src/lib-storage/mailbox-guid-cache.c

	mailbox-guid-cache.c revision bd4e36a8cd7257cca7d1434c49a1e343ed7c5100
/* Copyright (c) 2005-2011 Dovecot authors, see the included COPYING file */

#include "lib.h"
#include "hash.h"
#include "mail-storage.h"
#include "mailbox-list-private.h"
#include "mailbox-guid-cache.h"

struct mailbox_guid_cache_rec {
    uint8_t guid[MAIL_GUID_128_SIZE];
    const char *vname;
};

static unsigned int guid_cache_rec_hash(const void *_rec)
{
    const struct mailbox_guid_cache_rec *rec = _rec;
    unsigned int i, g, h = 0;

    for (i = 0; i < sizeof(rec->guid); i++) {
        h = (h << 4) + rec->guid[i];
        if ((g = h & 0xf0000000UL)) {
            h = h ^ (g >> 24);
            h = h ^ g;
        }
    }
    return h;
}

static int guid_cache_rec_cmp(const void *_r1, const void *_r2)
{
    const struct mailbox_guid_cache_rec *r1 = _r1, *r2 = _r2;

    return memcmp(r1->guid, r2->guid, sizeof(r1->guid));
}

int mailbox_guid_cache_find(struct mailbox_list *list,
                uint8_t guid[MAIL_GUID_128_SIZE],
                const char **vname_r)
{
    const struct mailbox_guid_cache_rec *rec;
    struct mailbox_guid_cache_rec lookup_rec;

    memcpy(lookup_rec.guid, guid, sizeof(lookup_rec.guid));
    if (list->guid_cache == NULL) {
        mailbox_guid_cache_refresh(list);
        rec = hash_table_lookup(list->guid_cache, &lookup_rec);
    } else {
        rec = hash_table_lookup(list->guid_cache, &lookup_rec);
        if (rec == NULL) {
            mailbox_guid_cache_refresh(list);
            rec = hash_table_lookup(list->guid_cache, &lookup_rec);
        }
    }
    if (rec == NULL) {
        *vname_r = NULL;
        return list->guid_cache_errors ? -1 : 0;
    }
    *vname_r = rec->vname;
    return 0;
}

void mailbox_guid_cache_refresh(struct mailbox_list *list)
{
    struct mailbox_list_iterate_context *ctx;
    const struct mailbox_info *info;
    struct mailbox *box;
    struct mailbox_metadata metadata;
    struct mailbox_guid_cache_rec *rec;

    if (list->guid_cache == NULL) {
        list->guid_cache_pool =
            pool_alloconly_create("guid cache", 1024*16);
        list->guid_cache = hash_table_create(default_pool,
                             list->guid_cache_pool, 0,
                             guid_cache_rec_hash,
                             guid_cache_rec_cmp);
    } else {
        hash_table_clear(list->guid_cache, TRUE);
        p_clear(list->guid_cache_pool);
    }
    list->guid_cache_errors = FALSE;

    ctx = mailbox_list_iter_init(list, "*",
                     MAILBOX_LIST_ITER_NO_AUTO_BOXES);
    while ((info = mailbox_list_iter_next(ctx)) != NULL) {
        if ((info->flags &
             (MAILBOX_NOSELECT | MAILBOX_NONEXISTENT)) != 0)
            continue;

        box = mailbox_alloc(list, info->name, MAILBOX_FLAG_KEEP_RECENT);
        if (mailbox_get_metadata(box, MAILBOX_METADATA_GUID,
                     &metadata) < 0) {
            i_error("Couldn't get mailbox %s GUID: %s",
                info->name, mailbox_get_last_error(box, NULL));
            list->guid_cache_errors = TRUE;
        } else {
            rec = p_new(list->guid_cache_pool,
                    struct mailbox_guid_cache_rec, 1);
            memcpy(rec->guid, metadata.guid, sizeof(rec->guid));
            rec->vname = p_strdup(list->guid_cache_pool, info->name);
            hash_table_insert(list->guid_cache, rec, rec);
        }
        mailbox_free(&box);
    }
    if (mailbox_list_iter_deinit(&ctx) < 0)
        list->guid_cache_errors = TRUE;
}