Module gamslib.sip.validation.bagit

Validation functions for the structure and contents of Bagit directories in GAMS projects.

This module provides functions to validate the general structure of a Bagit directory, the contents of the bagit.txt file, and the existence of required directories and files.

Features

• Checks for required directories and files in a Bagit directory.
• Validates the format and contents of bagit.txt.
• Raises BagValidationError for any validation failures.

Usage

Call validate_structure()(bag_dir) to check the directory structure and required files. Call validate_bagit_txt()(bag_dir) to validate the bagit.txt file.

Functions

def validate_bagit_txt(bag_dir: pathlib._local.Path) ‑> None

Expand source code

def validate_bagit_txt(bag_dir: Path) -> None:
    """
    Validate the bagit.txt file in a Bagit directory.

    Args:
        bag_dir (Path): Path to the Bagit directory.

    Raises:
        BagValidationError: If the bagit.txt file is missing or invalid.

    Notes:
        - Checks for exactly two lines: 'BagIt-Version: 1.0' and 'Tag-File-Character-Encoding: UTF-8'.
        - Raises an error if the format or values are incorrect.
    """
    bagit_txt_file = bag_dir / "bagit.txt"
    if not bagit_txt_file.is_file():
        raise BagValidationError(
            "'bagit.txt' file does not exist in the bag directory {bag_dir}"
        )
    line_entries = []
    with bagit_txt_file.open("r", encoding="utf-8", newline="") as f:
        for i, line in enumerate(f, start=1):
            try:
                stripped_line = line.rstrip()
                if stripped_line:
                    key, value = stripped_line.split(":", 1)
                    line_entries.append((key, value.strip()))
            except ValueError as e:
                raise BagValidationError(
                    f"Invalid line {i} in {bag_dir / 'bagit.txt'}: '{stripped_line}'"
                ) from e

    if len(line_entries) != 2:  # noqa: PLR2004
        raise BagValidationError(
            f"{bag_dir / 'bagit.txt'} has invalid number of lines. bagit.txt is incomplete"
        )

    if line_entries[0][0] != "BagIt-Version":
        raise BagValidationError(
            f"{bag_dir / 'bagit.txt'}: Missing line for 'BagIt-Version'"
        )

    if line_entries[0][1] != "1.0":
        raise BagValidationError(
            f"{bag_dir / 'bagit.txt'}: Invalid value for 'BagIt-Version'. Must be '1.0'"
        )

    if line_entries[1][0] != "Tag-File-Character-Encoding":
        raise BagValidationError(
            f"{bag_dir / 'bagit.txt'}: Missing line for 'Tag-File-Character-Encoding'"
        )

    if line_entries[1][1] != "UTF-8":
        raise BagValidationError(
            f"{bag_dir / 'bagit.txt'}: Invalid value for 'Tag-File-Character-Encoding'. "
            "Must be 'UTF-8'"
        )

Validate the bagit.txt file in a Bagit directory.

Args

bag_dir : Path

Path to the Bagit directory.

Raises

BagValidationError

If the bagit.txt file is missing or invalid.

Notes

• Checks for exactly two lines: 'BagIt-Version: 1.0' and 'Tag-File-Character-Encoding: UTF-8'.
• Raises an error if the format or values are incorrect.

def validate_structure(bag_dir: pathlib._local.Path) ‑> None

Expand source code

def validate_structure(bag_dir: Path) -> None:
    """
    Validate the general structure of a Bagit directory.

    Args:
        bag_dir (Path): Path to the Bagit directory to validate.

    Raises:
        BagValidationError: If a required directory or file is missing.

    Notes:
        - Checks for the existence of 'data', 'data/meta', and 'data/content' directories.
        - Checks for required files: bagit.txt, manifest-md5.txt, manifest-sha512.txt,
          data/meta/sip.json, and data/content/DC.xml.
    """
    required_dirs = ["data", "data/meta", "data/content"]
    required_files = [
        "bagit.txt",
        "manifest-md5.txt",
        "manifest-sha512.txt",
        "data/meta/sip.json",
        "data/content/DC.xml",
    ]

    for directory in required_dirs:
        if not (bag_dir / directory).is_dir():
            raise BagValidationError(f"Bag directory '{directory}' does not exist")

    for file in required_files:
        if not (bag_dir / file).is_file():
            raise BagValidationError(
                f"Bag file '{file}' does not exist for bag {bag_dir}"
            )

Validate the general structure of a Bagit directory.

Args

bag_dir : Path

Path to the Bagit directory to validate.

Raises

BagValidationError

If a required directory or file is missing.

Notes

• Checks for the existence of 'data', 'data/meta', and 'data/content' directories.
• Checks for required files: bagit.txt, manifest-md5.txt, manifest-sha512.txt, data/meta/sip.json, and data/content/DC.xml.