SerealFS

Introduction

SerealFS is a (toy) project to map Sereal-encoded files to the readonly FUSE-based file system. Excluding the attractiveness factor of idea, the project itself can be helpful:

• when user wants to use familiar command lines tools to analyze Sereal files;
• due to the Haskell's support of lazy computaion the Sereal-files are read and decoded on-demand.

Implementation

Mapping is mostly straighforward: hashes and arrays are mapped to the directory structures. The hash keys are the filenames/dirnames and contents of the file/dir is contents of that hash entry. Arrays are also mapped to dirs, but entry name in this case is the index of the entry(0-based).

Let's see an example. The following Perl structure

{
    Alibaba => {
        sons => [
            Ali,
            Liba,
            Baba
        ],

        age => 1728
    }
}

will be mapped as:

Alibaba/
    sons/
          0 (File with `Ali` as contents)
          1 (File with `Liba` as contents)
          2 (File with `Baba` as contents) 
    age (File with `1728` as contents)

Demo

Usage

Building procedure

To install the project you need ghc and cabal installed on your system. Installation steps are simple:

• git clone https://github.com/manzur/serealfs.git
• cd serealfs
• cabal install

How to mount

SerealFS works as a "presentation layer" over the directory with Sereal encoded files. So to use it you need to mount the dir with Sereal files in it you should execute: (MacOS users don't need to specify -o nonempty):

serealfs dir -o nonempty

And that's it, now you can traverse the dir to see the contents of your files. Note: SerealFS will show then directory entries only for the top-level Sereal encoded files in the mounted directory, others will be just hidden.

Examples

Find if the Sereal contains the given key:

find -name key .

Get the value of the key when the path is given:

cat ./path/to/key

List all the keys of the hash:

cd ./hash_or_array && ls

Get all the values for the given key(without separating files):

find -name key -exec cat '{}' \;

Known bugs

The SerealFS works only with the Sereal files of the version3 and does not support the following tags:

• ALIAS
• COPY
• EXTEND
• LONG DOUBLE
• MANY
• OBJECT
• OBJECTV
• OBJECT_FREEZE
• OBJECTV_FREEZE
• PACKET_START
• PAD
• REFP
• REGEXP
• WEAKEN