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qwen/nodejs/node_modules/node-int64/README.md

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+JavaScript Numbers are represented as [IEEE 754 double-precision floats](http://steve.hollasch.net/cgindex/coding/ieeefloat.html).  Unfortunately, this means they lose integer precision for values beyond +/- 2^^53.  For projects that need to accurately handle 64-bit ints, such as [node-thrift](https://github.com/wadey/node-thrift), a performant, Number-like class is needed.  Int64 is that class.
+
+Int64 instances look and feel much like JS-native Numbers.  By way of example ...
+```js
+// 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);
+```