xref: /external/icing/proto/icing/proto/schema.proto

// Copyright 2019 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

syntax = "proto2";

package icing.lib;

import "icing/proto/status.proto";
import "icing/proto/term.proto";

option java_package = "com.google.android.icing.proto";
option java_multiple_files = true;
option objc_class_prefix = "ICNG";

// Defines the schema that every Document of a specific "type" should adhere
// to. These can be considered as definitions of rich structured types for
// Documents accepted by IcingSearchEngine.
//
// NOTE: Instances of SchemaTypeConfigProto are strongly recommended to be
// based on types defined in schema.org. This makes the data/config/code more
// shareable and easier to extend in the future.
//
// TODO(cassiewang) Define a sample proto file that can be used by tests and for
// documentation.
//
// Next tag: 6
message SchemaTypeConfigProto {
  // REQUIRED: Named type that uniquely identifies the structured, logical
  // schema being defined.
  //
  // Recommended format: Human readable string that's one of the types defined
  // in http://schema.org. Eg: DigitalDocument, Message, Person, etc.
  optional string schema_type = 1;

  // List of all properties that are supported by Documents of this type.
  // An Document should never have properties that are not listed here.
  //
  // TODO(cassiewang) Figure out if we should disallow, ignore or accept
  // unknown properties. Accepting them could make switching between versions
  // easier.
  repeated PropertyConfigProto properties = 4;

  // Version is an arbitrary number that the client may use to keep track of
  // different incarnations of the schema. Icing library imposes no requirements
  // on this field and will not validate it in anyway. If a client calls
  // SetSchema with a schema that contains one or more new version numbers, then
  // those version numbers will be updated so long as the SetSchema call
  // succeeds. Clients are free to leave the version number unset, in which case
  // it will default to value == 0.
  optional int32 version = 5;

  reserved 2, 3;
}

// Describes how a string property should be indexed.
// Next tag: 3
message StringIndexingConfig {
  // Indicates how the content of this property should be matched in the index.
  //
  // TermMatchType.Code=UNKNOWN
  // Content in this property will not be tokenized or indexed. Useful if the
  // data type is not indexable. See schema-util for details.
  //
  // TermMatchType.Code=EXACT_ONLY
  // Content in this property should only be returned for queries matching the
  // exact tokens appearing in this property.
  // Ex. A property with "fool" should NOT match a query for "foo".
  //
  // TermMatchType.Code=PREFIX
  // Content in this property should be returned for queries that are either
  // exact matches or query matches of the tokens appearing in this property.
  // Ex. A property with "fool" *should* match a query for "foo".
  optional TermMatchType.Code term_match_type = 1;

  message TokenizerType {
    enum Code {
      // It is only valid for tokenizer_type to be 'NONE' if the data type is
      // not indexed.
      NONE = 0;

      // Tokenization for plain text.
      PLAIN = 1;
    }
  }
  optional TokenizerType.Code tokenizer_type = 2;
}

// Describes how a document property should be indexed.
// Next tag: 2
message DocumentIndexingConfig {
  // OPTIONAL: Whether nested properties within the document property should be
  // indexed. If true, then the nested properties will be indexed according to
  // the property's own indexing configurations. If false, nested documents'
  // properties will not be indexed even if they have an indexing configuration.
  //
  // The default value is false.
  optional bool index_nested_properties = 1;
}

// Describes the schema of a single property of Documents that belong to a
// specific SchemaTypeConfigProto. These can be considered as a rich, structured
// type for each property of Documents accepted by IcingSearchEngine.
// Next tag: 7
message PropertyConfigProto {
  // REQUIRED: Name that uniquely identifies a property within an Document of
  // a specific SchemaTypeConfigProto.
  //
  // Recommended format: Human readable string that's one of the properties
  // defined in schema.org for the parent SchemaTypeConfigProto.
  // Eg: 'author' for http://schema.org/DigitalDocument.
  // Eg: 'address' for http://schema.org/Place.
  optional string property_name = 1;

  // REQUIRED: Physical data-types of the contents of the property.
  message DataType {
    enum Code {
      // This value should never purposely be used. This is used for backwards
      // compatibility reasons.
      UNKNOWN = 0;

      STRING = 1;
      INT64 = 2;
      DOUBLE = 3;
      BOOLEAN = 4;

      // Unstructured BLOB.
      BYTES = 5;

      // Indicates that the property itself is an Document, making it part
      // a hierarchical Document schema. Any property using this data_type
      // MUST have a valid 'schema_type'.
      DOCUMENT = 6;
    }
  }
  optional DataType.Code data_type = 2;

  // REQUIRED if (data_type == DOCUMENT). OPTIONAL otherwise.
  // Indicates the logical schema-type of the contents of this property.
  //
  // TODO(cassiewang): This could be useful for non-document properties, e.g.
  // to set this field as a schema.org/address for some string property.
  // Re-evaluate what recommendation we should give clients if we want to start
  // using this for non-document properties as well.
  //
  // Recommended format: Human readable string that is one of the types defined
  // in schema.org, matching the SchemaTypeConfigProto.schema_type of another
  // type.
  optional string schema_type = 3;

  // REQUIRED: The cardinality of the property.
  message Cardinality {
    // NOTE: The order of the cardinality is purposefully set to be from least
    // restrictive (REPEATED) to most restrictive (REQUIRED). This makes it
    // easier to check if a field is backwards compatible by doing a simple
    // greater-than/less-than check on the enum ints. Changing/adding new
    // cardinalities should be done cautiously.
    enum Code {
      // This should never purposely be set. This is used for backwards
      // compatibility reasons.
      UNKNOWN = 0;

      // Any number of items (including zero) [0...*].
      REPEATED = 1;

      // Zero or one value [0,1].
      OPTIONAL = 2;

      // Exactly one value [1].
      REQUIRED = 3;
    }
  }
  optional Cardinality.Code cardinality = 4;

  // OPTIONAL: Describes how string properties should be indexed. String
  // properties that do not set the indexing config will not be indexed.
  optional StringIndexingConfig string_indexing_config = 5;

  // OPTIONAL: Describes how document properties should be indexed.
  optional DocumentIndexingConfig document_indexing_config = 6;
}

// List of all supported types constitutes the schema used by Icing.
// Next tag: 2
message SchemaProto {
  repeated SchemaTypeConfigProto types = 1;
}

// Result of a call to IcingSearchEngine.SetSchema
// Next tag: 4
message SetSchemaResultProto {
  // Status code can be one of:
  //   OK
  //   INVALID_ARGUMENT
  //   FAILED_PRECONDITION
  //   INTERNAL
  //
  // See status.proto for more details.
  //
  // TODO(b/147699081): Fix error codes: +ABORTED, +WARNING_DATA_LOSS,
  // -INTERNAL. go/icing-library-apis.
  optional StatusProto status = 1;

  // Schema types that existed in the previous schema, but were deleted from the
  // new schema. If ignore_errors_and_delete_documents=true, then all documents
  // of these types were also deleted.
  repeated string deleted_schema_types = 2;

  // Schema types that existed in the previous schema and were incompatible with
  // the new schema type. If ignore_errors_and_delete_documents=true, then any
  // documents that fail validation against the new schema types would also be
  // deleted.
  repeated string incompatible_schema_types = 3;
}

// Result of a call to IcingSearchEngine.GetSchema
// Next tag: 3
message GetSchemaResultProto {
  // Status code can be one of:
  //   OK
  //   FAILED_PRECONDITION
  //   NOT_FOUND
  //   INTERNAL
  //
  // See status.proto for more details.
  //
  // TODO(b/147699081): Fix error codes: +ABORTED, -INTERNAL
  // go/icing-library-apis.
  optional StatusProto status = 1;

  // Copy of the Schema proto. Modifying this does not affect the Schema that
  // IcingSearchEngine holds.
  optional SchemaProto schema = 2;
}

// Result of a call to IcingSearchEngine.GetSchemaType
// Next tag: 3
message GetSchemaTypeResultProto {
  // Status code can be one of:
  //   OK
  //   FAILED_PRECONDITION
  //   NOT_FOUND
  //   INTERNAL
  //
  // See status.proto for more details.
  //
  // TODO(b/147699081): Fix error codes: +ABORTED, -INTERNAL
  // go/icing-library-apis.
  optional StatusProto status = 1;

  // Copy of the SchemaTypeConfig proto with the specified schema_type.
  // Modifying this does not affect the SchemaTypeConfig that IcingSearchEngine
  // holds.
  optional SchemaTypeConfigProto schema_type_config = 2;
}