8_t la_type; /* always ZAP_CHUNK_ARRAY */
143 uint8_t la_array[ZAP_LEAF_ARRAY_BYTES];
144 uint16_t la_next; /* next blk or CHAIN_END */
146 struct zap_leaf_free {
147 uint8_t lf_type; /* always ZAP_CHUNK_FREE */
148 uint8_t lf_pad[ZAP_LEAF_ARRAY_BYTES];
149 uint16_t lf_next; /* next in free list, or CHAIN_END */
153 typedef struct zap_leaf {
155 uint64_t l_blkid; /* 1<<ZAP_BLOCK_SHIFT byte block off */
156 int l_bs; /* block size shift */
158 zap_leaf_phys_t *l_phys;
162 typedef struct zap_entry_handle {
163 /* below is set by zap_leaf.c and is public to zap.c */
164 uint64_t zeh_num_integers;
167 uint8_t zeh_integer_size;
169 /* below is private to zap_leaf.c */
170 uint16_t zeh_fakechunk;
171 uint16_t *zeh_chunkp;
172 zap_leaf_t *zeh_leaf;
173 } zap_entry_handle_t;
176 * Return a handle to the named entry, or ENOENT if not found. The hash
177 * value must equal zap_hash(name).
179 extern int zap_leaf_lookup(zap_leaf_t *l,
180 zap_name_t *zn, zap_entry_handle_t *zeh);
183 * Return a handle to the entry with this hash+cd, or the entry with the
184 * next closest hash+cd.
186 extern int zap_leaf_lookup_closest(zap_leaf_t *l,
187 uint64_t hash, uint32_t cd, zap_entry_handle_t *zeh);
190 * Read the first num_integers in the attribute. Integer size
191 * conversion will be done without sign extension. Return EINVAL if
192 * integer_size is too small. Return EOVERFLOW if there are more than
193 * num_integers in the attribute.
195 extern int zap_entry_read(const zap_entry_handle_t *zeh,
196 uint8_t integer_size, uint64_t num_integers, void *buf);
198 extern int zap_entry_read_name(const zap_entry_handle_t *zeh,
199 uint16_t buflen, char *buf);
202 * Replace the value of an existing entry.
204 * zap_entry_update may fail if it runs out of space (ENOSPC).
206 extern int zap_entry_update(zap_entry_handle_t *zeh,
207 uint8_t integer_size, uint64_t num_integers, const void *buf);
212 extern void zap_entry_remove(zap_entry_handle_t *zeh);
215 * Create an entry. An equal entry must not exist, and this entry must
216 * belong in this leaf (according to its hash value). Fills in the
217 * entry handle on success. Returns 0 on success or ENOSPC on failure.
219 extern int zap_entry_create(zap_leaf_t *l,
220 const char *name, uint64_t h, uint32_t cd,
221 uint8_t integer_size, uint64_t num_integers, const void *buf,
222 zap_entry_handle_t *zeh);
225 * Return true if there are additional entries with the same normalized
228 extern boolean_t zap_entry_normalization_conflict(zap_entry_handle_t *zeh,
229 zap_name_t *zn, const char *name, zap_t *zap);
235 extern void zap_leaf_init(zap_leaf_t *l, boolean_t sort);
236 extern void zap_leaf_byteswap(zap_leaf_phys_t *buf, int len);
237 extern void zap_leaf_split(zap_leaf_t *l, zap_leaf_t *nl, boolean_t sort);
238 extern void zap_leaf_stats(zap_t *zap, zap_leaf_t *l, zap_stats_t *zs);
244 #endif /* _SYS_ZAP_LEAF_H */