interpreter

Documentation

Overview

Package interpreter contains the GraphQL interpreter for EliasDB.

Index

• Constants
• Variables
• type DataSlice
  • func (d DataSlice) Len() int
  • func (d DataSlice) Less(i, j int) bool
  • func (d DataSlice) Swap(i, j int)
• type GraphQLRuntimeProvider
  • func NewGraphQLRuntimeProvider(name string, part string, gm *graph.Manager, op string, ...) *GraphQLRuntimeProvider
  • func (rtp *GraphQLRuntimeProvider) CheckWritePermission(path []string, node *parser.ASTNode) bool
  • func (rtp *GraphQLRuntimeProvider) FetchNode(part string, key string, kind string) (data.Node, error)
  • func (rtp *GraphQLRuntimeProvider) FetchNodePart(part string, key string, kind string, attrs []string) (data.Node, error)
  • func (rtp *GraphQLRuntimeProvider) InitSubscription(rt *documentRuntime)
  • func (rtp *GraphQLRuntimeProvider) Runtime(node *parser.ASTNode) parser.Runtime
  • func (rtp *GraphQLRuntimeProvider) TraverseAST(root *parser.ASTNode, visitor func(*parser.ASTNode))
• type QueryType
• type RuntimeError
  • func (re *RuntimeError) Error() string
• type SubscriptionCallbackHandler
• type SystemRuleGraphQLSubscriptions
  • func (r *SystemRuleGraphQLSubscriptions) AddHandler(handler *subscriptionHandler)
  • func (r *SystemRuleGraphQLSubscriptions) Handle(gm *graph.Manager, trans graph.Trans, event int, ed ...interface{}) error
  • func (r *SystemRuleGraphQLSubscriptions) Handles() []int
  • func (r *SystemRuleGraphQLSubscriptions) Name() string
  • func (r *SystemRuleGraphQLSubscriptions) RemoveHandler(handler *subscriptionHandler)

Constants

const (
	QueryTypeQuery        QueryType = "query"
	QueryTypeMutation               = "mutation"
	QueryTypeSubscription           = "subscription"
)

All known query types

const SystemRuleGraphQLSubscriptionsName = "system.graphqlsubscriptions"

SystemRuleGraphQLSubscriptionsName is the name of the graph manager rule which deals with subscriptions.

Variables

var (
	ErrInvalidConstruct    = errors.New("Invalid construct")
	ErrAmbiguousDefinition = errors.New("Ambiguous definition")
	ErrMissingOperation    = errors.New("Missing operation")
	ErrRuntimeError        = errors.New("Runtime error")
)

Runtime related error types

Types

type DataSlice

type DataSlice struct {
	// contains filtered or unexported fields
}

DataSlice attaches the methods of sort.Interface to []map[string]interface{}, sorting in ascending or descending order by a given attribute.

func (DataSlice) Len

func (d DataSlice) Len() int

Len belongs to the sort.Interface.

func (DataSlice) Less

func (d DataSlice) Less(i, j int) bool

Less belongs to the sort.Interface.

func (DataSlice) Swap

func (d DataSlice) Swap(i, j int)

Swap belongs to the sort.Interface.

type GraphQLRuntimeProvider

type GraphQLRuntimeProvider struct {
	Name           string                 // Name to identify the input
	QueryType      QueryType              // Query type (query, mutation, subscription)
	OperationName  string                 // Name of operation to execute
	VariableValues map[string]interface{} // Values of variables
	ErrorKeys      []string               // List of error hashes (used for deduplication)
	Errors         []*RuntimeError        // List of errors
	ErrorPaths     [][]string             // List of error paths
	// contains filtered or unexported fields
}

GraphQLRuntimeProvider defines the main interpreter datastructure and all functions for general evaluation.

func NewGraphQLRuntimeProvider

func NewGraphQLRuntimeProvider(name string, part string, gm *graph.Manager,
	op string, vars map[string]interface{}, callbackHandler SubscriptionCallbackHandler,
	readOnly bool) *GraphQLRuntimeProvider

NewGraphQLRuntimeProvider creates a new GraphQLRuntimeProvider object.

func (*GraphQLRuntimeProvider) CheckWritePermission

func (rtp *GraphQLRuntimeProvider) CheckWritePermission(path []string, node *parser.ASTNode) bool

CheckWritePermission checks if the current query is allowed to modify data. Returns true if data can be modified.

func (*GraphQLRuntimeProvider) FetchNode

func (rtp *GraphQLRuntimeProvider) FetchNode(part string, key string, kind string) (data.Node, error)

FetchNode intercepts a FetchNode call to the graph.Manager in order to subscribe to node updates if necessary.

func (*GraphQLRuntimeProvider) FetchNodePart

func (rtp *GraphQLRuntimeProvider) FetchNodePart(part string, key string, kind string, attrs []string) (data.Node, error)

FetchNodePart intercepts a FetchNodePart call to the graph.Manager in order to subscribe to node updates if necessary.

func (*GraphQLRuntimeProvider) InitSubscription

func (rtp *GraphQLRuntimeProvider) InitSubscription(rt *documentRuntime)

InitSubscription ensures that the current graph manager has a rule for subscriptions to monitor data changes and forwards events to the subscription callback handler.

func (*GraphQLRuntimeProvider) Runtime

func (rtp *GraphQLRuntimeProvider) Runtime(node *parser.ASTNode) parser.Runtime

Runtime returns a runtime component for a given ASTNode.

func (*GraphQLRuntimeProvider) TraverseAST

func (rtp *GraphQLRuntimeProvider) TraverseAST(root *parser.ASTNode,
	visitor func(*parser.ASTNode))

TraverseAST traverses the AST starting with a given root and executes a given visitor function on each node. An accumulator is given to track state. A path is given to track selection sets.

type QueryType

type QueryType string

QueryType is a know GraphQL query type

type RuntimeError

type RuntimeError struct {
	Source          string                  // Name of the source which was given to the parser
	Type            error                   // Error type (to be used for equal checks)
	Detail          string                  // Details of this error
	Node            *parser.ASTNode         // AST Node where the error occurred
	Line            int                     // Line of the error
	Pos             int                     // Position of the error
	IsFatal         bool                    // Is a fatal error which should stop the whole operation
	RuntimeProvider *GraphQLRuntimeProvider // Runtime provider which produced this error
}

RuntimeError is a runtime related error

func (*RuntimeError) Error

func (re *RuntimeError) Error() string

Error returns a human-readable string representation of this error.

type SubscriptionCallbackHandler

type SubscriptionCallbackHandler interface {

	/*
		Publish is called for every event in the source stream of a subscription.
		This function should map the source stream event to a response stream event.
	*/
	Publish(map[string]interface{}, error)

	/*
	   IsFinished should return true if this handler should no longer
	   receive events.
	*/
	IsFinished() bool
}

SubscriptionCallbackHandler receives source stream events for a subscription.

type SystemRuleGraphQLSubscriptions

type SystemRuleGraphQLSubscriptions struct {
	ID string // Unique ID which identifies the rule
	// contains filtered or unexported fields
}

SystemRuleGraphQLSubscriptions is a system rule to propagate state changes in the datastore to all relevant GraphQL subscriptions.

func (*SystemRuleGraphQLSubscriptions) AddHandler

func (r *SystemRuleGraphQLSubscriptions) AddHandler(handler *subscriptionHandler)

AddHandler adds a new handler for rule events.

func (*SystemRuleGraphQLSubscriptions) Handle

func (r *SystemRuleGraphQLSubscriptions) Handle(gm *graph.Manager, trans graph.Trans, event int, ed ...interface{}) error

Handle handles an event.

func (*SystemRuleGraphQLSubscriptions) Handles

func (r *SystemRuleGraphQLSubscriptions) Handles() []int

Handles returns a list of events which are handled by this rule.

func (*SystemRuleGraphQLSubscriptions) Name

func (r *SystemRuleGraphQLSubscriptions) Name() string

Name returns the name of the rule.

func (*SystemRuleGraphQLSubscriptions) RemoveHandler

func (r *SystemRuleGraphQLSubscriptions) RemoveHandler(handler *subscriptionHandler)

RemoveHandler removes a handler from receiving further rule events.