teen_process
Version:
A grown up version of Node's spawn/exec
58 lines • 1.99 kB
JavaScript
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.CircularBuffer = exports.MAX_BUFFER_SIZE = void 0;
exports.MAX_BUFFER_SIZE = 100 * 1024 * 1024; // 100 MiB
const THRESHOLD = 0.15;
class CircularBuffer {
_buf;
_size;
_maxSize;
constructor(maxSize = exports.MAX_BUFFER_SIZE) {
this._maxSize = maxSize;
this._buf = [];
this._size = 0;
}
get size() {
return this._size;
}
get count() {
return this._buf.length;
}
add(item) {
this._buf.push(item);
this._size += item.length;
this._align();
return this;
}
value() {
return Buffer.concat(this._buf);
}
_align() {
if (this._size <= this._maxSize) {
return;
}
let numberOfItemsToShift = 0;
// We add the threshold to avoid shifting the array for each `add` call,
// which reduces the CPU usage
const expectedSizeToShift = this._size - this._maxSize + Math.trunc(this._maxSize * THRESHOLD);
let actualShiftedSize = 0;
while (numberOfItemsToShift < this._buf.length - 1 &&
actualShiftedSize <= expectedSizeToShift) {
actualShiftedSize += this._buf[numberOfItemsToShift].length;
numberOfItemsToShift++;
}
if (numberOfItemsToShift > 0) {
this._buf.splice(0, numberOfItemsToShift);
this._size -= actualShiftedSize;
}
if (actualShiftedSize < expectedSizeToShift) {
// We have already deleted all buffer items, but one,
// although the recent item is still too big to fit into the allowed size limit
const remainderToShift = expectedSizeToShift - actualShiftedSize;
this._buf[0] = this._buf[0].subarray(remainderToShift);
this._size -= remainderToShift;
}
}
}
exports.CircularBuffer = CircularBuffer;
//# sourceMappingURL=circular-buffer.js.map