/
scraper.go
150 lines (131 loc) · 3.15 KB
/
scraper.go
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package shorttermrentals
import (
"compress/gzip"
"encoding/json"
"fmt"
"io"
"log"
"net/http"
"net/url"
"time"
"github.com/codefornola/nolabase/internal/infra"
"github.com/jackc/pgx/v4/pgxpool"
)
const (
ScraperName = "SHORT-TERM-RENTALS"
MergedVacationRentalsURL = "https://data.nola.gov/resource/en36-xvxg.json"
LimitPerPage = 1000
)
type JobMetadata struct {
Limit int
Offset int
}
type STRScraper struct {
repo *Repo
}
func NewScraper() *STRScraper {
return &STRScraper{}
}
func (s *STRScraper) Configure(pool *pgxpool.Pool) (err error) {
s.repo = NewRepo(pool)
return err
}
func (s *STRScraper) EnqueueJobs() (jobs []infra.Job, err error) {
metab, err := json.Marshal(&JobMetadata{
Limit: LimitPerPage,
Offset: 0,
})
if err != nil {
return jobs, err
}
job := infra.Job{
Url: MergedVacationRentalsURL,
ScraperName: ScraperName,
MetaData: string(metab),
}
jobs = append(jobs, job)
return jobs, nil
}
func (s *STRScraper) 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 *STRScraper) HandleResponse(j infra.Job, resp *http.Response, httpErr error) (*infra.Job, error) {
// 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
}
start := time.Now()
log.Println("Decoding")
var permits []*Permit
err = json.NewDecoder(reader).Decode(&permits)
if err != nil {
fmt.Println(err)
return nil, err
}
log.Printf("Decoded in %dms\n", time.Since(start).Milliseconds())
log.Println("AfterParse")
for _, p := range permits {
p.AfterParse()
}
log.Println("StorePermits")
start = time.Now()
err = s.repo.StorePermits(permits)
if err != nil {
return nil, err
}
log.Printf("Stored permits in %dms", time.Since(start).Milliseconds())
log.Println("rentals stored")
// if we have at least LimitPerPage, we need to check for another page
if len(permits) == LimitPerPage {
newUrl := stripQueryParam(resp.Request.URL.String(), "$limit")
newUrl = stripQueryParam(newUrl, "$offset")
meta.Offset += LimitPerPage
newMeta, err := json.Marshal(meta)
fmt.Println(string(newMeta))
if err != nil {
return nil, err
}
return &infra.Job{
Url: newUrl,
ScraperName: ScraperName,
MetaData: string(newMeta),
}, nil
} else {
fmt.Printf("num permits under 1000 %d", len(permits))
}
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()
}