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README.md |
SharedArrayBuffer
Constructor returning an object used to represent a generic, fixed-length raw binary data buffer which can be used to create views of shared memory.
Usage
var SharedArrayBuffer = require( '@stdlib/array/shared-buffer' );
SharedArrayBuffer( size )
Returns a SharedArrayBuffer
having a specified number of bytes.
try {
var buf = new SharedArrayBuffer( 5 );
// returns <SharedArrayBuffer>
} catch ( err ) {
console.log( 'Environment does not support SharedArrayBuffers.' );
}
Properties
SharedArrayBuffer.length
Number of input arguments the constructor accepts.
var len = SharedArrayBuffer.length;
// returns 1
SharedArrayBuffer.prototype.byteLength
Read-only property which returns the length (in bytes) of the SharedArrayBuffer
.
try {
var buf = new SharedArrayBuffer( 5 );
var byteLength = buf.byteLength;
// returns 5
} catch ( err ) {
console.log( 'Environment does not support SharedArrayBuffers.' );
}
Methods
SharedArrayBuffer.prototype.slice( [start[, end]] )
Copies the bytes of a SharedArrayBuffer
to a new SharedArrayBuffer
.
try {
var b1 = new SharedArrayBuffer( 10 );
var b2 = b1.slice();
// returns <SharedArrayBuffer>
var bool = ( b2 === b1 );
// returns false
} catch ( err ) {
console.log( 'Environment does not support SharedArrayBuffers.' );
}
By default, the method copies from the beginning of the SharedArrayBuffer
. To beginning copying from a different byte index, provide a start
argument, specifying the starting byte index (inclusive).
try {
var b1 = new SharedArrayBuffer( 10 );
var b2 = b1.slice( 2 );
var nbytes = b2.byteLength;
// returns 8
} catch ( err ) {
console.log( 'Environment does not support SharedArrayBuffers.' );
}
If start < 0
, the index is relative to the end of the SharedArrayBuffer
.
try {
var b1 = new SharedArrayBuffer( 10 );
var b2 = b1.slice( -2 );
var nbytes = b2.byteLength;
// returns 2
} catch ( err ) {
console.log( 'Environment does not support SharedArrayBuffers.' );
}
By default, the method copies to the end of the SharedArrayBuffer
. To copy until a particular byte index, provide an end
index, specifying the ending byte index (exclusive).
try {
var b1 = new SharedArrayBuffer( 10 );
var b2 = b1.slice( 2, 6 );
var nbytes = b2.byteLength;
// returns 4
} catch ( err ) {
console.log( 'Environment does not support SharedArrayBuffers.' );
}
If end < 0
, the index is relative to the end of the SharedArrayBuffer
.
try {
var b1 = new SharedArrayBuffer( 10 );
var b2 = b1.slice( 2, -2 );
var nbytes = b2.byteLength;
// returns 6
} catch ( err ) {
console.log( 'Environment does not support SharedArrayBuffers.' );
}
Examples
var randu = require( '@stdlib/random/base/randu' );
var Float64Array = require( '@stdlib/array/float64' );
var Uint8Array = require( '@stdlib/array/uint8' );
var toBinaryString = require( '@stdlib/number/uint8/base/to-binary-string' );
var SharedArrayBuffer = require( '@stdlib/array/shared-buffer' );
function main() {
var bytes;
var buf;
var arr;
var i;
// Create a new SharedArrayBuffer:
buf = new SharedArrayBuffer( 64 );
// Create a Float64 array buffer view:
arr = new Float64Array( buf.byteLength/8 );
for ( i = 0; i < arr.length; i++ ) {
arr[ i ] = randu() * 100.0;
}
// Create a "bytes" view of the array buffer:
bytes = new Uint8Array( arr.buffer );
// Print the bytes:
for ( i = 0; i < bytes.length; i++ ) {
console.log( 'byte %d: %s', i, toBinaryString( bytes[ i ] ) );
}
}
try {
main();
} catch ( err ) {
console.error( 'Environment does not provide SharedArrayBuffer support.' );
}