backend/helpers/pluginhelper/api/api_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 (
 	"bytes"
 	"context"
 	"fmt"
 	"io"
 	"net/http"
 	"net/url"
 	"time"

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

 // HttpMinStatusRetryCode is which status will retry
 var HttpMinStatusRetryCode = http.StatusBadRequest

 // ApiAsyncClient is built on top of ApiClient, to provide a asynchronous semantic
 // You may submit multiple requests at once by calling `DoGetAsync`, and those requests
 // will be performed in parallel with rate-limit support
 type ApiAsyncClient struct {
 	*ApiClient
 	*WorkerScheduler
 	maxRetry     int
 	numOfWorkers int
 	logger       log.Logger
 }

 const defaultTimeout = 120 * time.Second

 // CreateAsyncApiClient creates a new ApiAsyncClient
 func CreateAsyncApiClient(
 	taskCtx plugin.TaskContext,
 	apiClient *ApiClient,
 	rateLimiter *ApiRateLimitCalculator,
 ) (*ApiAsyncClient, errors.Error) {
 	// load retry/timeout from configuration
 	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 := time.ParseDuration(timeoutConf)
 		if err != nil {
 			return nil, errors.BadInput.Wrap(err, "failed to parse API_TIMEOUT")
 		}
 		apiClient.SetTimeout(timeout)
 	} else if apiClient.GetTimeout() == 0 {
 		// Use DEFAULT_TIMEOUT when API_TIMEOUT is empty and ApiClient has no timeout set
 		apiClient.SetTimeout(defaultTimeout)
 	}

 	apiClient.SetLogger(taskCtx.GetLogger())

 	globalRateLimitPerHour, err := utils.StrToIntOr(taskCtx.GetConfig("API_REQUESTS_PER_HOUR"), 18000)
 	if err != nil {
 		return nil, errors.Default.Wrap(err, "failed to parse API_REQUESTS_PER_HOUR")
 	}
 	if rateLimiter == nil {
 		rateLimiter = &ApiRateLimitCalculator{}
 	}
 	rateLimiter.GlobalRateLimitPerHour = globalRateLimitPerHour
 	rateLimiter.MaxRetry = retry

 	// ok, calculate api rate limit based on response (normally from headers)
 	requests, duration, err := rateLimiter.Calculate(apiClient)
 	if err != nil {
 		return nil, errors.Default.Wrap(err, "failed to calculate rateLimit for api")
 	}

 	// it is hard to tell how many workers would be sufficient, it depends on how slow the server responds.
 	// we need more workers when server is responding slowly, because requests are sent in a fixed pace.
 	// and because workers are relatively cheap, lets assume response takes 5 seconds
 	const RESPONSE_TIME = 5 * time.Second
 	// in order for scheduler to hold requests of 3 seconds, we need:
 	d := duration / RESPONSE_TIME
 	numOfWorkers := requests / int(d)
 	tickInterval, err := CalcTickInterval(requests, duration)
 	if err != nil {
 		return nil, err
 	}

 	logger := taskCtx.GetLogger().Nested("api async client")
 	logger.Info(
 		"creating scheduler for api \"%s\", number of workers: %d, %d reqs / %s (interval: %s)",
 		apiClient.GetEndpoint(),
 		numOfWorkers,
 		requests,
 		duration.String(),
 		tickInterval.String(),
 	)
 	scheduler, err := NewWorkerScheduler(
 		taskCtx.GetContext(),
 		numOfWorkers,
 		tickInterval,
 		logger,
 	)
 	if err != nil {
 		return nil, errors.Default.Wrap(err, "failed to create scheduler")
 	}

 	// finally, wrap around api client with async sematic
 	return &ApiAsyncClient{
 		apiClient,
 		scheduler,
 		retry,
 		numOfWorkers,
 		logger,
 	}, nil
 }

 // GetMaxRetry returns the maximum retry attempts for a request
 func (apiClient *ApiAsyncClient) GetMaxRetry() int {
 	return apiClient.maxRetry
 }

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

 // DoAsync would carry out an asynchronous request
 func (apiClient *ApiAsyncClient) DoAsync(
 	method string,
 	path string,
 	query url.Values,
 	body interface{},
 	header http.Header,
 	handler plugin.ApiAsyncCallback,
 	retry int,
 ) {
 	var request func() errors.Error
 	request = func() errors.Error {
 		var err error
 		var res *http.Response
 		var respBody []byte

 		apiClient.logger.Debug("endpoint: %s  method: %s  header: %s  body: %s query: %s", path, method, header, body, query)
 		res, err = apiClient.Do(method, path, query, body, header)
 		if err == ErrIgnoreAndContinue {
 			// make sure defer func got be executed
 			err = nil //nolint
 			return nil
 		}

 		// make sure response body is read successfully, or we might have to retry
 		if err == nil {
 			// make sure response.Body stream will be closed to avoid running out of file handle
 			defer func(readCloser io.ReadCloser) { _ = readCloser.Close() }(res.Body)
 			// replace NetworkStream with MemoryBuffer
 			respBody, err = io.ReadAll(res.Body)
 			if err == nil {
 				res.Body = io.NopCloser(bytes.NewBuffer(respBody))
 			}
 		}

 		// check
 		needRetry := false
 		errMessage := "unknown"
 		if err != nil {
 			needRetry = true
 			errMessage = err.Error()
 		} else if res.StatusCode >= HttpMinStatusRetryCode {
 			needRetry = true
 			errMessage = fmt.Sprintf("Http DoAsync error calling [method:%s path:%s query:%s]. Response: %s", method, path, query, string(respBody))
 			err = errors.HttpStatus(res.StatusCode).New(errMessage)
 		}

 		//  if it needs retry, check and retry
 		if needRetry {
 			// check whether we still have retry times and not error from handler and canceled error
 			if retry < apiClient.maxRetry && err != context.Canceled {
 				apiClient.logger.Warn(err, "retry #%d calling %s", retry, path)
 				retry++
 				apiClient.NextTick(func() errors.Error {
 					apiClient.SubmitBlocking(request)
 					return nil
 				})
 				return nil
 			}
 		}

 		if err != nil {
 			err = errors.Default.Wrap(err, fmt.Sprintf("Retry exceeded %d times calling %s. The last error was: %s", retry, path, errMessage))
 			apiClient.logger.Error(err, "")
 			return errors.Convert(err)
 		}

 		// it is important to let handler have a chance to handle error, or it can hang indefinitely
 		// when error occurs
 		return handler(res)
 	}
 	apiClient.SubmitBlocking(request)
 }

 // DoGetAsync Enqueue an api get request, the request may be sent sometime in future in parallel with other api requests
 func (apiClient *ApiAsyncClient) DoGetAsync(
 	path string,
 	query url.Values,
 	header http.Header,
 	handler plugin.ApiAsyncCallback,
 ) {
 	apiClient.DoAsync(http.MethodGet, path, query, nil, header, handler, 0)
 }

 // DoPostAsync Enqueue an api post request, the request may be sent sometime in future in parallel with other api requests
 func (apiClient *ApiAsyncClient) DoPostAsync(
 	path string,
 	query url.Values,
 	body interface{},
 	header http.Header,
 	handler plugin.ApiAsyncCallback,
 ) {
 	apiClient.DoAsync(http.MethodPost, path, query, body, header, handler, 0)
 }

 // GetNumOfWorkers to return the Workers count if scheduler.
 func (apiClient *ApiAsyncClient) GetNumOfWorkers() int {
 	return apiClient.numOfWorkers
 }

 // RateLimitedApiClient FIXME ...
 type RateLimitedApiClient interface {
 	DoGetAsync(path string, query url.Values, header http.Header, handler plugin.ApiAsyncCallback)
 	DoPostAsync(path string, query url.Values, body interface{}, header http.Header, handler plugin.ApiAsyncCallback)
 	WaitAsync() errors.Error
 	HasError() bool
 	NextTick(task func() errors.Error)
 	GetNumOfWorkers() int
 	GetAfterFunction() plugin.ApiClientAfterResponse
 	SetAfterFunction(callback plugin.ApiClientAfterResponse)
 	Reset(d time.Duration)
 	GetTickInterval() time.Duration
 	Release()
 }

 var _ RateLimitedApiClient = (*ApiAsyncClient)(nil)
	/*
	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 (
	"bytes"
	"context"
	"fmt"
	"io"
	"net/http"
	"net/url"
	"time"

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

	// HttpMinStatusRetryCode is which status will retry
	var HttpMinStatusRetryCode = http.StatusBadRequest

	// ApiAsyncClient is built on top of ApiClient, to provide a asynchronous semantic
	// You may submit multiple requests at once by calling `DoGetAsync`, and those requests
	// will be performed in parallel with rate-limit support
	type ApiAsyncClient struct {
	*ApiClient
	*WorkerScheduler
	maxRetry int
	numOfWorkers int
	logger log.Logger
	}

	const defaultTimeout = 120 * time.Second

	// CreateAsyncApiClient creates a new ApiAsyncClient
	func CreateAsyncApiClient(
	taskCtx plugin.TaskContext,
	apiClient *ApiClient,
	rateLimiter *ApiRateLimitCalculator,
	) (*ApiAsyncClient, errors.Error) {
	// load retry/timeout from configuration
	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 := time.ParseDuration(timeoutConf)
	if err != nil {
	return nil, errors.BadInput.Wrap(err, "failed to parse API_TIMEOUT")
	}
	apiClient.SetTimeout(timeout)
	} else if apiClient.GetTimeout() == 0 {
	// Use DEFAULT_TIMEOUT when API_TIMEOUT is empty and ApiClient has no timeout set
	apiClient.SetTimeout(defaultTimeout)
	}

	apiClient.SetLogger(taskCtx.GetLogger())

	globalRateLimitPerHour, err := utils.StrToIntOr(taskCtx.GetConfig("API_REQUESTS_PER_HOUR"), 18000)
	if err != nil {
	return nil, errors.Default.Wrap(err, "failed to parse API_REQUESTS_PER_HOUR")
	}
	if rateLimiter == nil {
	rateLimiter = &ApiRateLimitCalculator{}
	}
	rateLimiter.GlobalRateLimitPerHour = globalRateLimitPerHour
	rateLimiter.MaxRetry = retry

	// ok, calculate api rate limit based on response (normally from headers)
	requests, duration, err := rateLimiter.Calculate(apiClient)
	if err != nil {
	return nil, errors.Default.Wrap(err, "failed to calculate rateLimit for api")
	}

	// it is hard to tell how many workers would be sufficient, it depends on how slow the server responds.
	// we need more workers when server is responding slowly, because requests are sent in a fixed pace.
	// and because workers are relatively cheap, lets assume response takes 5 seconds
	const RESPONSE_TIME = 5 * time.Second
	// in order for scheduler to hold requests of 3 seconds, we need:
	d := duration / RESPONSE_TIME
	numOfWorkers := requests / int(d)
	tickInterval, err := CalcTickInterval(requests, duration)
	if err != nil {
	return nil, err
	}

	logger := taskCtx.GetLogger().Nested("api async client")
	logger.Info(
	"creating scheduler for api \"%s\", number of workers: %d, %d reqs / %s (interval: %s)",
	apiClient.GetEndpoint(),
	numOfWorkers,
	requests,
	duration.String(),
	tickInterval.String(),
	)
	scheduler, err := NewWorkerScheduler(
	taskCtx.GetContext(),
	numOfWorkers,
	tickInterval,
	logger,
	)
	if err != nil {
	return nil, errors.Default.Wrap(err, "failed to create scheduler")
	}

	// finally, wrap around api client with async sematic
	return &ApiAsyncClient{
	apiClient,
	scheduler,
	retry,
	numOfWorkers,
	logger,
	}, nil
	}

	// GetMaxRetry returns the maximum retry attempts for a request
	func (apiClient *ApiAsyncClient) GetMaxRetry() int {
	return apiClient.maxRetry
	}

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

	// DoAsync would carry out an asynchronous request
	func (apiClient *ApiAsyncClient) DoAsync(
	method string,
	path string,
	query url.Values,
	body interface{},
	header http.Header,
	handler plugin.ApiAsyncCallback,
	retry int,
	) {
	var request func() errors.Error
	request = func() errors.Error {
	var err error
	var res *http.Response
	var respBody []byte

	apiClient.logger.Debug("endpoint: %s method: %s header: %s body: %s query: %s", path, method, header, body, query)
	res, err = apiClient.Do(method, path, query, body, header)
	if err == ErrIgnoreAndContinue {
	// make sure defer func got be executed
	err = nil //nolint
	return nil
	}

	// make sure response body is read successfully, or we might have to retry
	if err == nil {
	// make sure response.Body stream will be closed to avoid running out of file handle
	defer func(readCloser io.ReadCloser) { _ = readCloser.Close() }(res.Body)
	// replace NetworkStream with MemoryBuffer
	respBody, err = io.ReadAll(res.Body)
	if err == nil {
	res.Body = io.NopCloser(bytes.NewBuffer(respBody))
	}
	}

	// check
	needRetry := false
	errMessage := "unknown"
	if err != nil {
	needRetry = true
	errMessage = err.Error()
	} else if res.StatusCode >= HttpMinStatusRetryCode {
	needRetry = true
	errMessage = fmt.Sprintf("Http DoAsync error calling [method:%s path:%s query:%s]. Response: %s", method, path, query, string(respBody))
	err = errors.HttpStatus(res.StatusCode).New(errMessage)
	}

	// if it needs retry, check and retry
	if needRetry {
	// check whether we still have retry times and not error from handler and canceled error
	if retry < apiClient.maxRetry && err != context.Canceled {
	apiClient.logger.Warn(err, "retry #%d calling %s", retry, path)
	retry++
	apiClient.NextTick(func() errors.Error {
	apiClient.SubmitBlocking(request)
	return nil
	})
	return nil
	}
	}

	if err != nil {
	err = errors.Default.Wrap(err, fmt.Sprintf("Retry exceeded %d times calling %s. The last error was: %s", retry, path, errMessage))
	apiClient.logger.Error(err, "")
	return errors.Convert(err)
	}

	// it is important to let handler have a chance to handle error, or it can hang indefinitely
	// when error occurs
	return handler(res)
	}
	apiClient.SubmitBlocking(request)
	}

	// DoGetAsync Enqueue an api get request, the request may be sent sometime in future in parallel with other api requests
	func (apiClient *ApiAsyncClient) DoGetAsync(
	path string,
	query url.Values,
	header http.Header,
	handler plugin.ApiAsyncCallback,
	) {
	apiClient.DoAsync(http.MethodGet, path, query, nil, header, handler, 0)
	}

	// DoPostAsync Enqueue an api post request, the request may be sent sometime in future in parallel with other api requests
	func (apiClient *ApiAsyncClient) DoPostAsync(
	path string,
	query url.Values,
	body interface{},
	header http.Header,
	handler plugin.ApiAsyncCallback,
	) {
	apiClient.DoAsync(http.MethodPost, path, query, body, header, handler, 0)
	}

	// GetNumOfWorkers to return the Workers count if scheduler.
	func (apiClient *ApiAsyncClient) GetNumOfWorkers() int {
	return apiClient.numOfWorkers
	}

	// RateLimitedApiClient FIXME ...
	type RateLimitedApiClient interface {
	DoGetAsync(path string, query url.Values, header http.Header, handler plugin.ApiAsyncCallback)
	DoPostAsync(path string, query url.Values, body interface{}, header http.Header, handler plugin.ApiAsyncCallback)
	WaitAsync() errors.Error
	HasError() bool
	NextTick(task func() errors.Error)
	GetNumOfWorkers() int
	GetAfterFunction() plugin.ApiClientAfterResponse
	SetAfterFunction(callback plugin.ApiClientAfterResponse)
	Reset(d time.Duration)
	GetTickInterval() time.Duration
	Release()
	}

	var _ RateLimitedApiClient = (*ApiAsyncClient)(nil)