Main Module

The main module provides core functionality for database and archive management in Specatalog. It handles database connections, archive file system access, and configuration loading.

Database and Archive Management

This module provides:

Database connection management
Archive file system access
Allowed values configuration loading
Session handling for database operations

Key Components

Database Connection

SQLAlchemy engine with connection pooling (10-30 connections)
Scoped session factory for thread-safe database operations
Automatic connection health checking
Context manager for transaction handling

Archive Access

SpecatalogArchive instance for file operations
Support for both local and remote archive configurations
Temporary file handling through context managers

Configuration

Allowed values loading from external module
Fallback to default values if configuration missing
Remote/local archive selection based on configuration

Configuration Parameters

Parameter	Description
`DATABASE_URL_USR`	Database connection URL from configuration
`BASE_PATH`	Base path for archive from configuration
`REMOTE_ARCHIVE`	Flag for remote archive usage from configuration

Usage Examples

Database Operations

from specatalog.main import db_session

with db_session() as session:
    # Perform database operations
    result = session.query(MyModel).all()

Archive Operations

from specatalog.main import archive

# List files in archive
files = archive.list_files("data/M1")

# Create temporary path
with archive.temporary_path("data/M1/measurement.h5") as temp_path:
    # Work with temporary file
    process_file(temp_path)

Allowed Values

from specatalog.main import ALLOWED_VALUES

Graceful fallback for missing configurations