| |
| """ |
| Shared lazy PostgreSQL helpers. |
| |
| Importing this module does not require PostgreSQL or psycopg2. A connection is |
| attempted only when a caller explicitly asks for one. |
| """ |
|
|
| from __future__ import annotations |
|
|
| import os |
|
|
|
|
| def _get_connection(): |
| """Return a PostgreSQL connection, creating schema on first use.""" |
| database_url = os.getenv("DATABASE_URL", "").strip() |
| if not database_url: |
| raise EnvironmentError("DATABASE_URL is not set") |
|
|
| try: |
| import psycopg2 |
| except Exception as exc: |
| raise EnvironmentError("psycopg2 is required for PostgreSQL session memory") from exc |
|
|
| conn = psycopg2.connect(database_url) |
| _ensure_schema(conn) |
| return conn |
|
|
|
|
| def _ensure_schema(conn) -> None: |
| with conn.cursor() as cur: |
| cur.execute( |
| """ |
| CREATE TABLE IF NOT EXISTS session_memory ( |
| session_id TEXT PRIMARY KEY, |
| doc_id TEXT NOT NULL, |
| created_at TIMESTAMP DEFAULT NOW(), |
| compressed_json JSONB NOT NULL, |
| raw_path TEXT |
| ); |
| """ |
| ) |
| cur.execute( |
| """ |
| CREATE TABLE IF NOT EXISTS response_signals ( |
| id SERIAL PRIMARY KEY, |
| session_id TEXT, |
| query_hash TEXT, |
| signal_type TEXT, |
| created_at TIMESTAMP DEFAULT NOW() |
| ); |
| """ |
| ) |
| cur.execute( |
| """ |
| CREATE TABLE IF NOT EXISTS session_graph ( |
| source_session TEXT, |
| target_session TEXT, |
| confidence FLOAT, |
| reason TEXT, |
| created_at TIMESTAMP DEFAULT NOW(), |
| PRIMARY KEY (source_session, target_session) |
| ); |
| """ |
| ) |
| conn.commit() |
|
|
