blocks|key|1588929|text|您可以编码为Base64，然后实现一个简单的无损压缩算法，比如游程编码或Golomb编码。这应该不会太难，而且可能会给你一点压力。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1588930|Golomb+encoding|offset|length|1588931|我还找到了JsZip。我猜你可以检查代码，并且只使用算法，如果它是兼容的。|1588932|希望这能有所帮助。|1588933|http://jszip.stuartk.co.uk/|1588934|entityMap|0|LINK|mutability|MUTABLE|url|http://en.wikipedia.org/wiki/Golomb_coding#Encoding|1^0|0|0|F|0|0|0|0|0|R|1|0^^$0|@$1|2|3|4|5|6|7|U|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|V|8|@]|9|@$D|W|E|X|1|Y]]|A|$]]|$1|F|3|G|5|6|7|Z|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|10|8|@]|9|@]|A|$]]|$1|J|3|K|5|6|7|11|8|@]|9|@$D|12|E|13|1|14]]|A|$]]|$1|L|3|-4|5|6|7|15|8|@]|9|@]|A|$]]]|M|$N|$5|O|P|Q|A|$R|S]]|T|$5|O|P|Q|A|$R|K]]]]

You could encode to Base64 and then implement a simple lossless compression algorithm, such as run-length encoding or Golomb encoding. This shouldn't be too hard to do and might give you a bit of ompression. 

<a href="http://en.wikipedia.org/wiki/Golomb_coding#Encoding">Golomb encoding</a>

I also found JsZip. I guess you could check the code and only use the algorithm, if it is compatible.

Hope this helps.

<a href="http://jszip.stuartk.co.uk/">http://jszip.stuartk.co.uk/</a>

blocks|key|1589025|text|This+Stackoverflow+Question有一个可能会有帮助的答案。这里有一个指向JavaScript压缩库的链接。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1589026|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/q/294297/143739^0|0|R|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

<a href="https://stackoverflow.com/q/294297/143739">This Stackoverflow Question</a> has an answer that may help. There is a link to a JavaScript compression library.

blocks|key|1803622|text|我最近不得不用localStorage保存巨大的JSON对象。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1803623|首先，是的，它们确实保留了unicode。但是，不要尝试将对象之类的内容直接保存到本地存储中。它需要是一个字符串。|1803624|以下是我在将对象转换为字符串之前使用的一些压缩技术(在我的例子中似乎工作得很好)：|1803625|通过执行类似(%2Bnum).toString(+36+)的操作，可以将任何数字从基数10转换为基数36。例如，数字48346942将是"ss8qm“，它(包括引号)少了1个字符。添加引号实际上可能会增加字符数。因此，数字越大，回报越好。要将其转换回来，您可以执行类似于parseInt("ss8qm"，36)的操作。|1803626|如果你正在存储一个带有任何重复键的对象，最好创建一个查找对象，在这个对象中，你可以给原始对象分配一个缩短的键。所以，为了举例，如果你有：|1803627|{
++++name:+'Frank',
++++age:+36,
++++family:+[{
++++++++name:+'Luke',
++++++++age:+14,
++++++++relation:+'cousin'
++++},+{
++++++++name:+'Sarah',
++++++++age:+22,
++++++++relation:+'sister'
++++},+{
++++++++name:+'Trish',
++++++++age:+31,
++++++++relation:+'wife'
++++}]
}|code-block|syntax|javascript|1803628|然后你就可以做到：|1803629|{
++++//+original+w/+shortened+keys
++++o:+{++++
++++++++n:+'Frank',
++++++++a:+36,
++++++++f:+[{
++++++++++++n:+'Luke',
++++++++++++a:+14,
++++++++++++r:+'cousin'
++++++++},+{
++++++++++++n:+'Sarah',
++++++++++++a:+22,
++++++++++++r:+'sister'
++++++++},+{
++++++++++++n:+'Trish',
++++++++++++a:+31,
++++++++++++r:+'wife'
++++++++}]
++++},

++++//+lookup
++++l:+{
++++++++n:+'name',
++++++++a:+'age',
++++++++r:+'relation',
++++++++f:+'family'
++++}
}|1803630|同样，这在大小上是值得的。和重复。在我的例子中，它工作得非常好。但这取决于主题。|1803631|所有这些都需要一个函数来收缩，一个函数来扩展。|1803632|另外，我建议创建一个用于从本地存储中存储和检索数据的类。我遇到了没有足够空间的情况。因此写入将会失败。其他站点也可能写入本地存储，这可能会占用一些空间。有关更多详细信息，请参阅this+post。|offset|length|1803633|在我构建的类中，我所做的是第一次尝试删除具有给定键的任何项。然后尝试setItem。这两行代码用try+catch包起来。如果失败，则假定存储已满。然后，它将清除localStorage中的所有内容，以便为其腾出空间。然后，在清除之后，它将再次尝试setItem。这也包含在try+catch中。因为如果字符串本身大于localStorage可以处理的大小，它可能会失败。|1803634|编辑:还有，你会遇到很多人提到的LZW压缩。我已经实现了这一点，它对小字符串有效。但对于大型字符串，它将开始使用无效字符，从而导致数据损坏。所以要小心，如果你要进行方向测试测试|1803635|entityMap|0|LINK|mutability|MUTABLE|url|https://stackoverflow.com/questions/2603682/is-anyone-else-receiving-a-quota-exceeded-err-on-their-ipad-when-accessing-locals^0|0|0|0|0|0|0|0|0|0|0|2G|9|0|0|0|0^^$0|@$1|2|3|4|5|6|7|1C|8|@]|9|@]|A|$]]|$1|B|3|C|5|6|7|1D|8|@]|9|@]|A|$]]|$1|D|3|E|5|6|7|1E|8|@]|9|@]|A|$]]|$1|F|3|G|5|6|7|1F|8|@]|9|@]|A|$]]|$1|H|3|I|5|6|7|1G|8|@]|9|@]|A|$]]|$1|J|3|K|5|L|7|1H|8|@]|9|@]|A|$M|N]]|$1|O|3|P|5|6|7|1I|8|@]|9|@]|A|$]]|$1|Q|3|R|5|L|7|1J|8|@]|9|@]|A|$M|N]]|$1|S|3|T|5|6|7|1K|8|@]|9|@]|A|$]]|$1|U|3|V|5|6|7|1L|8|@]|9|@]|A|$]]|$1|W|3|X|5|6|7|1M|8|@]|9|@$Y|1N|Z|1O|1|1P]]|A|$]]|$1|10|3|11|5|6|7|1Q|8|@]|9|@]|A|$]]|$1|12|3|13|5|6|7|1R|8|@]|9|@]|A|$]]|$1|14|3|-4|5|6|7|1S|8|@]|9|@]|A|$]]]|15|$16|$5|17|18|19|A|$1A|1B]]]]

I recently had to save huge JSON objects in localStorage.

Firstly, yeah, they do stay unicode. But don't try to save something like an object straight to local storage. It needs to be a string.

Here are some compression techniques I used (that seemed to work well in my case), before converting my object to a string:

Any numbers can be converted from a base of 10 to a base of 36 by doing something like (+num).toString(36). For example the number 48346942 will then be "ss8qm" which is (including the quotes) 1 character less. It is possible that the addition of the quotes will actually add to the character count. So the larger the number the better the payoff. To convert it back you would do something like parseInt("ss8qm", 36).

If you are storing an object with any key that will repeat it's best to create a lookup object where you assign a shortened key to the original. So, for the sake of example, if you have:

<pre><code>{
 name: 'Frank',
 age: 36,
 family: [{
 name: 'Luke',
 age: 14,
 relation: 'cousin'
 }, {
 name: 'Sarah',
 age: 22,
 relation: 'sister'
 }, {
 name: 'Trish',
 age: 31,
 relation: 'wife'
 }]
}
</code></pre>

Then you could make it:

<pre><code>{
 // original w/ shortened keys
 o: { 
 n: 'Frank',
 a: 36,
 f: [{
 n: 'Luke',
 a: 14,
 r: 'cousin'
 }, {
 n: 'Sarah',
 a: 22,
 r: 'sister'
 }, {
 n: 'Trish',
 a: 31,
 r: 'wife'
 }]
 },

 // lookup
 l: {
 n: 'name',
 a: 'age',
 r: 'relation',
 f: 'family'
 }
}
</code></pre>

Again, this pays off with size. And repetition. In my case it worked really well. But it depends on the subject.

All of these require a function to shrink and one to expand back out.

Also, I would recommend creating a class that is used to store &amp; retrieve data from local storage. I ran into there not being enough space. So the writes would fail. Other sites may also write to local storage which can take away some of that space. See <a href="https://stackoverflow.com/questions/2603682/is-anyone-else-receiving-a-quota-exceeded-err-on-their-ipad-when-accessing-locals">this post</a> for more details.

What I did, in the class I built, was first attempt to remove any item with the given key. Then attempt the setItem. These two lines are wrapped with a try catch. If it fails then it assumes the storage is full. It will then clear everything in localStorage in an attempt to make room for it. It will then, after the clear, attempt to setItem again. This, too, is wrapped in a try catch. Since it may fail if the string itself is larger than what localStorage can handle.

EDIT: Also, you will come across the LZW compression a lot of people mention. I had implemented that, and it worked for small strings. But with large strings it would begin using invalid characters which resulted in corrupt data. So just be careful, and if you go in that direction test test test

blocks|key|1803738|text|at+this+blog很好地解释了javascript的Base64压缩。当使用整个framework时，实现也是available+here。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1803739|entityMap|0|LINK|mutability|MUTABLE|url|http://j0rr1t.blogspot.com.es/2013/02/optimal-compression-for-client-side.html|1|https://github.com/venalis/VNLS|2|https://github.com/venalis/VNLS/blob/master/src/vnls.string.js^0|0|C|0|17|9|1|1M|E|2|0^^$0|@$1|2|3|4|5|6|7|P|8|@]|9|@$A|Q|B|R|1|S]|$A|T|B|U|1|V]|$A|W|B|X|1|Y]]|C|$]]|$1|D|3|-4|5|6|7|Z|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]|L|$5|G|H|I|C|$J|M]]|N|$5|G|H|I|C|$J|O]]]]

Base64 compression for javascript is very well explained <a href="http://j0rr1t.blogspot.com.es/2013/02/optimal-compression-for-client-side.html" rel="nofollow">at this blog</a>. Implementation is also <a href="https://github.com/venalis/VNLS/blob/master/src/vnls.string.js" rel="nofollow">available here</a> when using entire <a href="https://github.com/venalis/VNLS" rel="nofollow">framework</a>.

I am using <code>localStorage</code> in a project, and it will need to store lots of data, mostly of type int, bool and string. I know that javascript strings are unicode, but when stored in <code>localStorage</code>, do they stay unicode? If so, is there a way I could compress the string to use all of the data in a unicode byte, or should i just use base64 and have less compression? All of the data will be stored as one large string.

EDIT: Now that I think about it, base64 wouldn't do much compression at all, the data is already in base 64, <code>a-zA-Z0-9 ;:</code> is 65 characters.

javascript string compression with localStorage

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我在一个项目中使用localStorage，它需要存储大量的数据，主要是整型、布尔型和字符串类型。我知道javascript字符串是unicode，但是当它们存储在localStorage中时，它们会保持unicode吗？如果是这样的话，有没有一种方法可以压缩字符串以使用unicode字节中的所有数据，或者我应该只使用...

问使用localStorage进行javascript字符串压缩
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