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<p>A distributed, block-based implementation of {@link
org.apache.hadoop.fs.FileSystem} that uses <a href="http://aws.amazon.com/s3">Amazon S3</a>
as a backing store.</p>

<p>
Files are stored in S3 as blocks (represented by 
{@link org.apache.hadoop.fs.s3.Block}), which have an ID and a length.
Block metadata is stored in S3 as a small record (represented by 
{@link org.apache.hadoop.fs.s3.INode}) using the URL-encoded
path string as a key. Inodes record the file type (regular file or directory) and the list of blocks.
This design makes it easy to seek to any given position in a file by reading the inode data to compute
which block to access, then using S3's support for 
<a href="http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html#sec14.35.2">HTTP Range</a> headers
to start streaming from the correct position.
Renames are also efficient since only the inode is moved (by a DELETE followed by a PUT since 
S3 does not support renames).
</p>
<p>
For a single file <i>/dir1/file1</i> which takes two blocks of storage, the file structure in S3
would be something like this:
</p>
<pre>
/
/dir1
/dir1/file1
block-6415776850131549260
block-3026438247347758425
</pre>
<p>
Inodes start with a leading <code>/</code>, while blocks are prefixed with <code>block-</code>.
</p>

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