# Protocol Documentation
<a name="top"></a>

## Table of Contents

- [netmap/service.proto](#netmap/service.proto)
 - Services
    - [NetmapService](#neo.fs.v2.netmap.NetmapService)
    
  - Messages
    - [LocalNodeInfoRequest](#neo.fs.v2.netmap.LocalNodeInfoRequest)
    - [LocalNodeInfoRequest.Body](#neo.fs.v2.netmap.LocalNodeInfoRequest.Body)
    - [LocalNodeInfoResponse](#neo.fs.v2.netmap.LocalNodeInfoResponse)
    - [LocalNodeInfoResponse.Body](#neo.fs.v2.netmap.LocalNodeInfoResponse.Body)
    

- [netmap/types.proto](#netmap/types.proto)

  - Messages
    - [Filter](#neo.fs.v2.netmap.Filter)
    - [NodeInfo](#neo.fs.v2.netmap.NodeInfo)
    - [NodeInfo.Attribute](#neo.fs.v2.netmap.NodeInfo.Attribute)
    - [PlacementPolicy](#neo.fs.v2.netmap.PlacementPolicy)
    - [Replica](#neo.fs.v2.netmap.Replica)
    - [Selector](#neo.fs.v2.netmap.Selector)
    

- [Scalar Value Types](#scalar-value-types)



<a name="netmap/service.proto"></a>
<p align="right"><a href="#top">Top</a></p>

## netmap/service.proto




<a name="neo.fs.v2.netmap.NetmapService"></a>

### Service "neo.fs.v2.netmap.NetmapService"
`NetmapService` provides methods to work with `Network Map` and information
required to build it. The resulting `Network Map` is stored in sidechain
`Netmap` smart contract, while related information can be obtained from other
NeoFS nodes.

```
rpc LocalNodeInfo(LocalNodeInfoRequest) returns (LocalNodeInfoResponse);

```

#### Method LocalNodeInfo

Get NodeInfo structure from the particular node directly. Node information
can be taken from `Netmap` smart contract, but in some cases the one may
want to get recent information directly, or to talk to the node not yet
present in `Network Map` to find out what API version can be used for
further communication. Can also be used to check if node is up and running.

| Name | Input | Output |
| ---- | ----- | ------ |
| LocalNodeInfo | [LocalNodeInfoRequest](#neo.fs.v2.netmap.LocalNodeInfoRequest) | [LocalNodeInfoResponse](#neo.fs.v2.netmap.LocalNodeInfoResponse) |
 <!-- end services -->


<a name="neo.fs.v2.netmap.LocalNodeInfoRequest"></a>

### Message LocalNodeInfoRequest
Get NodeInfo structure from the particular node directly


| Field | Type | Label | Description |
| ----- | ---- | ----- | ----------- |
| body | [LocalNodeInfoRequest.Body](#neo.fs.v2.netmap.LocalNodeInfoRequest.Body) |  | Body of the LocalNodeInfo request message |
| meta_header | [neo.fs.v2.session.RequestMetaHeader](#neo.fs.v2.session.RequestMetaHeader) |  | Carries request meta information. Header data is used only to regulate message transport and does not affect request execution. |
| verify_header | [neo.fs.v2.session.RequestVerificationHeader](#neo.fs.v2.session.RequestVerificationHeader) |  | Carries request verification information. This header is used to authenticate the nodes of the message route and check the correctness of transmission. |


<a name="neo.fs.v2.netmap.LocalNodeInfoRequest.Body"></a>

### Message LocalNodeInfoRequest.Body
LocalNodeInfo request body is empty.



<a name="neo.fs.v2.netmap.LocalNodeInfoResponse"></a>

### Message LocalNodeInfoResponse
Local Node Info, including API Version in use


| Field | Type | Label | Description |
| ----- | ---- | ----- | ----------- |
| body | [LocalNodeInfoResponse.Body](#neo.fs.v2.netmap.LocalNodeInfoResponse.Body) |  | Body of the balance response message. |
| meta_header | [neo.fs.v2.session.ResponseMetaHeader](#neo.fs.v2.session.ResponseMetaHeader) |  | Carries response meta information. Header data is used only to regulate message transport and does not affect response execution. |
| verify_header | [neo.fs.v2.session.ResponseVerificationHeader](#neo.fs.v2.session.ResponseVerificationHeader) |  | Carries response verification information. This header is used to authenticate the nodes of the message route and check the correctness of transmission. |


<a name="neo.fs.v2.netmap.LocalNodeInfoResponse.Body"></a>

### Message LocalNodeInfoResponse.Body
Local Node Info, including API Version in use.


| Field | Type | Label | Description |
| ----- | ---- | ----- | ----------- |
| version | [neo.fs.v2.refs.Version](#neo.fs.v2.refs.Version) |  | Latest NeoFS API version in use |
| node_info | [NodeInfo](#neo.fs.v2.netmap.NodeInfo) |  | NodeInfo structure with recent information from node itself |

 <!-- end messages -->

 <!-- end enums -->



<a name="netmap/types.proto"></a>
<p align="right"><a href="#top">Top</a></p>

## netmap/types.proto


 <!-- end services -->


<a name="neo.fs.v2.netmap.Filter"></a>

### Message Filter
Filter will return the subset of nodes from `NetworkMap` or another filter's
results, that will satisfy filter's conditions.


| Field | Type | Label | Description |
| ----- | ---- | ----- | ----------- |
| name | [string](#string) |  | Name of the filter or a reference to the named filter. '*' means application to the whole unfiltered NetworkMap. At top level it's used as a filter name. At lower levels it's considered to be a reference to another named filter |
| key | [string](#string) |  | Key to filter |
| op | [Operation](#neo.fs.v2.netmap.Operation) |  | Filtering operation |
| value | [string](#string) |  | Value to match |
| filters | [Filter](#neo.fs.v2.netmap.Filter) | repeated | List of inner filters. Top level operation will be applied to the whole list. |


<a name="neo.fs.v2.netmap.NodeInfo"></a>

### Message NodeInfo
NeoFS node description


| Field | Type | Label | Description |
| ----- | ---- | ----- | ----------- |
| public_key | [bytes](#bytes) |  | Public key of the NeoFS node in a binary format. |
| address | [string](#string) |  | Ways to connect to a node |
| attributes | [NodeInfo.Attribute](#neo.fs.v2.netmap.NodeInfo.Attribute) | repeated | Carries list of the NeoFS node attributes in a key-value form. Key name must be a node-unique valid UTF-8 string. Value can't be empty. NodeInfo structures with duplicated attribute names or attributes with empty values will be considered invalid. |
| state | [NodeInfo.State](#neo.fs.v2.netmap.NodeInfo.State) |  | Carries state of the NeoFS node. |


<a name="neo.fs.v2.netmap.NodeInfo.Attribute"></a>

### Message NodeInfo.Attribute
Administrator-defined Attributes of the NeoFS Storage Node.

`Attribute` is a Key-Value metadata pair. Key name must be a valid UTF-8
string. Value can't be empty.

Node's attributes are mostly used during Storage Policy evaluation to
calculate object's placement and find a set of nodes satisfying policy
requirements. There are some "well-known" node attributes common to all the
Storage Nodes in the network and used implicitly with default values if not
explicitly set:

* Capacity \
  Total available disk space in Gigabytes.
* Price \
  Price in GAS tokens for storing one GB of data during one Epoch. In node
  attributes it's a string presenting floating point number with comma or
  point delimiter for decimal part. In the Network Map it will be saved as
  64-bit unsigned integer representing number of minimal token fractions.
* Subnet \
  String ID of Node's storage subnet. There can be only one subnet served
  by the Storage Node.
* Locode \
  Node's geographic location in
  [UN/LOCODE](https://www.unece.org/cefact/codesfortrade/codes_index.html)
  format approximated to the nearest point defined in standard.
* Country \
  Country code in
  [ISO 3166-1_alpha-2](https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2)
  format. Calculated automatically from `Locode` attribute
* Region \
  Country's administative subdivision where node is located. Calculated
  automatically from `Locode` attribute based on `SubDiv` field. Presented
  in [ISO 3166-2](https://en.wikipedia.org/wiki/ISO_3166-2) format.
* City \
  City, town, village or rural area name where node is located written
  without diacritics . Calculated automatically from `Locode` attribute.

For detailed description of each well-known attribute please see the
corresponding section in NeoFS Technical specification.


| Field | Type | Label | Description |
| ----- | ---- | ----- | ----------- |
| key | [string](#string) |  | Key of the node attribute. |
| value | [string](#string) |  | Value of the node attribute. |
| parents | [string](#string) | repeated | Parent keys, if any. For example for `City` it could be `Region` and `Country`. |


<a name="neo.fs.v2.netmap.PlacementPolicy"></a>

### Message PlacementPolicy
Set of rules to select a subset of nodes from `NetworkMap` able to store
container's objects. The format is simple enough to transpile from different
storage policy definition languages.


| Field | Type | Label | Description |
| ----- | ---- | ----- | ----------- |
| replicas | [Replica](#neo.fs.v2.netmap.Replica) | repeated | Rules to set number of object replicas and place each one into a named bucket |
| container_backup_factor | [uint32](#uint32) |  | Container backup factor controls how deep NeoFS will search for nodes alternatives to include into container's nodes subset |
| selectors | [Selector](#neo.fs.v2.netmap.Selector) | repeated | Set of Selectors to form the container's nodes subset |
| filters | [Filter](#neo.fs.v2.netmap.Filter) | repeated | List of named filters to reference in selectors |


<a name="neo.fs.v2.netmap.Replica"></a>

### Message Replica
Number of object replicas in a set of nodes from the defined selector. If no
selector set the root bucket containing all possible nodes will be used by
default.


| Field | Type | Label | Description |
| ----- | ---- | ----- | ----------- |
| count | [uint32](#uint32) |  | How many object replicas to put |
| selector | [string](#string) |  | Named selector bucket to put replicas |


<a name="neo.fs.v2.netmap.Selector"></a>

### Message Selector
Selector chooses a number of nodes from the bucket taking the nearest nodes
to the provided `ContainerID` by hash distance.


| Field | Type | Label | Description |
| ----- | ---- | ----- | ----------- |
| name | [string](#string) |  | Selector name to reference in object placement section |
| count | [uint32](#uint32) |  | How many nodes to select from the bucket |
| clause | [Clause](#neo.fs.v2.netmap.Clause) |  | Selector modifier showing how to form a bucket |
| attribute | [string](#string) |  | Attribute bucket to select from |
| filter | [string](#string) |  | Filter reference to select from |

 <!-- end messages -->


<a name="neo.fs.v2.netmap.Clause"></a>

### Clause
Selector modifier shows how the node set will be formed. By default selector
just groups nodes into a bucket by attribute, selecting nodes only by their
hash distance.

| Name | Number | Description |
| ---- | ------ | ----------- |
| CLAUSE_UNSPECIFIED | 0 | No modifier defined. Will select nodes from bucket randomly. |
| SAME | 1 | SAME will select only nodes having the same value of bucket attribute |
| DISTINCT | 2 | DISTINCT will select nodes having different values of bucket attribute |



<a name="neo.fs.v2.netmap.NodeInfo.State"></a>

### NodeInfo.State
Represents the enumeration of various states of the NeoFS node.

| Name | Number | Description |
| ---- | ------ | ----------- |
| UNSPECIFIED | 0 | Unknown state. |
| ONLINE | 1 | Active state in the network. |
| OFFLINE | 2 | Network unavailable state. |



<a name="neo.fs.v2.netmap.Operation"></a>

### Operation
Operations on filters

| Name | Number | Description |
| ---- | ------ | ----------- |
| OPERATION_UNSPECIFIED | 0 | No Operation defined |
| EQ | 1 | Equal |
| NE | 2 | Not Equal |
| GT | 3 | Greater then |
| GE | 4 | Greater or equal |
| LT | 5 | Less then |
| LE | 6 | Less or equal |
| OR | 7 | Logical OR |
| AND | 8 | Logical AND |


 <!-- end enums -->



## Scalar Value Types

| .proto Type | Notes | C++ Type | Java Type | Python Type |
| ----------- | ----- | -------- | --------- | ----------- |
| <a name="double" /> double |  | double | double | float |
| <a name="float" /> float |  | float | float | float |
| <a name="int32" /> int32 | Uses variable-length encoding. Inefficient for encoding negative numbers – if your field is likely to have negative values, use sint32 instead. | int32 | int | int |
| <a name="int64" /> int64 | Uses variable-length encoding. Inefficient for encoding negative numbers – if your field is likely to have negative values, use sint64 instead. | int64 | long | int/long |
| <a name="uint32" /> uint32 | Uses variable-length encoding. | uint32 | int | int/long |
| <a name="uint64" /> uint64 | Uses variable-length encoding. | uint64 | long | int/long |
| <a name="sint32" /> sint32 | Uses variable-length encoding. Signed int value. These more efficiently encode negative numbers than regular int32s. | int32 | int | int |
| <a name="sint64" /> sint64 | Uses variable-length encoding. Signed int value. These more efficiently encode negative numbers than regular int64s. | int64 | long | int/long |
| <a name="fixed32" /> fixed32 | Always four bytes. More efficient than uint32 if values are often greater than 2^28. | uint32 | int | int |
| <a name="fixed64" /> fixed64 | Always eight bytes. More efficient than uint64 if values are often greater than 2^56. | uint64 | long | int/long |
| <a name="sfixed32" /> sfixed32 | Always four bytes. | int32 | int | int |
| <a name="sfixed64" /> sfixed64 | Always eight bytes. | int64 | long | int/long |
| <a name="bool" /> bool |  | bool | boolean | boolean |
| <a name="string" /> string | A string must always contain UTF-8 encoded or 7-bit ASCII text. | string | String | str/unicode |
| <a name="bytes" /> bytes | May contain any arbitrary sequence of bytes. | string | ByteString | str |