tiferet-h5

HDF5 infrastructure extension for the Tiferet framework via PyTables.

tiferet-h5 mirrors the layered architecture of the Tiferet core — domain, interfaces, mappers, utils, repos — adapted to the hierarchical, columnar, and typed nature of HDF5 files. It introduces two mapper base classes that are the HDF5-native analogue of Tiferet's TransferObject: TableObject for row-oriented table storage and NodeObject for attribute-oriented node storage.

Requirements

• Python ≥ 3.10
• tiferet >= 2.0.0b1
• tables >= 3.10.0 (PyTables)

Installation

pip install tiferet-h5

Or in development mode from the repository root:

pip install -e .

Quick Start

This tutorial stores a simple feature catalog — groups with scalar metadata and child step tables — to demonstrate the full stack: domain objects, mapper classes, H5Client, and H5Repository.

1. Define Your Mappers

import tables
from typing import ClassVar, Dict, Any, List
from pydantic import Field, AliasChoices
from tiferet_h5 import TableObject, NodeObject

# ── Group-level metadata → node attributes ────────────────────────────────
# One instance per feature group, stored on the HDF5 group node.
class FeatureGroupObject(NodeObject):
    name: str = Field(default='', description='Feature name.')
    description: str = Field(
        default='',
        serialization_alias='desc',
        validation_alias=AliasChoices('desc', 'description'),
        description='Stored as "desc" in HDF5 to keep attribute keys short.',
    )
    _ROLES: ClassVar[Dict[str, Dict[str, Any]]] = {
        'to_h5.attrs': {'by_alias': True, 'exclude_none': True},
    }

# ── Child collection → table rows ─────────────────────────────────────────
# One row per step, stored in a table nested inside the feature group.
class FeatureStepObject(TableObject):
    name: str = Field(default='', description='Step name.')
    service_id: str = Field(
        default='',
        serialization_alias='svc',
        validation_alias=AliasChoices('svc', 'service_id'),
        description='Service ID; stored as "svc" column in HDF5.',
    )
    pass_on_error: bool = Field(
        default=False,
        serialization_alias='pass_err',
        validation_alias=AliasChoices('pass_err', 'pass_on_error'),
    )
    _H5_TYPES: ClassVar[Dict[str, Any]] = {
        'name':     tables.StringCol(256),
        'svc':      tables.StringCol(256),
        'pass_err': tables.BoolCol(),
    }

2. Write to HDF5

from tiferet_h5 import H5Client

# HDF5 layout:
#   /features/                ← group, attr: schema_ver
#       calc/                 ← group, attrs: name, desc
#           steps             ← table, cols: name, svc, pass_err

with H5Client('catalog.h5', mode='w') as h5:
    # Catalog root
    h5.create_group('/features')
    h5.set_node_attr('/features', 'schema_ver', '1.0')

    # Feature group
    h5.create_group('/features/calc')
    group = FeatureGroupObject(
        name='Calculator Features',
        description='Basic arithmetic operations',
    )
    for k, v in group.to_attrs().items():
        h5.set_node_attr('/features/calc', k, v)

    # Child steps table
    t = h5.create_table(
        '/features/calc/steps',
        FeatureStepObject.get_description(),
        title='Feature Steps',
    )
    FeatureStepObject(name='Add numbers', service_id='add_event').to_row(t)
    FeatureStepObject(name='Validate',    service_id='validate_event', pass_on_error=True).to_row(t)
    t.flush()

3. Read Back

with H5Client('catalog.h5', mode='r') as h5:
    schema_ver = h5.get_node_attr('/features', 'schema_ver')
    print('Schema version:', schema_ver)

    group = FeatureGroupObject.from_attrs(h5.get_node_attrs('/features/calc'))
    print('Feature:', group.name, '—', group.description)

    steps: List[FeatureStepObject] = [
        FeatureStepObject.from_row(r)
        for r in h5.read_rows('/features/calc/steps')
    ]
    for s in steps:
        print(f'  step  {s.name!r}  service_id={s.service_id!r}  pass_on_error={s.pass_on_error}')

Output:

Schema version: 1.0
Feature: Calculator Features — Basic arithmetic operations
  step  'Add numbers'  service_id='add_event'  pass_on_error=False
  step  'Validate'     service_id='validate_event'  pass_on_error=True

4. Use a Repository

Extend H5Repository for a clean, context-manager-driven persistence pattern:

from tiferet_h5 import H5Repository

class FeatureCatalogRepository(H5Repository):
    def save_feature(self, key: str, group: FeatureGroupObject, steps: List[FeatureStepObject]) -> None:
        with self.client() as h5:
            h5.create_group(f'/features/{key}')
            for k, v in group.to_attrs().items():
                h5.set_node_attr(f'/features/{key}', k, v)
            t = h5.get_or_create_table(
                f'/features/{key}/steps',
                FeatureStepObject.get_description(),
            )
            for step in steps:
                step.to_row(t)
            t.flush()

    def load_feature(self, key: str):
        with self.client(mode='r') as h5:
            group = FeatureGroupObject.from_attrs(h5.get_node_attrs(f'/features/{key}'))
            steps = [FeatureStepObject.from_row(r) for r in h5.read_rows(f'/features/{key}/steps')]
            return group, steps

repo = FeatureCatalogRepository('catalog.h5')

Package Layout

tiferet_h5/
├── __init__.py          Public exports and aliases
├── assets/
│   └── constants.py     H5 error code string constants
├── domain/
│   └── h5.py            H5Column, H5TableSchema, H5Node
├── interfaces/
│   └── h5.py            H5Service abstract interface
├── mappers/
│   └── settings.py      TableObject, NodeObject base classes
├── utils/
│   └── h5.py            H5Client (alias: H5)
└── repos/
    └── h5.py            H5Repository base

Documentation

• Domain Objects — H5Column, H5TableSchema, H5Node
• Mappers — TableObject, NodeObject, aliasing, nested modeling
• H5Client — full method reference and error codes

License

MIT