backend/helpers/pluginhelper/api/graphql_async_client.go - devlake - Git at Google

 /*
 Licensed to the Apache Software Foundation (ASF) under one or more
 contributor license agreements.  See the NOTICE file distributed with
 this work for additional information regarding copyright ownership.
 The ASF licenses this file to You 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.
 */

 package api

 import (
 	"context"
 	"fmt"
 	"strconv"
 	"sync"
 	"time"

 	"github.com/apache/incubator-devlake/core/errors"
 	"github.com/apache/incubator-devlake/core/log"
 	"github.com/apache/incubator-devlake/core/plugin"
 	"github.com/apache/incubator-devlake/core/utils"

 	"github.com/merico-ai/graphql"
 )

 // GraphqlAsyncClient send graphql one by one
 type GraphqlAsyncClient struct {
 	ctx       context.Context
 	cancel    context.CancelFunc
 	client    *graphql.Client
 	logger    log.Logger
 	mu        sync.Mutex
 	waitGroup sync.WaitGroup

 	maxRetry         int
 	waitBeforeRetry  time.Duration
 	rateExhaustCond  *sync.Cond
 	rateRemaining    int
 	getRateRemaining func(context.Context, *graphql.Client, log.Logger) (rateRemaining int, resetAt *time.Time, err errors.Error)
 	getRateCost      func(q interface{}) int
 }

 // defaultRateLimitConst is the generic fallback rate limit for GraphQL requests.
 // It is used as the initial remaining quota when dynamic rate limit
 // information is unavailable from the provider.
 const defaultRateLimitConst = 1000

 // CreateAsyncGraphqlClient creates a new GraphqlAsyncClient
 func CreateAsyncGraphqlClient(
 	taskCtx plugin.TaskContext,
 	graphqlClient *graphql.Client,
 	logger log.Logger,
 	getRateRemaining func(context.Context, *graphql.Client, log.Logger) (rateRemaining int, resetAt *time.Time, err errors.Error),
 	opts ...func(*GraphqlAsyncClient),
 ) (*GraphqlAsyncClient, errors.Error) {
 	ctxWithCancel, cancel := context.WithCancel(taskCtx.GetContext())

 	graphqlAsyncClient := &GraphqlAsyncClient{
 		ctx:              ctxWithCancel,
 		cancel:           cancel,
 		client:           graphqlClient,
 		logger:           logger,
 		rateExhaustCond:  sync.NewCond(&sync.Mutex{}),
 		rateRemaining:    defaultRateLimitConst,
 		getRateRemaining: getRateRemaining,
 	}

 	// apply options
 	for _, opt := range opts {
 		opt(graphqlAsyncClient)
 	}

 	// Env config wins over everything, only if explicitly set
 	if rateLimit := resolveRateLimit(taskCtx, logger); rateLimit != -1 {
 		logger.Info("GRAPHQL_RATE_LIMIT env override applied: %d (was %d)", rateLimit, graphqlAsyncClient.rateRemaining)
 		graphqlAsyncClient.rateRemaining = rateLimit
 	}

 	if getRateRemaining != nil {
 		rateRemaining, resetAt, err := getRateRemaining(taskCtx.GetContext(), graphqlClient, logger)
 		if err != nil {
 			graphqlAsyncClient.logger.Info("failed to fetch initial graphql rate limit, fallback to default: %v", err)
 			graphqlAsyncClient.updateRateRemaining(graphqlAsyncClient.rateRemaining, nil)
 		} else {
 			graphqlAsyncClient.updateRateRemaining(rateRemaining, resetAt)
 		}
 	} else {
 		graphqlAsyncClient.updateRateRemaining(graphqlAsyncClient.rateRemaining, nil)
 	}

 	// load retry/timeout from configuration
 	// use API_RETRY as max retry time
 	// use API_TIMEOUT as retry before wait seconds to confirm the prev request finish
 	timeout := 30 * time.Second
 	retry, err := utils.StrToIntOr(taskCtx.GetConfig("API_RETRY"), 3)
 	if err != nil {
 		return nil, errors.BadInput.Wrap(err, "failed to parse API_RETRY")
 	}
 	timeoutConf := taskCtx.GetConfig("API_TIMEOUT")
 	if timeoutConf != "" {
 		// override timeout value if API_TIMEOUT is provided
 		timeout, err = errors.Convert01(time.ParseDuration(timeoutConf))
 		if err != nil {
 			return nil, errors.BadInput.Wrap(err, "failed to parse API_TIMEOUT")
 		}
 	}
 	graphqlAsyncClient.SetMaxRetry(retry, timeout)

 	return graphqlAsyncClient, nil
 }

 // GetMaxRetry returns the maximum retry attempts for a request
 func (apiClient *GraphqlAsyncClient) GetMaxRetry() (int, time.Duration) {
 	return apiClient.maxRetry, apiClient.waitBeforeRetry
 }

 // SetMaxRetry sets the maximum retry attempts for a request
 func (apiClient *GraphqlAsyncClient) SetMaxRetry(
 	maxRetry int,
 	waitBeforeRetry time.Duration,
 ) {
 	apiClient.maxRetry = maxRetry
 	apiClient.waitBeforeRetry = waitBeforeRetry
 }

 // updateRateRemaining call getRateRemaining to update rateRemaining periodically
 func (apiClient *GraphqlAsyncClient) updateRateRemaining(rateRemaining int, resetAt *time.Time) {
 	apiClient.rateRemaining = rateRemaining
 	if rateRemaining > 0 {
 		apiClient.rateExhaustCond.Signal()
 	}
 	go func() {
 		if apiClient.getRateRemaining == nil {
 			return
 		}

 		nextDuring := 3 * time.Minute
 		if resetAt != nil && resetAt.After(time.Now()) {
 			nextDuring = time.Until(*resetAt)
 		}
 		select {
 		case <-apiClient.ctx.Done():
 			// finish go routine when context done
 			return
 		case <-time.After(nextDuring):
 			newRateRemaining, newResetAt, err := apiClient.getRateRemaining(apiClient.ctx, apiClient.client, apiClient.logger)
 			if err != nil {
 				apiClient.logger.Info("failed to update graphql rate limit, will retry next cycle: %v", err)
 				// Floor the reused value so Signal() always fires; prevents deadlock when
 				// rateRemaining is 0 and the rate-limit endpoint keeps erroring (e.g. GHE).
 				fallback := apiClient.rateRemaining
 				if fallback < defaultRateLimitConst {
 					fallback = defaultRateLimitConst
 				}
 				apiClient.updateRateRemaining(fallback, nil)
 				return
 			}
 			apiClient.updateRateRemaining(newRateRemaining, newResetAt)
 		}
 	}()
 }

 // SetGetRateCost to calculate how many rate cost
 // if not set, all query just cost 1
 func (apiClient *GraphqlAsyncClient) SetGetRateCost(getRateCost func(q interface{}) int) {
 	apiClient.getRateCost = getRateCost
 }

 // Query send a graphql request when get lock
 // []graphql.DataError are the errors returned in response body
 // errors.Error is other error
 func (apiClient *GraphqlAsyncClient) Query(q interface{}, variables map[string]interface{}) ([]graphql.DataError, error) {
 	apiClient.waitGroup.Add(1)
 	defer apiClient.waitGroup.Done()
 	apiClient.mu.Lock()
 	defer apiClient.mu.Unlock()

 	apiClient.rateExhaustCond.L.Lock()
 	defer apiClient.rateExhaustCond.L.Unlock()
 	for apiClient.rateRemaining <= 0 {
 		apiClient.logger.Info(`rate limit remaining exhausted, waiting for next period.`)
 		apiClient.rateExhaustCond.Wait()
 	}

 	retryTime := 0
 	var err error
 	//  if it needs retry, check and retry
 	for retryTime < apiClient.maxRetry {
 		select {
 		case <-apiClient.ctx.Done():
 			return nil, nil
 		default:
 			var dataErrors []graphql.DataError
 			dataErrors, err := apiClient.client.Query(apiClient.ctx, q, variables)
 			if err == context.Canceled {
 				return nil, err
 			}
 			if err != nil {
 				apiClient.logger.Warn(err, "retry #%d graphql calling after %ds", retryTime, apiClient.waitBeforeRetry/time.Second)
 				retryTime++
 				<-time.After(apiClient.waitBeforeRetry)
 				continue
 			}
 			if dataErrors != nil {
 				return dataErrors, nil
 			}
 			cost := 1
 			if apiClient.getRateCost != nil {
 				cost = apiClient.getRateCost(q)
 			}
 			apiClient.rateRemaining -= cost
 			apiClient.logger.Debug(`query cost %d in %v`, cost, variables)
 			return nil, nil
 		}
 	}
 	return nil, errors.Default.Wrap(err, fmt.Sprintf("got error when querying GraphQL (from the %dth retry)", retryTime))
 }

 // NextTick to return the NextTick of scheduler
 func (apiClient *GraphqlAsyncClient) NextTick(task func() errors.Error, taskErrorChecker func(err error)) {
 	// to make sure task will be enqueued
 	apiClient.waitGroup.Add(1)
 	go func() {
 		select {
 		case <-apiClient.ctx.Done():
 			return
 		default:
 			go func() {
 				// if set waitGroup done here, a serial of goroutine will block until sub-goroutine finish.
 				// But if done out of this go func, so task will run after waitGroup finish
 				// I have no idea about this now...
 				defer apiClient.waitGroup.Done()
 				taskErrorChecker(task())
 			}()
 		}
 	}()
 }

 // Wait blocks until all async requests were done
 func (apiClient *GraphqlAsyncClient) Wait() {
 	apiClient.waitGroup.Wait()
 }

 // Release will release the ApiAsyncClient with scheduler
 func (apiClient *GraphqlAsyncClient) Release() {
 	apiClient.cancel()
 }

 // WithFallbackRateLimit sets the initial/fallback rate limit used when
 // rate limit information cannot be fetched dynamically.
 // This value may be overridden later by getRateRemaining.
 func WithFallbackRateLimit(limit int) func(*GraphqlAsyncClient) {
 	return func(c *GraphqlAsyncClient) {
 		if limit > 0 {
 			c.rateRemaining = limit
 		}
 	}
 }

 // resolveRateLimit returns -1 if GRAPHQL_RATE_LIMIT is not set or invalid
 func resolveRateLimit(taskCtx plugin.TaskContext, logger log.Logger) int {
 	if v := taskCtx.GetConfig("GRAPHQL_RATE_LIMIT"); v != "" {
 		if parsed, err := strconv.Atoi(v); err == nil {
 			return parsed
 		}
 		logger.Warn(nil, "invalid GRAPHQL_RATE_LIMIT, using default")
 	}
 	return -1
 }
	/*
	Licensed to the Apache Software Foundation (ASF) under one or more
	contributor license agreements. See the NOTICE file distributed with
	this work for additional information regarding copyright ownership.
	The ASF licenses this file to You 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.
	*/

	package api

	import (
	"context"
	"fmt"
	"strconv"
	"sync"
	"time"

	"github.com/apache/incubator-devlake/core/errors"
	"github.com/apache/incubator-devlake/core/log"
	"github.com/apache/incubator-devlake/core/plugin"
	"github.com/apache/incubator-devlake/core/utils"

	"github.com/merico-ai/graphql"
	)

	// GraphqlAsyncClient send graphql one by one
	type GraphqlAsyncClient struct {
	ctx context.Context
	cancel context.CancelFunc
	client *graphql.Client
	logger log.Logger
	mu sync.Mutex
	waitGroup sync.WaitGroup

	maxRetry int
	waitBeforeRetry time.Duration
	rateExhaustCond *sync.Cond
	rateRemaining int
	getRateRemaining func(context.Context, graphql.Client, log.Logger) (rateRemaining int, resetAt time.Time, err errors.Error)
	getRateCost func(q interface{}) int
	}

	// defaultRateLimitConst is the generic fallback rate limit for GraphQL requests.
	// It is used as the initial remaining quota when dynamic rate limit
	// information is unavailable from the provider.
	const defaultRateLimitConst = 1000

	// CreateAsyncGraphqlClient creates a new GraphqlAsyncClient
	func CreateAsyncGraphqlClient(
	taskCtx plugin.TaskContext,
	graphqlClient *graphql.Client,
	logger log.Logger,
	getRateRemaining func(context.Context, graphql.Client, log.Logger) (rateRemaining int, resetAt time.Time, err errors.Error),
	opts ...func(*GraphqlAsyncClient),
	) (*GraphqlAsyncClient, errors.Error) {
	ctxWithCancel, cancel := context.WithCancel(taskCtx.GetContext())

	graphqlAsyncClient := &GraphqlAsyncClient{
	ctx: ctxWithCancel,
	cancel: cancel,
	client: graphqlClient,
	logger: logger,
	rateExhaustCond: sync.NewCond(&sync.Mutex{}),
	rateRemaining: defaultRateLimitConst,
	getRateRemaining: getRateRemaining,
	}

	// apply options
	for _, opt := range opts {
	opt(graphqlAsyncClient)
	}

	// Env config wins over everything, only if explicitly set
	if rateLimit := resolveRateLimit(taskCtx, logger); rateLimit != -1 {
	logger.Info("GRAPHQL_RATE_LIMIT env override applied: %d (was %d)", rateLimit, graphqlAsyncClient.rateRemaining)
	graphqlAsyncClient.rateRemaining = rateLimit
	}

	if getRateRemaining != nil {
	rateRemaining, resetAt, err := getRateRemaining(taskCtx.GetContext(), graphqlClient, logger)
	if err != nil {
	graphqlAsyncClient.logger.Info("failed to fetch initial graphql rate limit, fallback to default: %v", err)
	graphqlAsyncClient.updateRateRemaining(graphqlAsyncClient.rateRemaining, nil)
	} else {
	graphqlAsyncClient.updateRateRemaining(rateRemaining, resetAt)
	}
	} else {
	graphqlAsyncClient.updateRateRemaining(graphqlAsyncClient.rateRemaining, nil)
	}

	// load retry/timeout from configuration
	// use API_RETRY as max retry time
	// use API_TIMEOUT as retry before wait seconds to confirm the prev request finish
	timeout := 30 * time.Second
	retry, err := utils.StrToIntOr(taskCtx.GetConfig("API_RETRY"), 3)
	if err != nil {
	return nil, errors.BadInput.Wrap(err, "failed to parse API_RETRY")
	}
	timeoutConf := taskCtx.GetConfig("API_TIMEOUT")
	if timeoutConf != "" {
	// override timeout value if API_TIMEOUT is provided
	timeout, err = errors.Convert01(time.ParseDuration(timeoutConf))
	if err != nil {
	return nil, errors.BadInput.Wrap(err, "failed to parse API_TIMEOUT")
	}
	}
	graphqlAsyncClient.SetMaxRetry(retry, timeout)

	return graphqlAsyncClient, nil
	}

	// GetMaxRetry returns the maximum retry attempts for a request
	func (apiClient *GraphqlAsyncClient) GetMaxRetry() (int, time.Duration) {
	return apiClient.maxRetry, apiClient.waitBeforeRetry
	}

	// SetMaxRetry sets the maximum retry attempts for a request
	func (apiClient *GraphqlAsyncClient) SetMaxRetry(
	maxRetry int,
	waitBeforeRetry time.Duration,
	) {
	apiClient.maxRetry = maxRetry
	apiClient.waitBeforeRetry = waitBeforeRetry
	}

	// updateRateRemaining call getRateRemaining to update rateRemaining periodically
	func (apiClient GraphqlAsyncClient) updateRateRemaining(rateRemaining int, resetAt time.Time) {
	apiClient.rateRemaining = rateRemaining
	if rateRemaining > 0 {
	apiClient.rateExhaustCond.Signal()
	}
	go func() {
	if apiClient.getRateRemaining == nil {
	return
	}

	nextDuring := 3 * time.Minute
	if resetAt != nil && resetAt.After(time.Now()) {
	nextDuring = time.Until(*resetAt)
	}
	select {
	case <-apiClient.ctx.Done():
	// finish go routine when context done
	return
	case <-time.After(nextDuring):
	newRateRemaining, newResetAt, err := apiClient.getRateRemaining(apiClient.ctx, apiClient.client, apiClient.logger)
	if err != nil {
	apiClient.logger.Info("failed to update graphql rate limit, will retry next cycle: %v", err)
	// Floor the reused value so Signal() always fires; prevents deadlock when
	// rateRemaining is 0 and the rate-limit endpoint keeps erroring (e.g. GHE).
	fallback := apiClient.rateRemaining
	if fallback < defaultRateLimitConst {
	fallback = defaultRateLimitConst
	}
	apiClient.updateRateRemaining(fallback, nil)
	return
	}
	apiClient.updateRateRemaining(newRateRemaining, newResetAt)
	}
	}()
	}

	// SetGetRateCost to calculate how many rate cost
	// if not set, all query just cost 1
	func (apiClient *GraphqlAsyncClient) SetGetRateCost(getRateCost func(q interface{}) int) {
	apiClient.getRateCost = getRateCost
	}

	// Query send a graphql request when get lock
	// []graphql.DataError are the errors returned in response body
	// errors.Error is other error
	func (apiClient *GraphqlAsyncClient) Query(q interface{}, variables map[string]interface{}) ([]graphql.DataError, error) {
	apiClient.waitGroup.Add(1)
	defer apiClient.waitGroup.Done()
	apiClient.mu.Lock()
	defer apiClient.mu.Unlock()

	apiClient.rateExhaustCond.L.Lock()
	defer apiClient.rateExhaustCond.L.Unlock()
	for apiClient.rateRemaining <= 0 {
	apiClient.logger.Info(`rate limit remaining exhausted, waiting for next period.`)
	apiClient.rateExhaustCond.Wait()
	}

	retryTime := 0
	var err error
	// if it needs retry, check and retry
	for retryTime < apiClient.maxRetry {
	select {
	case <-apiClient.ctx.Done():
	return nil, nil
	default:
	var dataErrors []graphql.DataError
	dataErrors, err := apiClient.client.Query(apiClient.ctx, q, variables)
	if err == context.Canceled {
	return nil, err
	}
	if err != nil {
	apiClient.logger.Warn(err, "retry #%d graphql calling after %ds", retryTime, apiClient.waitBeforeRetry/time.Second)
	retryTime++
	<-time.After(apiClient.waitBeforeRetry)
	continue
	}
	if dataErrors != nil {
	return dataErrors, nil
	}
	cost := 1
	if apiClient.getRateCost != nil {
	cost = apiClient.getRateCost(q)
	}
	apiClient.rateRemaining -= cost
	apiClient.logger.Debug(`query cost %d in %v`, cost, variables)
	return nil, nil
	}
	}
	return nil, errors.Default.Wrap(err, fmt.Sprintf("got error when querying GraphQL (from the %dth retry)", retryTime))
	}

	// NextTick to return the NextTick of scheduler
	func (apiClient *GraphqlAsyncClient) NextTick(task func() errors.Error, taskErrorChecker func(err error)) {
	// to make sure task will be enqueued
	apiClient.waitGroup.Add(1)
	go func() {
	select {
	case <-apiClient.ctx.Done():
	return
	default:
	go func() {
	// if set waitGroup done here, a serial of goroutine will block until sub-goroutine finish.
	// But if done out of this go func, so task will run after waitGroup finish
	// I have no idea about this now...
	defer apiClient.waitGroup.Done()
	taskErrorChecker(task())
	}()
	}
	}()
	}

	// Wait blocks until all async requests were done
	func (apiClient *GraphqlAsyncClient) Wait() {
	apiClient.waitGroup.Wait()
	}

	// Release will release the ApiAsyncClient with scheduler
	func (apiClient *GraphqlAsyncClient) Release() {
	apiClient.cancel()
	}

	// WithFallbackRateLimit sets the initial/fallback rate limit used when
	// rate limit information cannot be fetched dynamically.
	// This value may be overridden later by getRateRemaining.
	func WithFallbackRateLimit(limit int) func(*GraphqlAsyncClient) {
	return func(c *GraphqlAsyncClient) {
	if limit > 0 {
	c.rateRemaining = limit
	}
	}
	}

	// resolveRateLimit returns -1 if GRAPHQL_RATE_LIMIT is not set or invalid
	func resolveRateLimit(taskCtx plugin.TaskContext, logger log.Logger) int {
	if v := taskCtx.GetConfig("GRAPHQL_RATE_LIMIT"); v != "" {
	if parsed, err := strconv.Atoi(v); err == nil {
	return parsed
	}
	logger.Warn(nil, "invalid GRAPHQL_RATE_LIMIT, using default")
	}
	return -1
	}