github.com/weaviate/weaviate@v1.24.6/adapters/handlers/graphql/schema.go (about)

     1  //                           _       _
     2  // __      _____  __ ___   ___  __ _| |_ ___
     3  // \ \ /\ / / _ \/ _` \ \ / / |/ _` | __/ _ \
     4  //  \ V  V /  __/ (_| |\ V /| | (_| | ||  __/
     5  //   \_/\_/ \___|\__,_| \_/ |_|\__,_|\__\___|
     6  //
     7  //  Copyright © 2016 - 2024 Weaviate B.V. All rights reserved.
     8  //
     9  //  CONTACT: hello@weaviate.io
    10  //
    11  
    12  // Package graphql provides the graphql endpoint for Weaviate
    13  package graphql
    14  
    15  import (
    16  	"context"
    17  	"fmt"
    18  	"runtime/debug"
    19  
    20  	"github.com/sirupsen/logrus"
    21  	"github.com/tailor-inc/graphql"
    22  	"github.com/weaviate/weaviate/adapters/handlers/graphql/local"
    23  	"github.com/weaviate/weaviate/adapters/handlers/graphql/local/get"
    24  	"github.com/weaviate/weaviate/entities/schema"
    25  	"github.com/weaviate/weaviate/usecases/config"
    26  	"github.com/weaviate/weaviate/usecases/modules"
    27  )
    28  
    29  type Traverser interface {
    30  	local.Resolver
    31  }
    32  
    33  type RequestsLogger interface {
    34  	get.RequestsLog
    35  }
    36  
    37  // The communication interface between the REST API and the GraphQL API.
    38  type GraphQL interface {
    39  	// Resolve the GraphQL query in 'query'.
    40  	Resolve(context context.Context, query string, operationName string, variables map[string]interface{}) *graphql.Result
    41  }
    42  
    43  type graphQL struct {
    44  	schema    graphql.Schema
    45  	traverser Traverser
    46  	config    config.Config
    47  }
    48  
    49  // Construct a GraphQL API from the database schema, and resolver interface.
    50  func Build(schema *schema.Schema, traverser Traverser,
    51  	logger logrus.FieldLogger, config config.Config, modulesProvider *modules.Provider,
    52  ) (GraphQL, error) {
    53  	logger.WithField("action", "graphql_rebuild").
    54  		WithField("schema", schema).
    55  		Debug("rebuilding the graphql schema")
    56  
    57  	graphqlSchema, err := buildGraphqlSchema(schema, logger, config, modulesProvider)
    58  	if err != nil {
    59  		return nil, err
    60  	}
    61  
    62  	return &graphQL{
    63  		schema:    graphqlSchema,
    64  		traverser: traverser,
    65  		config:    config,
    66  	}, nil
    67  }
    68  
    69  // Resolve at query time
    70  func (g *graphQL) Resolve(context context.Context, query string, operationName string, variables map[string]interface{}) *graphql.Result {
    71  	return graphql.Do(graphql.Params{
    72  		Schema: g.schema,
    73  		RootObject: map[string]interface{}{
    74  			"Resolver": g.traverser,
    75  			"Config":   g.config,
    76  		},
    77  		RequestString:  query,
    78  		OperationName:  operationName,
    79  		VariableValues: variables,
    80  		Context:        context,
    81  	})
    82  }
    83  
    84  func buildGraphqlSchema(dbSchema *schema.Schema, logger logrus.FieldLogger,
    85  	config config.Config, modulesProvider *modules.Provider,
    86  ) (graphql.Schema, error) {
    87  	localSchema, err := local.Build(dbSchema, logger, config, modulesProvider)
    88  	if err != nil {
    89  		return graphql.Schema{}, err
    90  	}
    91  
    92  	schemaObject := graphql.ObjectConfig{
    93  		Name:        "WeaviateObj",
    94  		Description: "Location of the root query",
    95  		Fields:      localSchema,
    96  	}
    97  
    98  	// Run graphql.NewSchema in a sub-closure, so that we can recover from panics.
    99  	// We need to use panics to return errors deep inside the dynamic generation of the GraphQL schema,
   100  	// inside the FieldThunks. There is _no_ way to bubble up an error besides panicking.
   101  	var result graphql.Schema
   102  	func() {
   103  		defer func() {
   104  			if r := recover(); r != nil {
   105  				err = fmt.Errorf("%v at %s", r, debug.Stack())
   106  			}
   107  		}()
   108  
   109  		result, err = graphql.NewSchema(graphql.SchemaConfig{
   110  			Query: graphql.NewObject(schemaObject),
   111  		})
   112  	}()
   113  
   114  	if err != nil {
   115  		return graphql.Schema{}, fmt.Errorf("Could not build GraphQL schema, because: %v", err)
   116  	}
   117  
   118  	return result, nil
   119  }