git.ozlabs.org Git - ccan/blob - ccan/tdb2/test/layout.c

   1 /* TDB tools to create various canned database layouts. */
   2 #include "layout.h"
   3 #include <stdlib.h>
   4 #include <string.h>
   5 #include <assert.h>
   6 #include "logging.h"
   7
   8 struct tdb_layout *new_tdb_layout(void)
   9 {
  10         struct tdb_layout *layout = malloc(sizeof(*layout));
  11         layout->num_elems = 0;
  12         layout->elem = NULL;
  13         layout->htable = -1;
  14         return layout;
  15 }
  16
  17 static void add(struct tdb_layout *layout, union tdb_layout_elem elem)
  18 {
  19         layout->elem = realloc(layout->elem,
  20                                sizeof(layout->elem[0])
  21                                * (layout->num_elems+1));
  22         layout->elem[layout->num_elems++] = elem;
  23 }
  24
  25 void tdb_layout_add_zone(struct tdb_layout *layout,
  26                          unsigned int zone_bits,
  27                          bool fill_prev)
  28 {
  29         union tdb_layout_elem elem;
  30         if (fill_prev)
  31                 tdb_layout_add_free(layout, 0);
  32         elem.base.type = ZONE;
  33         elem.zone.zone_bits = zone_bits;
  34         add(layout, elem);
  35 }
  36
  37 void tdb_layout_add_free(struct tdb_layout *layout, tdb_len_t len)
  38 {
  39         union tdb_layout_elem elem;
  40         elem.base.type = FREE;
  41         elem.free.len = len;
  42         add(layout, elem);
  43 }
  44
  45 static struct tdb_data dup_key(struct tdb_data key)
  46 {
  47         struct tdb_data ret;
  48         ret.dsize = key.dsize;
  49         ret.dptr = malloc(ret.dsize);
  50         memcpy(ret.dptr, key.dptr, ret.dsize);
  51         return ret;
  52 }
  53
  54 void tdb_layout_add_used(struct tdb_layout *layout,
  55                          TDB_DATA key, TDB_DATA data,
  56                          tdb_len_t extra)
  57 {
  58         union tdb_layout_elem elem;
  59         elem.base.type = DATA;
  60         elem.used.key = dup_key(key);
  61         elem.used.data = dup_key(data);
  62         elem.used.extra = extra;
  63         add(layout, elem);
  64 }
  65
  66 void tdb_layout_add_hashtable(struct tdb_layout *layout,
  67                               unsigned int hash_bits,
  68                               tdb_len_t extra)
  69 {
  70         union tdb_layout_elem elem;
  71         elem.base.type = HASHTABLE;
  72         elem.hashtable.hash_bits = hash_bits;
  73         elem.hashtable.extra = extra;
  74         assert(layout->htable == -1U);
  75         layout->htable = layout->num_elems;
  76         add(layout, elem);
  77 }
  78
  79 static tdb_len_t free_record_len(tdb_len_t len)
  80 {
  81         return sizeof(struct tdb_used_record) + len;
  82 }
  83
  84 static tdb_len_t data_record_len(struct tle_used *used)
  85 {
  86         tdb_len_t len;
  87         len = sizeof(struct tdb_used_record)
  88                 + used->key.dsize + used->data.dsize + used->extra;
  89         assert(len >= sizeof(struct tdb_free_record));
  90         return len;
  91 }
  92
  93 static tdb_len_t hashtable_len(struct tle_hashtable *htable)
  94 {
  95         return sizeof(struct tdb_used_record)
  96                 + (sizeof(tdb_off_t) << htable->hash_bits);
  97 }
  98
  99 static tdb_len_t zone_header_len(struct tle_zone *zone)
 100 {
 101         return sizeof(struct free_zone_header)
 102                 + sizeof(tdb_off_t) * (BUCKETS_FOR_ZONE(zone->zone_bits)+1);
 103 }
 104
 105 static void set_free_record(void *mem, tdb_len_t len)
 106 {
 107         /* We do all the work in add_to_freetable */
 108 }
 109
 110 static void set_data_record(void *mem, struct tdb_context *tdb,
 111                             struct tle_zone *last_zone,
 112                             struct tle_used *used)
 113 {
 114         struct tdb_used_record *u = mem;
 115
 116         set_header(tdb, u, used->key.dsize, used->data.dsize,
 117                    used->key.dsize + used->data.dsize + used->extra,
 118                    tdb_hash(tdb, used->key.dptr, used->key.dsize),
 119                    last_zone->zone_bits);
 120         memcpy(u + 1, used->key.dptr, used->key.dsize);
 121         memcpy((char *)(u + 1) + used->key.dsize,
 122                used->data.dptr, used->data.dsize);
 123 }
 124
 125 static void set_hashtable(void *mem, struct tdb_context *tdb,
 126                           struct tle_zone *last_zone,
 127                           struct tle_hashtable *htable)
 128 {
 129         struct tdb_used_record *u = mem;
 130         tdb_len_t len = sizeof(tdb_off_t) << htable->hash_bits;
 131
 132         set_header(tdb, u, 0, len, len + htable->extra, 0,
 133                    last_zone->zone_bits);
 134         memset(u + 1, 0, len);
 135 }
 136
 137 static void set_zone(void *mem, struct tdb_context *tdb,
 138                      struct tle_zone *zone)
 139 {
 140         struct free_zone_header *fz = mem;
 141         memset(fz, 0, zone_header_len(zone));
 142         fz->zone_bits = zone->zone_bits;
 143 }
 144
 145 static void add_to_freetable(struct tdb_context *tdb,
 146                              struct tle_zone *last_zone,
 147                              tdb_off_t eoff,
 148                              tdb_off_t elen)
 149 {
 150         add_free_record(tdb, last_zone->zone_bits, eoff,
 151                         sizeof(struct tdb_used_record) + elen);
 152 }
 153
 154 static void add_to_hashtable(struct tdb_context *tdb,
 155                              tdb_off_t eoff,
 156                              struct tdb_data key)
 157 {
 158         uint64_t hash = tdb_hash(tdb, key.dptr, key.dsize);
 159         tdb_off_t hoff;
 160
 161         while (tdb_read_off(tdb, hoff = hash_off(tdb, hash)) != 0)
 162                 hash++;
 163
 164         tdb_write_off(tdb, hoff, eoff);
 165 }
 166
 167 /* FIXME: Support TDB_CONVERT */
 168 struct tdb_context *tdb_layout_get(struct tdb_layout *layout)
 169 {
 170         unsigned int i;
 171         tdb_off_t off, len;
 172         tdb_len_t zone_left;
 173         struct tdb_header *hdr;
 174         char *mem;
 175         struct tdb_context *tdb;
 176         struct tle_zone *last_zone = NULL;
 177
 178         assert(layout->htable != -1U);
 179         assert(layout->elem[0].base.type == ZONE);
 180
 181         zone_left = 0;
 182         off = sizeof(struct tdb_header);
 183
 184         /* First pass of layout: calc lengths */
 185         for (i = 0; i < layout->num_elems; i++) {
 186                 union tdb_layout_elem *e = &layout->elem[i];
 187                 e->base.off = off;
 188                 switch (e->base.type) {
 189                 case ZONE:
 190                         assert(zone_left == 0);
 191                         len = zone_header_len(&e->zone);
 192                         zone_left = 1ULL << e->zone.zone_bits;
 193                         break;
 194                 case FREE:
 195                         if (e->free.len == 0)
 196                                 e->free.len = zone_left
 197                                         - sizeof(struct tdb_used_record);
 198                         len = free_record_len(e->free.len);
 199                         break;
 200                 case DATA:
 201                         len = data_record_len(&e->used);
 202                         break;
 203                 case HASHTABLE:
 204                         len = hashtable_len(&e->hashtable);
 205                         break;
 206                 }
 207                 off += len;
 208                 assert(zone_left >= len);
 209                 zone_left -= len;
 210         }
 211
 212         /* Fill final zone with free record. */
 213         if (zone_left != 0) {
 214                 tdb_layout_add_free(layout,
 215                                     zone_left
 216                                     - sizeof(struct tdb_used_record));
 217                 layout->elem[layout->num_elems-1].base.off = off;
 218                 off += zone_left;
 219         }
 220
 221         mem = malloc(off+1);
 222         /* Now populate our header, cribbing from a real TDB header. */
 223         tdb = tdb_open(NULL, TDB_INTERNAL, O_RDWR, 0, &tap_log_attr);
 224         hdr = (void *)mem;
 225         *hdr = tdb->header;
 226         hdr->v.generation++;
 227         hdr->v.hash_bits = layout->elem[layout->htable].hashtable.hash_bits;
 228         hdr->v.hash_off = layout->elem[layout->htable].base.off
 229                 + sizeof(struct tdb_used_record);
 230
 231         /* Mug the tdb we have to make it use this. */
 232         free(tdb->map_ptr);
 233         tdb->map_ptr = mem;
 234         tdb->map_size = off+1;
 235         header_changed(tdb);
 236
 237         for (i = 0; i < layout->num_elems; i++) {
 238                 union tdb_layout_elem *e = &layout->elem[i];
 239                 switch (e->base.type) {
 240                 case ZONE:
 241                         set_zone(mem + e->base.off, tdb, &e->zone);
 242                         last_zone = &e->zone;
 243                         break;
 244                 case FREE:
 245                         set_free_record(mem + e->base.off, e->free.len);
 246                         break;
 247                 case DATA:
 248                         set_data_record(mem + e->base.off, tdb, last_zone,
 249                                         &e->used);
 250                         break;
 251                 case HASHTABLE:
 252                         set_hashtable(mem + e->base.off, tdb, last_zone,
 253                                       &e->hashtable);
 254                         break;
 255                 }
 256         }
 257
 258         /* Now fill the free and hash tables. */
 259         for (i = 0; i < layout->num_elems; i++) {
 260                 union tdb_layout_elem *e = &layout->elem[i];
 261                 switch (e->base.type) {
 262                 case ZONE:
 263                         last_zone = &e->zone;
 264                         break;
 265                 case FREE:
 266                         add_to_freetable(tdb, last_zone,
 267                                          e->base.off, e->free.len);
 268                         break;
 269                 case DATA:
 270                         add_to_hashtable(tdb, e->base.off, e->used.key);
 271                         break;
 272                 default:
 273                         break;
 274                 }
 275         }
 276
 277         /* Write tailer. */
 278         ((uint8_t *)tdb->map_ptr)[tdb->map_size-1] = last_zone->zone_bits;
 279         return tdb;
 280 }