int64 was a workaround JS' lack of support for Int64 data types. Somewhat to my surprise, people have found it useful. However, it looks like BigInts will soon be a formally accepted feature, obsoleting the need for this package.
If a trustworthy organization or individual would like to take over as maintainer, I'm happy to hand this off. Please contact me at firstname.lastname@example.org if you're interested. Otherwise I'll be npm-deprecating this at some future date.
Int64 instances look and feel much like JS-native Numbers. By way of example ...
// First, let's illustrate the problem ... > (0x123456789).toString(16) '123456789' // <- what we expect. > (0x123456789abcdef0).toString(16) '123456789abcdf00' // <- Ugh! JS doesn't do big ints. :( // So let's create a couple Int64s using the above values ... // Require, of course > Int64 = require('node-int64') // x's value is what we expect (the decimal value of 0x123456789) > x = new Int64(0x123456789) [Int64 value:4886718345 octets:00 00 00 01 23 45 67 89] // y's value is Infinity because it's outside the range of integer // precision. But that's okay - it's still useful because it's internal // representation (octets) is what we passed in > y = new Int64('123456789abcdef0') [Int64 value:Infinity octets:12 34 56 78 9a bc de f0] // Let's do some math. Int64's behave like Numbers. (Sorry, Int64 isn't // for doing 64-bit integer arithmetic (yet) - it's just for carrying // around int64 values > x + 1 4886718346 > y + 1 Infinity // Int64 string operations ... > 'value: ' + x 'value: 4886718345' > 'value: ' + y 'value: Infinity' > x.toString(2) '100100011010001010110011110001001' > y.toString(2) 'Infinity' // Use JS's isFinite() method to see if the Int64 value is in the // integer-precise range of JS values > isFinite(x) true > isFinite(y) false // Get an octet string representation. (Yay, y is what we put in!) > x.toOctetString() '0000000123456789' > y.toOctetString() '123456789abcdef0' // Finally, some other ways to create Int64s ... // Pass hi/lo words > new Int64(0x12345678, 0x9abcdef0) [Int64 value:Infinity octets:12 34 56 78 9a bc de f0] // Pass a Buffer > new Int64(new Buffer([0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf0])) [Int64 value:Infinity octets:12 34 56 78 9a bc de f0] // Pass a Buffer and offset > new Int64(new Buffer([0,0,0,0,0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf0]), 4) [Int64 value:Infinity octets:12 34 56 78 9a bc de f0] // Pull out into a buffer > new Int64(new Buffer([0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf0])).toBuffer() <Buffer 12 34 56 78 9a bc de f0> // Or copy into an existing one (at an offset) > var buf = new Buffer(1024); > new Int64(new Buffer([0x12, 0x34, 0x56, 0x78, 0x9a, 0xbc, 0xde, 0xf0])).copy(buf, 512);