tildefriends/packages/cory/liblist/liblist.js

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//! {"category": "libraries"}
"use strict";
class DatabaseList {
constructor(name) {
this._prefix = name;
}
async _insert(item, end, desiredKey) {
let key = this._prefix + ":head";
let listNode = await database.get(key);
if (!listNode) {
await database.set(key, JSON.stringify({next: key, previous: key, value: item, count: 1, nextId: 1, key: desiredKey}));
} if (listNode) {
listNode = JSON.parse(listNode);
listNode.count++;
let id = desiredKey;
if (id && await database.get(this._prefix + ":node:" + id.toString())) {
throw new Error("Key '" + desiredKey + "' already exists.");
}
if (!id) {
id = listNode.nextId++;
}
if (end) {
let newKey = this._prefix + ":node:" + id.toString();
await database.set(newKey, JSON.stringify({next: key, previous: listNode.previous, value: item}));
if (listNode.previous !== key) {
let previous = JSON.parse(await database.get(listNode.previous));
previous.next = newKey;
await database.set(listNode.previous, JSON.stringify(previous));
listNode.previous = newKey;
await database.set(key, JSON.stringify(listNode));
} else {
listNode.previous = newKey;
listNode.next = newKey;
await database.set(key, JSON.stringify(listNode));
}
} else {
let newKey = listNode.key || id.toString();
await database.set(newKey, JSON.stringify({next: listNode.next, previous: key, value: listNode.value}));
listNode.value = item;
listNode.key = id;
if (listNode.next !== key) {
let next = JSON.parse(await database.get(listNode.next));
next.previous = newKey;
await database.set(listNode.next, JSON.stringify(next));
listNode.next = newKey;
await database.set(key, JSON.stringify(listNode));
} else {
listNode.previous = newKey;
listNode.next = newKey;
await database.set(key, JSON.stringify(listNode));
}
}
}
}
async _remove(end) {
let key = this._prefix + ":head";
let listNode = await database.get(key);
let result;
if (listNode) {
listNode = JSON.parse(listNode);
listNode.count--;
if (end) {
if (listNode.previous === key) {
await database.remove(key);
result = listNode.value;
} else {
let removeKey = listNode.previous;
let previous = JSON.parse(await database.get(listNode.previous));
result = previous.value;
if (previous.previous !== key) {
let previousPrevious = JSON.parse(await database.get(previous.previous));
previousPrevious.next = key;
listNode.previous = previous.previous;
await database.set(previous.previous, JSON.stringify(previousPrevious));
await database.set(key, JSON.stringify(listNode));
await database.remove(removeKey);
} else {
listNode.next = key;
listNode.previous = key;
await database.set(key, JSON.stringify(listNode));
await database.remove(removeKey);
}
}
} else {
result = listNode.value;
if (listNode.next === key) {
await database.remove(key);
} else {
let removeKey = listNode.next;
let next = JSON.parse(await database.get(listNode.next));
listNode.value = next.value;
if (next.next !== key) {
let nextNext = JSON.parse(await database.get(next.next));
nextNext.previous = key;
listNode.next = next.next;
await database.set(next.next, JSON.stringify(nextNext));
await database.set(key, JSON.stringify(listNode));
await database.remove(removeKey);
} else {
listNode.next = key;
listNode.previous = key;
await database.set(key, JSON.stringify(listNode));
await database.remove(removeKey);
}
}
}
}
return result;
}
push(item, key) {
return this._insert(item, true, key);
}
unshift(item, key) {
return this._insert(item, false, key);
}
pop() {
return this._remove(true);
}
shift() {
return this._remove(false);
}
async get(offset, count) {
const head = this._prefix + ":head";
let key = head;
let result = [];
while (offset) {
let node = await database.get(key);
if (!node) {
break;
}
node = JSON.parse(node);
if (offset > 0) {
key = node.next;
offset--;
} else if (offset < 0) {
key = node.previous;
offset++;
}
}
while (count) {
let node = await database.get(key);
if (!node) {
break;
}
node = JSON.parse(node);
result.push(node.value);
if (count > 0) {
key = node.next;
if (key == head) {
break;
}
count--;
} else if (count < 0) {
key = node.previous;
count++;
if (key == head) {
count = -1;
}
}
}
return result;
}
async getByKey(key) {
let value = await database.get(this._prefix + ":node:" + key.toString());
if (value !== undefined) {
value = JSON.parse(value);
} else {
let node = await database.get(this._prefix + ":head");
if (node !== undefined) {
node = JSON.parse(node);
if (node.key == key) {
value = node;
}
}
}
return value;
}
async setByKey(key, value) {
let node = await database.get(this._prefix + ":head");
let done = false;
if (node !== undefined) {
node = JSON.parse(node);
if (node.key == key) {
node.value = value;
await database.set(this._prefix + ":head", JSON.stringify(node));
done = true;
}
}
if (!done) {
node = JSON.parse(await database.get(this._prefix + ":node:" + key));
node.value = value;
await database.set(this._prefix + ":node:" + key, JSON.stringify(node));
done = true;
}
}
}
function wipeDatabase() {
let promises = [];
return database.getAll().then(function(list) {
for (let i = 0; i < list.length; i++) {
promises.push(database.remove(list[i]));
}
});
return Promise.all(promises);
}
async function dumpDatabase() {
for (let key of await database.getAll()) {
let value = await database.get(key);
try {
value = JSON.parse(value);
} catch (error) {
// eh
}
terminal.print("DUMP: ", key, " ", JSON.stringify(value, 0, 2));
}
}
/*async function test() {
let x = new DatabaseList("list");
await x.push("1");
await x.push("2");
await x.push("3");
await dumpDatabase();
terminal.print(await x.get(0, 10));
terminal.print(await x.get(-1, -10));
terminal.print(await x.pop());
terminal.print(await x.pop());
terminal.print(await x.pop());
await dumpDatabase();
await x.unshift("1");
await x.unshift("2");
await x.unshift("3");
await dumpDatabase();
await x.push("cory", "coryKey");
await x.push("yo", "yoKey");
terminal.print(await x.get(0, 10));
terminal.print(await x.shift());
terminal.print(await x.shift());
terminal.print(await x.shift());
await dumpDatabase();
}*/
if (imports.terminal) {
//wipeDatabase();
//dumpDatabase().then(wipeDatabase).then(test).catch(terminal.print);
/*let x = new DatabaseList("list");
core.register("onInput", function(input) {
if (input == "clear") {
wipeDatabase().then(function() {
terminal.print("Database is now empty.");
});
} else if (input.substring(0, "push ".length) == "push ") {
x.push(input.substring("push ".length)).then(dumpDatabase).catch(terminal.print);
} else if (input.substring(0, "unshift ".length) == "unshift ") {
x.unshift(input.substring("unshift ".length)).then(dumpDatabase).catch(terminal.print);
} else if (input == "pop") {
x.pop().then(function(out) {
terminal.print("POPPED: ", out);
}).then(dumpDatabase).catch(terminal.print);
} else if (input == "shift") {
x.shift().then(function(out) {
terminal.print("SHIFTED: ", out);
}).then(dumpDatabase).catch(terminal.print);
} else if (input.substring(0, "get ".length) == "get ") {
let parts = input.split(" ");
x.get(parseInt(parts[1])).then(function(result) {
terminal.print(JSON.stringify(result))
}).catch(terminal.print);
} else {
dumpDatabase();
}
});*/
}
exports.ListStore = function(name) {
let ls = new DatabaseList(name);
return {
push: ls.push.bind(ls),
pop: ls.pop.bind(ls),
shift: ls.shift.bind(ls),
unshift: ls.unshift.bind(ls),
get: ls.get.bind(ls),
getByKey: ls.getByKey.bind(ls),
setByKey: ls.setByKey.bind(ls),
};
}