RT-Thread-使用FlashDB迭代器，无法遍历所有KV，使用for循环加读取函数，可以读取到这个kvRT-Thread问答社区

使用FlashDB迭代器，无法遍历所有KV，使用for循环加读取函数，可以读取到这个kv

发布于 2024-04-29 14:22:55 浏览：363 订阅该版

我按照官方给的例程，在使用迭代器遍历所有KV时，发现并不能获取到我已经存储的KV，但是通过读取函数，可以直接读取；
下面是遍历所有 键值对的代码及其日志

```c
void check_wireless_device(uint8_t dbid, uint8_t type, uint8_t max_size)
{
    struct fdb_kv_iterator iterator;
    fdb_kv_t cur_kv;
    struct fdb_blob blob;
    size_t data_size;
    uint8_t *data_buf;
    int32_t i = 0;
    uint32_t  y = 0;
    uint32_t wireless_base_data = dbid*1000;
    uint32_t addr = 0;

int count = 0;

fdb_kv_iterator_init(&iterator);

while (fdb_kv_iterate(ptr_pt_global_kvdb, &iterator)) 
    {
        cur_kv = &(iterator.curr_kv);
        data_size = (size_t) cur_kv->value_len;
        data_buf = (uint8_t *) malloc(data_size);
        if (data_buf == NULL)
        {
            break;
        }
        fdb_blob_read((fdb_db_t) ptr_pt_global_kvdb, fdb_kv_to_blob(cur_kv, fdb_blob_make(&blob, data_buf, data_size)));

y = atoi(cur_kv->name);
        i = y-(wireless_base_data);
        addr = *((uint32_t *)data_buf);
        PT_LOGD("[index:%d]kv_name:%s ,addr: 0x%x", count++, cur_kv->name, addr);
        if(i > 0 && i <max_size && !(addr & 0xff00000f) && addr != 0)
        {
            cache_wireless_id[cache_wireless_count].addr = addr;
            cache_wireless_id[cache_wireless_count].id = i;
            cache_wireless_id[cache_wireless_count].type = type;
            cache_wireless_count++;
            if(cache_wireless_count >= 128+32 -1)
            {
                return;
            }
        }

free(data_buf);
    }
}

```
日志
```
[pt_check_wireless_device][887](D)> [index:0]kv_name:29000 ,addr: 0xffffff01
[pt_check_wireless_device][887](D)> [index:1]kv_name:29010 ,addr: 0xffffff0a
[pt_check_wireless_device][887](D)> [index:2]kv_name:29002 ,addr: 0xffffff0a
[pt_check_wireless_device][887](D)> [index:3]kv_name:29005 ,addr: 0xffffff0a
[pt_check_wireless_device][887](D)> [index:4]kv_name:29006 ,addr: 0xffffff0a
[pt_check_wireless_device][887](D)> [index:5]kv_name:29007 ,addr: 0xffffff0a
[pt_check_wireless_device][887](D)> [index:6]kv_name:29004 ,addr: 0xffffff0a
[pt_check_wireless_device][887](D)> [index:7]kv_name:29008 ,addr: 0xffffff0a
[pt_check_wireless_device][887](D)> [index:8]kv_name:29003 ,addr: 0xffffff0a
[pt_check_wireless_device][887](D)> [index:9]kv_name:22003 ,addr: 0xffff0001
[pt_check_wireless_device][887](D)> [index:10]kv_name:22004 ,addr: 0xffff0001
[pt_check_wireless_device][887](D)> [index:11]kv_name:22006 ,addr: 0xffff0001
[pt_check_wireless_device][887](D)> [index:12]kv_name:22007 ,addr: 0xffff0001
[pt_check_wireless_device][887](D)> [index:13]kv_name:22008 ,addr: 0xffff0001
[pt_check_wireless_device][887](D)> [index:14]kv_name:22002 ,addr: 0xffff0001
[pt_check_wireless_device][887](D)> [index:15]kv_name:23001 ,addr: 0x3
[pt_check_wireless_device][887](D)> [index:16]kv_name:25001 ,addr: 0x1
[pt_check_wireless_device][887](D)> [index:17]kv_name:44001 ,addr: 0x81
[pt_check_wireless_device][887](D)> [index:18]kv_name:29067 ,addr: 0xa
[pt_check_wireless_device][887](D)> [index:19]kv_name:29068 ,addr: 0xa
[pt_check_wireless_device][887](D)> [index:20]kv_name:29069 ,addr: 0xa
[pt_check_wireless_device][887](D)> [index:21]kv_name:29070 ,addr: 0xa
[pt_check_wireless_device][887](D)> [index:22]kv_name:29072 ,addr: 0xa
[pt_check_wireless_device][887](D)> [index:23]kv_name:29073 ,addr: 0xa
[pt_check_wireless_device][887](D)> [index:24]kv_name:22000 ,addr: 0x1
[pt_check_wireless_device][887](D)> [index:25]kv_name:29071 ,addr: 0xa
[pt_check_wireless_device][887](D)> [index:26]kv_name:29014 ,addr: 0x1
[pt_check_wireless_device][887](D)> [index:27]kv_name:29001 ,addr: 0xa
[pt_check_wireless_device][887](D)> [index:28]kv_name:29066 ,addr: 0xa
[pt_check_wireless_device][887](D)> [index:29]kv_name:23066 ,addr: 0x1
[pt_check_wireless_device][887](D)> [index:30]kv_name:23067 ,addr: 0x1
[pt_check_wireless_device][887](D)> [index:31]kv_name:23068 ,addr: 0x1
[pt_check_wireless_device][887](D)> [index:32]kv_name:23069 ,addr: 0x1
[pt_check_wireless_device][887](D)> [index:33]kv_name:23070 ,addr: 0x1
[pt_check_wireless_device][887](D)> [index:34]kv_name:23014 ,addr: 0x1
[pt_check_wireless_device][887](D)> [index:35]kv_name:23071 ,addr: 0x1
[pt_check_wireless_device][887](D)> [index:36]kv_name:23072 ,addr: 0x1
[pt_check_wireless_device][887](D)> [index:37]kv_name:23073 ,addr: 0x1
[pt_check_wireless_device][887](D)> [index:38]kv_name:29100 ,addr: 0xa
[pt_check_wireless_device][887](D)> [index:39]kv_name:23100 ,addr: 0x1
[pt_check_wireless_device][887](D)> [index:40]kv_name:29101 ,addr: 0xa
[pt_check_wireless_device][887](D)> [index:41]kv_name:23101 ,addr: 0x1
[pt_check_wireless_device][887](D)> [index:42]kv_name:23002 ,addr: 0x1
[pt_check_wireless_device][887](D)> [index:43]kv_name:23004 ,addr: 0x1
[pt_check_wireless_device][887](D)> [index:44]kv_name:23010 ,addr: 0x1
[pt_check_wireless_device][887](D)> [index:45]kv_name:29011 ,addr: 0xa
[pt_check_wireless_device][887](D)> [index:46]kv_name:23011 ,addr: 0x1
```

下边是直接调用for循环读取的相关代码：
```C
    pt_db_data_t read_data = {
        .type = PT_DATA_UINT32};
    int err = pt_fdb_read(9, 1, &read_data);
    PT_LOGD("err:%d addr:0x%x", err, read_data.val.val_u32);
    rt_thread_mdelay(2000);

pt_db_data_t write_data = {
        .type = PT_DATA_UINT32,
        .val.val_u32 = 0x10,
        .len = sizeof(uint32_t)};

err = pt_fdb_write(70, 1, &write_data);
    PT_LOGD("err:%d addr:0x%x", err, write_data.val.val_u32);
    rt_thread_mdelay(2000);

err = pt_fdb_read(70, 1, &read_data);
    PT_LOGD("err:%d addr:0x%x", err, read_data.val.val_u32);
    rt_thread_mdelay(2000);

int count = 0;
    for (uint8_t i = 0; i < 100; i++)
    {

for (uint8_t j = 0; j < 20; j++)
        {
            err = pt_fdb_read(i, j, &read_data);
            if (err == PT_DB_ERR_CODE_EOK)
            {
                count++;
                PT_LOGD("dbid:%d, group_id:%d, count:%d", i, j, count);
            }
        }
    }
    PT_LOGD("end");
```
日志：
```
[main][94](D)> err:0 addr:0x10
[main][98](D)> err:0 addr:0x10
[main][111](D)> dbid:9, group_id:0, count:1
[main][111](D)> dbid:9, group_id:1, count:2
[main][111](D)> dbid:9, group_id:2, count:3
[main][111](D)> dbid:9, group_id:8, count:4
[main][111](D)> dbid:10, group_id:1, count:5
[main][111](D)> dbid:10, group_id:2, count:6
[main][111](D)> dbid:10, group_id:3, count:7
[main][111](D)> dbid:10, group_id:4, count:8
[main][111](D)> dbid:10, group_id:5, count:9
[main][111](D)> dbid:10, group_id:8, count:10
[main][111](D)> dbid:10, group_id:9, count:11
[main][111](D)> dbid:15, group_id:0, count:12
[main][111](D)> dbid:16, group_id:0, count:13
[main][111](D)> dbid:17, group_id:0, count:14
[main][111](D)> dbid:20, group_id:0, count:15
[main][111](D)> dbid:21, group_id:0, count:16
[main][111](D)> dbid:22, group_id:0, count:17
[main][111](D)> dbid:22, group_id:1, count:18
[main][111](D)> dbid:22, group_id:2, count:19
[main][111](D)> dbid:22, group_id:3, count:20
[main][111](D)> dbid:22, group_id:4, count:21
[main][111](D)> dbid:22, group_id:5, count:22
[main][111](D)> dbid:22, group_id:6, count:23
[main][111](D)> dbid:22, group_id:7, count:24
[main][111](D)> dbid:22, group_id:8, count:25
[main][111](D)> dbid:22, group_id:11, count:26
[main][111](D)> dbid:23, group_id:1, count:27
[main][111](D)> dbid:23, group_id:2, count:28
[main][111](D)> dbid:23, group_id:3, count:29
[main][111](D)> dbid:23, group_id:4, count:30
[main][111](D)> dbid:23, group_id:5, count:31
[main][111](D)> dbid:23, group_id:6, count:32
[main][111](D)> dbid:23, group_id:7, count:33
[main][111](D)> dbid:23, group_id:8, count:34
[main][111](D)> dbid:23, group_id:10, count:35
[main][111](D)> dbid:23, group_id:11, count:36
[main][111](D)> dbid:23, group_id:14, count:37
[main][111](D)> dbid:23, group_id:19, count:38
[main][111](D)> dbid:24, group_id:1, count:39
[main][111](D)> dbid:25, group_id:1, count:40
[main][111](D)> dbid:25, group_id:3, count:41
[main][111](D)> dbid:26, group_id:0, count:42
[main][111](D)> dbid:27, group_id:0, count:43
[main][111](D)> dbid:29, group_id:0, count:44
[main][111](D)> dbid:29, group_id:1, count:45
[main][111](D)> dbid:29, group_id:2, count:46
[main][111](D)> dbid:29, group_id:3, count:47
[main][111](D)> dbid:29, group_id:4, count:48
[main][111](D)> dbid:29, group_id:5, count:49
[main][111](D)> dbid:29, group_id:6, count:50
[main][111](D)> dbid:29, group_id:7, count:51
[main][111](D)> dbid:29, group_id:8, count:52
[main][111](D)> dbid:29, group_id:10, count:53
[main][111](D)> dbid:29, group_id:11, count:54
[main][111](D)> dbid:29, group_id:12, count:55
[main][111](D)> dbid:29, group_id:13, count:56
[main][111](D)> dbid:29, group_id:14, count:57
[main][111](D)> dbid:29, group_id:15, count:58
[main][111](D)> dbid:43, group_id:0, count:59
[main][111](D)> dbid:43, group_id:1, count:60
[main][111](D)> dbid:44, group_id:1, count:61
[main][111](D)> dbid:44, group_id:2, count:62
[main][111](D)> dbid:44, group_id:5, count:63
[main][111](D)> dbid:44, group_id:6, count:64
[main][111](D)> dbid:44, group_id:7, count:65
[main][111](D)> dbid:61, group_id:0, count:66
[main][111](D)> dbid:70, group_id:1, count:67
[main][115](D)> end

```