Read a Int64 in an ArrayBuffer using DataView

I am using Web Sockets.

I am passing an ArrayBuffer to my JavaScript page.

I have this in C# code:

 byte packet = new byte[2];

 packet[0] = (byte)1;

 packet[1] = (byte)0;



 byte tickArray = BitConverter.GetBytes( 635744635349556838 );

 byte packet2 = new byte[2 + tickArray.Length];

 Buffer.BlockCopy(packet, 0, packet2, 0, packet.Length);

 Buffer.BlockCopy(tickArray, 0, packet2, packet.Length, tickArray.Length);

In my JavaScript Client I have this:

 var dv = new DataView(e.data);

 var marker = dv.getInt8(0);

 var tripped = dv.getInt8(1);



 var x = dv.getInt8(2);

I get the results:

if change to this:

var x= dv.getInt16(1);



-7389

How do I get my value of 635744635349556838?

Thanks

asked Aug 6 '15 at 13:40

Andrew Simpson

2,818739107

actually with javascript 635744635349556838 == 635744635349556900 if you can send it as string. What does e.data output with a console.log ?

– Hacketo
Aug 6 '15 at 13:56

Hi, yes, I was looking into doing that. This number I am using is the UTC tick of the server. I am assuming the length can change over time. Also, this byte array is put at the beginning of a larger byte array before being sent to the client(s). It is this varying length of string that will task me

– Andrew Simpson
Aug 6 '15 at 13:59

FWIW, your value exceeds Number.MAX_SAFE_INTEGER.

– robertklep
Aug 6 '15 at 14:09

@robertklep Thanks, I came to the same result myself. I had to convert number to string and then use the length of as my header in int16

– Andrew Simpson
Aug 6 '15 at 14:22

add a comment |

I am using Web Sockets.

I am passing an ArrayBuffer to my JavaScript page.

I have this in C# code:

 byte packet = new byte[2];

 packet[0] = (byte)1;

 packet[1] = (byte)0;



 byte tickArray = BitConverter.GetBytes( 635744635349556838 );

 byte packet2 = new byte[2 + tickArray.Length];

 Buffer.BlockCopy(packet, 0, packet2, 0, packet.Length);

 Buffer.BlockCopy(tickArray, 0, packet2, packet.Length, tickArray.Length);

In my JavaScript Client I have this:

 var dv = new DataView(e.data);

 var marker = dv.getInt8(0);

 var tripped = dv.getInt8(1);



 var x = dv.getInt8(2);

I get the results:

if change to this:

var x= dv.getInt16(1);



-7389

How do I get my value of 635744635349556838?

Thanks

asked Aug 6 '15 at 13:40

Andrew Simpson

2,818739107

actually with javascript 635744635349556838 == 635744635349556900 if you can send it as string. What does e.data output with a console.log ?

– Hacketo
Aug 6 '15 at 13:56

Hi, yes, I was looking into doing that. This number I am using is the UTC tick of the server. I am assuming the length can change over time. Also, this byte array is put at the beginning of a larger byte array before being sent to the client(s). It is this varying length of string that will task me

– Andrew Simpson
Aug 6 '15 at 13:59

FWIW, your value exceeds Number.MAX_SAFE_INTEGER.

– robertklep
Aug 6 '15 at 14:09

@robertklep Thanks, I came to the same result myself. I had to convert number to string and then use the length of as my header in int16

– Andrew Simpson
Aug 6 '15 at 14:22

add a comment |

I am using Web Sockets.

I am passing an ArrayBuffer to my JavaScript page.

I have this in C# code:

 byte packet = new byte[2];

 packet[0] = (byte)1;

 packet[1] = (byte)0;



 byte tickArray = BitConverter.GetBytes( 635744635349556838 );

 byte packet2 = new byte[2 + tickArray.Length];

 Buffer.BlockCopy(packet, 0, packet2, 0, packet.Length);

 Buffer.BlockCopy(tickArray, 0, packet2, packet.Length, tickArray.Length);

In my JavaScript Client I have this:

 var dv = new DataView(e.data);

 var marker = dv.getInt8(0);

 var tripped = dv.getInt8(1);



 var x = dv.getInt8(2);

I get the results:

if change to this:

var x= dv.getInt16(1);



-7389

How do I get my value of 635744635349556838?

Thanks

asked Aug 6 '15 at 13:40

Andrew Simpson

2,818739107

I am using Web Sockets.

I am passing an ArrayBuffer to my JavaScript page.

I have this in C# code:

 byte packet = new byte[2];

 packet[0] = (byte)1;

 packet[1] = (byte)0;



 byte tickArray = BitConverter.GetBytes( 635744635349556838 );

 byte packet2 = new byte[2 + tickArray.Length];

 Buffer.BlockCopy(packet, 0, packet2, 0, packet.Length);

 Buffer.BlockCopy(tickArray, 0, packet2, packet.Length, tickArray.Length);

In my JavaScript Client I have this:

 var dv = new DataView(e.data);

 var marker = dv.getInt8(0);

 var tripped = dv.getInt8(1);



 var x = dv.getInt8(2);

I get the results:

if change to this:

var x= dv.getInt16(1);



-7389

How do I get my value of 635744635349556838?

Thanks

javascript arraybuffer

asked Aug 6 '15 at 13:40

Andrew Simpson

2,818739107

asked Aug 6 '15 at 13:40

Andrew Simpson

2,818739107

asked Aug 6 '15 at 13:40

Andrew Simpson

2,818739107

asked Aug 6 '15 at 13:40

Andrew Simpson

2,818739107

asked Aug 6 '15 at 13:40

Andrew Simpson

2,818739107

actually with javascript 635744635349556838 == 635744635349556900 if you can send it as string. What does e.data output with a console.log ?

– Hacketo
Aug 6 '15 at 13:56

Hi, yes, I was looking into doing that. This number I am using is the UTC tick of the server. I am assuming the length can change over time. Also, this byte array is put at the beginning of a larger byte array before being sent to the client(s). It is this varying length of string that will task me

– Andrew Simpson
Aug 6 '15 at 13:59

FWIW, your value exceeds Number.MAX_SAFE_INTEGER.

– robertklep
Aug 6 '15 at 14:09

@robertklep Thanks, I came to the same result myself. I had to convert number to string and then use the length of as my header in int16

– Andrew Simpson
Aug 6 '15 at 14:22

add a comment |

actually with javascript 635744635349556838 == 635744635349556900 if you can send it as string. What does e.data output with a console.log ?

– Hacketo
Aug 6 '15 at 13:56

Hi, yes, I was looking into doing that. This number I am using is the UTC tick of the server. I am assuming the length can change over time. Also, this byte array is put at the beginning of a larger byte array before being sent to the client(s). It is this varying length of string that will task me

– Andrew Simpson
Aug 6 '15 at 13:59

FWIW, your value exceeds Number.MAX_SAFE_INTEGER.

– robertklep
Aug 6 '15 at 14:09

@robertklep Thanks, I came to the same result myself. I had to convert number to string and then use the length of as my header in int16

– Andrew Simpson
Aug 6 '15 at 14:22

actually with javascript 635744635349556838 == 635744635349556900 if you can send it as string. What does e.data output with a console.log ?

– Hacketo
Aug 6 '15 at 13:56

Hi, yes, I was looking into doing that. This number I am using is the UTC tick of the server. I am assuming the length can change over time. Also, this byte array is put at the beginning of a larger byte array before being sent to the client(s). It is this varying length of string that will task me

– Andrew Simpson
Aug 6 '15 at 13:59

FWIW, your value exceeds Number.MAX_SAFE_INTEGER.

– robertklep
Aug 6 '15 at 14:09

@robertklep Thanks, I came to the same result myself. I had to convert number to string and then use the length of as my header in int16

– Andrew Simpson
Aug 6 '15 at 14:22

add a comment |

1 Answer
1

active

oldest

votes

I wrote a code. Would be it helpful?

function getUint64(bytes, littleEndian)

{

  var low = 4, high = 0;

  if (littleEndian)

  {

    low = 0;

    high = 4;

  }



  var dv = new DataView(Uint8Array.from(bytes ).buffer);



  return (dv.getUint32(high, littleEndian) << 32) |

        dv.getUint32(low, littleEndian);

}

    var bytes = [ 124, 22, 124, 22, 124, 22, 124, 22];

    var value = getUint64(bytes, false);

    console.log(value);

answered Nov 25 '18 at 19:23

JQ22

113

add a comment |

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1 Answer
1

active

oldest

votes

1 Answer
1

active

oldest

votes

I wrote a code. Would be it helpful?

function getUint64(bytes, littleEndian)

{

  var low = 4, high = 0;

  if (littleEndian)

  {

    low = 0;

    high = 4;

  }



  var dv = new DataView(Uint8Array.from(bytes ).buffer);



  return (dv.getUint32(high, littleEndian) << 32) |

        dv.getUint32(low, littleEndian);

}

    var bytes = [ 124, 22, 124, 22, 124, 22, 124, 22];

    var value = getUint64(bytes, false);

    console.log(value);

answered Nov 25 '18 at 19:23

JQ22

113

add a comment |

I wrote a code. Would be it helpful?

function getUint64(bytes, littleEndian)

{

  var low = 4, high = 0;

  if (littleEndian)

  {

    low = 0;

    high = 4;

  }



  var dv = new DataView(Uint8Array.from(bytes ).buffer);



  return (dv.getUint32(high, littleEndian) << 32) |

        dv.getUint32(low, littleEndian);

}

    var bytes = [ 124, 22, 124, 22, 124, 22, 124, 22];

    var value = getUint64(bytes, false);

    console.log(value);

answered Nov 25 '18 at 19:23

JQ22

113

add a comment |

I wrote a code. Would be it helpful?

function getUint64(bytes, littleEndian)

{

  var low = 4, high = 0;

  if (littleEndian)

  {

    low = 0;

    high = 4;

  }



  var dv = new DataView(Uint8Array.from(bytes ).buffer);



  return (dv.getUint32(high, littleEndian) << 32) |

        dv.getUint32(low, littleEndian);

}

    var bytes = [ 124, 22, 124, 22, 124, 22, 124, 22];

    var value = getUint64(bytes, false);

    console.log(value);

answered Nov 25 '18 at 19:23

JQ22

113

I wrote a code. Would be it helpful?

function getUint64(bytes, littleEndian)

{

  var low = 4, high = 0;

  if (littleEndian)

  {

    low = 0;

    high = 4;

  }



  var dv = new DataView(Uint8Array.from(bytes ).buffer);



  return (dv.getUint32(high, littleEndian) << 32) |

        dv.getUint32(low, littleEndian);

}

    var bytes = [ 124, 22, 124, 22, 124, 22, 124, 22];

    var value = getUint64(bytes, false);

    console.log(value);

answered Nov 25 '18 at 19:23

JQ22

113

answered Nov 25 '18 at 19:23

JQ22

113

answered Nov 25 '18 at 19:23

JQ22

113

answered Nov 25 '18 at 19:23

JQ22

113

add a comment |

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