103 lines
2.3 KiB
JavaScript
103 lines
2.3 KiB
JavaScript
|
'use strict';
|
||
|
|
|
||
|
|
|
||
|
|
var TYPED_OK = (typeof Uint8Array !== 'undefined') &&
|
||
|
|
(typeof Uint16Array !== 'undefined') &&
|
||
|
|
(typeof Int32Array !== 'undefined');
|
||
|
|
|
||
|
|
|
||
|
|
exports.assign = function (obj /*from1, from2, from3, ...*/) {
|
||
|
|
var sources = Array.prototype.slice.call(arguments, 1);
|
||
|
|
while (sources.length) {
|
||
|
|
var source = sources.shift();
|
||
|
|
if (!source) { continue; }
|
||
|
|
|
||
|
|
if (typeof source !== 'object') {
|
||
|
|
throw new TypeError(source + 'must be non-object');
|
||
|
|
}
|
||
|
|
|
||
|
|
for (var p in source) {
|
||
|
|
if (source.hasOwnProperty(p)) {
|
||
|
|
obj[p] = source[p];
|
||
|
|
}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return obj;
|
||
|
|
};
|
||
|
|
|
||
|
|
|
||
|
|
// reduce buffer size, avoiding mem copy
|
||
|
|
exports.shrinkBuf = function (buf, size) {
|
||
|
|
if (buf.length === size) { return buf; }
|
||
|
|
if (buf.subarray) { return buf.subarray(0, size); }
|
||
|
|
buf.length = size;
|
||
|
|
return buf;
|
||
|
|
};
|
||
|
|
|
||
|
|
|
||
|
|
var fnTyped = {
|
||
|
|
arraySet: function (dest, src, src_offs, len, dest_offs) {
|
||
|
|
if (src.subarray && dest.subarray) {
|
||
|
|
dest.set(src.subarray(src_offs, src_offs + len), dest_offs);
|
||
|
|
return;
|
||
|
|
}
|
||
|
|
// Fallback to ordinary array
|
||
|
|
for (var i = 0; i < len; i++) {
|
||
|
|
dest[dest_offs + i] = src[src_offs + i];
|
||
|
|
}
|
||
|
|
},
|
||
|
|
// Join array of chunks to single array.
|
||
|
|
flattenChunks: function (chunks) {
|
||
|
|
var i, l, len, pos, chunk, result;
|
||
|
|
|
||
|
|
// calculate data length
|
||
|
|
len = 0;
|
||
|
|
for (i = 0, l = chunks.length; i < l; i++) {
|
||
|
|
len += chunks[i].length;
|
||
|
|
}
|
||
|
|
|
||
|
|
// join chunks
|
||
|
|
result = new Uint8Array(len);
|
||
|
|
pos = 0;
|
||
|
|
for (i = 0, l = chunks.length; i < l; i++) {
|
||
|
|
chunk = chunks[i];
|
||
|
|
result.set(chunk, pos);
|
||
|
|
pos += chunk.length;
|
||
|
|
}
|
||
|
|
|
||
|
|
return result;
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
var fnUntyped = {
|
||
|
|
arraySet: function (dest, src, src_offs, len, dest_offs) {
|
||
|
|
for (var i = 0; i < len; i++) {
|
||
|
|
dest[dest_offs + i] = src[src_offs + i];
|
||
|
|
}
|
||
|
|
},
|
||
|
|
// Join array of chunks to single array.
|
||
|
|
flattenChunks: function (chunks) {
|
||
|
|
return [].concat.apply([], chunks);
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
|
||
|
|
// Enable/Disable typed arrays use, for testing
|
||
|
|
//
|
||
|
|
exports.setTyped = function (on) {
|
||
|
|
if (on) {
|
||
|
|
exports.Buf8 = Uint8Array;
|
||
|
|
exports.Buf16 = Uint16Array;
|
||
|
|
exports.Buf32 = Int32Array;
|
||
|
|
exports.assign(exports, fnTyped);
|
||
|
|
} else {
|
||
|
|
exports.Buf8 = Array;
|
||
|
|
exports.Buf16 = Array;
|
||
|
|
exports.Buf32 = Array;
|
||
|
|
exports.assign(exports, fnUntyped);
|
||
|
|
}
|
||
|
|
};
|
||
|
|
|
||
|
|
exports.setTyped(TYPED_OK);
|