path: root/src/registry_db.c

#include "registry_internals.h"

int registry_db_should_be_saved(void) {
    debug(D_REGISTRY, "log entries %llu, max %llu", registry.log_count, registry.save_registry_every_entries);
    return registry.log_count > registry.save_registry_every_entries;
}

// ----------------------------------------------------------------------------
// INTERNAL FUNCTIONS FOR SAVING REGISTRY OBJECTS

static int registry_machine_save_url(void *entry, void *file) {
    REGISTRY_MACHINE_URL *mu = entry;
    FILE *fp = file;

    debug(D_REGISTRY, "Registry: registry_machine_save_url('%s')", mu->url->url);

    int ret = fprintf(fp, "V\t%08x\t%08x\t%08x\t%02x\t%s\n",
            mu->first_t,
            mu->last_t,
            mu->usages,
            mu->flags,
            mu->url->url
    );

    // error handling is done at registry_db_save()

    return ret;
}

static int registry_machine_save(void *entry, void *file) {
    REGISTRY_MACHINE *m = entry;
    FILE *fp = file;

    debug(D_REGISTRY, "Registry: registry_machine_save('%s')", m->guid);

    int ret = fprintf(fp, "M\t%08x\t%08x\t%08x\t%s\n",
            m->first_t,
            m->last_t,
            m->usages,
            m->guid
    );

    if(ret >= 0) {
        int ret2 = dictionary_get_all(m->machine_urls, registry_machine_save_url, fp);
        if(ret2 < 0) return ret2;
        ret += ret2;
    }

    // error handling is done at registry_db_save()

    return ret;
}

static inline int registry_person_save_url(void *entry, void *file) {
    REGISTRY_PERSON_URL *pu = entry;
    FILE *fp = file;

    debug(D_REGISTRY, "Registry: registry_person_save_url('%s')", pu->url->url);

    int ret = fprintf(fp, "U\t%08x\t%08x\t%08x\t%02x\t%s\t%s\t%s\n",
            pu->first_t,
            pu->last_t,
            pu->usages,
            pu->flags,
            pu->machine->guid,
            pu->machine_name,
            pu->url->url
    );

    // error handling is done at registry_db_save()

    return ret;
}

static inline int registry_person_save(void *entry, void *file) {
    REGISTRY_PERSON *p = entry;
    FILE *fp = file;

    debug(D_REGISTRY, "Registry: registry_person_save('%s')", p->guid);

    int ret = fprintf(fp, "P\t%08x\t%08x\t%08x\t%s\n",
            p->first_t,
            p->last_t,
            p->usages,
            p->guid
    );

    if(ret >= 0) {
        //int ret2 = dictionary_get_all(p->person_urls, registry_person_save_url, fp);
        int ret2 = avl_traverse(&p->person_urls, registry_person_save_url, fp);
        if (ret2 < 0) return ret2;
        ret += ret2;
    }

    // error handling is done at registry_db_save()

    return ret;
}

// ----------------------------------------------------------------------------
// SAVE THE REGISTRY DATABASE

int registry_db_save(void) {
    if(unlikely(!registry.enabled))
        return -1;

    if(unlikely(!registry_db_should_be_saved()))
        return -2;

    error_log_limit_unlimited();

    char tmp_filename[FILENAME_MAX + 1];
    char old_filename[FILENAME_MAX + 1];

    snprintfz(old_filename, FILENAME_MAX, "%s.old", registry.db_filename);
    snprintfz(tmp_filename, FILENAME_MAX, "%s.tmp", registry.db_filename);

    debug(D_REGISTRY, "Registry: Creating file '%s'", tmp_filename);
    FILE *fp = fopen(tmp_filename, "w");
    if(!fp) {
        error("Registry: Cannot create file: %s", tmp_filename);
        error_log_limit_reset();
        return -1;
    }

    // dictionary_get_all() has its own locking, so this is safe to do

    debug(D_REGISTRY, "Saving all machines");
    int bytes1 = dictionary_get_all(registry.machines, registry_machine_save, fp);
    if(bytes1 < 0) {
        error("Registry: Cannot save registry machines - return value %d", bytes1);
        fclose(fp);
        error_log_limit_reset();
        return bytes1;
    }
    debug(D_REGISTRY, "Registry: saving machines took %d bytes", bytes1);

    debug(D_REGISTRY, "Saving all persons");
    int bytes2 = dictionary_get_all(registry.persons, registry_person_save, fp);
    if(bytes2 < 0) {
        error("Registry: Cannot save registry persons - return value %d", bytes2);
        fclose(fp);
        error_log_limit_reset();
        return bytes2;
    }
    debug(D_REGISTRY, "Registry: saving persons took %d bytes", bytes2);

    // save the totals
    fprintf(fp, "T\t%016llx\t%016llx\t%016llx\t%016llx\t%016llx\t%016llx\n",
            registry.persons_count,
            registry.machines_count,
            registry.usages_count + 1, // this is required - it is lost on db rotation
            registry.urls_count,
            registry.persons_urls_count,
            registry.machines_urls_count
    );

    fclose(fp);

    errno = 0;

    // remove the .old db
    debug(D_REGISTRY, "Registry: Removing old db '%s'", old_filename);
    if(unlink(old_filename) == -1 && errno != ENOENT)
        error("Registry: cannot remove old registry file '%s'", old_filename);

    // rename the db to .old
    debug(D_REGISTRY, "Registry: Link current db '%s' to .old: '%s'", registry.db_filename, old_filename);
    if(link(registry.db_filename, old_filename) == -1 && errno != ENOENT)
        error("Registry: cannot move file '%s' to '%s'. Saving registry DB failed!", registry.db_filename, old_filename);

    else {
        // remove the database (it is saved in .old)
        debug(D_REGISTRY, "Registry: removing db '%s'", registry.db_filename);
        if (unlink(registry.db_filename) == -1 && errno != ENOENT)
            error("Registry: cannot remove old registry file '%s'", registry.db_filename);

        // move the .tmp to make it active
        debug(D_REGISTRY, "Registry: linking tmp db '%s' to active db '%s'", tmp_filename, registry.db_filename);
        if (link(tmp_filename, registry.db_filename) == -1) {
            error("Registry: cannot move file '%s' to '%s'. Saving registry DB failed!", tmp_filename,
                    registry.db_filename);

            // move the .old back
            debug(D_REGISTRY, "Registry: linking old db '%s' to active db '%s'", old_filename, registry.db_filename);
            if(link(old_filename, registry.db_filename) == -1)
                error("Registry: cannot move file '%s' to '%s'. Recovering the old registry DB failed!", old_filename, registry.db_filename);
        }
        else {
            debug(D_REGISTRY, "Registry: removing tmp db '%s'", tmp_filename);
            if(unlink(tmp_filename) == -1)
                error("Registry: cannot remove tmp registry file '%s'", tmp_filename);

            // it has been moved successfully
            // discard the current registry log
            registry_log_recreate();
            registry.log_count = 0;
        }
    }

    // continue operations
    error_log_limit_reset();

    return -1;
}

// ----------------------------------------------------------------------------
// LOAD THE REGISTRY DATABASE

size_t registry_db_load(void) {
    char *s, buf[4096 + 1];
    REGISTRY_PERSON *p = NULL;
    REGISTRY_MACHINE *m = NULL;
    REGISTRY_URL *u = NULL;
    size_t line = 0;

    debug(D_REGISTRY, "Registry: loading active db from: '%s'", registry.db_filename);
    FILE *fp = fopen(registry.db_filename, "r");
    if(!fp) {
        error("Registry: cannot open registry file: '%s'", registry.db_filename);
        return 0;
    }

    size_t len = 0;
    buf[4096] = '\0';