1
0
mirror of https://github.com/laurent22/joplin.git synced 2024-12-03 08:35:29 +02:00
joplin/docs/spec/history/index.html
2020-12-09 22:01:02 +00:00

473 lines
15 KiB
HTML

<!doctype html>
<html>
<!--
!!! WARNING !!!
This file was auto-generated from readme/spec/history.md and any manual change
made to it will be overwritten. To make a change to this file please modify
the source Markdown file:
https://github.com/laurent22/joplin/blob/dev/readme/spec/history.md
-->
<head>
<title>Note history | Joplin</title>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1">
<link rel="stylesheet" href="https://joplinapp.org/css/bootstrap.min.css">
<link rel="shortcut icon" type="image/x-icon" href="https://joplinapp.org/favicon.ico">
<!-- <link rel="stylesheet" href="https://joplinapp.org/css/fontawesome-all.min.css"> -->
<link rel="stylesheet" href="https://joplinapp.org/css/fork-awesome.min.css">
<script src="https://joplinapp.org/js/jquery-3.2.1.slim.min.js"></script>
<style>
body {
background-color: #F1F1F1;
color: #333333;
}
.root {
overflow: hidden;
}
a[href^="mailto:"] {
word-break: break-all;
}
table {
margin-bottom: 1em;
}
td, th {
padding: .8em;
border: 1px solid #ccc;
}
.page-markdown table pre,
.page-markdown table blockquote {
margin-bottom: 0;
}
.page-markdown table pre,
.page-markdown table blockquote {
margin-bottom: 0;
}
.page-markdown table pre {
background-color: rgba(0,0,0,0);
border: none;
margin: 0;
padding: 0;
}
h1, h2 {
border-bottom: 1px solid #eaecef;
padding-bottom: 0.3em;
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
font-weight: 600;
font-size: 2em;
margin-bottom: 16px;
}
h2 {
font-size: 1.6em;
}
h3 {
font-size: 1.3em;
}
code {
color: black;
background-color: #eee;
border: 1px solid #ccc;
font-size: .85em;
word-break: break-all;
}
pre code {
border: none;
}
pre {
font-size: .85em;
}
blockquote {
font-size: 1em;
color: #555;
};
#toc ul {
margin-bottom: 10px;
}
#toc > ul > li {
margin-bottom: 10px;
}
#toc {
padding-bottom: 1em;
}
.title {
display: flex;
align-items: center;
}
.title-icon {
display: flex;
height: 1em;
}
.title-text {
display: flex;
font-weight: normal;
margin-bottom: .2em;
margin-left: .5em;
}
.sub-title {
font-weight: normal;
}
.container {
background-color: white;
padding: 0;
box-shadow: 0 10px 20px #888888;
}
table.screenshots {
margin-top: 2em;
margin-bottom: 2em;
}
table.screenshots th {
height: 3em;
text-align: center;
}
table.screenshots th,
table.screenshots td {
border: 1px solid #C2C2C2;
}
img[align="left"] {
margin-right: 10px;
margin-bottom: 10px;
}
.mobile-screenshot {
height: 40em;
padding: 1em;
}
.cli-screenshot-wrapper {
background-color: black;
vertical-align: top;
padding: 1em 2em 1em 1em;
}
.cli-screenshot {
font-family: "Monaco", "Inconsolata", "CONSOLAS", "Deja Vu Sans Mono", "Droid Sans Mono", "Andale Mono", monospace;
background-color: black;
color: white;
border: none;
}
.cli-screenshot .prompt {
color: #48C2F0;
}
.top-screenshot {
margin-top: 2em;
text-align: center;
}
.header {
position: relative;
padding-left: 2em;
padding-right: 2em;
padding-top: 1em;
padding-bottom: 1em;
color: white;
background-color: #2B2B3D;
}
.header a h1 {
color: white;
}
.header a:hover {
text-decoration: none;
}
.content {
padding-left: 2em;
padding-right: 2em;
padding-bottom: 2em;
padding-top: 2em;
}
.forkme {
position: absolute;
right: 0;
top:0;
}
.nav-wrapper {
position: relative;
width: inherit;
}
.nav {
background-color: black;
display: flex;
flex-direction: row;
align-items: center;
}
.nav.sticky {
position:fixed;
top: 0;
width: inherit;
box-shadow: 0 0 10px #000000;
}
.nav a {
color: white;
display: inline-block;
padding: .6em .9em .6em .9em;
}
.nav ul {
padding-left: 2em;
margin-bottom: 0;
display: table-cell;
display: flex;
width: 100%;
}
.nav ul li {
display: inline-block;
padding: 0;
}
.nav li.selected {
background-color: #222;
font-weight: bold;
}
.nav-right {
display: flex;
text-align: right;
vertical-align: middle;
line-height: 0;
margin-right: 10px;
}
.nav-right .share-btn {
display: none;
}
.nav-right .small-share-btn {
display: none;
}
.footer {
padding: 2em;
border-top: 1px solid #d4d4d4;
margin-top: 2em;
color: gray;
font-size: .9em;
}
a.heading-anchor {
display: inline-block;
opacity: 0;
width: 1.3em;
font-size: 0.7em;
margin-left: 0.4em;
line-height: 1em;
text-decoration: none;
transition: opacity 0.3s;
}
a.heading-anchor:hover,
h1:hover a.heading-anchor,
h2:hover a.heading-anchor,
h3:hover a.heading-anchor,
h4:hover a.heading-anchor,
h5:hover a.heading-anchor,
h6:hover a.heading-anchor {
opacity: 1;
}
@media (min-width: 992px) {
.content{
display: flex;
}
#toc{
display: block!important;
align-self: flex-start;
width: 300px;
position: sticky; top: 20px; left: 0;
}
.main{
width: calc(100% - 300px);
}
}
.bottom-links {
display: flex;
justify-content: center;
border-top: 1px solid #d4d4d4;
margin-top: 30px;
padding-top: 25px;
}
@media all and (min-width: 400px) {
.nav-right .share-btn {
display: inline-block;
}
.nav-right .small-share-btn {
display: none;
}
}
</style>
</head>
<body>
<div class="container root page-history">
<div class="header">
<a class="forkme" href="https://github.com/laurent22/joplin"><img src="https://joplinapp.org/images/ForkMe.png"/></a>
<a href="https://joplinapp.org"><h1 class="title"><img class="title-icon" src="https://joplinapp.org/images/Icon512.png"><span class="title-text">Joplin</span></h1></a>
<p class="sub-title">An open source note taking and to-do application with synchronisation capabilities</p>
</div>
<div class="nav-wrapper">
<div class="nav">
<ul>
<li class=""><a href="https:&#x2F;&#x2F;joplinapp.org/" title="Home"><i class="fa fa-home"></i></a></li>
<li><a href="https://discourse.joplinapp.org" title="Forum">Forum</a></li>
<li><a class="help" href="#" title="Menu">Menu</a></li>
<!-- <li><a class="gsod" href="https://joplinapp.org/gsod2020/" title="Google Season of Docs 2020">GSoD 2020</a></li> -->
</ul>
<div class="nav-right">
<!--
<iframe class="share-btn" src="https://www.facebook.com/plugins/share_button.php?href=http%3A%2F%2Fjoplinapp.org&layout=button&size=small&mobile_iframe=true&width=60&height=20&appId" width="60" height="20" style="border:none;overflow:hidden" scrolling="no" frameborder="0" allowTransparency="true"></iframe>
<iframe class="share-btn" src="https://platform.twitter.com/widgets/tweet_button.html?url=http%3A%2F%2Fjoplinapp.org" width="62" height="20" title="Tweet" style="border: 0; overflow: hidden;"></iframe>
-->
<iframe class="share-btn share-btn-github" src="https://ghbtns.com/github-btn.html?user=laurent22&repo=joplin&type=star&count=true" frameborder="0" scrolling="0" width="100px" height="20px"></iframe>
</div>
</div>
</div>
<div class="content">
<div id="toc"><ul>
<li>
<p>Applications</p>
<ul>
<li><a href="https://joplinapp.org/desktop/">Desktop application</a></li>
<li><a href="https://joplinapp.org/mobile/">Mobile applications</a></li>
<li><a href="https://joplinapp.org/terminal/">Terminal application</a></li>
<li><a href="https://joplinapp.org/clipper/">Web Clipper</a></li>
</ul>
</li>
<li>
<p>Support</p>
<ul>
<li><a href="https://discourse.joplinapp.org">Joplin Forum</a></li>
<li><a href="https://joplinapp.org/markdown/">Markdown Guide</a></li>
<li><a href="https://joplinapp.org/e2ee/">How to enable end-to-end encryption</a></li>
<li><a href="https://joplinapp.org/conflict/">What is a conflict?</a></li>
<li><a href="https://joplinapp.org/debugging/">How to enable debug mode</a></li>
<li><a href="https://joplinapp.org/rich_text_editor/">About the Rich Text editor limitations</a></li>
<li><a href="https://joplinapp.org/faq/">FAQ</a></li>
</ul>
</li>
<li>
<p>Joplin API - Get Started</p>
<ul>
<li><a href="https://joplinapp.org/api/overview/">Joplin API Overview</a></li>
<li><a href="https://joplinapp.org/api/get_started/plugins/">Plugin development</a></li>
<li><a href="https://joplinapp.org/api/tutorials/toc_plugin/">Plugin tutorial</a></li>
</ul>
</li>
<li>
<p>Joplin API - References</p>
<ul>
<li><a href="https://joplinapp.org/api/references/plugin_api/classes/joplin.html">Plugin API</a></li>
<li><a href="https://joplinapp.org/api/references/rest_api/">Data API</a></li>
<li><a href="https://joplinapp.org/api/references/plugin_manifest/">Plugin manifest</a></li>
<li><a href="https://joplinapp.org/api/references/plugin_loading_rules/">Plugin loading rules</a></li>
</ul>
</li>
<li>
<p>Development</p>
<ul>
<li><a href="https://github.com/laurent22/joplin/blob/dev/BUILD.md">How to build the apps</a></li>
<li><a href="https://joplinapp.org/spec/e2ee/">End-to-end encryption spec</a></li>
<li><a href="https://joplinapp.org/spec/history/">Note History spec</a></li>
<li><a href="https://joplinapp.org/spec/sync_lock/">Sync Lock spec</a></li>
<li><a href="https://joplinapp.org/spec/plugins/">Plugin Architecture spec</a></li>
<li><a href="https://joplinapp.org/spec/search_sorting/">Search Sorting spec</a></li>
</ul>
</li>
<li>
<p>Google Summer of Code 2020</p>
<ul>
<li><a href="https://joplinapp.org/gsoc2020/index/">Google Summer of Code 2020</a></li>
<li><a href="https://joplinapp.org/gsoc2020/ideas/">Project Ideas</a></li>
</ul>
</li>
<li>
<p>About</p>
<ul>
<li><a href="https://joplinapp.org/changelog/">Changelog (Desktop App)</a></li>
<li><a href="https://joplinapp.org/changelog_cli/">Changelog (CLI App)</a></li>
<li><a href="https://joplinapp.org/stats/">Stats</a></li>
<li><a href="https://joplinapp.org/donate/">Donate</a></li>
</ul>
</li>
</ul>
</div>
<div class="main">
<h1>Note history<a name="note-history" href="#note-history" class="heading-anchor">🔗</a></h1>
<p>The note history preserves versions of the notes at regular interval. All the revisions are synced and shared across all devices.</p>
<h2>Revision format<a name="revision-format" href="#revision-format" class="heading-anchor">🔗</a></h2>
<p>To save space, only the diff of a note is saved: the title and body are saved as text diff, while the other properties are saved as an object diff (i.e. only the modified properties are saved).</p>
<p>Advantages: it saves space, and writes are fast.</p>
<p>Disadvantages: reading a note version back is slower since it needs to be rebuilt, starting from the oldest revision and applying diffs to it one at a time.</p>
<h2>Revision service<a name="revision-service" href="#revision-service" class="heading-anchor">🔗</a></h2>
<p>Every time an object is changed in Joplin, some metadata is added to the changed_items table. The revision service uses this to know what notes need a new revision. Specifically it will create a revision under these conditions:</p>
<ol>
<li>
<p>The note hadn't had a revision for more than 10 minutes</p>
</li>
<li>
<p>The note was recently modified, but before that it hadn't had a revision for more than 7 days</p>
</li>
</ol>
<p>Condition 1 saves the current state of the note (i.e. <strong>after</strong> the edit). Condition 2 saves the state has it was <strong>before</strong> the edit.</p>
<p>The reason for that is that we save revisions every 10 minutes, but if you make many changes within a few minutes and then stop modifying the note, the final revision will not contain the current content of the note. Basically at one point (let's say at t1) the service will see there's a revision from less than 10 minutes, and will not save a new one.</p>
<p>That's why when you change the note again more than 7 days later, we save that revision that wasn't saved at t1. The logic is a bit complicated but the goal is to preserve the last significant state of a note. If you make many changes to a note then stop editing it for several months, the last significant state was at the end of that series of edits, so we need to save that.</p>
<p>Additionally, notes that were created before the service existed never had revisions. So the 7 days logic ensure that they get one the first time they are modified.</p>
<h2>Revision deletion<a name="revision-deletion" href="#revision-deletion" class="heading-anchor">🔗</a></h2>
<p>Revisions are deleted once they are older than a given interval as set in <code>revisionService.oldNoteInterval</code> (90 days by default).</p>
<h2>Disabling the service<a name="disabling-the-service" href="#disabling-the-service" class="heading-anchor">🔗</a></h2>
<p>When disabled, no new revision is saved, but the existing one remain there, and will only be deleted after the interval specified in <code>revisionService.oldNoteInterval</code>.</p>
<h2>Revision settings are global<a name="revision-settings-are-global" href="#revision-settings-are-global" class="heading-anchor">🔗</a></h2>
<p>Since all the revisions are synced across all devices, it means these settings are kind of global. So for example, if on one device you set it to keep revisions for 30 days, and on another to 100 days, the revisions older than 30 days will be deleted, and then this deletion will be synced. So in practice it means revisions are kept for whatever is the minimum number of days as set on any of the devices. In that particular case, the 100 days setting will be essentially ignored, and only the 30 days one will apply.</p>
<h2>Why is there less than 10 minutes between some revisions?<a name="why-is-there-less-than-10-minutes-between-some-revisions" href="#why-is-there-less-than-10-minutes-between-some-revisions" class="heading-anchor">🔗</a></h2>
<p>It can happen if a note is changed on two different devices within less than 10 minutes. A revision will be created on each device, then when they are synced it will appear that there's less than 10 min between the revisions.</p>
<div class="bottom-links">
<a href="https://github.com/laurent22/joplin/blob/dev/readme/spec/history.md">
<i class="fa fa-github"></i> Improve this doc
</a>
</div>
<script>
function stickyHeader() {
return; // Disabled
if ($(window).scrollTop() > 179) {
$('.nav').addClass('sticky');
} else {
$('.nav').removeClass('sticky');
}
}
$('#toc').hide();
$('.help').click(function(event) {
event.preventDefault();
$('#toc').show();
});
$(window).scroll(function() {
stickyHeader();
});
(function(i,s,o,g,r,a,m){i['GoogleAnalyticsObject']=r;i[r]=i[r]||function(){
(i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o),
m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m)
})(window,document,'script','https://www.google-analytics.com/analytics.js','ga');
ga('create', 'UA-103586105-1', 'auto');
ga('send', 'pageview');
</script>
</div></div>
<div class="footer">
Copyright (C) 2016-2020 Laurent Cozic
</div>
</body>
</html>