docs: add RAR 5.0 archive format doc

muja · Aug 28, 2024 · 1df450f · 1df450f
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diff --git a/unrar_sys/vendor/Documentation/RAR5Format.md b/unrar_sys/vendor/Documentation/RAR5Format.md
@@ -0,0 +1,95 @@
+<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN">
+<html>
+<head>
+<TITLE>RAR 5.0 archive format</TITLE>
+</head>
+
+<body>
+
+<P class="title"><A NAME="HELPRAR5Format"></A>RAR 5.0 archive format<hr></P>
+
+
+<P>WinRAR 5.0 introduces a new verson of RAR archive format.</P>
+
+<P>New features of RAR 5.0 format include:</P>
+
+<ul>
+<li>Compression <a href="HELPGetArcGeneral.htm#DictSize">dictionary size</a>
+up to 1 GB. When compressing big files, especially
+in <a href="HELPArcSolid.htm">solid</a> mode, larger dictionary frequently
+allows to achieve a higher compression ratio.</li>
+
+<li>Encryption based on AES-256 algorithm, which is theoretically
+stronger than RAR 4.x AES-128.</li>
+
+<li><a href="HELPArcRecovery.htm">Recovery record</a> using Reed-Solomon
+error correction codes with much higher resistance to multiple damages
+comparing to RAR 4.x recovery record.</li>
+
+<li>Faster <a href="HELPArcRecVolumes.htm">recovery volume</a> operations.
+Maximum number of RAR+REV volumes in RAR 5.0 is 65535 instead of 255.</li>
+
+<li>File times stored as Coordinated Universal Time (UTC) instead of
+RAR 4.x local time, making file exchange among several time zones
+more straightforward.</li>
+
+<li>Optional <a href="HELPGetArcOptions.htm#BLAKE2">BLAKE2sp checksums</a>
+for file data. Unlike CRC32 checksum, it is practically impossible 
+for BLAKE2 to have two different files with the same checksum value.
+So BLAKE2 can be used for file identification purpose.</li>
+
+<li>Optional <a href="HELPGetArcOptions.htm#QO">quick open information</a>
+can be added to archive to provide a faster access to archive contents.</li>
+
+<li>Multithreading support in decompression algorithm. Its speed benefit
+is more noticeable on large files with poorly compressible data or with
+BLAKE2 checksums.</li>
+
+<li>Support for NTFS 
+<a href="HELPGetArcAdvanced.htm#symlinks">reparse points</a>,
+<a href="HELPGetArcAdvanced.htm#symlinks">symbolic links</a>,
+<a href="HELPGetArcAdvanced.htm#hardlinks">hard links</a>.</li>
+
+<li>Possibility to store second and following copies of 
+<a href="HELPGetArcOptions.htm#ident">identical files</a>
+as references to first copy of such file.</li>
+
+<li>Complete Unicode awareness. File names and comments are stored in UTF-8
+format.</li>
+</ul>
+
+<br>
+<p>Some obsolete or inefficient RAR 4.x features are not included in
+RAR 5.0 format:</p>
+
+<ul>
+<li>Special algorithms including text compression, raw audio and true color
+compression, cannot be used in RAR 5.0 archives. Those formats of raw audio
+and true color data, which were recognized by older RAR versions,
+become significantly less widespread. Text compression performance
+on modern multi-core CPUs is too low comparing to general compression.
+Even though these algorithms are not supported in RAR 5.0, latest WinRAR
+can decompress any 4.x RAR archives, including those using mentioned above
+algorithms. RAR 5.0 still includes Intel IA-32 executable and delta
+compression algorithms, which are efficient for modern data and hardware.</li>
+
+<li>Creating old style volume names in archive.r00, archive.r01 format
+is not supported. Main purpose of these names was compatibility with
+MS DOS file system. But such naming convention does not work well with
+platforms like Windows, where file extensions are used to define file types
+and associations.</li>
+</ul>
+
+<br>
+<p>Older applications including WinRAR versions earlier than 5.0 are not
+able to recognize RAR 5.0 archives. So if you wish to be sure that archive
+can be decompressed by older software, you may prefer to select RAR 4.x
+archiving format. It can be done either in 
+<a href="HELPGetArcGeneral.htm#SetFmt">Archive name and parameters</a> dialog
+or with <a href="HELPSwMA.htm">-ma command line switch</a>.
+Also RAR 4.x may be preferable if you need special text or multimedia
+compression algorithms or old style volume naming scheme.
+</p>
+
+</body>
+</html>
diff --git a/unrar_sys/vendor/Documentation/index.md b/unrar_sys/vendor/Documentation/index.md
@@ -35,6 +35,11 @@
 <a href="RARHeaderDataEx.md">RARHeaderDataEx</a><br>
 </blockquote>
 
+<h3>Format</h3>
+<blockquote>
+<a href="RAR5Format.md">RAR5Format</a><br>
+</blockquote>
+
 </body>
 
 </html>