feat: show indexing progress gracefully

pyproject.toml

@@ -23,7 +23,7 @@ classifiers = [
 
 dependencies = [
     "mcp>=1.0.0",
-    "cocoindex[litellm]==1.0.0a31",
+    "cocoindex[litellm]==1.0.0a32",
     "sentence-transformers>=2.2.0",
     "sqlite-vec>=0.1.0",
     "pydantic>=2.0.0",

src/cocoindex_code/cli.py

@@ -10,7 +10,7 @@
 if TYPE_CHECKING:
     from .client import DaemonClient
 
-from .protocol import ProjectStatusResponse, SearchResponse
+from .protocol import IndexingProgress, ProjectStatusResponse, SearchResponse
 from .settings import (
     default_project_settings,
     default_user_settings,
@@ -80,8 +80,21 @@ def resolve_default_path(project_root: Path) -> str | None:
     return f"{rel.as_posix()}/*"
 
 
+def _format_progress(progress: IndexingProgress) -> str:
+    """Format an IndexingProgress snapshot as a human-readable string."""
+    return (
+        f"{progress.num_execution_starts} files listed"
+        f" | {progress.num_adds} added, {progress.num_deletes} deleted,"
+        f" {progress.num_reprocesses} reprocessed,"
+        f" {progress.num_unchanged} unchanged,"
+        f" error: {progress.num_errors}"
+    )
+
+
 def print_index_stats(status: ProjectStatusResponse) -> None:
     """Print formatted index statistics."""
+    if status.progress is not None:
+        _typer.echo(f"Indexing in progress: {_format_progress(status.progress)}")
     _typer.echo("\nIndex stats:")
     _typer.echo(f"  Chunks: {status.total_chunks}")
     _typer.echo(f"  Files:  {status.total_files}")
@@ -153,13 +166,40 @@ def init(
 @app.command()
 def index() -> None:
     """Create/update index for the codebase."""
+    from rich.console import Console as _Console
+    from rich.live import Live as _Live
+    from rich.spinner import Spinner as _Spinner
+
     client, project_root = require_daemon_for_project()
-    _typer.echo("Indexing...")
-    try:
-        resp = client.index(project_root)
-    except RuntimeError as e:
-        _typer.echo(f"Indexing failed: {e}", err=True)
-        raise _typer.Exit(code=1)
+    err_console = _Console(stderr=True)
+    last_progress_line: str | None = None
+
+    with _Live(_Spinner("dots", "Indexing..."), console=err_console, transient=True) as live:
+
+        def _on_waiting() -> None:
+            live.update(
+                _Spinner(
+                    "dots",
+                    "Another indexing is ongoing, waiting for it to finish...",
+                )
+            )
+
+        def _on_progress(progress: IndexingProgress) -> None:
+            nonlocal last_progress_line
+            last_progress_line = f"Indexing: {_format_progress(progress)}"
+            live.update(_Spinner("dots", last_progress_line))
+
+        try:
+            resp = client.index(project_root, on_progress=_on_progress, on_waiting=_on_waiting)
+        except RuntimeError as e:
+            live.stop()
+            _typer.echo(f"Indexing failed: {e}", err=True)
+            raise _typer.Exit(code=1)
+
+    # Print the final progress line so it remains visible after the spinner clears
+    if last_progress_line is not None:
+        _typer.echo(last_progress_line, err=True)
+
     if not resp.success:
         _typer.echo(f"Indexing failed: {resp.message}", err=True)
         raise _typer.Exit(code=1)

src/cocoindex_code/client.py

@@ -8,6 +8,7 @@
 import subprocess
 import sys
 import time
+from collections.abc import Callable
 from multiprocessing.connection import Client, Connection
 from pathlib import Path
 
@@ -18,8 +19,11 @@
     ErrorResponse,
     HandshakeRequest,
     HandshakeResponse,
+    IndexingProgress,
+    IndexProgressUpdate,
     IndexRequest,
     IndexResponse,
+    IndexWaitingNotice,
     ProjectStatusRequest,
     ProjectStatusResponse,
     Request,
@@ -59,9 +63,30 @@ def handshake(self) -> HandshakeResponse:
         """Send version handshake."""
         return self._send(HandshakeRequest(version=__version__))  # type: ignore[return-value]
 
-    def index(self, project_root: str) -> IndexResponse:
-        """Request indexing. Blocks until complete."""
-        return self._send(IndexRequest(project_root=project_root))  # type: ignore[return-value]
+    def index(
+        self,
+        project_root: str,
+        on_progress: Callable[[IndexingProgress], None] | None = None,
+        on_waiting: Callable[[], None] | None = None,
+    ) -> IndexResponse:
+        """Request indexing with streaming progress. Blocks until complete."""
+        self._conn.send_bytes(encode_request(IndexRequest(project_root=project_root)))
+        while True:
+            data = self._conn.recv_bytes()
+            resp = decode_response(data)
+            if isinstance(resp, ErrorResponse):
+                raise RuntimeError(f"Daemon error: {resp.message}")
+            if isinstance(resp, IndexWaitingNotice):
+                if on_waiting is not None:
+                    on_waiting()
+                continue
+            if isinstance(resp, IndexProgressUpdate):
+                if on_progress is not None:
+                    on_progress(resp.progress)
+                continue
+            if isinstance(resp, IndexResponse):
+                return resp
+            raise RuntimeError(f"Unexpected response: {type(resp).__name__}")
 
     def search(
         self,

src/cocoindex_code/daemon.py

@@ -9,6 +9,7 @@
 import sys
 import threading
 import time
+from collections.abc import AsyncIterator
 from multiprocessing.connection import Connection, Listener
 from pathlib import Path
 from typing import Any
@@ -22,8 +23,12 @@
     ErrorResponse,
     HandshakeRequest,
     HandshakeResponse,
+    IndexingProgress,
+    IndexProgressUpdate,
     IndexRequest,
     IndexResponse,
+    IndexStreamResponse,
+    IndexWaitingNotice,
     ProjectStatusRequest,
     ProjectStatusResponse,
     Request,
@@ -113,14 +118,43 @@ async def get_project(self, project_root: str) -> Project:
             self._indexing[project_root] = False
         return self._projects[project_root]
 
-    async def update_index(self, project_root: str) -> None:
-        """Update index for project, serialized by per-project lock."""
+    async def update_index(self, project_root: str) -> AsyncIterator[IndexStreamResponse]:
+        """Update index, yielding progress updates and a final IndexResponse."""
         project = await self.get_project(project_root)
         lock = self._index_locks[project_root]
+
+        # If lock is already held, notify the client and block until released
+        if lock.locked():
+            yield IndexWaitingNotice()
+
         async with lock:
             self._indexing[project_root] = True
             try:
-                await project.update_index()
+                progress_queue: asyncio.Queue[IndexingProgress] = asyncio.Queue()
+
+                def on_progress(progress: IndexingProgress) -> None:
+                    progress_queue.put_nowait(progress)
+
+                update_task = asyncio.create_task(project.update_index(on_progress=on_progress))
+
+                # Drain the queue until the update completes
+                while not update_task.done():
+                    try:
+                        progress = await asyncio.wait_for(progress_queue.get(), timeout=0.1)
+                        yield IndexProgressUpdate(progress=progress)
+                    except TimeoutError:
+                        continue
+
+                # Drain any remaining items
+                while not progress_queue.empty():
+                    yield IndexProgressUpdate(progress=progress_queue.get_nowait())
+
+                # Propagate any exception from the update task
+                update_task.result()
+
+                yield IndexResponse(success=True)
+            except Exception as e:
+                yield IndexResponse(success=False, message=str(e))
             finally:
                 self._indexing[project_root] = False
 
@@ -177,11 +211,14 @@ def get_status(self, project_root: str) -> ProjectStatusResponse:
                 " GROUP BY language ORDER BY cnt DESC"
             ).fetchall()
 
+        is_indexing = self._indexing.get(project_root, False)
+        progress = project.indexing_stats if is_indexing else None
         return ProjectStatusResponse(
-            indexing=self._indexing.get(project_root, False),
+            indexing=is_indexing,
             total_chunks=total_chunks,
             total_files=total_files,
             languages={lang: cnt for lang, cnt in lang_rows},
+            progress=progress,
         )
 
     def list_projects(self) -> list[DaemonProjectInfo]:
@@ -246,8 +283,12 @@ def _recv() -> bytes:
                 handshake_done = True
                 continue
 
-            resp = await _dispatch(req, registry, start_time, shutdown_event)
-            conn.send_bytes(encode_response(resp))
+            result = await _dispatch(req, registry, start_time, shutdown_event)
+            if isinstance(result, AsyncIterator):
+                async for resp in result:
+                    conn.send_bytes(encode_response(resp))
+            else:
+                conn.send_bytes(encode_response(result))
 
             if isinstance(req, StopRequest):
                 break
@@ -265,16 +306,21 @@ async def _dispatch(
     registry: ProjectRegistry,
     start_time: float,
     shutdown_event: asyncio.Event,
-) -> Response:
-    """Dispatch a request to the appropriate handler."""
+) -> Response | AsyncIterator[IndexStreamResponse]:
+    """Dispatch a request to the appropriate handler.
+
+    Returns a single Response for most requests, or an AsyncIterator for
+    streaming requests (IndexRequest).
+    """
     try:
         if isinstance(req, IndexRequest):
-            await registry.update_index(req.project_root)
-            return IndexResponse(success=True)
+            return registry.update_index(req.project_root)
 
         if isinstance(req, SearchRequest):
             if req.refresh:
-                await registry.update_index(req.project_root)
+                # Consume the index stream silently for refresh
+                async for _ in registry.update_index(req.project_root):
+                    pass
             results = await registry.search(
                 project_root=req.project_root,
                 query=req.query,

src/cocoindex_code/project.py

@@ -3,12 +3,14 @@
 from __future__ import annotations
 
 import asyncio
+from collections.abc import Callable
 from pathlib import Path
 
 import cocoindex as coco
 from cocoindex.connectors import sqlite
 
 from .indexer import indexer_main
+from .protocol import IndexingProgress
 from .settings import PROJECT_SETTINGS, ProjectSettings
 from .shared import CODEBASE_DIR, EMBEDDER, SQLITE_DB, Embedder
 
@@ -18,14 +20,43 @@ class Project:
     _app: coco.App[[], None]
     _index_lock: asyncio.Lock
     _initial_index_done: bool = False
+    _indexing_stats: IndexingProgress | None = None
 
-    async def update_index(self, *, report_to_stdout: bool = False) -> None:
-        """Update the index, serializing concurrent calls via lock."""
-        async with self._index_lock:
-            try:
-                await self._app.update(report_to_stdout=report_to_stdout)
-            finally:
-                self._initial_index_done = True
+    async def update_index(
+        self,
+        *,
+        on_progress: Callable[[IndexingProgress], None] | None = None,
+    ) -> None:
+        """Update the index, streaming progress via callback.
+
+        The lock is NOT acquired here — callers (e.g. ProjectRegistry) are
+        responsible for serialization so they can inspect lock state and
+        yield one-shot snapshots before blocking.
+        """
+        try:
+            handle = self._app.update()
+            async for snapshot in handle.watch():
+                file_stats = snapshot.stats.by_processor.get("process_file")
+                if file_stats is not None:
+                    progress = IndexingProgress(
+                        num_execution_starts=file_stats.num_execution_starts,
+                        num_unchanged=file_stats.num_unchanged,
+                        num_adds=file_stats.num_adds,
+                        num_deletes=file_stats.num_deletes,
+                        num_reprocesses=file_stats.num_reprocesses,
+                        num_errors=file_stats.num_errors,
+                    )
+                    self._indexing_stats = progress
+                    if on_progress is not None:
+                        on_progress(progress)
+                    await asyncio.sleep(0.1)
+        finally:
+            self._indexing_stats = None
+            self._initial_index_done = True
+
+    @property
+    def indexing_stats(self) -> IndexingProgress | None:
+        return self._indexing_stats
 
     @property
     def env(self) -> coco.Environment:

src/cocoindex_code/protocol.py

@@ -63,6 +63,29 @@ class IndexResponse(_msgspec.Struct, tag="index"):
     message: str | None = None
 
 
+class IndexingProgress(_msgspec.Struct):
+    """Indexing stats snapshot, shared between progress updates and status responses."""
+
+    num_execution_starts: int
+    num_unchanged: int
+    num_adds: int
+    num_deletes: int
+    num_reprocesses: int
+    num_errors: int
+
+
+class IndexProgressUpdate(_msgspec.Struct, tag="index_progress"):
+    """Streamed during indexing — one per stats change, before the final IndexResponse."""
+
+    progress: IndexingProgress
+
+
+class IndexWaitingNotice(_msgspec.Struct, tag="index_waiting"):
+    """Sent when another indexing is already in progress and the client must wait."""
+
+    pass
+
+
 class SearchResult(_msgspec.Struct):
     file_path: str
     language: str
@@ -85,6 +108,7 @@ class ProjectStatusResponse(_msgspec.Struct, tag="project_status"):
     total_chunks: int
     total_files: int
     languages: dict[str, int]
+    progress: IndexingProgress | None = None
 
 
 class DaemonProjectInfo(_msgspec.Struct):
@@ -109,13 +133,17 @@ class ErrorResponse(_msgspec.Struct, tag="error"):
 Response = (
     HandshakeResponse
     | IndexResponse
+    | IndexProgressUpdate
+    | IndexWaitingNotice
     | SearchResponse
     | ProjectStatusResponse
     | DaemonStatusResponse
     | StopResponse
     | ErrorResponse
 )
 
+IndexStreamResponse = IndexProgressUpdate | IndexWaitingNotice | IndexResponse | ErrorResponse
+
 # ---------------------------------------------------------------------------
 # Encode / decode helpers (msgpack binary)
 # ---------------------------------------------------------------------------