How to open tab in new window of the same browser?
Some web applications do not work in an inactive tab.
In the example, several windows open, but only the first window is available for management. When creating the rest, an error occurs
chrome failed to start: A window or tab will open in the current browser session.
package main
import (
"context"
"log"
"time"
"github.com/chromedp/chromedp"
)
func main() {
userDir := "someUserDir"
opts := append(chromedp.DefaultExecAllocatorOptions[:],
chromedp.DisableGPU,
chromedp.UserDataDir(userDir),
chromedp.WindowSize(1368, 768),
chromedp.Flag("headless", false),
chromedp.Flag("enable-automation", false),
chromedp.Flag("restore-on-startup", false),
chromedp.Flag("new-window", true),
)
for i := 0; i < 5; i++ {
log.Printf("open window %d", i)
allocCtx, _ := chromedp.NewExecAllocator(context.Background(), opts...)
ctx, _ := chromedp.NewContext(allocCtx)
if err := chromedp.Run(ctx, chromedp.Navigate("https://example.com")); err != nil {
log.Println(err)
}
}
time.Sleep(time.Minute)
}
package main
import (
"context"
"log"
"time"
"github.com/chromedp/cdproto/runtime"
"github.com/chromedp/chromedp"
)
func main() {
opts := append(chromedp.DefaultExecAllocatorOptions[:],
chromedp.DisableGPU,
chromedp.UserDataDir("someUserDir"),
chromedp.Flag("headless", false),
chromedp.Flag("enable-automation", false),
chromedp.Flag("restore-on-startup", false),
)
allocCtx, _ := chromedp.NewExecAllocator(context.Background(), opts...)
ctx, _ := chromedp.NewContext(allocCtx)
if err := chromedp.Run(ctx, chromedp.Navigate("about:blank")); err != nil {
log.Fatalln(err)
}
for i := 0; i < 5; i++ {
var res *runtime.RemoteObject
if err := chromedp.Run(ctx, chromedp.Evaluate(`window.open("about:blank", "", "resizable,scrollbars,status")`, &res)); err != nil {
log.Fatalln(err)
}
targets, err := chromedp.Targets(ctx)
if err != nil {
log.Fatalln(err)
}
for _, t := range targets {
if !t.Attached {
newCtx, _ := chromedp.NewContext(ctx, chromedp.WithTargetID(t.TargetID))
if err := chromedp.Run(newCtx, chromedp.Navigate("https://example.com")); err != nil {
log.Fatalln(err)
}
}
}
}
time.Sleep(time.Minute)
}
Related
Following code on Go 1.16.6 hangs on last Exec call (or crashes if same functions are called from different goroutines)
Both libraries "github.com/mattn/go-sqlite3" and "modernc.org/sqlite" give same results
package main
import (
"os"
"testing"
"database/sql"
_ "github.com/mattn/go-sqlite3"
// _ "modernc.org/sqlite"
)
func Test_Bug3(t *testing.T) {
DBPath := "test.db"
os.Remove(DBPath)
DB, err := sql.Open("sqlite3", DBPath)
if err != nil {
t.Fatalf("%s: %v", DBPath, err)
}
if _, err := DB.Exec(`CREATE TABLE IF NOT EXISTS verdictcache (sha1 text);`); err != nil {
t.Fatalf("%s: %v", DBPath, err)
}
_, err = DB.Exec("INSERT OR REPLACE INTO verdictcache (sha1) VALUES ($1)", "a")
if err != nil {
t.Fatalf("%s: %v", DBPath, err)
}
_, err = DB.Query("SELECT * FROM verdictcache WHERE sha1=$1", "a")
if err != nil {
t.Fatalf("%s: %v", DBPath, err)
}
_, err = DB.Exec("INSERT OR REPLACE INTO verdictcache (sha1) VALUES ($1)", "b")
if err != nil {
t.Fatalf("%s: %v", DBPath, err)
}
}
What is happening is almost certainly that you did not call Close() (or otherwise consumed the rows) on the result returned by DB.Query(...).
Try:
func Test_Bug3(t *testing.T) {
DBPath := "test.db"
os.Remove(DBPath)
DB, err := sql.Open("sqlite3", DBPath)
if err != nil {
t.Fatalf("%s: %v", DBPath, err)
}
if _, err := DB.Exec(`CREATE TABLE IF NOT EXISTS verdictcache (sha1 text);`); err != nil {
t.Fatalf("%s: %v", DBPath, err)
}
_, err = DB.Exec("INSERT OR REPLACE INTO verdictcache (sha1) VALUES ($1)", "a")
if err != nil {
t.Fatalf("%s: %v", DBPath, err)
}
res, err := DB.Query("SELECT * FROM verdictcache WHERE sha1=$1", "a")
if err != nil {
t.Fatalf("%s: %v", DBPath, err)
}
res.Close()
_, err = DB.Exec("INSERT OR REPLACE INTO verdictcache (sha1) VALUES ($1)", "b")
if err != nil {
t.Fatalf("%s: %v", DBPath, err)
}
}
When I do fmt.Printf("...\n") it doesn't move the cursor to the 0th column and the next line is therefore indented:
13
13
13
13
13
13
113 ('q')
Here is my code:
package main
import (
"bufio"
"fmt"
"os"
"unicode"
"golang.org/x/crypto/ssh/terminal"
)
func main() {
oldState, err := terminal.MakeRaw(0)
if err != nil {
panic(err)
}
defer terminal.Restore(0, oldState)
reader := bufio.NewReader(os.Stdin)
var c rune
for err == nil {
if c == 'q' {
break
}
c, _, err = reader.ReadRune()
if unicode.IsControl(c) {
fmt.Printf("%d\n", c)
} else {
fmt.Printf("%d ('%c')\n", c, c)
}
}
if err != nil {
panic(err)
}
}
Comment: You're putting the terminal in raw mode, doesn't that require a
carriage return to put the cursor at the start of the line? – JimB
For example,
terminal.go:
package main
import (
"bufio"
"fmt"
"os"
"unicode"
"golang.org/x/crypto/ssh/terminal"
)
func main() {
oldState, err := terminal.MakeRaw(0)
if err != nil {
panic(err)
}
defer terminal.Restore(0, oldState)
reader := bufio.NewReader(os.Stdin)
var c rune
for err == nil {
if c == 'q' {
break
}
c, _, err = reader.ReadRune()
if unicode.IsControl(c) {
fmt.Printf("%d\r\n", c)
} else {
fmt.Printf("%d ('%c')\r\n", c, c)
}
}
if err != nil {
panic(err)
}
}
Output:
$ go run terminal.go
13
13
13
13
13
113 ('q')
$
I am trying to call the TransmitPackets function on windows using GO.
The goal is to be able to send multiple packets with one syscall (can't be achieved with WSASend [it'll send fragmented IP packets]).
My code panics
panic: write udp 192.168.1.26:51817->8.8.8.8:8000: transmitpackets: An invalid argument was supplied.
goroutine 1 [running]:
main.main()
c:/Users/amit/dev/go/src/rio/main.go:26 +0x210
exit status 2
Process exiting with code: 1
Here's my test code
package main
import (
"math/rand"
"net"
)
func main() {
raddr, err := net.ResolveUDPAddr("udp", "8.8.8.8:8000")
if err != nil {
panic(err)
}
con, err := net.DialUDP("udp", nil, raddr)
if err != nil {
panic(err)
}
packets := make(net.Buffers, 10)
for i := 0; i < len(packets); i++ {
packets[i] = make([]byte, 1400)
rand.Read(packets[i])
}
_, err = con.WriteMultiple(packets)
if err != nil {
panic(err)
}
}
and Here's my call to TransmitPackets:
type TransmitPacketsElement struct {
dwElFlags uint32
cLength uint32
pBuffer unsafe.Pointer
nFileOffset uint64
hFile uintptr
}
func transmitPackets(s Handle, bufs [][]byte, overlapped *Overlapped) (err error) {
var maxPacketLen = 0
tpElements := make([]TransmitPacketsElement, len(bufs))
for i, tpElement := range tpElements {
buffer := bufs[i]
if len(buffer) > maxPacketLen {
maxPacketLen = len(buffer)
}
tpElement.cLength = uint32(len(buffer))
tpElement.dwElFlags = uint32(uint32(TP_ELEMENT_MEMORY) | uint32(TP_ELEMENT_EOP))
tpElement.pBuffer = unsafe.Pointer(&buffer[0])
}
r1, _, e1 := Syscall6(transmitPacketsFunc.addr, 6, uintptr(s), uintptr(unsafe.Pointer(&tpElements[0])), uintptr(uint32(len(tpElements))), uintptr(uint32(maxPacketLen)), uintptr(unsafe.Pointer(overlapped)), 0)
if r1 == 0 {
if e1 != 0 {
err = error(e1)
} else {
err = EINVAL
}
}
return
}
You can see the full implementation in my modified go 1.8.3 source on github
I'm working with Go in an API for the bus frequency of my city, but i'm a little bit stuck on the threads when i try to make HTTP Get to many urls.
Without concurrency, the programs takes over 16 minutes to complete the 1500 url calls to take the HTTP status code, and i was trying to use the concurrency, but after reading many posts i don't understand how goroutines work...
The idea is to make ONE function and change the number of requests, like here:
go getBusPostStatus(600, 800)
But i'm completely stucked on that...
Here is the code:
package main
import (
"fmt"
"net/http"
"strconv"
"time"
)
var i int = 0
var convStr string
var message = make(chan string)
/*func main(){
for i = 0; i < 1500; i++ {
z = strconv.Itoa(i)
url := "http://www.urbanosdezaragoza.es/frm_esquemaparadatime.php?poste=" + z
resp, err := http.Get(url)
if err != nil {
fmt.Println("Houston, we've got problems")
}else{
if resp.StatusCode == 200{
fmt.Println("OK: El poste "+z+" existe")
}else{
fmt.Println("WARN: El poste "+z+" NO existe")
}
}
}
}*/
//Return 2 houndred posts
func returnTH(c chan string){
for i = 0; i < 200; i++ {
convStr = strconv.Itoa(i)
url := "http://www.urbanosdezaragoza.es/frm_esquemaparadatime.php?poste=" + convStr
resp, err := http.Get(url)
if err != nil {
fmt.Println("Houston, we've got problems")
}else{
if resp.StatusCode == 200{
//fmt.Println("OK: El poste "+z+" existe")
c <- "OK: The bus post "+convStr+" exists"
}else{
//fmt.Println("WARN: El poste "+z+" NO existe")
c <- "WARN: The bus post "+convStr+" does not exist"
}
}
}
}
func returnFH(z chan string){
for i = 201; i < 400; i++ {
convStr = strconv.Itoa(i)
url := "http://www.urbanosdezaragoza.es/frm_esquemaparadatime.php?poste=" + convStr
resp, err := http.Get(url)
if err != nil {
fmt.Println("Houston, we've got problems")
}else{
if resp.StatusCode == 200{
//fmt.Println("OK: El poste "+z+" existe")
z <- "OK: The bus post "+convStr+" exists"
}else{
//fmt.Println("WARN: El poste "+z+" NO existe")
z <- "WARN: The bus post "+convStr+" does not exist"
}
}
}
}
func threadPrint(c, z chan string){
for {
threadOne := <- c
threadTwo := <- z
fmt.Println(threadOne)
fmt.Println(threadTwo)
}
}
func main(){
start := time.Now()
var c chan string = make(chan string)
var z chan string = make(chan string)
//for i = 0; i < 1500; i++{
go returnTH(c)
go returnFH(z)
go threadPrint(c,z)
/*go getBusPostStatus(400, 600)
go getBusPostStatus(600, 800)
go getBusPostStatus(800, 1000)
go getBusPostStatus(1000, 1200)
go getBusPostStatus(1200, 1400)
go getBusPostStatus(1400, 1500)*/
//}
timeExec:= time.Since(start)
fmt.Println("Time to exec code = ", timeExec)
/*var input string
fmt.Scanln(&input)
fmt.Println("done")*/
}
Many thanks in advance!!
Following is a simplified example code which requests 100 times concurrently and prints results, using goroutine and channel. Hope this code helps.
package main
import (
"fmt"
"math/rand"
"time"
)
func main() {
rep := 100
results := make(chan string)
// Use goroutine to send multiple time-consuming jobs to the channel.
for i := 0; i < rep; i++ {
go func(num int) {
results <- mockHTTPRequest(num)
}(i)
}
// Receive results from the channel and use them.
for i := 0; i < rep; i++ {
fmt.Println(<-results)
}
}
func mockHTTPRequest(num int) string {
timeDelay := rand.Intn(5000)
time.Sleep(time.Duration(timeDelay) * time.Millisecond)
if timeDelay%2 == 0 {
return fmt.Sprintf("OK: The bus post %v exists", num)
}
return fmt.Sprintf("WARN: The bus post %v does not exist", num)
}
You can run this code on https://play.golang.org/p/RR34roRIl4 .
How to cast reflect.Value to its type?
type Cat struct {
Age int
}
cat := reflect.ValueOf(obj)
fmt.Println(cat.Type()) // Cat
fmt.Println(Cat(cat).Age) // doesn't compile
fmt.Println((cat.(Cat)).Age) // same
Thanks!
concreteCat,_ := reflect.ValueOf(cat).Interface().(Cat)
see http://golang.org/doc/articles/laws_of_reflection.html
fox example
type MyInt int
var x MyInt = 7
v := reflect.ValueOf(x)
y := v.Interface().(float64) // y will have type float64.
fmt.Println(y)
Ok, I found it
reflect.Value has a function Interface() that converts it to interface{}
This func auto-converts types as needed. It loads a config file values into a simple struct based on struct name and fields:
import (
"fmt"
toml "github.com/pelletier/go-toml"
"log"
"os"
"reflect"
)
func LoadConfig(configFileName string, configStruct interface{}) {
defer func() {
if r := recover(); r != nil {
fmt.Println("LoadConfig.Recovered: ", r)
}
}()
conf, err := toml.LoadFile(configFileName)
if err == nil {
v := reflect.ValueOf(configStruct)
typeOfS := v.Elem().Type()
sectionName := getTypeName(configStruct)
for i := 0; i < v.Elem().NumField(); i++ {
if v.Elem().Field(i).CanInterface() {
kName := conf.Get(sectionName + "." + typeOfS.Field(i).Name)
kValue := reflect.ValueOf(kName)
if (kValue.IsValid()) {
v.Elem().Field(i).Set(kValue.Convert(typeOfS.Field(i).Type))
}
}
}
} else {
fmt.Println("LoadConfig.Error: " + err.Error())
}
}
Seems the only way would be to do a switch statement similar to (code below) (also, something like the commented line would've-been nice though doesn't work (:()):
func valuesFromStruct (rawV interface{}) []interface{} {
v := reflect.ValueOf(rawV)
out := make([]interface{}, 0)
for i := 0; i < v.NumField(); i += 1 {
field := v.Field(i)
fieldType := field.Type()
// out = append(out, field.Interface().(reflect.PtrTo(fieldType)))
switch (fieldType.Name()) {
case "int64":
out = append(out, field.Interface().(int64))
break`enter code here`
case "float64":
out = append(out, field.Interface().(float64))
break
case "string":
out = append(out, field.Interface().(string))
break
// And all your other types (here) ...
default:
out = append(out, field.Interface())
break
}
}
return out
}
Cheers!