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'use strict';
var TYPED_OK = (typeof Uint8Array !== 'undefined') &&
(typeof Uint16Array !== 'undefined') &&
(typeof Int32Array !== 'undefined');
function _has(obj, key) {
return Object.prototype.hasOwnProperty.call(obj, key);
}
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 (_has(source, 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);