fix my rss feed
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@ -16,265 +16,7 @@
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<guid>https://squi.bid/blog/Serializing-data-in-C/index.html</guid>
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<guid>https://squi.bid/blog/Serializing-data-in-C/index.html</guid>
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<link>https://squi.bid/blog/Serializing-data-in-C/index.html</link>
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<link>https://squi.bid/blog/Serializing-data-in-C/index.html</link>
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<pubDate>Sat, 09 Aug 2025 08:50:12 -0400</pubDate>
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<pubDate>Sat, 09 Aug 2025 08:50:12 -0400</pubDate>
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||||||
<description><![CDATA[<!DOCTYPE HTML>
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<description><![CDATA[This post seems to screw up my rss feed. You can read it on my website: https://squi.bid/blog/Serializing-data-in-C/index.html]]></description>
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<html lang="en">
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<title>'Serializing data in C'</title>
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||||||
<meta name="date" content="2025/07/14">
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<meta name="colorscheme" content="mellow"></meta>
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<link rel="stylesheet" href="/style.css">
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<style>
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||||||
.-spell {}
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.Number {color: #e29eca}
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.Function {color: #c1c0d4}
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||||||
.String {color: #90b99f}
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.Character {color: #90b99f}
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.PreCondit {color: #ea83a5}
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.-property {color: #c1c0d4}
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.Comment {color: #757581; font-style: italic}
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.Macro {color: #ea83a5}
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.-type-builtin {color: #e29eca}
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.Type {color: #b9aeda}
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||||||
.Keyword {color: #aca1cf}
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||||||
.Constant {color: #ea83a5}
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||||||
.-variable-parameter {color: #e29eca}
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||||||
.-punctuation-delimiter {color: #9998a8}
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.-punctuation-bracket {color: #9998a8}
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.Include {color: #aca1cf}
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||||||
.Structure {color: #e6b99d}
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.-variable {color: #c9c7cd}
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.Operator {color: #e6b99d}
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</style>
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||||||
<body id="blog">
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<h1>Serializing data in C</h1>
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<p>
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||||||
I've started work on a new project! The project in question is one that
|
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||||||
I have wanted to tackle for a long time but did not have the courage to
|
|
||||||
do so. However at long last it is time...
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||||||
</p>
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||||||
<p>
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time to get funky...
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||||||
</p>
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||||||
<p>
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||||||
I'm writing a music player, and not one that simply plays music like
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|
||||||
spotify. This music player falls more inline with MPD in which it's a
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|
||||||
daemon running in the background playing the music and clients may
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||||||
communicate with it to tell it what to play when and the likes.
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||||||
</p>
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||||||
<p>
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||||||
Currently I'm at that very important part in which the daemon needs to
|
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||||||
communicate to clients via a protocol *fancy*, and to do so I have decided
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||||||
to go with a socket that way <i>in theory</i> I can control my daemon from
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||||||
other devices on the network. With the communication method decided I now
|
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||||||
have to define what data goes between devices. At the current moment I've
|
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||||||
settled on an enum for different signals.
|
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||||||
</p>
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||||||
<p>
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||||||
As seen here:
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||||||
</p>
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||||||
<pre>
|
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||||||
<span class="Structure"><span class="Keyword">enum</span></span> <span class="Type">libmoo_signal</span> <span class="-punctuation-bracket">{</span>
|
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||||||
<span class="Comment"><span class="Comment"><span class="-spell">/* core signals are in the < 100 range */</span></span></span>
|
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||||||
<span class="-variable"><span class="Constant"><span class="Constant">LIBMOO_SIGNAL_ESTCON</span></span></span> <span class="Operator">=</span> <span class="Number"><span class="Number">1</span></span><span class="-punctuation-delimiter">,</span>
|
|
||||||
<span class="-variable"><span class="Constant"><span class="Constant">LIBMOO_SIGNAL_ESTDCON</span></span></span> <span class="Operator">=</span> <span class="Number"><span class="Number">2</span></span><span class="-punctuation-delimiter">,</span>
|
|
||||||
<span class="-variable"><span class="Constant"><span class="Constant">LIBMOO_SIGNAL_INCOMPATABLE_VERSION</span></span></span> <span class="Operator">=</span> <span class="Number"><span class="Number">3</span></span><span class="-punctuation-delimiter">,</span>
|
|
||||||
<span class="-variable"><span class="Constant"><span class="Constant">LIBMOO_SIGNAL_OK</span></span></span> <span class="Operator">=</span> <span class="Number"><span class="Number">50</span></span><span class="-punctuation-delimiter">,</span> <span class="Comment"><span class="Comment"><span class="-spell">/* previous message received was ok */</span></span></span>
|
|
||||||
<span class="-variable"><span class="Constant"><span class="Constant">LIBMOO_SIGNAL_NOK</span></span></span> <span class="Operator">=</span> <span class="Number"><span class="Number">51</span></span><span class="-punctuation-delimiter">,</span> <span class="Comment"><span class="Comment"><span class="-spell">/* previous message received was not ok */</span></span></span>
|
|
||||||
<span class="Comment"><span class="Comment"><span class="-spell">/* setting/adding data happens in the 100 range */</span></span></span>
|
|
||||||
<span class="-variable"><span class="Constant"><span class="Constant">LIBMOO_SIGNAL_ADD_SONG</span></span></span> <span class="Operator">=</span> <span class="Number"><span class="Number">101</span></span><span class="-punctuation-delimiter">,</span>
|
|
||||||
<span class="-variable"><span class="Constant"><span class="Constant">LIBMOO_SIGNAL_SET_PLAY</span></span></span> <span class="Operator">=</span> <span class="Number"><span class="Number">103</span></span><span class="-punctuation-delimiter">,</span>
|
|
||||||
<span class="-variable"><span class="Constant"><span class="Constant">LIBMOO_SIGNAL_SET_PAUSE</span></span></span> <span class="Operator">=</span> <span class="Number"><span class="Number">104</span></span><span class="-punctuation-delimiter">,</span>
|
|
||||||
<span class="-variable"><span class="Constant"><span class="Constant">LIBMOO_SIGNAL_SET_TOGGLE_PAUSE</span></span></span> <span class="Operator">=</span> <span class="Number"><span class="Number">105</span></span><span class="-punctuation-delimiter">,</span>
|
|
||||||
<span class="-variable"><span class="Constant"><span class="Constant">LIBMOO_SIGNAL_SET_SKIP_NEXT</span></span></span> <span class="Operator">=</span> <span class="Number"><span class="Number">110</span></span><span class="-punctuation-delimiter">,</span>
|
|
||||||
<span class="-variable"><span class="Constant"><span class="Constant">LIBMOO_SIGNAL_SET_SKIP_PREV</span></span></span> <span class="Operator">=</span> <span class="Number"><span class="Number">111</span></span><span class="-punctuation-delimiter">,</span>
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|
||||||
<span class="Comment"><span class="Comment"><span class="-spell">/* removing data happens in the 200 range */</span></span></span>
|
|
||||||
<span class="-variable"><span class="Constant"><span class="Constant">LIBMOO_SIGNAL_REM_SONG</span></span></span> <span class="Operator">=</span> <span class="Number"><span class="Number">201</span></span><span class="-punctuation-delimiter">,</span>
|
|
||||||
<span class="Comment"><span class="Comment"><span class="-spell">/* getting data happens in the 300 range */</span></span></span>
|
|
||||||
<span class="-variable"><span class="Constant"><span class="Constant">LIBMOO_SIGNAL_GET_CUR_SONG</span></span></span> <span class="Operator">=</span> <span class="Number"><span class="Number">301</span></span><span class="-punctuation-delimiter">,</span>
|
|
||||||
<span class="-variable"><span class="Constant"><span class="Constant">LIBMOO_SIGNAL_GET_PAUSE</span></span></span> <span class="Operator">=</span> <span class="Number"><span class="Number">303</span></span><span class="-punctuation-delimiter">,</span>
|
|
||||||
<span class="-variable"><span class="Constant"><span class="Constant">LIBMOO_SIGNAL_GET_PROGRESS</span></span></span> <span class="Operator">=</span> <span class="Number"><span class="Number">310</span></span><span class="-punctuation-delimiter">,</span>
|
|
||||||
<span class="-punctuation-bracket">}</span><span class="-punctuation-delimiter">;</span>
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|
||||||
</pre>
|
|
||||||
<p>
|
|
||||||
As for how I actually transmit the signals, I've settled on a format which
|
|
||||||
defaults to 42 bytes of data being sent with the option to send more by
|
|
||||||
setting the 41st-42nd bytes to a uint16 containing the additional number
|
|
||||||
of bytes being sent.
|
|
||||||
</p>
|
|
||||||
<pre>
|
|
||||||
<span class="Comment"><span class="Comment"><span class="-spell">/* byte - data</span></span><span class="-spell">
|
|
||||||
<span class="Comment"> *</span>
|
|
||||||
<span class="Comment"> * 0-7 - libmoo protocol version</span>
|
|
||||||
<span class="Comment"> *</span>
|
|
||||||
<span class="Comment"> * 8-31 - reserved for the future</span>
|
|
||||||
<span class="Comment"> *</span>
|
|
||||||
<span class="Comment"> * 32-40 - libmoo_signal</span>
|
|
||||||
<span class="Comment"> *</span>
|
|
||||||
<span class="Comment"> * 41-42 - uint16 more_data</span>
|
|
||||||
<span class="Comment"> *</span>
|
|
||||||
<span class="Comment"> * 43-8191 - char *data</span>
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|
||||||
<span class="Comment"> */</span></span><span class="Comment"></span></span>
|
|
||||||
<span class="Structure"><span class="Keyword">typedef</span></span> <span class="Type"><span class="-type-builtin">char</span></span> <span class="Operator">*</span> <span class="Type">libmoo_payload</span><span class="-punctuation-delimiter">;</span>
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|
||||||
</pre>
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|
||||||
<p>
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|
||||||
I'm not sure how this compares to other protocols used to transmit data,
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|
||||||
but I'm quite proud of how I've laid this out.
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|
||||||
</p>
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|
||||||
<p>
|
|
||||||
Moving on to actual the point of this article: serialization. For the sake
|
|
||||||
of useablilty I've defined a datatype which models our payload which you
|
|
||||||
can see here:
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|
||||||
</p>
|
|
||||||
<pre>
|
|
||||||
<span class="Structure"><span class="Keyword">typedef</span></span> <span class="Structure"><span class="Keyword">struct</span></span> <span class="-punctuation-bracket">{</span>
|
|
||||||
<span class="Structure"><span class="Keyword">enum</span></span> <span class="Type">libmoo_signal</span> <span class="-property">signal</span><span class="-punctuation-delimiter">;</span> <span class="Comment"><span class="Comment"><span class="-spell">/* the signal */</span></span></span>
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|
||||||
<span class="Type"><span class="-type-builtin">uint16_t</span></span> <span class="-property">more_data</span><span class="-punctuation-delimiter">;</span> <span class="Comment"><span class="Comment"><span class="-spell">/* the number bytes of the additional data */</span></span></span>
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|
||||||
<span class="Type"><span class="-type-builtin">char</span></span> <span class="Operator">*</span><span class="-property">data</span><span class="-punctuation-delimiter">;</span> <span class="Comment"><span class="Comment"><span class="-spell">/* additional data */</span></span></span>
|
|
||||||
<span class="-punctuation-bracket">}</span> <span class="Type"><span class="Type">libmoo_data</span></span><span class="-punctuation-delimiter">;</span>
|
|
||||||
</pre>
|
|
||||||
<p>
|
|
||||||
And a function which allows you to easily create libmoo_data:
|
|
||||||
</p>
|
|
||||||
<pre>
|
|
||||||
<span class="Comment"><span class="Comment"><span class="-spell"><span class="Comment">/**</span>
|
|
||||||
<span class="Comment"> * @brief create a new libmoo_data</span>
|
|
||||||
<span class="Comment"> *</span>
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|
||||||
<span class="Comment"> * @param signal the signal to set</span>
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|
||||||
<span class="Comment"> * @param data the data to set</span>
|
|
||||||
<span class="Comment"> * @return the data object</span>
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|
||||||
<span class="Comment"> */</span></span></span></span>
|
|
||||||
<span class="Type">libmoo_data</span> <span class="Operator">*</span><span class="-variable"><span class="Function">libmoo_create_data</span></span><span class="-punctuation-bracket">(</span><span class="Structure"><span class="Keyword">enum</span></span> <span class="Type">libmoo_signal</span> <span class="-variable"><span class="-variable-parameter">signal</span></span><span class="-punctuation-delimiter">,</span> <span class="Type"><span class="-type-builtin">char</span></span> <span class="-variable-parameter"><span class="Operator">*</span><span class="-variable">data</span></span><span class="-punctuation-bracket">)</span><span class="-punctuation-delimiter">;</span>
|
|
||||||
</pre>
|
|
||||||
<p>
|
|
||||||
I've provided this so that you don't have to deal with manually setting
|
|
||||||
the size of the data that you pass into the object, although (if you so
|
|
||||||
choose) you may easily override it.
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|
||||||
</p>
|
|
||||||
<h2>Serializing</h2>
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|
||||||
<p>
|
|
||||||
Now that we've gone over the interface for interacting with the payload
|
|
||||||
let's get to the intersting stage in which we get the data ready for
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|
||||||
launch.
|
|
||||||
</p>
|
|
||||||
<pre>
|
|
||||||
<span class="Comment"><span class="Comment"><span class="-spell"><span class="Comment">/**</span>
|
|
||||||
<span class="Comment"> * @brief convert data into a payload.</span>
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|
||||||
<span class="Comment"> * The payload must be allocated prior to calling this function it should be</span>
|
|
||||||
<span class="Comment"> * LIBMOO_PAYLOAD_SIZE chars long unless you think you know better.</span>
|
|
||||||
<span class="Comment"> *</span>
|
|
||||||
<span class="Comment"> * @param payload pointer to the payload</span>
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|
||||||
<span class="Comment"> * @param data data which will be serialized</span>
|
|
||||||
<span class="Comment"> * @return the size of the resulting payload</span>
|
|
||||||
<span class="Comment"> */</span></span></span></span>
|
|
||||||
<span class="Type"><span class="-type-builtin">size_t</span></span>
|
|
||||||
<span class="-variable"><span class="Function">libmoo_serialize_data</span></span><span class="-punctuation-bracket">(</span><span class="Type">libmoo_payload</span> <span class="-variable"><span class="-variable-parameter">payload</span></span><span class="-punctuation-delimiter">,</span> <span class="Type">libmoo_data</span> <span class="-variable-parameter"><span class="Operator">*</span><span class="-variable">data</span></span><span class="-punctuation-bracket">)</span>
|
|
||||||
<span class="-punctuation-bracket">{</span>
|
|
||||||
<span class="Type"><span class="-type-builtin">void</span></span> <span class="Operator">*</span><span class="-variable">ptr</span><span class="-punctuation-delimiter">;</span>
|
|
||||||
<span class="-variable">ptr</span> <span class="Operator">=</span> <span class="-variable">payload</span><span class="-punctuation-delimiter">;</span>
|
|
||||||
<span class="Comment"><span class="Comment"><span class="-spell">/* add LIBMOO_VERSION */</span></span></span>
|
|
||||||
<span class="-variable"><span class="Function">mempcpy</span></span><span class="-punctuation-bracket">(</span><span class="-variable">ptr</span><span class="-punctuation-delimiter">,</span> <span class="-variable"><span class="Constant">LIBMOO_VERSION</span></span><span class="-punctuation-delimiter">,</span> <span class="-variable"><span class="Function">strlen</span></span><span class="-punctuation-bracket">(</span><span class="-variable"><span class="Constant">LIBMOO_VERSION</span></span><span class="-punctuation-bracket">)</span><span class="-punctuation-bracket">)</span><span class="-punctuation-delimiter">;</span>
|
|
||||||
<span class="Comment"><span class="Comment"><span class="-spell">/* skip the reserved space */</span></span></span>
|
|
||||||
<span class="-variable">ptr</span> <span class="Operator">+=</span> <span class="Number"><span class="Number">24</span></span><span class="-punctuation-delimiter">;</span>
|
|
||||||
<span class="Comment"><span class="Comment"><span class="-spell">/* add the signal type */</span></span></span>
|
|
||||||
<span class="-variable"><span class="Function">mempcpy</span></span><span class="-punctuation-bracket">(</span><span class="-variable">ptr</span><span class="-punctuation-delimiter">,</span> <span class="Operator">&</span><span class="-_parent"><span class="-variable">data</span><span class="Operator">-></span><span class="-property">signal</span></span><span class="-punctuation-delimiter">,</span> <span class="Operator"><span class="Keyword">sizeof</span></span><span class="-punctuation-bracket">(</span><span class="-_parent"><span class="-variable">data</span><span class="Operator">-></span><span class="-property">signal</span></span><span class="-punctuation-bracket">)</span><span class="-punctuation-bracket">)</span><span class="-punctuation-delimiter">;</span>
|
|
||||||
<span class="Comment"><span class="Comment"><span class="-spell">/* add the size of the more data */</span></span></span>
|
|
||||||
<span class="-variable"><span class="Function">mempcpy</span></span><span class="-punctuation-bracket">(</span><span class="-variable">ptr</span><span class="-punctuation-delimiter">,</span> <span class="Operator">&</span><span class="-_parent"><span class="-variable">data</span><span class="Operator">-></span><span class="-property">more_data</span></span><span class="-punctuation-delimiter">,</span> <span class="Operator"><span class="Keyword">sizeof</span></span><span class="-punctuation-bracket">(</span><span class="-_parent"><span class="-variable">data</span><span class="Operator">-></span><span class="-property">more_data</span></span><span class="-punctuation-bracket">)</span><span class="-punctuation-bracket">)</span><span class="-punctuation-delimiter">;</span>
|
|
||||||
<span class="Comment"><span class="Comment"><span class="-spell">/* the more data */</span></span></span>
|
|
||||||
<span class="Conditional"><span class="Keyword">if</span></span> <span class="-punctuation-bracket">(</span><span class="-_parent"><span class="-variable">data</span><span class="Operator">-></span><span class="-property">more_data</span></span><span class="-punctuation-bracket">)</span> <span class="-punctuation-bracket">{</span>
|
|
||||||
<span class="-variable"><span class="Function">mempcpy</span></span><span class="-punctuation-bracket">(</span><span class="-variable">ptr</span><span class="-punctuation-delimiter">,</span> <span class="-_parent"><span class="-variable">data</span><span class="Operator">-></span><span class="-property">data</span></span><span class="-punctuation-delimiter">,</span> <span class="-variable"><span class="Function">strlen</span></span><span class="-punctuation-bracket">(</span><span class="-_parent"><span class="-variable">data</span><span class="Operator">-></span><span class="-property">data</span></span><span class="-punctuation-bracket">)</span><span class="-punctuation-bracket">)</span><span class="-punctuation-delimiter">;</span>
|
|
||||||
<span class="-punctuation-bracket">}</span>
|
|
||||||
<span class="Statement"><span class="Keyword">return</span></span> <span class="-variable"><span class="Constant">LIBMOO_HEADER_SIZE</span></span> <span class="Operator">+</span> <span class="Operator"><span class="Keyword">sizeof</span></span><span class="-punctuation-bracket">(</span><span class="-_parent"><span class="-variable">data</span><span class="Operator">-></span><span class="-property">more_data</span></span><span class="-punctuation-bracket">)</span> <span class="Operator">+</span> <span class="-_parent"><span class="-variable">data</span><span class="Operator">-></span><span class="-property">more_data</span></span><span class="-punctuation-delimiter">;</span>
|
|
||||||
<span class="-punctuation-bracket">}</span>
|
|
||||||
</pre>
|
|
||||||
<p>
|
|
||||||
As you may have noticed in the code snippet above libmoo_serialize_data is
|
|
||||||
a function that takes in a pre-allocated payload, and the data to
|
|
||||||
serialize. I've opted to allow the user to allocate space for the payload
|
|
||||||
if they determine that they know what they're doing incase my dumb
|
|
||||||
function is too generous. Moving onto the body of the function you'll see
|
|
||||||
an unfamiliar function called mempcpy which is a macro for copying data
|
|
||||||
into the payload. This macro takes in the same arguments as memcpy (dest,
|
|
||||||
src, size), but in addition it increments dest by size so I can append
|
|
||||||
data to the payload without making this code horrible to read.
|
|
||||||
</p>
|
|
||||||
<p>
|
|
||||||
In earlier stages of development I didn't actually return the size of the
|
|
||||||
resulting payload, thinking that I could just strlen it. This was a rookie
|
|
||||||
mistake. Because I've included extra space (bytes 8-31) when you run
|
|
||||||
strlen on any payload it results in 5 (the length of the version string).
|
|
||||||
After finding this out I decided that I do actually want to send more
|
|
||||||
than the version information, and so now libmoo_serialize_data returns a
|
|
||||||
size_t continaing the number of bytes that have been serialized.
|
|
||||||
</p>
|
|
||||||
<h2>Deserializing</h2>
|
|
||||||
<p>
|
|
||||||
Now that we've serialized and <i>presumably</i> sent the data to a client
|
|
||||||
we need to do the magic part which completes this transaction:
|
|
||||||
deserialization.
|
|
||||||
</p>
|
|
||||||
<p>
|
|
||||||
Below is my method of deserializing the data. It's pretty much the
|
|
||||||
opposite of the serialization function with the key exception that we
|
|
||||||
need to do some validation. <i>Which I haven't implemented yet.</i>
|
|
||||||
</p>
|
|
||||||
<pre>
|
|
||||||
<span class="Type">libmoo_data</span>
|
|
||||||
<span class="Operator">*</span><span class="-variable"><span class="Function">libmoo_deserialize_data</span></span><span class="-punctuation-bracket">(</span><span class="Type">libmoo_payload</span> <span class="-variable"><span class="-variable-parameter">payload</span></span><span class="-punctuation-delimiter">,</span> <span class="Type"><span class="-type-builtin">unsigned</span></span> <span class="Type"><span class="-type-builtin"><span class="-type-builtin">int</span></span></span> <span class="-variable"><span class="-variable-parameter">payload_size</span></span><span class="-punctuation-bracket">)</span>
|
|
||||||
<span class="-punctuation-bracket">{</span>
|
|
||||||
<span class="Type">libmoo_data</span> <span class="Operator">*</span><span class="-variable">data</span><span class="-punctuation-delimiter">;</span>
|
|
||||||
<span class="Type"><span class="-type-builtin">char</span></span> <span class="-variable">libmoo_version</span><span class="-punctuation-bracket">[</span><span class="-variable"><span class="Constant">LIBMOO_VERSION_LEN</span></span> <span class="Operator">+</span> <span class="Number"><span class="Number">1</span></span><span class="-punctuation-bracket">]</span><span class="-punctuation-delimiter">;</span>
|
|
||||||
<span class="Comment"><span class="Comment"><span class="-spell">/* ensure that there's enough data to comply to spec */</span></span></span>
|
|
||||||
<span class="Conditional"><span class="Keyword">if</span></span> <span class="-punctuation-bracket">(</span><span class="-variable">payload_size</span> <span class="Operator"><</span> <span class="-variable"><span class="Constant">LIBMOO_HEADER_SIZE</span></span><span class="-punctuation-bracket">)</span> <span class="-punctuation-bracket">{</span>
|
|
||||||
<span class="-variable">errno</span> <span class="Operator">=</span> <span class="-variable"><span class="Constant">EBADE</span></span><span class="-punctuation-delimiter">;</span>
|
|
||||||
<span class="Statement"><span class="Keyword">return</span></span> <span class="Constant"><span class="-constant-builtin">NULL</span></span><span class="-punctuation-delimiter">;</span>
|
|
||||||
<span class="-punctuation-bracket">}</span>
|
|
||||||
<span class="Comment"><span class="Comment"><span class="-spell">/* attempt to allocate space and if we fail return NULL errno contains the</span></span><span class="-spell">
|
|
||||||
<span class="Comment"> * error</span>
|
|
||||||
<span class="Comment"> */</span></span><span class="Comment"></span></span>
|
|
||||||
<span class="-variable">data</span> <span class="Operator">=</span> <span class="-variable"><span class="Function">calloc</span></span><span class="-punctuation-bracket">(</span><span class="Number"><span class="Number">1</span></span><span class="-punctuation-delimiter">,</span> <span class="Operator"><span class="Keyword">sizeof</span></span><span class="-punctuation-bracket">(</span><span class="-variable">libmoo_data</span><span class="-punctuation-bracket">)</span><span class="-punctuation-bracket">)</span><span class="-punctuation-delimiter">;</span>
|
|
||||||
<span class="Conditional"><span class="Keyword">if</span></span> <span class="-punctuation-bracket">(</span><span class="-variable">data</span> <span class="Operator">==</span> <span class="Constant"><span class="-constant-builtin">NULL</span></span><span class="-punctuation-bracket">)</span> <span class="-punctuation-bracket">{</span>
|
|
||||||
<span class="-variable">errno</span> <span class="Operator">=</span> <span class="Constant"><span class="-variable"><span class="Constant">ENOMEM</span></span></span><span class="-punctuation-delimiter">;</span>
|
|
||||||
<span class="Statement"><span class="Keyword">return</span></span> <span class="Constant"><span class="-constant-builtin">NULL</span></span><span class="-punctuation-delimiter">;</span>
|
|
||||||
<span class="-punctuation-bracket">}</span>
|
|
||||||
<span class="Comment"><span class="Comment"><span class="-spell">/* get the libmoo_version */</span></span></span>
|
|
||||||
<span class="-variable"><span class="Function">memscpy</span></span><span class="-punctuation-bracket">(</span><span class="-variable">libmoo_version</span><span class="-punctuation-delimiter">,</span> <span class="-variable">payload</span><span class="-punctuation-delimiter">,</span> <span class="-variable"><span class="Constant">LIBMOO_VERSION_LEN</span></span><span class="-punctuation-bracket">)</span><span class="-punctuation-delimiter">;</span>
|
|
||||||
<span class="-variable">libmoo_version</span><span class="-punctuation-bracket">[</span><span class="-variable"><span class="Constant">LIBMOO_VERSION_LEN</span></span><span class="-punctuation-bracket">]</span> <span class="Operator">=</span> <span class="SpecialChar"><span class="Character">'<span class="-string-escape"> </span>'</span></span><span class="-punctuation-delimiter">;</span>
|
|
||||||
<span class="Comment"><span class="Comment"><span class="-spell">/*<span class="TodoBgNOTE"> </span></span></span><span class="-spell"><span class="TodoBgNOTE"><span class="Todo">TODO</span><span class="Comment"><span class="TodoFgNOTE">:</span></span></span><span class="Comment"><span class="TodoFgNOTE"> check that the version of the library we're talking to and our</span></span>
|
|
||||||
<span class="Comment"> * <span class="TodoFgNOTE">version are compatable</span></span>
|
|
||||||
<span class="Comment"> */</span></span><span class="Comment"></span></span>
|
|
||||||
<span class="Comment"><span class="Comment"><span class="-spell">/* gotta tell the client that we're incompatible */</span></span></span>
|
|
||||||
<span class="Conditional"><span class="Keyword">if</span></span> <span class="-punctuation-bracket">(</span><span class="-variable"><span class="Function">strcmp</span></span><span class="-punctuation-bracket">(</span><span class="-variable">libmoo_version</span><span class="-punctuation-delimiter">,</span> <span class="-variable"><span class="Constant">LIBMOO_VERSION</span></span><span class="-punctuation-bracket">)</span> <span class="Operator">!=</span> <span class="Number"><span class="Number">0</span></span><span class="-punctuation-bracket">)</span> <span class="-punctuation-bracket">{</span>
|
|
||||||
<span class="-variable">errno</span> <span class="Operator">=</span> <span class="Constant"><span class="-variable"><span class="Constant">EINVAL</span></span></span><span class="-punctuation-delimiter">;</span>
|
|
||||||
<span class="-variable"><span class="Function">free</span></span><span class="-punctuation-bracket">(</span><span class="-variable">data</span><span class="-punctuation-bracket">)</span><span class="-punctuation-delimiter">;</span>
|
|
||||||
<span class="Statement"><span class="Keyword">return</span></span> <span class="Constant"><span class="-constant-builtin">NULL</span></span><span class="-punctuation-delimiter">;</span>
|
|
||||||
<span class="-punctuation-bracket">}</span>
|
|
||||||
<span class="Comment"><span class="Comment"><span class="-spell">/* skip the reserved space */</span></span></span>
|
|
||||||
<span class="-variable">payload</span> <span class="Operator">+=</span> <span class="Number"><span class="Number">24</span></span><span class="-punctuation-delimiter">;</span>
|
|
||||||
<span class="Comment"><span class="Comment"><span class="-spell">/* get the signal */</span></span></span>
|
|
||||||
<span class="-variable"><span class="Function">memscpy</span></span><span class="-punctuation-bracket">(</span><span class="Operator">&</span><span class="-_parent"><span class="-variable">data</span><span class="Operator">-></span><span class="-property">signal</span></span><span class="-punctuation-delimiter">,</span> <span class="-variable">payload</span><span class="-punctuation-delimiter">,</span> <span class="Operator"><span class="Keyword">sizeof</span></span><span class="-punctuation-bracket">(</span><span class="-_parent"><span class="-variable">data</span><span class="Operator">-></span><span class="-property">signal</span></span><span class="-punctuation-bracket">)</span><span class="-punctuation-bracket">)</span><span class="-punctuation-delimiter">;</span>
|
|
||||||
<span class="Comment"><span class="Comment"><span class="-spell">/* get the more data marker */</span></span></span>
|
|
||||||
<span class="-variable"><span class="Function">memscpy</span></span><span class="-punctuation-bracket">(</span><span class="Operator">&</span><span class="-_parent"><span class="-variable">data</span><span class="Operator">-></span><span class="-property">more_data</span></span><span class="-punctuation-delimiter">,</span> <span class="-variable">payload</span><span class="-punctuation-delimiter">,</span> <span class="Operator"><span class="Keyword">sizeof</span></span><span class="-punctuation-bracket">(</span><span class="-_parent"><span class="-variable">data</span><span class="Operator">-></span><span class="-property">more_data</span></span><span class="-punctuation-bracket">)</span><span class="-punctuation-bracket">)</span><span class="-punctuation-delimiter">;</span>
|
|
||||||
<span class="Comment"><span class="Comment"><span class="-spell">/* get the data */</span></span></span>
|
|
||||||
<span class="Conditional"><span class="Keyword">if</span></span> <span class="-punctuation-bracket">(</span><span class="-_parent"><span class="-variable">data</span><span class="Operator">-></span><span class="-property">more_data</span></span><span class="-punctuation-bracket">)</span> <span class="-punctuation-bracket">{</span>
|
|
||||||
<span class="-_parent"><span class="-variable">data</span><span class="Operator">-></span><span class="-property">data</span></span> <span class="Operator">=</span> <span class="-variable"><span class="Function">malloc</span></span><span class="-punctuation-bracket">(</span><span class="-punctuation-bracket">(</span><span class="-_parent"><span class="-variable">data</span><span class="Operator">-></span><span class="-property">more_data</span></span> <span class="Operator">+</span> <span class="Number"><span class="Number">1</span></span><span class="-punctuation-bracket">)</span> <span class="Operator">*</span> <span class="Operator"><span class="Keyword">sizeof</span></span><span class="-punctuation-bracket">(</span><span class="Type"><span class="Type"><span class="-type-builtin">char</span></span></span><span class="-punctuation-bracket">)</span><span class="-punctuation-bracket">)</span><span class="-punctuation-delimiter">;</span>
|
|
||||||
<span class="-variable"><span class="Function">memscpy</span></span><span class="-punctuation-bracket">(</span><span class="-_parent"><span class="-variable">data</span><span class="Operator">-></span><span class="-property">data</span></span><span class="-punctuation-delimiter">,</span> <span class="-variable">payload</span><span class="-punctuation-delimiter">,</span> <span class="-_parent"><span class="-variable">data</span><span class="Operator">-></span><span class="-property">more_data</span></span> <span class="Operator">*</span> <span class="Operator"><span class="Keyword">sizeof</span></span><span class="-punctuation-bracket">(</span><span class="Type"><span class="Type"><span class="-type-builtin">char</span></span></span><span class="-punctuation-bracket">)</span><span class="-punctuation-bracket">)</span><span class="-punctuation-delimiter">;</span>
|
|
||||||
<span class="-_parent"><span class="-variable">data</span><span class="Operator">-></span><span class="-property">data</span></span><span class="-punctuation-bracket">[</span><span class="-_parent"><span class="-variable">data</span><span class="Operator">-></span><span class="-property">more_data</span></span><span class="-punctuation-bracket">]</span> <span class="Operator">=</span> <span class="SpecialChar"><span class="Character">'<span class="-string-escape"> </span>'</span></span><span class="-punctuation-delimiter">;</span> <span class="Comment"><span class="Comment"><span class="-spell">/* null terminate this string, yo */</span></span></span>
|
|
||||||
<span class="-punctuation-bracket">}</span>
|
|
||||||
<span class="Statement"><span class="Keyword">return</span></span> <span class="-variable">data</span><span class="-punctuation-delimiter">;</span>
|
|
||||||
<span class="-punctuation-bracket">}</span>
|
|
||||||
</pre>
|
|
||||||
<p>
|
|
||||||
And that's kinda it just like with the mempcpy macro I've made a memscpy
|
|
||||||
macro which increments the src by the size of the data to make reading
|
|
||||||
the data easy.
|
|
||||||
</p>
|
|
||||||
<p>
|
|
||||||
See you next year o/
|
|
||||||
<sub>I might have my project done by then, who knows</sub>
|
|
||||||
</p>
|
|
||||||
<br>
|
|
||||||
<br>
|
|
||||||
|
|
||||||
]]></description>
|
|
||||||
</item>
|
</item>
|
||||||
|
|
||||||
|
|
||||||
@ -329,7 +71,7 @@
|
|||||||
it can serve as a great starting place to hack upon until you get the
|
it can serve as a great starting place to hack upon until you get the
|
||||||
software of your dreams.
|
software of your dreams.
|
||||||
</p>
|
</p>
|
||||||
|
|
||||||
]]></description>
|
]]></description>
|
||||||
</item>
|
</item>
|
||||||
|
|
||||||
@ -357,7 +99,7 @@
|
|||||||
squibid. Eventually, when trying to find a good username I chose squibid
|
squibid. Eventually, when trying to find a good username I chose squibid
|
||||||
because that would cover both the username and profile picture.
|
because that would cover both the username and profile picture.
|
||||||
</p>
|
</p>
|
||||||
|
|
||||||
]]></description>
|
]]></description>
|
||||||
</item>
|
</item>
|
||||||
|
|
||||||
|
|||||||
Reference in New Issue
Block a user