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address review comment 

Signed-off-by: haojinming <jinming.hao@pingcap.com>
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haojinming 2022-11-16 17:38:32 +08:00
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commit 1318a775b9
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content/docs/dev/develop/rawkv/checksum.md
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@ -4,7 +4,7 @@ description: Learn how to use RawKV's Checksum API.
menu: menu:
"dev": "dev":
parent: RawKV-dev parent: RawKV-dev
weight: 2 weight: 5
identifier: Checksum-dev identifier: Checksum-dev
--- ---
@ -12,19 +12,19 @@ This document walks you through how to use RawKV's `Checksum` API.
`Checksum` API returns `Crc64Xor`, `TotalKvs` and `TotalBytes` from TiKV cluster. `Checksum` API returns `Crc64Xor`, `TotalKvs` and `TotalBytes` from TiKV cluster.
- `Crc64Xor`: The [XOR](https://en.wikipedia.org/wiki/Exclusive_or) of every key-value pair's [crc64](https://en.wikipedia.org/wiki/Cyclic_redundancy_check) value. - `Crc64Xor`: The [XOR](https://en.wikipedia.org/wiki/Exclusive_or) of every key-value pair's [crc64](https://en.wikipedia.org/wiki/Cyclic_redundancy_check) value.
- `TotalKVs`: The count of key-value pairs. - `TotalKVs`: The number of key-value pairs.
- `TotalBytes`: The size of key-value pairs in bytes. - `TotalBytes`: The size of key-value pairs in bytes.
_Note: If [API V2](../../../concepts/explore-tikv-features/api-v2) is enabled in tikv cluster, tikv client will encode prefix for raw key [here](https://github.com/tikv/client-go/blob/9c0835c80eba6cbda6fc4ae460d645de9d36cd05/internal/client/api_version.go#L57), and `Checksum` API also counts prefix into `Crc64Xor` and `TotalBytes`._ *Note: If [API V2](../../../concepts/explore-tikv-features/api-v2) is enabled, a `4` bytes prefix is encoded with keys, and also calculated by `Checksum` API*
## Go ## Go
### Checksum with range ### Checksum with range
Using the `Checksum` API, you can get `{Crc64Xor, TotalKvs, TotalBytes}` from TiKV in a range (from a `startKey` to an `endKey`). Using the `Checksum` API, you can get `{Crc64Xor, TotalKvs, TotalBytes}` of a range from `startKey` (inclusive) to `endKey` (exclusive).
{{< info >}} {{< info >}}
`startKey` is inclusive while `endKey` is exclusive. To calculate checksum of all keys, specify `startKey` and `endKey` as `[]byte("")`.
{{< /info >}} {{< /info >}}
@ -48,7 +48,7 @@ func main() {
} }
defer cli.Close() defer cli.Close()
fmt.Printf("cluster ID: %d\n", cli.ClusterID()) fmt.Printf("Cluster ID: %d\n", cli.ClusterID())
// put key into tikv // put key into tikv
cli.Put(ctx, []byte("k1"), []byte("v1")) cli.Put(ctx, []byte("k1"), []byte("v1"))
@ -62,8 +62,13 @@ func main() {
panic(err) panic(err)
} }
fmt.Printf("Get checksum=, Crc64Xor:%d, TotalKvs:%d, TotalBytes:%d.\n", fmt.Printf("Get checksum, Crc64Xor:%d, TotalKvs:%d, TotalBytes:%d.\n",
checksum.Crc64Xor, checksum.TotalKvs, checksum.TotalBytes) checksum.Crc64Xor, checksum.TotalKvs, checksum.TotalBytes)
} }
``` ```
If you want to check all the data, the `startKey` and `endKey` can be specified as `[]byte("")`. You will get the result as following:
```bash
Cluster ID: 7166545317297238572
Get checksum, Crc64Xor:7402990595130313958, TotalKvs:5, TotalBytes:40.
```