Function RM_ScanKey

app/redis-6.2.6/src/module.c:7774–7843

Scan api that allows a module to scan the elements in a hash, set or sorted set key * * Callback for scan implementation. * * void scan_callback(RedisModuleKey *key, RedisModuleString* field, RedisModuleString* value, void *privdata); * * - key - the redis key context provided to for the scan. * - field - field name, owned by the caller and need to be retained if used * after this fu

 * deleting the current element of the data structure is safe, while removing
 * the key you are iterating is not safe. */
int RM_ScanKey(RedisModuleKey *key, RedisModuleScanCursor *cursor, RedisModuleScanKeyCB fn, void *privdata) {
    if (key == NULL || key->value == NULL) {
        errno = EINVAL;
        return 0;
    }
    dict *ht = NULL;
    robj *o = key->value;
    if (o->type == OBJ_SET) {
        if (o->encoding == OBJ_ENCODING_HT)
            ht = o->ptr;
    } else if (o->type == OBJ_HASH) {
        if (o->encoding == OBJ_ENCODING_HT)
            ht = o->ptr;
    } else if (o->type == OBJ_ZSET) {
        if (o->encoding == OBJ_ENCODING_SKIPLIST)
            ht = ((zset *)o->ptr)->dict;
    } else {
        errno = EINVAL;
        return 0;
    }
    if (cursor->done) {
        errno = ENOENT;
        return 0;
    }
    int ret = 1;
    if (ht) {
        ScanKeyCBData data = { key, privdata, fn };
        cursor->cursor = dictScan(ht, cursor->cursor, moduleScanKeyCallback, NULL, &data);
        if (cursor->cursor == 0) {
            cursor->done = 1;
            ret = 0;
        }
    } else if (o->type == OBJ_SET && o->encoding == OBJ_ENCODING_INTSET) {
        int pos = 0;
        int64_t ll;
        while(intsetGet(o->ptr,pos++,&ll)) {
            robj *field = createObject(OBJ_STRING,sdsfromlonglong(ll));
            fn(key, field, NULL, privdata);
            decrRefCount(field);
        }
        cursor->cursor = 1;
        cursor->done = 1;
        ret = 0;
    } else if (o->type == OBJ_HASH || o->type == OBJ_ZSET) {
        unsigned char *p = ziplistIndex(o->ptr,0);
        unsigned char *vstr;
        unsigned int vlen;
        long long vll;
        while(p) {
            ziplistGet(p,&vstr,&vlen,&vll);
            robj *field = (vstr != NULL) ?
                createStringObject((char*)vstr,vlen) :
                createObject(OBJ_STRING,sdsfromlonglong(vll));
            p = ziplistNext(o->ptr,p);
            ziplistGet(p,&vstr,&vlen,&vll);
            robj *value = (vstr != NULL) ?
                createStringObject((char*)vstr,vlen) :
                createObject(OBJ_STRING,sdsfromlonglong(vll));