/
scraper.go
180 lines (158 loc) · 4.01 KB
/
scraper.go
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package callsforservice
import (
"compress/gzip"
"encoding/json"
"fmt"
"io"
"net/http"
"net/url"
"time"
"github.com/codefornola/nolabase/internal/infra"
"github.com/jackc/pgx/v4/pgxpool"
"github.com/sirupsen/logrus"
)
const (
ScraperName = "CALLS-FOR-SERVICE"
CFS2011URL = "https://data.nola.gov/resource/28ec-c8d6.json"
CFS2012URL = "https://data.nola.gov/resource/rv3g-ypg7.json"
CFS2013URL = "https://data.nola.gov/resource/5fn8-vtui.json"
CFS2014URL = "https://data.nola.gov/resource/jsyu-nz5r.json"
CFS2015URL = "https://data.nola.gov/resource/w68y-xmk6.json"
CFS2016URL = "https://data.nola.gov/resource/wgrp-d3ma.json"
CFS2017URL = "https://data.nola.gov/resource/bqmt-f3jk.json"
CFS2018URL = "https://data.nola.gov/resource/9san-ivhk.json"
CFS2019URL = "https://data.nola.gov/resource/qf6q-pp4b.json"
CFS2020URL = "https://data.nola.gov/resource/hp7u-i9hf.json"
LimitPerPage = 1000
)
var log = logrus.WithField("package", "callsforservice")
type JobMetadata struct {
Limit int
Offset int
}
type CfsScraper struct {
repo *Repo
}
func NewScraper() *CfsScraper {
return &CfsScraper{}
}
func (s *CfsScraper) Configure(pool *pgxpool.Pool) (err error) {
s.repo = NewRepo(pool)
return err
}
func (s *CfsScraper) newJob(url string) (j infra.Job, err error) {
metab, err := json.Marshal(&JobMetadata{
Limit: LimitPerPage,
Offset: 0,
})
if err != nil {
return j, err
}
return infra.Job{
Url: url,
ScraperName: ScraperName,
MetaData: string(metab),
}, nil
}
func (s *CfsScraper) EnqueueJobs() ([]infra.Job, error) {
var jobs []infra.Job
urls := []string{
CFS2011URL,
CFS2012URL,
CFS2013URL,
CFS2014URL,
CFS2015URL,
CFS2016URL,
CFS2017URL,
CFS2018URL,
CFS2019URL,
CFS2020URL,
}
for _, u := range urls {
job, err := s.newJob(u)
if err != nil {
return jobs, err
}
jobs = append(jobs, job)
}
return jobs, nil
}
func (s *CfsScraper) MakeRequest(j infra.Job) (*http.Request, error) {
var meta JobMetadata
err := json.Unmarshal([]byte(j.MetaData), &meta)
if err != nil {
return nil, err
}
url := fmt.Sprintf("%s?$limit=%d&$offset=%d", j.Url, meta.Limit, meta.Offset)
req, err := http.NewRequest("GET", url, nil)
if err != nil {
return nil, err
}
req.Header.Set("Accept-Encoding", "deflate, gzip;q=1.0, *;q=0.5")
return req, nil
}
func (s *CfsScraper) HandleResponse(j infra.Job, resp *http.Response, httpErr error) (*infra.Job, error) {
scraperLog := log.WithField("job", j.Id).WithField("url", resp.Request.URL.String())
// if we have an http error just return it
if httpErr != nil {
return nil, httpErr
}
var meta JobMetadata
err := json.Unmarshal([]byte(j.MetaData), &meta)
if err != nil {
return nil, err
}
var reader io.ReadCloser
switch resp.Header.Get("Content-Encoding") {
case "gzip":
reader, err = gzip.NewReader(resp.Body)
defer reader.Close()
default:
reader = resp.Body
}
var calls []*ServiceCall
err = json.NewDecoder(reader).Decode(&calls)
if err != nil {
scraperLog.Error(err)
return nil, err
}
for _, c := range calls {
c.AfterParse()
}
start := time.Now()
err = s.repo.StoreCalls(calls)
if err != nil {
scraperLog.Error(err)
return nil, err
}
scraperLog.Debugf("Stored calls in %dms", time.Since(start).Milliseconds())
// if we have at least LimitPerPage, we need to check for another page
if len(calls) == LimitPerPage {
newUrl := stripQueryParam(resp.Request.URL.String(), "$limit")
newUrl = stripQueryParam(newUrl, "$offset")
meta.Offset += LimitPerPage
newMeta, err := json.Marshal(meta)
scraperLog.Debug("New Job Metadata" + string(newMeta))
if err != nil {
return nil, err
}
return &infra.Job{
Url: newUrl,
ScraperName: ScraperName,
MetaData: string(newMeta),
}, nil
} else {
scraperLog.Debugf("num calls under 1000 %d", len(calls))
}
return nil, err
}
func stripQueryParam(inURL, stripKey string) string {
u, err := url.Parse(inURL)
if err != nil {
return inURL
}
q := u.Query()
q.Del(stripKey)
u.RawQuery = q.Encode()
return u.String()
}