PBC Data Type Store
A request to update the value of a Riak Data Type.
Request
A DtUpdateReq message requires that you specify the location of the
Data Type in Riak, which operations are to be performed, and whether the
Data Type’s opaque context should be returned in the resulting
DtUpdateResp.
The DtOp value specifies which Data Type-specific operation is being
performed. More on that in the PBC Data Type Union document.
message DtUpdateReq {
required bytes bucket = 1;
optional bytes key = 2;
required bytes type = 3;
optional bytes context = 4;
required DtOp op = 5;
optional uint32 w = 6;
optional uint32 dw = 7;
optional uint32 pw = 8;
optional bool return_body = 9 [default=false];
optional uint32 timeout = 10;
optional bool sloppy_quorum = 11;
optional uint32 n_val = 12;
optional bool include_context = 13 [default=true];
}
Required Parameters
| Parameter | Description |
|---|---|
bucket |
The name of the bucket in which the Data Type is stored |
type |
The bucket type of the bucket in which the Data Type is stored, not the type of Data Type (i.e. counter, set, or map). Learn more about using bucket types. |
Also required is a DtOp message that specifies which operation is to
be performed, depending on whether the Data Type being updated is a
counter, set, or map.
message DtOp {
optional CounterOp counter_op = 1;
optional SetOp set_op = 2;
optional MapOp map_op = 3;
}
Optional Parameters
All of the optional parameters below have default values determined on a per-bucket basis. Please refer to the documentation on setting bucket properties for more information.
Furthermore, you can assign an integer value to the w, dw, pr, and
pw, provided that that integer value is less than or equal to N, or
a special value denoting one (4294967295-1), quorum
(4294967295-2), all (4294967295-3), or default (4294967295-4).
| Parameter | Description |
|---|---|
key |
The key where the Data Type is stored. If not specified, Riak will assign a random key and return that key to the client if return_body is set to true. |
context |
The opaque binary “context” that informs Riak which version of a data type the client has seen, analogous to vector clocks |
w |
Write quorum, i.e. how many replicas to write to before returning a successful response |
dw |
Durable write quorum, i.e. how many replicas to commit to durable storage before returning a successful response |
pw |
Primary write quorum, i.e. how many primary nodes must be up when the write is attempted |
return_body |
Whether to return the contents of the stored object. Defaults to false. |
timeout |
The timeout duration, in milliseconds, after which Riak will return an error message |
sloppy_quorum |
If this parameter is set to true, the next available node in the ring will accept requests if any primary node is unavailable |
n_val |
The number of nodes on which the value is to be stored |
include_context |
If return_body is set to true, the Data Type’s opaque “context” will be returned to the client when the DtUpdateResp is sent to the client. |
Response
The response to a Data Type update request is analogous to
RpbPutResp for KV operations. If the
return_body is set in the update request message (as explained above),
the message will include the opaque context of the Data Type (context)
and the new value of the Data Type after the update has completed
(depending on whether the Data Type is a counter, set, or map). If no
key was specified in the update request, it will include the
Riak-assigned key (key).
message DtUpdateResp {
optional bytes key = 1;
optional bytes context = 2;
optional sint64 counter_value = 3;
repeated bytes set_value = 4;
repeated MapEntry map_value = 5;
}
Assuming return_body is set to true: if a counter is updated, the
response will include an integer as the counter_value; if a set is
updated, a list of binaries will be return as the set_value; and if a
map is updated, the returned map_value will be a MapEntry message.
That message takes the following form:
message MapEntry {
required MapField field = 1;
optional sint64 counter_value = 2;
repeated bytes set_value = 3;
optional bytes register_value = 4;
optional bool flag_value = 5;
repeated MapEntry map_value = 6;
}