- SQLAlchemy integration for TTS queue management

- Model pre-loading and database initialization in the FastAPI app lifespan.

Dockerfile

@@ -27,7 +27,8 @@ RUN pip3 install --no-cache-dir \
     uvicorn==0.34.0 \
     pydantic==2.10.4 \
     pydantic-settings==2.7.0 \
-    python-dotenv==1.0.1
+    python-dotenv==1.0.1 \
+    sqlalchemy==2.0.27
 
 # Set working directory
 WORKDIR /app

api/src/database/database.py

@@ -0,0 +1,26 @@
+from sqlalchemy import create_engine
+from sqlalchemy.orm import sessionmaker
+from pathlib import Path
+import os
+
+from .models import Base
+
+DB_PATH = Path(__file__).parent.parent / "output" / "queue.db"
+os.makedirs(os.path.dirname(DB_PATH), exist_ok=True)
+
+SQLALCHEMY_DATABASE_URL = f"sqlite:///{DB_PATH}"
+engine = create_engine(SQLALCHEMY_DATABASE_URL, connect_args={"check_same_thread": False})
+
+SessionLocal = sessionmaker(autocommit=False, autoflush=False, bind=engine)
+
+def init_db():
+    """Create tables if they don't exist"""
+    Base.metadata.create_all(bind=engine)
+
+def get_db():
+    """Get database session"""
+    db = SessionLocal()
+    try:
+        yield db
+    finally:
+        db.close()

api/src/database/models.py

@@ -0,0 +1,19 @@
+from datetime import datetime
+from sqlalchemy import Column, Integer, String, Float, Boolean, DateTime, Enum as SQLEnum
+from sqlalchemy.ext.declarative import declarative_base
+from ..models.schemas import TTSStatus
+
+Base = declarative_base()
+
+class TTSQueue(Base):
+    __tablename__ = "tts_queue"
+
+    id = Column(Integer, primary_key=True, index=True)
+    text = Column(String, nullable=False)
+    voice = Column(String, default="af")
+    speed = Column(Float, default=1.0)
+    stitch_long_output = Column(Boolean, default=True)
+    status = Column(SQLEnum(TTSStatus), default=TTSStatus.PENDING)
+    output_file = Column(String, nullable=True)
+    processing_time = Column(Float, nullable=True)
+    created_at = Column(DateTime, default=datetime.utcnow)

api/src/database/queue.py

@@ -1,153 +1,52 @@
-import sqlite3
-import os
-from pathlib import Path
-from typing import Optional, Tuple
-
-DB_PATH = Path(__file__).parent.parent / "output" / "queue.db"
+from typing import Optional
+from sqlalchemy.orm import Session
+from .models import TTSQueue
+from .database import init_db
+from ..models.schemas import TTSStatus
 
 
 class QueueDB:
-    def __init__(self, db_path: str = str(DB_PATH)):
-        self.db_path = db_path
-        os.makedirs(os.path.dirname(db_path), exist_ok=True)
-        self._init_db()
-
-    def _init_db(self):
-        """Initialize the database with required tables"""
-        conn = sqlite3.connect(self.db_path)
-        c = conn.cursor()
-        c.execute("""
-            CREATE TABLE IF NOT EXISTS tts_queue
-            (id INTEGER PRIMARY KEY AUTOINCREMENT,
-             text TEXT NOT NULL,
-             voice TEXT DEFAULT 'af',
-             stitch_long_output BOOLEAN DEFAULT 1,
-             status TEXT DEFAULT 'pending',
-             output_file TEXT,
-             processing_time REAL,
-             speed REAL,
-             created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP)
-        """)
-        conn.commit()
-        conn.close()
-
-    def _ensure_table_if_needed(self, conn: sqlite3.Connection):
-        """Create table if it doesn't exist, only called for write operations"""
-        c = conn.cursor()
-        c.execute("""
-            CREATE TABLE IF NOT EXISTS tts_queue
-            (id INTEGER PRIMARY KEY AUTOINCREMENT,
-             text TEXT NOT NULL,
-             voice TEXT DEFAULT 'af',
-             stitch_long_output BOOLEAN DEFAULT 1,
-             status TEXT DEFAULT 'pending',
-             output_file TEXT,
-             processing_time REAL,
-             speed REAL,
-             created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP)
-        """)
-        conn.commit()
+    def __init__(self, db: Session):
+        self.db = db
+        init_db()  # Ensure tables exist
 
     def add_request(self, text: str, voice: str, speed: float, stitch_long_output: bool = True) -> int:
         """Add a new TTS request to the queue"""
-        conn = sqlite3.connect(self.db_path)
-        try:
-            c = conn.cursor()
-            c.execute(
-                "INSERT INTO tts_queue (text, voice, speed, stitch_long_output) VALUES (?, ?, ?, ?)",
-                (text, voice, speed, stitch_long_output)
-            )
-            request_id = c.lastrowid
-            conn.commit()
-            return request_id
-        except sqlite3.OperationalError:  # Table doesn't exist
-            self._ensure_table_if_needed(conn)
-            c = conn.cursor()
-            c.execute(
-                "INSERT INTO tts_queue (text, voice, speed, stitch_long_output) VALUES (?, ?, ?, ?)",
-                (text, voice, speed, stitch_long_output)
-            )
-            request_id = c.lastrowid
-            conn.commit()
-            return request_id
-        finally:
-            conn.close()
+        db_item = TTSQueue(
+            text=text,
+            voice=voice,
+            speed=speed,
+            stitch_long_output=stitch_long_output
+        )
+        self.db.add(db_item)
+        self.db.commit()
+        self.db.refresh(db_item)
+        return db_item.id
 
-    def get_next_pending(self) -> Optional[Tuple[int, str, float, str]]:
+    def get_next_pending(self) -> Optional[TTSQueue]:
         """Get the next pending request"""
-        conn = sqlite3.connect(self.db_path)
-        try:
-            c = conn.cursor()
-            c.execute(
-                'SELECT id, text, voice, speed, stitch_long_output FROM tts_queue WHERE status = "pending" ORDER BY created_at ASC LIMIT 1'
-            )
-            return c.fetchone()
-        except sqlite3.OperationalError:  # Table doesn't exist
-            return None
-        finally:
-            conn.close()
+        return self.db.query(TTSQueue)\
+            .filter(TTSQueue.status == TTSStatus.PENDING)\
+            .order_by(TTSQueue.created_at)\
+            .first()
 
     def update_status(
         self,
         request_id: int,
-        status: str,
+        status: TTSStatus,
         output_file: Optional[str] = None,
         processing_time: Optional[float] = None,
     ):
         """Update request status, output file, and processing time"""
-        conn = sqlite3.connect(self.db_path)
-        try:
-            c = conn.cursor()
-            if output_file and processing_time is not None:
-                c.execute(
-                    "UPDATE tts_queue SET status = ?, output_file = ?, processing_time = ? WHERE id = ?",
-                    (status, output_file, processing_time, request_id),
-                )
-            elif output_file:
-                c.execute(
-                    "UPDATE tts_queue SET status = ?, output_file = ? WHERE id = ?",
-                    (status, output_file, request_id),
-                )
-            else:
-                c.execute(
-                    "UPDATE tts_queue SET status = ? WHERE id = ?", (status, request_id)
-                )
-            conn.commit()
-        except sqlite3.OperationalError:  # Table doesn't exist
-            self._ensure_table_if_needed(conn)
-            # Retry the update
-            c = conn.cursor()
-            if output_file and processing_time is not None:
-                c.execute(
-                    "UPDATE tts_queue SET status = ?, output_file = ?, processing_time = ? WHERE id = ?",
-                    (status, output_file, processing_time, request_id),
-                )
-            elif output_file:
-                c.execute(
-                    "UPDATE tts_queue SET status = ?, output_file = ? WHERE id = ?",
-                    (status, output_file, request_id),
-                )
-            else:
-                c.execute(
-                    "UPDATE tts_queue SET status = ? WHERE id = ?", (status, request_id)
-                )
-            conn.commit()
-        finally:
-            conn.close()
+        request = self.db.query(TTSQueue).filter(TTSQueue.id == request_id).first()
+        if request:
+            request.status = status
+            if output_file:
+                request.output_file = output_file
+            if processing_time is not None:
+                request.processing_time = processing_time
+            self.db.commit()
 
-    def get_status(
-        self, request_id: int
-    ) -> Optional[Tuple[str, Optional[str], Optional[float]]]:
-        """Get status, output file, and processing time for a request"""
-        conn = sqlite3.connect(self.db_path)
-        try:
-            c = conn.cursor()
-            c.execute(
-                "SELECT status, output_file, processing_time FROM tts_queue WHERE id = ?",
-                (request_id,),
-            )
-            return c.fetchone()
-        except sqlite3.OperationalError:  # Table doesn't exist
-            return None
-        finally:
-            conn.close()
+    def get_status(self, request_id: int) -> Optional[TTSQueue]:
+        """Get full request details by ID"""
+        return self.db.query(TTSQueue).filter(TTSQueue.id == request_id).first()

api/src/main.py

@@ -1,15 +1,32 @@
 import uvicorn
+from contextlib import asynccontextmanager
 from fastapi import FastAPI
 from fastapi.middleware.cors import CORSMiddleware
 
 from .core.config import settings
 from .routers import tts_router
+from .database.database import init_db
+from .services.tts import TTSModel
+
+@asynccontextmanager
+async def lifespan(app: FastAPI):
+    """Lifespan context manager for database and model initialization"""
+    print("Initializing database and preloading models...")
+    init_db()  # Initialize database tables
+    
+    # Preload TTS model and default voice
+    TTSModel.get_instance()  # This loads the model
+    TTSModel.get_voicepack("af")  # Preload default voice, optional
+    print("Initialization complete!")
+    
+    yield
 
 # Initialize FastAPI app
 app = FastAPI(
     title=settings.api_title,
     description=settings.api_description,
     version=settings.api_version,
+    lifespan=lifespan
 )
 
 # Add CORS middleware

api/src/models/schemas.py

@@ -1,6 +1,29 @@
-from pydantic import BaseModel
-
+from datetime import datetime
+from pydantic import BaseModel, Field
 from typing import Optional
+from enum import Enum
+
+
+class TTSStatus(str, Enum):
+    PENDING = "pending"
+    PROCESSING = "processing"
+    COMPLETED = "completed"
+    FAILED = "failed"
+
+
+class TTSQueueModel(BaseModel):
+    id: Optional[int] = None
+    text: str
+    voice: str = "af"
+    speed: float = 1.0
+    stitch_long_output: bool = True
+    status: TTSStatus = TTSStatus.PENDING
+    output_file: Optional[str] = None
+    processing_time: Optional[float] = None
+    created_at: datetime = Field(default_factory=datetime.utcnow)
+
+    class Config:
+        from_attributes = True
 
 
 class TTSRequest(BaseModel):

api/src/routers/tts.py

@@ -1,7 +1,9 @@
 import os
-from fastapi import APIRouter, HTTPException, Response
+from fastapi import APIRouter, HTTPException, Response, Depends
+from sqlalchemy.orm import Session
 from ..models.schemas import TTSRequest, TTSResponse, VoicesResponse
 from ..services.tts import TTSService
+from ..database.database import get_db
 
 router = APIRouter(
     prefix="/tts",
@@ -9,19 +11,20 @@ router = APIRouter(
     responses={404: {"description": "Not found"}},
 )
 
-# Initialize TTS service
-tts_service = TTSService()
+def get_tts_service(db: Session = Depends(get_db)) -> TTSService:
+    """Dependency to get TTSService instance with database session"""
+    return TTSService(db)
 
 
 @router.get("/voices", response_model=VoicesResponse)
-async def get_voices():
+async def get_voices(tts_service: TTSService = Depends(get_tts_service)):
     """List all available voices"""
     voices = tts_service.list_voices()
     return {"voices": voices, "default": "af"}
 
 
 @router.post("", response_model=TTSResponse)
-async def create_tts(request: TTSRequest):
+async def create_tts(request: TTSRequest, tts_service: TTSService = Depends(get_tts_service)):
     """Submit text for TTS generation"""
     # Validate voice exists
     voices = tts_service.list_voices()
@@ -47,37 +50,35 @@ async def create_tts(request: TTSRequest):
 
 
 @router.get("/{request_id}", response_model=TTSResponse)
-async def get_status(request_id: int):
+async def get_status(request_id: int, tts_service: TTSService = Depends(get_tts_service)):
     """Check the status of a TTS request"""
-    status = tts_service.get_request_status(request_id)
-    if not status:
+    request = tts_service.get_request_status(request_id)
+    if not request:
         raise HTTPException(status_code=404, detail="Request not found")
 
-    status_str, output_file, processing_time = status
     return {
-        "request_id": request_id,
-        "status": status_str,
-        "output_file": output_file,
-        "processing_time": processing_time,
+        "request_id": request.id,
+        "status": request.status,
+        "output_file": request.output_file,
+        "processing_time": request.processing_time,
     }
 
 
 @router.get("/file/{request_id}")
-async def get_file(request_id: int):
+async def get_file(request_id: int, tts_service: TTSService = Depends(get_tts_service)):
     """Download the generated audio file"""
-    status = tts_service.get_request_status(request_id)
-    if not status:
+    request = tts_service.get_request_status(request_id)
+    if not request:
         raise HTTPException(status_code=404, detail="Request not found")
 
-    status_str, output_file, _ = status
-    if status_str != "completed":
+    if request.status != "completed":
         raise HTTPException(status_code=400, detail="Audio generation not complete")
 
-    if not output_file or not os.path.exists(output_file):
+    if not request.output_file or not os.path.exists(request.output_file):
         raise HTTPException(status_code=404, detail="Audio file not found")
 
     # Read file and ensure it's closed after
-    with open(output_file, "rb") as f:
+    with open(request.output_file, "rb") as f:
         content = f.read()
 
     return Response(

api/src/services/tts.py

@@ -2,7 +2,10 @@ import os
 import threading
 import time
 import io
-from typing import Optional, Tuple, List
+from typing import Optional, List, Tuple
+from sqlalchemy.orm import Session, sessionmaker
+from ..models.schemas import TTSStatus
+from ..database.models import TTSQueue
 import numpy as np
 import torch
 import scipy.io.wavfile as wavfile
@@ -45,11 +48,12 @@ class TTSModel:
 
 
 class TTSService:
-    def __init__(self, output_dir: str = None):
+    def __init__(self, db: Session, output_dir: str = None):
         if output_dir is None:
             output_dir = os.path.join(os.path.dirname(__file__), "..", "output")
         self.output_dir = output_dir
-        self.db = QueueDB()
+        self.db = QueueDB(db)
+        self.engine = db.get_bind()  # Get engine from session
         os.makedirs(output_dir, exist_ok=True)
         self._start_worker()
 
@@ -146,31 +150,41 @@ class TTSService:
 
     def _process_queue(self):
         """Background worker that processes the queue"""
+        # Create a new session for the background worker
+        Session = sessionmaker(bind=self.engine)
+        
         while True:
-            next_request = self.db.get_next_pending()
-            if next_request:
-                request_id, text, voice, speed, stitch_long_output = next_request
-                try:
-                    # Generate audio and measure time
-                    audio, processing_time = self._generate_audio(text, voice, speed, stitch_long_output)
+            # Create a new session for each iteration
+            with Session() as session:
+                db = QueueDB(session)
+                request = db.get_next_pending()
+                if request:
+                    try:
+                        # Generate audio and measure time
+                        audio, processing_time = self._generate_audio(
+                            request.text, 
+                            request.voice, 
+                            request.speed, 
+                            request.stitch_long_output
+                        )
 
-                    # Save to file
-                    output_file = os.path.abspath(os.path.join(
-                        self.output_dir, f"speech_{request_id}.wav"
-                    ))
-                    self._save_audio(audio, output_file)
+                        # Save to file
+                        output_file = os.path.abspath(os.path.join(
+                            self.output_dir, f"speech_{request.id}.wav"
+                        ))
+                        self._save_audio(audio, output_file)
 
-                    # Update status with processing time
-                    self.db.update_status(
-                        request_id,
-                        "completed",
-                        output_file=output_file,
-                        processing_time=processing_time,
-                    )
+                        # Update status with processing time
+                        db.update_status(
+                            request.id,
+                            TTSStatus.COMPLETED,
+                            output_file=output_file,
+                            processing_time=processing_time,
+                        )
 
-                except Exception as e:
-                    print(f"Error processing request {request_id}: {str(e)}")
-                    self.db.update_status(request_id, "failed")
+                    except Exception as e:
+                        print(f"Error processing request {request.id}: {str(e)}")
+                        db.update_status(request.id, TTSStatus.FAILED)
 
             time.sleep(1)  # Prevent busy waiting
 
@@ -190,8 +204,6 @@ class TTSService:
         """Create a new TTS request and return the request ID"""
         return self.db.add_request(text, voice, speed, stitch_long_output)
 
-    def get_request_status(
-        self, request_id: int
-    ) -> Optional[Tuple[str, Optional[str], Optional[float]]]:
-        """Get the status, output file path, and processing time for a request"""
+    def get_request_status(self, request_id: int) -> Optional[TTSQueue]:
+        """Get the full request details"""
         return self.db.get_status(request_id)

requirements.txt

@@ -3,6 +3,7 @@ fastapi==0.115.6
 uvicorn==0.34.0
 pydantic==2.10.4
 python-dotenv==1.0.1
+sqlalchemy==2.0.27
 
 # ML/DL
 torch==2.5.1