ts-postgres
Version:
PostgreSQL client in TypeScript
112 lines • 6.93 kB
JavaScript
"use strict";
var __classPrivateFieldGet = (this && this.__classPrivateFieldGet) || function (receiver, state, kind, f) {
if (kind === "a" && !f) throw new TypeError("Private accessor was defined without a getter");
if (typeof state === "function" ? receiver !== state || !f : !state.has(receiver)) throw new TypeError("Cannot read private member from an object whose class did not declare it");
return kind === "m" ? f : kind === "a" ? f.call(receiver) : f ? f.value : state.get(receiver);
};
var __classPrivateFieldSet = (this && this.__classPrivateFieldSet) || function (receiver, state, value, kind, f) {
if (kind === "m") throw new TypeError("Private method is not writable");
if (kind === "a" && !f) throw new TypeError("Private accessor was defined without a setter");
if (typeof state === "function" ? receiver !== state || !f : !state.has(receiver)) throw new TypeError("Cannot write private member to an object whose class did not declare it");
return (kind === "a" ? f.call(receiver, value) : f ? f.value = value : state.set(receiver, value)), value;
};
var _Queue_head, _Queue_tail, _Queue_capacityMask, _Queue_list;
Object.defineProperty(exports, "__esModule", { value: true });
exports.Queue = void 0;
/** A double-ended queue. All queue operations are `O(1)`. */
class Queue {
constructor() {
_Queue_head.set(this, 0);
_Queue_tail.set(this, 0);
_Queue_capacityMask.set(this, 0b11);
_Queue_list.set(this, new Array(__classPrivateFieldGet(this, _Queue_capacityMask, "f") + 1));
}
/** Returns the current number of elements in the queue. */
get length() {
return __classPrivateFieldGet(this, _Queue_head, "f") <= __classPrivateFieldGet(this, _Queue_tail, "f") ?
__classPrivateFieldGet(this, _Queue_tail, "f") - __classPrivateFieldGet(this, _Queue_head, "f")
: __classPrivateFieldGet(this, _Queue_capacityMask, "f") + 1 - (__classPrivateFieldGet(this, _Queue_head, "f") - __classPrivateFieldGet(this, _Queue_tail, "f"));
}
/** Returns whether the deque is empty. */
get empty() {
return __classPrivateFieldGet(this, _Queue_head, "f") === __classPrivateFieldGet(this, _Queue_tail, "f");
}
/** Inserts item to first slot. Returns the new length of the deque. */
unshift(item) {
const len = __classPrivateFieldGet(this, _Queue_list, "f").length;
__classPrivateFieldSet(this, _Queue_head, (__classPrivateFieldGet(this, _Queue_head, "f") - 1 + len) & __classPrivateFieldGet(this, _Queue_capacityMask, "f"), "f");
__classPrivateFieldGet(this, _Queue_list, "f")[__classPrivateFieldGet(this, _Queue_head, "f")] = item;
if (__classPrivateFieldGet(this, _Queue_tail, "f") === __classPrivateFieldGet(this, _Queue_head, "f"))
this.growArray();
if (__classPrivateFieldGet(this, _Queue_head, "f") < __classPrivateFieldGet(this, _Queue_tail, "f"))
return __classPrivateFieldGet(this, _Queue_tail, "f") - __classPrivateFieldGet(this, _Queue_head, "f");
return __classPrivateFieldGet(this, _Queue_capacityMask, "f") + 1 - (__classPrivateFieldGet(this, _Queue_head, "f") - __classPrivateFieldGet(this, _Queue_tail, "f"));
}
/** Removes and returns the first element. */
shift() {
const item = this.shiftMaybe();
if (item !== undefined)
return item;
throw new Error('Queue is empty');
}
/** Removes and returns the first element or undefined. */
shiftMaybe() {
if (this.empty)
return;
const head = __classPrivateFieldGet(this, _Queue_head, "f");
const item = __classPrivateFieldGet(this, _Queue_list, "f")[head];
__classPrivateFieldGet(this, _Queue_list, "f")[head] = undefined;
__classPrivateFieldSet(this, _Queue_head, (head + 1) & __classPrivateFieldGet(this, _Queue_capacityMask, "f"), "f");
if (head < 2 &&
__classPrivateFieldGet(this, _Queue_tail, "f") > 10000 &&
__classPrivateFieldGet(this, _Queue_tail, "f") <= __classPrivateFieldGet(this, _Queue_list, "f").length >>> 2)
this.shrinkArray();
return item;
}
expect(expected) {
const item = this.shift();
if (item === undefined ||
(expected !== undefined && expected !== item)) {
throw new Error(`Unexpected item: ${item} !== ${expected}`);
}
return item;
}
/** Inserts item to the last slot. Returns the new length of the deque. */
push(item) {
const tail = __classPrivateFieldGet(this, _Queue_tail, "f");
__classPrivateFieldGet(this, _Queue_list, "f")[tail] = item;
__classPrivateFieldSet(this, _Queue_tail, (tail + 1) & __classPrivateFieldGet(this, _Queue_capacityMask, "f"), "f");
if (this.empty)
this.growArray();
if (__classPrivateFieldGet(this, _Queue_head, "f") < __classPrivateFieldGet(this, _Queue_tail, "f"))
return __classPrivateFieldGet(this, _Queue_tail, "f") - __classPrivateFieldGet(this, _Queue_head, "f");
return __classPrivateFieldGet(this, _Queue_capacityMask, "f") + 1 - (__classPrivateFieldGet(this, _Queue_head, "f") - __classPrivateFieldGet(this, _Queue_tail, "f"));
}
shrinkArray() {
__classPrivateFieldGet(this, _Queue_list, "f").length >>>= 1;
__classPrivateFieldSet(this, _Queue_capacityMask, __classPrivateFieldGet(this, _Queue_capacityMask, "f") >>> 1, "f");
}
growArray() {
// Perform rotate-left if necessary
if (__classPrivateFieldGet(this, _Queue_head, "f") > 0) {
// Copy existing data from head to end
const deleted = __classPrivateFieldGet(this, _Queue_list, "f").splice(__classPrivateFieldGet(this, _Queue_head, "f"));
// Then, plop all preceding elements after `deleted`
deleted.push(...__classPrivateFieldGet(this, _Queue_list, "f"));
// Shift pointers accordingly
__classPrivateFieldSet(this, _Queue_tail, __classPrivateFieldGet(this, _Queue_tail, "f") - __classPrivateFieldGet(this, _Queue_head, "f"), "f");
__classPrivateFieldSet(this, _Queue_head, 0, "f");
// Discard old array
__classPrivateFieldSet(this, _Queue_list, deleted, "f");
}
// Head is at 0 and array is now full,
// therefore safe to extend
__classPrivateFieldSet(this, _Queue_tail, __classPrivateFieldGet(this, _Queue_list, "f").length, "f");
// Double the capacity
__classPrivateFieldGet(this, _Queue_list, "f").length *= 2;
__classPrivateFieldSet(this, _Queue_capacityMask, (__classPrivateFieldGet(this, _Queue_capacityMask, "f") << 1) | 1, "f");
}
}
exports.Queue = Queue;
_Queue_head = new WeakMap(), _Queue_tail = new WeakMap(), _Queue_capacityMask = new WeakMap(), _Queue_list = new WeakMap();
//# sourceMappingURL=queue.js.map