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package main
import (
"encoding/json"
"fmt"
"log"
"net/http"
"net/url"
"strconv"
"github.com/gorilla/mux"
"git.darknebu.la/GalaxySimulator/structs"
)
var (
treeArray []*structs.Node
starCount []int
)
// indexHandler
func indexHandler(w http.ResponseWriter, r *http.Request) {
infostring := `Galaxy Simulator Database
API:
/ GET
/new POST w float64
/insert/{treeindex} POST x float64, y float64, vx float64, vy float64, m float64
/starlist/{treeindex}
/printall GET
/metrics GET
`
_, _ = fmt.Fprintf(w, infostring)
}
// newTreeHandler creates a new tree
func newTreeHandler(w http.ResponseWriter, r *http.Request) {
// set the content type to json (looks fancy in firefox :D)
w.Header().Set("Content-Type", "application/json")
fmt.Println("Creating a new tree")
// get the star by parsing http-post parameters
errParseForm := r.ParseForm() // parse the POST form
if errParseForm != nil { // handle errors
panic(errParseForm)
}
// default values
width := 100.0
// value from the user
userWidth, _ := strconv.ParseFloat(r.Form.Get("w"), 64) // bounding box width
log.Printf("width: %f", userWidth)
// overwrite the default width
if userWidth != width {
width = userWidth
}
jsonData := newTree(width)
// return the new tree as json
_, _ = fmt.Fprintf(w, "%v", string(jsonData))
}
// newTree generates a new tree using the width it is given and returns it as json in an array of bytes
func newTree(width float64) []byte {
// generate a new tree and add it to the treeArray
newTree := structs.NewRoot(width)
treeArray = append(treeArray, newTree)
starCount = append(starCount, 0)
// convert the tree to json format
jsonData, jsonMarshalErr := json.Marshal(newTree)
if jsonMarshalErr != nil {
panic(jsonMarshalErr)
}
return jsonData
}
// printAllHandler prints all the trees in the treeArray
func printAllHandler(w http.ResponseWriter, r *http.Request) { // set the content type to json (looks fancy in firefox :D)
w.Header().Set("Content-Type", "application/json")
// Convert the data to json
jsonData, jsonMarshalerError := json.Marshal(treeArray)
if jsonMarshalerError != nil {
panic(jsonMarshalerError)
}
// print the jsonData to the ResponseWriter
_, printTreeErr := fmt.Fprintf(w, "%v\n", string(jsonData))
if printTreeErr != nil {
panic(printTreeErr)
}
log.Printf("The printAll endpoint was accessed.\n")
}
// insertStarHandler inserts a star into the given tree
func insertStarHandler(w http.ResponseWriter, r *http.Request) {
log.Println("The insert handler was accessed")
// get the treeindex in which the star should be inserted into
vars := mux.Vars(r)
treeindex, _ := strconv.ParseInt(vars["treeindex"], 10, 0)
// get the star by parsing http-post parameters
errParseForm := r.ParseForm() // parse the POST form
if errParseForm != nil { // handle errors
panic(errParseForm)
}
// get the star coordinates
x, _ := strconv.ParseFloat(r.Form.Get("x"), 64)
y, _ := strconv.ParseFloat(r.Form.Get("y"), 64)
vx, _ := strconv.ParseFloat(r.Form.Get("vx"), 64)
vy, _ := strconv.ParseFloat(r.Form.Get("vy"), 64)
m, _ := strconv.ParseFloat(r.Form.Get("m"), 64)
log.Printf("treeindex: %d", treeindex)
log.Printf("x: %f", x)
log.Printf("y: %f", y)
log.Printf("vx: %f", vx)
log.Printf("vy: %f", vy)
log.Printf("m: %f", m)
s1 := structs.Star2D{
C: structs.Vec2{x, y},
V: structs.Vec2{vx, vy},
M: m,
}
log.Printf("s1: %v", s1)
treeInsertError := treeArray[treeindex].Insert(s1)
if treeInsertError != nil {
panic(fmt.Sprintf("Error inserting %v into tree %d: %v", s1, treeindex, treeInsertError))
}
fmt.Println("-------------")
fmt.Println(treeArray)
fmt.Println("-------------")
log.Println("Done inserting the star")
starCount[treeindex] += 1
pushMetricsNumOfStars("http://db:80/metrics", treeindex)
_, _ = fmt.Fprintf(w, "%d", starCount[treeindex])
}
// pushMetricsNumOfStars pushes the amount of stars in the given galaxy with the given index to the given host
// the host is (normally) the service bundling the metrics
func pushMetricsNumOfStars(host string, treeindex int64) {
// define a post-request and send it to the given host
requestURL := fmt.Sprintf("%s", host)
resp, err := http.PostForm(requestURL,
url.Values{
"key": {fmt.Sprintf("db_%s{nr=\"%s\"}", "stars_num", treeindex)},
"value": {fmt.Sprintf("%d", starCount[treeindex])},
},
)
if err != nil {
fmt.Printf("Cound not make a POST request to %s", requestURL)
}
// close the response body
defer resp.Body.Close()
}
// starlistHandler lists all the stars in the given tree
func starlistHandler(w http.ResponseWriter, r *http.Request) {
log.Println("The starlist handler was accessed")
w.Header().Set("Content-Type", "application/json")
vars := mux.Vars(r)
treeindex, _ := strconv.ParseInt(vars["treeindex"], 10, 0)
listofallstars := treeArray[treeindex].GetAllStars()
log.Printf("listofallstars: %v", listofallstars)
// listofallstars: [{{-42 10} {0 0} 100} {{10 10} {0 0} 100}]
// convert the list of all stars to json
jsonlistofallstars, jsonMarshalErr := json.Marshal(listofallstars)
if jsonMarshalErr != nil {
panic(jsonMarshalErr)
}
log.Printf("jsonlistofallstars: %v", string(jsonlistofallstars))
_, _ = fmt.Fprintln(w, string(jsonlistofallstars))
log.Println("Done")
}
// dumptreeHandler dumps the requested tree
func dumptreeHandler(w http.ResponseWriter, r *http.Request) {
log.Printf("The dumptree endpoint was accessed.\n")
w.Header().Set("Content-Type", "application/json")
vars := mux.Vars(r)
treeindex, _ := strconv.ParseInt(vars["treeindex"], 10, 0)
// Convert the data to json
jsonData, jsonMarshalerError := json.Marshal(treeArray[treeindex])
if jsonMarshalerError != nil {
panic(jsonMarshalerError)
}
// print the jsonData to the ResponseWriter
_, printTreeErr := fmt.Fprintf(w, "%v\n", string(jsonData))
if printTreeErr != nil {
panic(printTreeErr)
}
}
// updateCenterOfMassHandler updates the center of mass in each node in tree with the given index
func updateCenterOfMassHandler(w http.ResponseWriter, r *http.Request) {
log.Println("Updating the center of mass")
vars := mux.Vars(r)
treeindex, _ := strconv.ParseInt(vars["treeindex"], 10, 0)
treeArray[treeindex].CalcCenterOfMass()
}
// updateTotalMassHandler updates the total mass in each node in the tree with the given index
func updateTotalMassHandler(w http.ResponseWriter, r *http.Request) {
log.Println("Updating the total mass")
vars := mux.Vars(r)
treeindex, _ := strconv.ParseInt(vars["treeindex"], 10, 0)
treeArray[treeindex].CalcTotalMass()
}
// metricHandler prints all the metrics to the ResponseWriter
func metricHandler(w http.ResponseWriter, r *http.Request) {
var metricsString string
metricsString += fmt.Sprintf("nr_galaxies %d\n", len(treeArray))
for i := 0; i < len(starCount); i++ {
metricsString += fmt.Sprintf("galaxy_star_count{galaxy_nr=\"%d\"} %d\n", i, starCount[i])
}
log.Println(metricsString)
_, _ = fmt.Fprintf(w, metricsString)
}
func main() {
router := mux.NewRouter()
router.HandleFunc("/", indexHandler).Methods("GET")
router.HandleFunc("/new", newTreeHandler).Methods("POST")
router.HandleFunc("/printall", printAllHandler).Methods("GET")
router.HandleFunc("/insert/{treeindex}", insertStarHandler).Methods("POST")
router.HandleFunc("/starlist/{treeindex}", starlistHandler).Methods("GET")
router.HandleFunc("/dumptree/{treeindex}", dumptreeHandler).Methods("GET")
router.HandleFunc("/updatetotalmass/{treeindex}", updateTotalMassHandler).Methods("GET")
router.HandleFunc("/updatecenterofmass/{treeindex}", updateCenterOfMassHandler).Methods("GET")
router.HandleFunc("/metrics", metricHandler).Methods("GET")
fmt.Println("Database Container up")
log.Fatal(http.ListenAndServe(":80", router))
}
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