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Bag level

Table of contents

  1. manifest-md5.txt (file)
  2. bagit.txt (file)
  3. /data (directory)

The bag is the top level of the meemoo SIP and is essentially a wrapper around a SIP submitted by a CP for ingest in the meemoo archive. It is a compressed directory that conforms to the BagIt 1.0 specification (RFC 8493).

A bag serves a purely practical purpose as a transfer container between a CP’s archive and meemoo’s ingest space. Therefore, it will be unpacked during ingest and is deleted after processing. As such it will not appear in the meemoo archive as a separate entity.

Example

root_directory
│── manifest-md5.txt
│── bagit.txt
│
└──data
   │   ...

Requirements

  • A bag MUST be a compressed archive file.
  • A bag MUST contain a bagit.txt file.
  • A bag MUST contain a manifest-md5.txt file.
  • A bag MUST contain a /data directory.
  • The contents of a bag MUST be character-encoded according to UTF-8.
  • A bag MUST be a ZIP file.
  • A bag MAY contain a bag-info.txt file.

manifest-md5.txt (file)

The manifest-md5.txt file lists all files in the bag across the different directories together with their corresponding checksums created with the MD5 message-digest algorithm. It is used during processing of the bag to allow for data integrity checking.

Example

2c28e2b32a6e5e94669a516036838429  ./data/mets.xml
95fc1f5cfd89b97bacf49473267752f5  ./data/representations/representation_2/mets.xml
18513a8d61c6f2cbaaeeedd754b01d6b  ./data/representations/representation_2/data/D523F963.jpg
fde6c913b4105cc06174fba8cd3b864e  ./data/representations/representation_2/metadata/preservation/premis.xml
31d402b829f673afe24f698dc462bbde  ./data/representations/representation_2/metadata/descriptive/dc_1.xml
fc030be17b9c7fd3f86b0cf095a64a33  ./data/representations/representation_1/mets.xml
d4985ba4b67ff067a0e84c53b6d35355  ./data/representations/representation_1/data/1450.jpeg
b7ae37f6094794e313402b9d064978e8  ./data/representations/representation_1/data/1445.jpeg
7a1a5145d1f54b01537b76e52b19b804  ./data/representations/representation_1/metadata/preservation/premis.xml
e45622b2b8536d312203e1cb7d5548c7  ./data/representations/representation_1/metadata/descriptive/dc_1.xml
c50c40b09a5f04ecf441f136c1c6581e  ./data/metadata/preservation/premis.xml
9d55815152e83db76a32f74990d79cd3  ./data/metadata/descriptive/dc_3.xml
cd17cbb2153946c8462e10b337e0e9c1  ./data/metadata/descriptive/dc_1.xml
fbab574560f2d548fd84c6c1fd1cb7f2  ./data/metadata/descriptive/dc_2.xml
eaa2c609ff6371712f623f5531945b44  ./bagit.txt
d67fe46437a03a307c7b28c819b56a95  ./manifest-md5.txt

Requirements

  • The manifest-md5.txt file MUST list all files contained in the bag.
  • The manifest-md5.txt file MUST NOT list any directories.
  • The manifest-md5.txt file MUST NOT list any files outside of the bag.
  • Each line of the manifest-md5.txt file MUST be of the form checksum filepath, where filepath is the pathname of a file relative to the bag-level directory, and checksum is a hex-encoded checksum calculated by the MD5 message-digest algorithm.
  • The slash (‘/’) character MUST be used as a path separator in filepath.
  • One or more linear whitespace characters (spaces or tabs) MUST separate each checksum from each filepath.
  • Each line of the manifest-md5.txt file MUST be terminated with an LF, a CR or a CRLF.

bagit.txt (file)

The bagit.txt file contains exactly two lines in the exact order specified in the example below. The first line specifies to which version of the BagIt specification the bag conforms, while the second line identifies the character set encoding of the bag and its files.

Example

BagIt-Version: 1.0
Tag-File-Character-Encoding: UTF-8

Requirements

  • The first line of the bagit.txt file MUST specify the exact version of the BagIt standard.
  • The second line of the bagit.txt file MUST specify the character set encoding of the bag and its files. This encoding MUST be UTF-8.

/data (directory)

The /data directory contains the content of the bag divided across a number of different files and directories. Each /data directory MUST contain exactly one package, consisting of the combination of a mets.xml file, a /metadata directory and a /representations directory. See the package level for more information and the requirements of the /data directory.

Example

root_directory
│   ...
│
└──data
   │──mets.xml
   │
   │──metadata
   │      ...
   │──representations
   │      ...

Continue to package level.