aboutsummaryrefslogblamecommitdiffstats
path: root/camel/camel-partition-table.c
blob: eb44d9c197ad6fdcf0adbb249d9090a9a5da86d1 (plain) (tree)
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471









































                                                                    
                        











































































































































































































































































































































































































































                                                                                                                     
                                                               















































































































































                                                                                           

                                                                                
                                                                                 
                 























































                                                                                                              









                                                                       


































                                                                                               

                                                                                                                                 













































































































































                                                                                                                

                                                                    
                                   





                                                                                                              

































                                                                                                                  








                                       











                                                                     

                                                         
                                 
                 











                                                                     

                                                              

                                                                                             

                                                                    

                                                                                                       
































                                                                            
/*
 * Copyright (C) 2001 Ximian Inc.
 *
 * Authors: Michael Zucchi <notzed@ximian.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 02111-1307, USA.
 */

#ifdef HAVE_CONFIG_H
#include <config.h>
#endif

#include <sys/stat.h>
#include <sys/uio.h>
#include <unistd.h>
#include <errno.h>
#include <string.h>
#include <stdlib.h>

#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#include "e-util/e-msgport.h"

#include "camel-block-file.h"
#include "camel-partition-table.h"

/* Do we synchronously write table updates - makes the
   tables consistent after program crash without sync */
/*#define SYNC_UPDATES*/

#ifdef ENABLE_THREADS
#include <pthread.h>
#endif

#define d(x) /*(printf("%s(%d):%s: ",  __FILE__, __LINE__, __PRETTY_FUNCTION__),(x))*/
/* key index debug */
#define k(x) /*(printf("%s(%d):%s: ",  __FILE__, __LINE__, __PRETTY_FUNCTION__),(x))*/

#ifdef ENABLE_THREADS

struct _CamelPartitionTablePrivate {
    pthread_mutex_t lock;   /* for locking partition */
};

#define CAMEL_PARTITION_TABLE_LOCK(kf, lock) (pthread_mutex_lock(&(kf)->priv->lock))
#define CAMEL_PARTITION_TABLE_UNLOCK(kf, lock) (pthread_mutex_unlock(&(kf)->priv->lock))
#else
#define CAMEL_PARTITION_TABLE_LOCK(kf, lock)
#define CAMEL_PARTITION_TABLE_UNLOCK(kf, lock)
#endif

static void
camel_partition_table_class_init(CamelPartitionTableClass *klass)
{
}

static void
camel_partition_table_init(CamelPartitionTable *cpi)
{
    struct _CamelPartitionTablePrivate *p;

    e_dlist_init(&cpi->partition);

    p = cpi->priv = g_malloc0(sizeof(*cpi->priv));
#ifdef ENABLE_THREADS
    pthread_mutex_init(&p->lock, NULL);
#endif
}

static void
camel_partition_table_finalise(CamelPartitionTable *cpi)
{
    CamelBlock *bl;
    struct _CamelPartitionTablePrivate *p;

    p = cpi->priv;

    if (cpi->blocks) {
        camel_block_file_sync(cpi->blocks);
        while ((bl = (CamelBlock *)e_dlist_remhead(&cpi->partition))) {
            camel_block_file_sync_block(cpi->blocks, bl);
            camel_block_file_unref_block(cpi->blocks, bl);
        }

        camel_object_unref((CamelObject *)cpi->blocks);
    }

#ifdef ENABLE_THREADS
    pthread_mutex_destroy(&p->lock);
#endif
    g_free(p);

}

CamelType
camel_partition_table_get_type(void)
{
    static CamelType type = CAMEL_INVALID_TYPE;
    
    if (type == CAMEL_INVALID_TYPE) {
        type = camel_type_register(camel_object_get_type(), "CamelPartitionTable",
                       sizeof (CamelPartitionTable),
                       sizeof (CamelPartitionTableClass),
                       (CamelObjectClassInitFunc) camel_partition_table_class_init,
                       NULL,
                       (CamelObjectInitFunc) camel_partition_table_init,
                       (CamelObjectFinalizeFunc) camel_partition_table_finalise);
    }
    
    return type;
}

/* ********************************************************************** */

/*
  Have 2 hashes:
  Name -> nameid
  Word -> wordid

nameid is pointer to name file, includes a bit to say if name is deleted
wordid is a pointer to word file, includes pointer to start of word entries

delete a name -> set it as deleted, do nothing else though

lookup word, if nameid is deleted, mark it in wordlist as unused and mark for write (?)
*/

/* ********************************************************************** */

/* This simple hash seems to work quite well */
static camel_hash_t hash_key(const char *key)
{
    camel_hash_t hash = 0xABADF00D;

    while (*key) {
        hash = hash * (*key) ^ (*key);
        key++;
    }

    return hash;
}

/* Call with lock held */
static CamelBlock *find_partition(CamelPartitionTable *cpi, camel_hash_t id, int *indexp)
{
    int index, jump;
    CamelBlock *bl;
    CamelPartitionMapBlock *ptb;
    CamelPartitionMap *part;

    /* first, find the block this key might be in, then binary search the block */
    bl = (CamelBlock *)cpi->partition.head;
    while (bl->next) {
        ptb = (CamelPartitionMapBlock *)&bl->data;
        part = ptb->partition;
        if (ptb->used > 0 && id <= part[ptb->used-1].hashid) {
            index = ptb->used/2;
            jump = ptb->used/4;

            if (jump == 0)
                jump = 1;

            while (1) {
                if (id <= part[index].hashid) {
                    if (index == 0 || id > part[index-1].hashid)
                        break;
                    index -= jump;
                } else {
                    if (index >= ptb->used-1)
                        break;
                    index += jump;
                }
                jump = jump/2;
                if (jump == 0)
                    jump = 1;
            }
            *indexp = index;

            return bl;
        }
        bl = bl->next;
    }

    g_warning("could not find a partition that could fit !  partition table corrupt!");

    /* This should never be reached */

    return NULL;
}

CamelPartitionTable *camel_partition_table_new(struct _CamelBlockFile *bs, camel_block_t root)
{
    CamelPartitionTable *cpi;
    CamelPartitionMapBlock *ptb;
    CamelPartitionKeyBlock *kb;
    CamelBlock *block, *pblock;

    cpi = (CamelPartitionTable *)camel_object_new(camel_partition_table_get_type());
    cpi->rootid = root;
    cpi->blocks = bs;
    camel_object_ref((CamelObject *)bs);

    /* read the partition table into memory */
    do {
        block = camel_block_file_get_block(bs, root);
        if (block == NULL)
            goto fail;

        ptb = (CamelPartitionMapBlock *)&block->data;

        d(printf("Adding partition block, used = %d, hashid = %08x\n", ptb->used, ptb->partition[0].hashid));

        /* if we have no data, prime initial block */
        if (ptb->used == 0 && e_dlist_empty(&cpi->partition) && ptb->next == 0) {
            pblock = camel_block_file_new_block(bs);
            if (pblock == NULL) {
                camel_block_file_unref_block(bs, block);
                goto fail;
            }
            kb = (CamelPartitionKeyBlock *)&pblock->data;
            kb->used = 0;
            ptb->used = 1;
            ptb->partition[0].hashid = 0xffffffff;
            ptb->partition[0].blockid = pblock->id;
            camel_block_file_touch_block(bs, pblock);
            camel_block_file_unref_block(bs, pblock);
            camel_block_file_touch_block(bs, block);
#ifdef SYNC_UPDATES
            camel_block_file_sync_block(bs, block);
#endif
        }

        root = ptb->next;
        camel_block_file_detach_block(bs, block);
        e_dlist_addtail(&cpi->partition, (EDListNode *)block);
    } while (root);

    return cpi;

fail:
    camel_object_unref((CamelObject *)cpi);
    return NULL;
}

camel_key_t camel_partition_table_lookup(CamelPartitionTable *cpi, const char *key)
{
    CamelPartitionKeyBlock *pkb;
    CamelPartitionMapBlock *ptb;
    CamelBlock *block, *ptblock;
    camel_hash_t hashid;
    camel_key_t keyid = 0;
    int index, i;

    hashid = hash_key(key);

    CAMEL_PARTITION_TABLE_LOCK(cpi, lock);

    ptblock = find_partition(cpi, hashid, &index);
    if (ptblock == NULL) {
        CAMEL_PARTITION_TABLE_UNLOCK(cpi, lock);
        return 0;
    }
    ptb = (CamelPartitionMapBlock *)&ptblock->data;
    block = camel_block_file_get_block(cpi->blocks, ptb->partition[index].blockid);
    if (block == NULL) {
        CAMEL_PARTITION_TABLE_UNLOCK(cpi, lock);
        return 0;
    }

    pkb = (CamelPartitionKeyBlock *)&block->data;

    /* What to do about duplicate hash's? */
    for (i=0;i<pkb->used;i++) {
        if (pkb->keys[i].hashid == hashid) {
            /* !! need to: lookup and compare string value */
            /* get_key() if key == key ... */
            keyid = pkb->keys[i].keyid;
            break;
        }
    }

    CAMEL_PARTITION_TABLE_UNLOCK(cpi, lock);
    
    camel_block_file_unref_block(cpi->blocks, block);

    return keyid;
}

void camel_partition_table_remove(CamelPartitionTable *cpi, const char *key)
{
    CamelPartitionKeyBlock *pkb;
    CamelPartitionMapBlock *ptb;
    CamelBlock *block, *ptblock;
    camel_hash_t hashid;
    camel_key_t keyid = 0;
    int index, i;

    hashid = hash_key(key);

    CAMEL_PARTITION_TABLE_LOCK(cpi, lock);
    
    ptblock = find_partition(cpi, hashid, &index);
    if (ptblock == NULL) {
        CAMEL_PARTITION_TABLE_UNLOCK(cpi, lock);
        return;
    }
    ptb = (CamelPartitionMapBlock *)&ptblock->data;
    block = camel_block_file_get_block(cpi->blocks, ptb->partition[index].blockid);
    if (block == NULL) {
        CAMEL_PARTITION_TABLE_UNLOCK(cpi, lock);
        return;
    }
    pkb = (CamelPartitionKeyBlock *)&block->data;

    /* What to do about duplicate hash's? */
    for (i=0;i<pkb->used;i++) {
        if (pkb->keys[i].hashid == hashid) {
            /* !! need to: lookup and compare string value */
            /* get_key() if key == key ... */
            keyid = pkb->keys[i].keyid;

            /* remove this key */
            pkb->used--;
            for (;i<pkb->used;i++) {
                pkb->keys[i].keyid = pkb->keys[i+1].keyid;
                pkb->keys[i].hashid = pkb->keys[i+1].hashid;
            }
            camel_block_file_touch_block(cpi->blocks, block);
            break;
        }
    }

    CAMEL_PARTITION_TABLE_UNLOCK(cpi, lock);
    
    camel_block_file_unref_block(cpi->blocks, block);
}

static int
keys_cmp(const void *ap, const void *bp)
{
    const CamelPartitionKey *a = ap;
    const CamelPartitionKey *b = bp;

    if (a->hashid < b->hashid)
        return -1;
    else if (a->hashid > b->hashid)
        return 1;

    return 0;
}

int
camel_partition_table_add(CamelPartitionTable *cpi, const char *key, camel_key_t keyid)
{
    camel_hash_t hashid, partid;
    int index, newindex = 0; /* initialisation of this and pkb/nkb is just to silence compiler */
    CamelPartitionMapBlock *ptb, *ptn;
    CamelPartitionKeyBlock *kb, *newkb, *nkb = NULL, *pkb = NULL;
    CamelBlock *block, *ptblock, *ptnblock;
    int i, half, len;
    struct _CamelPartitionKey keys[CAMEL_BLOCK_SIZE/4];
    int ret = -1;

#define KEY_SIZE (sizeof(kb->keys)/sizeof(kb->keys[0]))

    hashid = hash_key(key);

    CAMEL_PARTITION_TABLE_LOCK(cpi, lock);
    ptblock = find_partition(cpi, hashid, &index);
    if (ptblock == NULL) {
        CAMEL_PARTITION_TABLE_UNLOCK(cpi, lock);
        return -1;
    }
    ptb = (CamelPartitionMapBlock *)&ptblock->data;
    block = camel_block_file_get_block(cpi->blocks, ptb->partition[index].blockid);
    if (block == NULL) {
        CAMEL_PARTITION_TABLE_UNLOCK(cpi, lock);
        return -1;
    }
    kb = (CamelPartitionKeyBlock *)&block->data;

    /* TODO: Keep the key array in sorted order, cheaper lookups and split operation */

    if (kb->used < sizeof(kb->keys)/sizeof(kb->keys[0])) {
        /* Have room, just put it in */
        kb->keys[kb->used].hashid = hashid;
        kb->keys[kb->used].keyid = keyid;
        kb->used++;
    } else {
        CamelBlock *newblock = NULL, *nblock = NULL, *pblock = NULL;

        /* Need to split?  See if previous or next has room, then split across that instead */

        /* TODO: Should look at next/previous partition table block as well ... */

        if (index > 0) {
            pblock = camel_block_file_get_block(cpi->blocks, ptb->partition[index-1].blockid);
            if (pblock == NULL)
                goto fail;
            pkb = (CamelPartitionKeyBlock *)&pblock->data;
        }
        if (index < (ptb->used-1)) {
            nblock = camel_block_file_get_block(cpi->blocks, ptb->partition[index+1].blockid);
            if (nblock == NULL) {
                if (pblock)
                    camel_block_file_unref_block(cpi->blocks, pblock);
                goto fail;
            }
            nkb = (CamelPartitionKeyBlock *)&nblock->data;
        }

        if (pblock && pkb->used < KEY_SIZE) {
            if (nblock && nkb->used < KEY_SIZE) {
                if (pkb->used < nkb->used) {
                    newindex = index+1;
                    newblock = nblock;
                } else {
                    newindex = index-1;
                    newblock = pblock;
                }
            } else {
                newindex = index-1;
                newblock = pblock;
            }
        } else {
            if (nblock && nkb->used < KEY_SIZE) {
                newindex = index+1;
                newblock = nblock;
            }
        }

        /* We had no room, need to split across another block */
        if (newblock == NULL) {
            /* See if we have room in the partition table for this block or need to split that too */
            if (ptb->used >= sizeof(ptb->partition)/sizeof(ptb->partition[0])) {
                /* TODO: Could check next block to see if it'll fit there first */
                ptnblock = camel_block_file_new_block(cpi->blocks);
                if (ptnblock == NULL) {
                    if (nblock)
                        camel_block_file_unref_block(cpi->blocks, nblock);
                    if (pblock)
                        camel_block_file_unref_block(cpi->blocks, pblock);
                    goto fail;
                }
                camel_block_file_detach_block(cpi->blocks, ptnblock);

                /* split block and link on-disk, always sorted */
                ptn = (CamelPartitionMapBlock *)&ptnblock->data;
                ptn->next = ptb->next;
                ptb->next = ptnblock->id;
                len = ptb->used / 2;
                ptn->used = ptb->used - len;
                ptb->used = len;
                memcpy(ptn->partition, &ptb->partition[len], ptn->used * sizeof(ptb->partition[0]));

                /* link in-memory */
                ptnblock->next = ptblock->next;
                ptblock->next->prev = ptnblock;
                ptblock->next = ptnblock;
                ptnblock->prev = ptblock;

                /* write in right order to ensure structure */
                camel_block_file_touch_block(cpi->blocks, ptnblock);
#ifdef SYNC_UPDATES
                camel_block_file_sync_block(cpi->blocks, ptnblock);
#endif
                if (index > len) {
                    camel_block_file_touch_block(cpi->blocks, ptblock);
#ifdef SYNC_UPDATES
                    camel_block_file_sync_block(cpi->blocks, ptblock);
#endif
                    index -= len;
                    ptb = ptn;
                    ptblock = ptnblock;
                }
            }

            /* try get newblock before modifying existing */
            newblock = camel_block_file_new_block(cpi->blocks);
            if (newblock == NULL) {
                if (nblock)
                    camel_block_file_unref_block(cpi->blocks, nblock);
                if (pblock)
                    camel_block_file_unref_block(cpi->blocks, pblock);
                goto fail;
            }

            for (i=ptb->used-1;i>index;i--) {
                ptb->partition[i+1].hashid = ptb->partition[i].hashid;
                ptb->partition[i+1].blockid = ptb->partition[i].blockid;
            }
            ptb->used++;

            newkb = (CamelPartitionKeyBlock *)&newblock->data;
            newkb->used = 0;
            newindex = index+1;

            ptb->partition[newindex].hashid = ptb->partition[index].hashid;
            ptb->partition[newindex].blockid = newblock->id;

            if (nblock)
                camel_block_file_unref_block(cpi->blocks, nblock);
            if (pblock)
                camel_block_file_unref_block(cpi->blocks, pblock);
        } else {
            newkb = (CamelPartitionKeyBlock *)&newblock->data;

            if (newblock == pblock) {
                if (nblock)
                    camel_block_file_unref_block(cpi->blocks, nblock);
            } else {
                if (pblock)
                    camel_block_file_unref_block(cpi->blocks, pblock);
            }
        }

        /* sort keys to find midpoint */
        len = kb->used;
        memcpy(keys, kb->keys, sizeof(kb->keys[0])*len);
        memcpy(keys+len, newkb->keys, sizeof(newkb->keys[0])*newkb->used);
        len += newkb->used;
        keys[len].hashid = hashid;
        keys[len].keyid = keyid;
        len++;
        qsort(keys, len, sizeof(keys[0]), keys_cmp);

        /* Split keys, fix partition table */
        half = len/2;
        partid = keys[half-1].hashid;

        if (index < newindex) {
            memcpy(kb->keys, keys, sizeof(keys[0])*half);
            kb->used = half;
            memcpy(newkb->keys, keys+half, sizeof(keys[0])*(len-half));
            newkb->used = len-half;
            ptb->partition[index].hashid = partid;
        } else {
            memcpy(newkb->keys, keys, sizeof(keys[0])*half);
            newkb->used = half;
            memcpy(kb->keys, keys+half, sizeof(keys[0])*(len-half));
            kb->used = len-half;
            ptb->partition[newindex].hashid = partid;
        }

        camel_block_file_touch_block(cpi->blocks, ptblock);
#ifdef SYNC_UPDATES
        camel_block_file_sync_block(cpi->blocks, ptblock);
#endif
        camel_block_file_touch_block(cpi->blocks, newblock);
        camel_block_file_unref_block(cpi->blocks, newblock);
    }

    camel_block_file_touch_block(cpi->blocks, block);
    camel_block_file_unref_block(cpi->blocks, block);

    ret = 0;
fail:
    CAMEL_PARTITION_TABLE_UNLOCK(cpi, lock);

    return ret;
}

/* ********************************************************************** */


#ifdef ENABLE_THREADS

struct _CamelKeyTablePrivate {
    pthread_mutex_t lock;   /* for locking key */
};

#define CAMEL_KEY_TABLE_LOCK(kf, lock) (pthread_mutex_lock(&(kf)->priv->lock))
#define CAMEL_KEY_TABLE_UNLOCK(kf, lock) (pthread_mutex_unlock(&(kf)->priv->lock))
#else
#define CAMEL_KEY_TABLE_LOCK(kf, lock)
#define CAMEL_KEY_TABLE_UNLOCK(kf, lock)
#endif

static void
camel_key_table_class_init(CamelKeyTableClass *klass)
{
}

static void
camel_key_table_init(CamelKeyTable *ki)
{
    struct _CamelKeyTablePrivate *p;

    p = ki->priv = g_malloc0(sizeof(*ki->priv));
#ifdef ENABLE_THREADS
    pthread_mutex_init(&p->lock, NULL);
#endif
}

static void
camel_key_table_finalise(CamelKeyTable *ki)
{
    struct _CamelKeyTablePrivate *p;

    p = ki->priv;

    if (ki->blocks) {
        if (ki->root_block) {
            camel_block_file_sync_block(ki->blocks, ki->root_block);
            camel_block_file_unref_block(ki->blocks, ki->root_block);
        }
        camel_block_file_sync(ki->blocks);
        camel_object_unref((CamelObject *)ki->blocks);
    }

#ifdef ENABLE_THREADS
    pthread_mutex_destroy(&p->lock);
#endif
    g_free(p);

}

CamelType
camel_key_table_get_type(void)
{
    static CamelType type = CAMEL_INVALID_TYPE;
    
    if (type == CAMEL_INVALID_TYPE) {
        type = camel_type_register(camel_object_get_type(), "CamelKeyTable",
                       sizeof (CamelKeyTable),
                       sizeof (CamelKeyTableClass),
                       (CamelObjectClassInitFunc) camel_key_table_class_init,
                       NULL,
                       (CamelObjectInitFunc) camel_key_table_init,
                       (CamelObjectFinalizeFunc) camel_key_table_finalise);
    }
    
    return type;
}


CamelKeyTable *
camel_key_table_new(CamelBlockFile *bs, camel_block_t root)
{
    CamelKeyTable *ki;

    ki = (CamelKeyTable *)camel_object_new(camel_key_table_get_type());

    ki->blocks = bs;
    camel_object_ref((CamelObject *)bs);
    ki->rootid = root;

    ki->root_block = camel_block_file_get_block(bs, ki->rootid);
    if (ki->root_block == NULL) {
        camel_object_unref((CamelObject *)ki);
        ki = NULL;
    } else {
        camel_block_file_detach_block(bs, ki->root_block);
        ki->root = (CamelKeyRootBlock *)&ki->root_block->data;

        k(printf("Opening key index\n"));
        k(printf(" first %u\n last %u\n free %u\n", ki->root->first, ki->root->last, ki->root->free));
    }

    return ki;
}

int
camel_key_table_sync(CamelKeyTable *ki)
{
#ifdef SYNC_UPDATES
    return 0;
#else
    return camel_block_file_sync_block(ki->blocks, ki->root_block);
#endif
}

camel_key_t
camel_key_table_add(CamelKeyTable *ki, const char *key, camel_block_t data, unsigned int flags)
{
    CamelBlock *last, *next;
    CamelKeyBlock *kblast, *kbnext;
    int len, left;
    unsigned int offset;
    camel_key_t keyid = 0;

    /* Maximum key size = 128 chars */
    len = strlen(key);
    if (len > CAMEL_KEY_TABLE_MAX_KEY)
        len = 128;

    CAMEL_KEY_TABLE_LOCK(ki, lock);

    if (ki->root->last == 0) {
        last = camel_block_file_new_block(ki->blocks);
        if (last == NULL)
            goto fail;
        ki->root->last = ki->root->first = last->id;
        camel_block_file_touch_block(ki->blocks, ki->root_block);
        k(printf("adding first block, first = %u\n", ki->root->first));
    } else {
        last = camel_block_file_get_block(ki->blocks, ki->root->last);
        if (last == NULL)
            goto fail;
    }

    kblast = (CamelKeyBlock *)&last->data;

    if (kblast->used >= 127)
        goto fail;

    if (kblast->used > 0) {
        /*left = &kblast->u.keydata[kblast->u.keys[kblast->used-1].offset] - (char *)(&kblast->u.keys[kblast->used+1]);*/
        left = kblast->u.keys[kblast->used-1].offset - sizeof(kblast->u.keys[0])*(kblast->used+1);
        d(printf("used = %d (%d), filled = %d, left = %d  len = %d?\n",
             kblast->used, kblast->used * sizeof(kblast->u.keys[0]),
             sizeof(kblast->u.keydata) - kblast->u.keys[kblast->used-1].offset,
             left, len));
        if (left < len) {
            next = camel_block_file_new_block(ki->blocks);
            if (next == NULL) {
                camel_block_file_unref_block(ki->blocks, last);
                goto fail;
            }
            kbnext = (CamelKeyBlock *)&next->data;
            kblast->next = next->id;
            ki->root->last = next->id;
            k(printf("adding new block, first = %u, last = %u\n", ki->root->first, ki->root->last));
            camel_block_file_touch_block(ki->blocks, ki->root_block);
            camel_block_file_touch_block(ki->blocks, last);
            camel_block_file_unref_block(ki->blocks, last);
            kblast = kbnext;
            last = next;
        }
    }

    if (kblast->used > 0)
        offset = kblast->u.keys[kblast->used-1].offset - len;
    else
        offset = sizeof(kblast->u.keydata)-len;

    kblast->u.keys[kblast->used].flags = flags;
    kblast->u.keys[kblast->used].data = data;
    kblast->u.keys[kblast->used].offset = offset;
    memcpy(kblast->u.keydata + offset, key, len);

    keyid = (last->id & (~(CAMEL_BLOCK_SIZE-1))) | kblast->used;

    kblast->used++;

    g_assert(kblast->used < 127);

    camel_block_file_touch_block(ki->blocks, last);
    camel_block_file_unref_block(ki->blocks, last);

#ifdef SYNC_UPDATES
    camel_block_file_sync_block(ki->blocks, ki->root_block);
#endif
fail:
    CAMEL_KEY_TABLE_UNLOCK(ki, lock);

    return keyid;
}

void
camel_key_table_set_data(CamelKeyTable *ki, camel_key_t keyid, camel_block_t data)
{
    CamelBlock *bl;
    camel_block_t blockid;
    int index;
    CamelKeyBlock *kb;

    if (keyid == 0)
        return;

    blockid =  keyid & (~(CAMEL_BLOCK_SIZE-1));
    index = keyid & (CAMEL_BLOCK_SIZE-1);

    bl = camel_block_file_get_block(ki->blocks, blockid);
    if (bl == NULL)
        return;
    kb = (CamelKeyBlock *)&bl->data;

    CAMEL_KEY_TABLE_LOCK(ki, lock);

    if (kb->u.keys[index].data != data) {
        kb->u.keys[index].data = data;
        camel_block_file_touch_block(ki->blocks, bl);
    }

    CAMEL_KEY_TABLE_UNLOCK(ki, lock);

    camel_block_file_unref_block(ki->blocks, bl);
}

void
camel_key_table_set_flags(CamelKeyTable *ki, camel_key_t keyid, unsigned int flags, unsigned int set)
{
    CamelBlock *bl;
    camel_block_t blockid;
    int index;
    CamelKeyBlock *kb;
    unsigned int old;

    if (keyid == 0)
        return;

    blockid =  keyid & (~(CAMEL_BLOCK_SIZE-1));
    index = keyid & (CAMEL_BLOCK_SIZE-1);

    bl = camel_block_file_get_block(ki->blocks, blockid);
    if (bl == NULL)
        return;
    kb = (CamelKeyBlock *)&bl->data;

    g_assert(kb->used < 127);
    g_assert(index < kb->used);

    CAMEL_KEY_TABLE_LOCK(ki, lock);

    old = kb->u.keys[index].flags;
    if ((old & set) != (flags & set)) {
        kb->u.keys[index].flags = (old & (~set)) | (flags & set);
        camel_block_file_touch_block(ki->blocks, bl);
    }

    CAMEL_KEY_TABLE_UNLOCK(ki, lock);

    camel_block_file_unref_block(ki->blocks, bl);
}

camel_block_t
camel_key_table_lookup(CamelKeyTable *ki, camel_key_t keyid, char **keyp, unsigned int *flags)
{
    CamelBlock *bl;
    camel_block_t blockid;
    int index, len, off;
    char *key;
    CamelKeyBlock *kb;

    if (keyp)
        *keyp = 0;
    if (flags)
        *flags = 0;
    if (keyid == 0)
        return 0;

    blockid =  keyid & (~(CAMEL_BLOCK_SIZE-1));
    index = keyid & (CAMEL_BLOCK_SIZE-1);

    bl = camel_block_file_get_block(ki->blocks, blockid);
    if (bl == NULL)
        return 0;

    kb = (CamelKeyBlock *)&bl->data;

#if 1
    g_assert(kb->used < 127); /* this should be more accurate */
    g_assert(index < kb->used);
#else
    if (kb->used >=127 || index >= kb->used) {
        g_warning("Block %x: Invalid index or content: index %d used %d\n", blockid, index, kb->used);
        return 0;
    }
#endif

    CAMEL_KEY_TABLE_LOCK(ki, lock);

    blockid = kb->u.keys[index].data;
    if (flags)
        *flags = kb->u.keys[index].flags;

    if (keyp) {
        off = kb->u.keys[index].offset;
        if (index == 0)
            len = sizeof(kb->u.keydata) - off;
        else
            len = kb->u.keys[index-1].offset - off;
        *keyp = key = g_malloc(len+1);
        memcpy(key, kb->u.keydata + off, len);
        key[len] = 0;
    }

    CAMEL_KEY_TABLE_UNLOCK(ki, lock);

    camel_block_file_unref_block(ki->blocks, bl);

    return blockid;
}

/* iterate through all keys */
camel_key_t
camel_key_table_next(CamelKeyTable *ki, camel_key_t next, char **keyp, unsigned int *flagsp, camel_block_t *datap)
{
    CamelBlock *bl;
    CamelKeyBlock *kb;
    camel_block_t blockid;
    int index;

    if (keyp)
        *keyp = 0;
    if (flagsp)
        *flagsp = 0;
    if (datap)
        *datap = 0;

    CAMEL_KEY_TABLE_LOCK(ki, lock);

    if (next == 0) {
        next = ki->root->first;
        if (next == 0)
            return 0;
    } else
        next++;

    do {
        blockid =  next & (~(CAMEL_BLOCK_SIZE-1));
        index = next & (CAMEL_BLOCK_SIZE-1);
        
        bl = camel_block_file_get_block(ki->blocks, blockid);
        if (bl == NULL) {
            CAMEL_KEY_TABLE_UNLOCK(ki, lock);
            return 0;
        }

        kb = (CamelKeyBlock *)&bl->data;

        /* see if we need to goto the next block */
        if (index >= kb->used) {
            /* FIXME: check for loops */
            next = kb->next;
            camel_block_file_unref_block(ki->blocks, bl);
            bl = NULL;
        }
    } while (bl == NULL);

    /* invalid block data */
    if ((kb->u.keys[index].offset >= sizeof(kb->u.keydata)
         /*|| kb->u.keys[index].offset < kb->u.keydata - (char *)&kb->u.keys[kb->used])*/
         || kb->u.keys[index].offset < sizeof(kb->u.keys[0]) * kb->used
        || (index > 0 &&
        (kb->u.keys[index-1].offset >= sizeof(kb->u.keydata)
         /*|| kb->u.keys[index-1].offset < kb->u.keydata - (char *)&kb->u.keys[kb->used]))) {*/
         || kb->u.keys[index-1].offset < sizeof(kb->u.keys[0]) * kb->used)))) {
        g_warning("Block %u invalid scanning keys", bl->id);
        camel_block_file_unref_block(ki->blocks, bl);
        CAMEL_KEY_TABLE_UNLOCK(ki, lock);
        return 0;
    }

    if (datap)
        *datap = kb->u.keys[index].data;

    if (flagsp)
        *flagsp = kb->u.keys[index].flags;

    if (keyp) {
        int len, off = kb->u.keys[index].offset;
        char *key;

        if (index == 0)
            len = sizeof(kb->u.keydata) - off;
        else
            len = kb->u.keys[index-1].offset - off;
        *keyp = key = g_malloc(len+1);
        memcpy(key, kb->u.keydata + off, len);
        key[len] = 0;
    }

    CAMEL_KEY_TABLE_UNLOCK(ki, lock);

    camel_block_file_unref_block(ki->blocks, bl);

    return next;
}

/* ********************************************************************** */