tildefriends/packages/cory/libdocument/libdocument.js

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2.8 KiB
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"use strict";
// A document store.
//! {"category": "libraries"}
class DocumentStore {
constructor(prefix) {
this._prefix = prefix;
}
async _get(name) {
let node;
try {
node = JSON.parse(await database.get(this._prefix + ":node:" + JSON.stringify(name)));
} catch (error) {
node = {version: null};
}
return node;
}
async _addKey(name) {
let list = JSON.parse(await database.get(this._prefix + ":keys") || "[]");
if (list.indexOf(name) == -1) {
list.push(name);
list.sort();
}
await database.set(this._prefix + ":keys", JSON.stringify(list));
}
async _removeKey(name) {
let list = JSON.parse(await database.get(this._prefix + ":keys") || "[]");
let index = list.indexOf(name);
if (index != -1) {
list.splice(index, 1);
}
await database.set(this._prefix + ":keys", JSON.stringify(list));
}
async set(name, value) {
let node = await this._get(name);
let version = (node.version || 0) + 1;
await database.set(this._prefix + ":version:" + JSON.stringify(name) + ":" + version.toString(), JSON.stringify(value));
node.deleted = value == undefined;
node.version = version;
await database.set(this._prefix + ":node:" + JSON.stringify(name), JSON.stringify(node));
if (node.deleted) {
await this._removeKey(name);
} else {
await this._addKey(name);
}
}
async get(name, version) {
let queryVersion = version || (await this._get(name)).version || 0;
let value = await database.get(this._prefix + ":version:" + JSON.stringify(name) + ":" + queryVersion.toString());
return value ? JSON.parse(value) : undefined;
}
async getAll() {
return JSON.parse(await database.get(this._prefix + ":keys") || "[]");
}
async setVersion(name, version, value) {
await database.set(this._prefix + ":version:" + JSON.stringify(name) + ":" + version.toString(), JSON.stringify(value));
}
}
async function dump() {
terminal.print("Dumping everything.");
let keys = await database.getAll();
for (let key in keys) {
terminal.print(keys[key], " = ", await database.get(keys[key]));
database.remove(keys[key]);
}
}
async function test() {
terminal.print("Running a test.");
let ds = new DocumentStore("cory");
await ds.set("cory", 1);
await ds.set("cory", 2);
await ds.set("cory", 3);
terminal.print((await ds.get("cory")).toString());
await ds.set("alice", "hello, world!");
terminal.print(await ds.get("alice"));
terminal.print(JSON.stringify(await ds.getAll()));
await ds.set("cory", null);
terminal.print(JSON.stringify(await ds.getAll()));
terminal.print((await ds.get("cory", 2)).toString());
terminal.print("Done.");
}
if (imports.terminal) {
//dump().then(test).then(dump).catch(terminal.print);
}
exports.DocumentStore = function(name) {
let ds = new DocumentStore(name);
return {
get: ds.get.bind(ds),
set: ds.set.bind(ds),
getAll: ds.getAll.bind(ds),
setVersion: ds.setVersion.bind(ds),
};
}