RoutingRule class

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
• GeneratedMessage
• RoutingRule

Available extensions

• GeneratedMessageGenericExtensions

Constructors

RoutingRule.new({Iterable<RoutingParameter>? routingParameters})

factory

RoutingRule.fromBuffer(List<int> i, [ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY])

factory

RoutingRule.fromJson(String i, [ExtensionRegistry r = $pb.ExtensionRegistry.EMPTY])

factory

Properties

hashCode → int

Calculates a hash code based on the contents of the protobuf.

no setter, inherited

info_ → BuilderInfo

no setter, override

isFrozen → bool

Returns true if this message is marked read-only. Otherwise false.

no setter, inherited

routingParameters → PbList<RoutingParameter>

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.

no setter

runtimeType → Type

A representation of the runtime type of the object.

no setter, inherited

unknownFields → UnknownFieldSet

no setter, inherited

Methods

addExtension(Extension extension, Object? value) → void

Adds an extension field value to a repeated field.

inherited

check() → void

Throws a StateError if the message has required fields without a value.

inherited

clear() → void

Clears all data that was set in this message.

inherited

clearExtension(Extension extension) → void

Clears an extension field and also removes the extension.

inherited

clearField(int tagNumber) → void

Clears the contents of a given field.

inherited

clone() → RoutingRule

Creates a deep copy of the fields in this message. (The generated code uses mergeFromMessage.)

override

copyWith(void updates(RoutingRule)) → RoutingRule

Apply updates to a copy of this message.

override

createEmptyInstance() → RoutingRule

Creates an empty instance of the same message type as this.

override

deepCopy() → T

Available on T, provided by the GeneratedMessageGenericExtensions extension

Returns a writable deep copy of this message.

extensionsAreInitialized() → bool

inherited

freeze() → GeneratedMessage

Make this message read-only.

inherited

getDefaultForField(int tagNumber) → dynamic

Returns the default value for the given field.

inherited

getExtension(Extension extension) → dynamic

Returns the value of extension.

inherited

getField(int tagNumber) → dynamic

Returns the value of the field associated with tagNumber, or the default value if it is not set.

inherited

getFieldOrNull(int tagNumber) → dynamic

Returns the value of a field, ignoring any defaults.

inherited

getTagNumber(String fieldName) → int?

inherited

hasExtension(Extension extension) → bool

Returns true if a value of extension is present.

inherited

hasField(int tagNumber) → bool

Whether this message has a field associated with tagNumber.

inherited

hasRequiredFields() → bool

Whether the message has required fields.

inherited

isInitialized() → bool

Whether all required fields in the message and embedded messages are set.

inherited

mergeFromBuffer(List<int> input, [ExtensionRegistry extensionRegistry = ExtensionRegistry.EMPTY]) → void

Merges serialized protocol buffer data into this message.

inherited

mergeFromCodedBufferReader(CodedBufferReader input, [ExtensionRegistry extensionRegistry = ExtensionRegistry.EMPTY]) → void

Same as mergeFromBuffer, but takes a CodedBufferReader input.

inherited

mergeFromJson(String data, [ExtensionRegistry extensionRegistry = ExtensionRegistry.EMPTY]) → void

Merges field values from data, a JSON object, encoded as described by GeneratedMessage.writeToJson.

inherited

mergeFromJsonMap(Map<String, dynamic> json, [ExtensionRegistry extensionRegistry = ExtensionRegistry.EMPTY]) → void

Merges field values from a JSON object represented as a Dart map.

inherited

mergeFromMessage(GeneratedMessage other) → void

Merges the contents of the other into this message.

inherited

mergeFromProto3Json(Object? json, {TypeRegistry typeRegistry = const TypeRegistry.empty(), bool ignoreUnknownFields = false, bool supportNamesWithUnderscores = true, bool permissiveEnums = false}) → void

Merges field values from json, a JSON object using proto3 encoding.

inherited

mergeUnknownFields(UnknownFieldSet unknownFieldSet) → void

inherited

noSuchMethod(Invocation invocation) → dynamic

Invoked when a nonexistent method or property is accessed.

inherited

rebuild(void updates(T)) → T

Available on T, provided by the GeneratedMessageGenericExtensions extension

Apply updates to a copy of this message.

setExtension(Extension extension, Object value) → void

Sets the value of a non-repeated extension field to value.

inherited

setField(int tagNumber, Object value) → void

Sets the value of a field by its tagNumber.

inherited

toBuilder() → GeneratedMessage

Creates a writable, shallow copy of this message.

inherited

toDebugString() → String

Returns a String representation of this message.

inherited

toProto3Json({TypeRegistry typeRegistry = const TypeRegistry.empty()}) → Object?

Returns an Object representing Proto3 JSON serialization of this.

inherited

toString() → String

Returns a String representation of this message.

inherited

writeToBuffer() → Uint8List

Serialize the message as the protobuf binary format.

inherited

writeToCodedBufferWriter(CodedBufferWriter output) → void

Same as writeToBuffer, but serializes to the given CodedBufferWriter.

inherited

writeToJson() → String

Returns a JSON string that encodes this message.

inherited

writeToJsonMap() → Map<String, dynamic>

Returns the JSON encoding of this message as a Dart Map.

inherited

Operators

operator ==(Object other) → bool

The equality operator.

inherited

Static Methods

create() → RoutingRule

createRepeated() → PbList<RoutingRule>

getDefault() → RoutingRule