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Status: WIP

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

b5ab2782919f67d4779de9825c538f01  ./data/mets.xml
2f3f71fadf038f86ba512c16702af864  ./data/representations/representation_2/mets.xml
18513a8d61c6f2cbaaeeedd754b01d6b  ./data/representations/representation_2/data/D523F963.jpg
d890aedac3b9d8620b4ead534c774e6c  ./data/representations/representation_2/metadata/preservation/preservation.xml
bcb7a509d68156d2c5f349da4d46b757  ./data/representations/representation_2/metadata/descriptive/descriptive.xml
b31b2224cef22b22d29f62a03f30aaa3  ./data/representations/representation_1/mets.xml
d4985ba4b67ff067a0e84c53b6d35355  ./data/representations/representation_1/data/1450.jpeg
b7ae37f6094794e313402b9d064978e8  ./data/representations/representation_1/data/1445.jpeg
ee4a938670222a8aab7a03dd4e64cb1d  ./data/representations/representation_1/metadata/preservation/preservation.xml
254acb652404702061d8552b658eb46a  ./data/representations/representation_1/metadata/descriptive/descriptive.xml
8c2914e1df1e2827c9c4059804075120  ./data/metadata/preservation/preservation.xml
7c513b9cb8848860ddcb4d4b680171bc  ./data/metadata/descriptive/descriptive.xml
eaa2c609ff6371712f623f5531945b44  ./bagit.txt
b87cd3b7924b79f2d60f8abc6a94a95e  ./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.