Class RoutingRule (2.10.0) 

public sealed class RoutingRule : IMessage<RoutingRule>, IEquatable<RoutingRule>, IDeepCloneable<RoutingRule>, IBufferMessage, IMessage

Specifies the routing information that should be sent along with the request in the form of routing header. NOTE: All service configuration rules follow the "last one wins" order.

The examples below will apply to an RPC which has the following request type:

Message Definition:

message Request {
  // The name of the Table
  // Values can be of the following formats:
  // - `projects/<project>/tables/<table>`
  // - `projects/<project>/instances/<instance>/tables/<table>`
  // - `region/<region>/zones/<zone>/tables/<table>`
  string table_name = 1;

  // This value specifies routing for replication.
  // It can be in the following formats:
  // - `profiles/<profile_id>`
  // - a legacy `profile_id` that can be any string
  string app_profile_id = 2;
}

Example message:

{
  table_name: projects/proj_foo/instances/instance_bar/table/table_baz,
  app_profile_id: profiles/prof_qux
}

The routing header consists of one or multiple key-value pairs. Every key and value must be percent-encoded, and joined together in the format of key1=value1&key2=value2. In the examples below I am skipping the percent-encoding for readablity.

Example 1

Extracting a field from the request to put into the routing header unchanged, with the key equal to the field name.

annotation:

option (google.api.routing) = {
  // Take the `app_profile_id`.
  routing_parameters {
    field: "app_profile_id"
  }
};

result:

x-goog-request-params: app_profile_id=profiles/prof_qux

Example 2

Extracting a field from the request to put into the routing header unchanged, with the key different from the field name.

annotation:

option (google.api.routing) = {
  // Take the `app_profile_id`, but name it `routing_id` in the header.
  routing_parameters {
    field: "app_profile_id"
    path_template: "{routing_id=**}"
  }
};

result:

x-goog-request-params: routing_id=profiles/prof_qux

Example 3

Extracting a field from the request to put into the routing header, while matching a path template syntax on the field's value.

NB: it is more useful to send nothing than to send garbage for the purpose of dynamic routing, since garbage pollutes cache. Thus the matching.

Sub-example 3a

The field matches the template.

annotation:

option (google.api.routing) = {
  // Take the `table_name`, if it's well-formed (with project-based
  // syntax).
  routing_parameters {
    field: "table_name"
    path_template: "{table_name=projects/*/instances/*/**}"
  }
};

result:

x-goog-request-params:
table_name=projects/proj_foo/instances/instance_bar/table/table_baz

Sub-example 3b

The field does not match the template.

annotation:

option (google.api.routing) = {
  // Take the `table_name`, if it's well-formed (with region-based
  // syntax).
  routing_parameters {
    field: "table_name"
    path_template: "{table_name=regions/*/zones/*/**}"
  }
};

result:

<no routing header will be sent>

Sub-example 3c

Multiple alternative conflictingly named path templates are specified. The one that matches is used to construct the header.

annotation:

option (google.api.routing) = {
  // Take the `table_name`, if it's well-formed, whether
  // using the region- or projects-based syntax.

  routing_parameters {
    field: "table_name"
    path_template: "{table_name=regions/*/zones/*/**}"
  }
  routing_parameters {
    field: "table_name"
    path_template: "{table_name=projects/*/instances/*/**}"
  }
};

result:

x-goog-request-params:
table_name=projects/proj_foo/instances/instance_bar/table/table_baz

Example 4

Extracting a single routing header key-value pair by matching a template syntax on (a part of) a single request field.

annotation:

option (google.api.routing) = {
  // Take just the project id from the `table_name` field.
  routing_parameters {
    field: "table_name"
    path_template: "{routing_id=projects/*}/**"
  }
};

result:

x-goog-request-params: routing_id=projects/proj_foo

Example 5

Extracting a single routing header key-value pair by matching several conflictingly named path templates on (parts of) a single request field. The last template to match "wins" the conflict.

annotation:

option (google.api.routing) = {
  // If the `table_name` does not have instances information,
  // take just the project id for routing.
  // Otherwise take project + instance.

  routing_parameters {
    field: "table_name"
    path_template: "{routing_id=projects/*}/**"
  }
  routing_parameters {
    field: "table_name"
    path_template: "{routing_id=projects/*/instances/*}/**"
  }
};

result:

x-goog-request-params:
routing_id=projects/proj_foo/instances/instance_bar

Example 6

Extracting multiple routing header key-value pairs by matching several non-conflicting path templates on (parts of) a single request field.

Sub-example 6a

Make the templates strict, so that if the table_name does not have an instance information, nothing is sent.

annotation:

option (google.api.routing) = {
  // The routing code needs two keys instead of one composite
  // but works only for the tables with the "project-instance" name
  // syntax.

  routing_parameters {
    field: "table_name"
    path_template: "{project_id=projects/*}/instances/*/**"
  }
  routing_parameters {
    field: "table_name"
    path_template: "projects/*/{instance_id=instances/*}/**"
  }
};

result:

x-goog-request-params:
project_id=projects/proj_foo&instance_id=instances/instance_bar

Sub-example 6b

Make the templates loose, so that if the table_name does not have an instance information, just the project id part is sent.

annotation:

option (google.api.routing) = {
  // The routing code wants two keys instead of one composite
  // but will work with just the `project_id` for tables without
  // an instance in the `table_name`.

  routing_parameters {
    field: "table_name"
    path_template: "{project_id=projects/*}/**"
  }
  routing_parameters {
    field: "table_name"
    path_template: "projects/*/{instance_id=instances/*}/**"
  }
};

result (is the same as 6a for our example message because it has the instance information):

x-goog-request-params:
project_id=projects/proj_foo&instance_id=instances/instance_bar

Example 7

Extracting multiple routing header key-value pairs by matching several path templates on multiple request fields.

NB: note that here there is no way to specify sending nothing if one of the fields does not match its template. E.g. if the table_name is in the wrong format, the project_id will not be sent, but the routing_id will be. The backend routing code has to be aware of that and be prepared to not receive a full complement of keys if it expects multiple.

annotation:

option (google.api.routing) = {
  // The routing needs both `project_id` and `routing_id`
  // (from the `app_profile_id` field) for routing.

  routing_parameters {
    field: "table_name"
    path_template: "{project_id=projects/*}/**"
  }
  routing_parameters {
    field: "app_profile_id"
    path_template: "{routing_id=**}"
  }
};

result:

x-goog-request-params:
project_id=projects/proj_foo&routing_id=profiles/prof_qux

Example 8

Extracting a single routing header key-value pair by matching several conflictingly named path templates on several request fields. The last template to match "wins" the conflict.

annotation:

option (google.api.routing) = {
  // The `routing_id` can be a project id or a region id depending on
  // the table name format, but only if the `app_profile_id` is not set.
  // If `app_profile_id` is set it should be used instead.

  routing_parameters {
    field: "table_name"
    path_template: "{routing_id=projects/*}/**"
  }
  routing_parameters {
     field: "table_name"
     path_template: "{routing_id=regions/*}/**"
  }
  routing_parameters {
    field: "app_profile_id"
    path_template: "{routing_id=**}"
  }
};

result:

x-goog-request-params: routing_id=profiles/prof_qux

Example 9

Bringing it all together.

annotation:

option (google.api.routing) = {
  // For routing both `table_location` and a `routing_id` are needed.
  //
  // table_location can be either an instance id or a region+zone id.
  //
  // For `routing_id`, take the value of `app_profile_id`
  // - If it's in the format `profiles/<profile_id>`, send
  // just the `<profile_id>` part.
  // - If it's any other literal, send it as is.
  // If the `app_profile_id` is empty, and the `table_name` starts with
  // the project_id, send that instead.

  routing_parameters {
    field: "table_name"
    path_template: "projects/*/{table_location=instances/*}/tables/*"
  }
  routing_parameters {
    field: "table_name"
    path_template: "{table_location=regions/*/zones/*}/tables/*"
  }
  routing_parameters {
    field: "table_name"
    path_template: "{routing_id=projects/*}/**"
  }
  routing_parameters {
    field: "app_profile_id"
    path_template: "{routing_id=**}"
  }
  routing_parameters {
    field: "app_profile_id"
    path_template: "profiles/{routing_id=*}"
  }
};

result:

x-goog-request-params:
table_location=instances/instance_bar&routing_id=prof_qux

Inheritance

object > RoutingRule

Namespace

Google.Api

Assembly

Google.Api.CommonProtos.dll

Constructors

RoutingRule()

public RoutingRule()

RoutingRule(RoutingRule)

public RoutingRule(RoutingRule other)
Parameter
Name Description
other RoutingRule

Fields

RoutingParametersFieldNumber

public const int RoutingParametersFieldNumber = 2

Field number for the "routing_parameters" field.

Field Value
Type Description
int

Properties

Descriptor

public static MessageDescriptor Descriptor { get; }
Property Value
Type Description
MessageDescriptor

Parser

public static MessageParser<RoutingRule> Parser { get; }
Property Value
Type Description
MessageParserRoutingRule

RoutingParameters

public RepeatedField<RoutingParameter> RoutingParameters { get; }

A collection of Routing Parameter specifications. NOTE: If multiple Routing Parameters describe the same key (via the path_template field or via the field field when path_template is not provided), "last one wins" rule determines which Parameter gets used. See the examples for more details.

Property Value
Type Description
RepeatedFieldRoutingParameter

Methods

CalculateSize()

public int CalculateSize()
Returns
Type Description
int

Clone()

public RoutingRule Clone()
Returns
Type Description
RoutingRule

Equals(RoutingRule)

public bool Equals(RoutingRule other)
Parameter
Name Description
other RoutingRule
Returns
Type Description
bool

Equals(object)

public override bool Equals(object other)
Parameter
Name Description
other object
Returns
Type Description
bool
Overrides

GetHashCode()

public override int GetHashCode()
Returns
Type Description
int
Overrides

MergeFrom(RoutingRule)

public void MergeFrom(RoutingRule other)
Parameter
Name Description
other RoutingRule

MergeFrom(CodedInputStream)

public void MergeFrom(CodedInputStream input)
Parameter
Name Description
input CodedInputStream

ToString()

public override string ToString()
Returns
Type Description
string
Overrides

WriteTo(CodedOutputStream)

public void WriteTo(CodedOutputStream output)
Parameter
Name Description
output CodedOutputStream