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mcp-nextcloud/nextcloud_mcp_server/providers/ollama.py
T
Chris CoutinhoandClaude Opus 4.8 a0bb5642cb fix(usage): embed query once across doc_types; address review round 1
Round-1 claude-review findings:

- 🔴 Multi-doc_type search billed N embedding calls as 1. nc_semantic_search
  loops search() once per doc_type on one BM25HybridSearchAlgorithm instance,
  and each call re-embedded the query, so only the last query_token_count was
  recorded. Cache the dense embedding per query on the (per-request) instance
  so the query is embedded — and metered — exactly once regardless of how many
  doc_types are searched. This also removes the redundant per-type embed work
  and avoids billing a user N× for one logical query.
- 🟡 Ollama embed() now delegates to embed_with_usage() so single and batch
  embeds use the same /api/embed endpoint (was the legacy /api/embeddings),
  keeping _detect_dimension and other embed() callers consistent.
- 🟢 round() instead of truncating int() when coercing provider-reported token
  counts (forward-compatible if a provider ever returns a float).

Tests: per-instance query-embedding cache (embedded once across 3 doc_types;
re-embeds on a different query).

Deferred (stated on the PR): mistral/openai single-embed dual path (changes
tested error/request semantics on the cloud-critical path — separate refactor),
bedrock boto3 sync-in-async (pre-existing; no new invoke_model calls per doc).

Deck #67.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
2026-06-08 01:07:22 +02:00

273 lines
9.4 KiB
Python

"""Unified Ollama provider for embeddings and text generation."""
import logging
import httpx
from .base import Provider
logger = logging.getLogger(__name__)
class OllamaProvider(Provider):
"""
Ollama provider supporting both embeddings and text generation.
Supports TLS, SSL verification, and automatic model loading.
"""
def __init__(
self,
base_url: str,
embedding_model: str | None = None,
generation_model: str | None = None,
verify_ssl: bool = True,
timeout: httpx.Timeout | None = None,
):
"""
Initialize Ollama provider.
Args:
base_url: Ollama API base URL (e.g., https://ollama.internal.example.com:443)
embedding_model: Model for embeddings (e.g., "nomic-embed-text"). None disables embeddings.
generation_model: Model for text generation (e.g., "llama3.2:1b"). None disables generation.
verify_ssl: Verify SSL certificates (default: True)
timeout: HTTP timeout configuration
"""
self.base_url = base_url.rstrip("/")
self.embedding_model = embedding_model
self.generation_model = generation_model
self.verify_ssl = verify_ssl
if timeout is None:
timeout = httpx.Timeout(timeout=120, connect=5)
self.client = httpx.AsyncClient(verify=verify_ssl, timeout=timeout)
self._dimension: int | None = None # Detected dynamically for embeddings
logger.info(
"Initialized Ollama provider: %s (embedding_model=%s, generation_model=%s, verify_ssl=%s)",
base_url,
embedding_model,
generation_model,
verify_ssl,
)
# Pre-check and auto-load models
if embedding_model:
self._check_model_is_loaded(embedding_model, autoload=True)
if generation_model:
self._check_model_is_loaded(generation_model, autoload=True)
@property
def supports_embeddings(self) -> bool:
"""Whether this provider supports embedding generation."""
return self.embedding_model is not None
@property
def supports_generation(self) -> bool:
"""Whether this provider supports text generation."""
return self.generation_model is not None
async def embed(self, text: str) -> list[float]:
"""
Generate embedding vector for text.
Args:
text: Input text to embed
Returns:
Vector embedding as list of floats
Raises:
NotImplementedError: If embeddings not enabled (no embedding_model)
"""
# Delegate to embed_with_usage so single and batch embeds use the same
# /api/embed endpoint (the legacy /api/embeddings differs in payload and
# omits prompt_eval_count). _detect_dimension() and other embed() callers
# therefore stay consistent with the search/indexing path.
embedding, _ = await self.embed_with_usage(text)
return embedding
async def embed_batch(
self, texts: list[str], batch_size: int = 32
) -> list[list[float]]:
"""
Generate embeddings for multiple texts using Ollama's batch API.
Uses /api/embed endpoint with array input for efficient batch processing.
Conservative batch size (32) prevents quality degradation observed in
Ollama issue #6262 with larger batches.
Note: Ollama processes batches serially, not in parallel.
Args:
texts: List of texts to embed
batch_size: Maximum texts per batch (default: 32)
Returns:
List of vector embeddings
Raises:
NotImplementedError: If embeddings not enabled (no embedding_model)
"""
embeddings, _ = await self.embed_batch_with_usage(texts, batch_size=batch_size)
return embeddings
async def embed_with_usage(self, text: str) -> tuple[list[float], int]:
"""Embed one text, reporting the request's token count.
Routes through ``/api/embed`` (which carries ``prompt_eval_count``)
rather than the legacy ``/api/embeddings`` so a token count is
available; falls back to a char-based estimate when the field is
absent. Used by the usage-metering hooks (Deck #67).
"""
embeddings, tokens = await self.embed_batch_with_usage([text])
if not embeddings:
raise RuntimeError(
"Ollama embeddings API returned no embedding for model "
f"{self.embedding_model}"
)
return embeddings[0], tokens
async def embed_batch_with_usage(
self, texts: list[str], batch_size: int = 32
) -> tuple[list[list[float]], int]:
"""Embed multiple texts, summing ``prompt_eval_count`` token usage.
Returns ``(embeddings, total_tokens)``. Ollama's ``/api/embed`` may
omit ``prompt_eval_count`` (older versions); a char-based estimate is
used per batch when it does.
"""
if not self.supports_embeddings:
raise NotImplementedError(
"Embedding not supported - no embedding_model configured"
)
if not texts:
return [], 0
all_embeddings: list[list[float]] = []
total_tokens = 0
for i in range(0, len(texts), batch_size):
batch = texts[i : i + batch_size]
response = await self.client.post(
f"{self.base_url}/api/embed",
json={"model": self.embedding_model, "input": batch},
)
response.raise_for_status()
data = response.json()
all_embeddings.extend(data["embeddings"])
prompt_eval = data.get("prompt_eval_count")
total_tokens += (
round(prompt_eval)
if isinstance(prompt_eval, (int, float))
else self._estimate_tokens(batch)
)
return all_embeddings, total_tokens
async def _detect_dimension(self):
"""
Detect embedding dimension by generating a test embedding.
This method queries the model to determine the actual dimension
instead of relying on hardcoded values.
"""
if self._dimension is None and self.supports_embeddings:
logger.debug(
"Detecting embedding dimension for model %s...", self.embedding_model
)
test_embedding = await self.embed("test")
self._dimension = len(test_embedding)
logger.info(
"Detected embedding dimension: %s for model %s",
self._dimension,
self.embedding_model,
)
def get_dimension(self) -> int:
"""
Get embedding dimension.
Returns:
Vector dimension for the configured embedding model
Raises:
NotImplementedError: If embeddings not enabled (no embedding_model)
RuntimeError: If dimension not detected yet (call _detect_dimension first)
"""
if not self.supports_embeddings:
raise NotImplementedError(
"Embedding not supported - no embedding_model configured"
)
if self._dimension is None:
raise RuntimeError(
f"Embedding dimension not detected yet for model {self.embedding_model}. "
"Call _detect_dimension() first or generate an embedding."
)
return self._dimension
async def generate(self, prompt: str, max_tokens: int = 500) -> str:
"""
Generate text from a prompt.
Args:
prompt: The prompt to generate from
max_tokens: Maximum tokens to generate
Returns:
Generated text
Raises:
NotImplementedError: If generation not enabled (no generation_model)
"""
if not self.supports_generation:
raise NotImplementedError(
"Text generation not supported - no generation_model configured"
)
response = await self.client.post(
f"{self.base_url}/api/generate",
json={
"model": self.generation_model,
"prompt": prompt,
"stream": False,
"options": {
"num_predict": max_tokens,
"temperature": 0.7,
},
},
)
response.raise_for_status()
data = response.json()
return data["response"]
def _check_model_is_loaded(self, model: str, autoload: bool = True):
"""
Check if model is loaded in Ollama, optionally auto-loading it.
Args:
model: Model name to check
autoload: Whether to automatically pull the model if not loaded
"""
response = httpx.get(f"{self.base_url}/api/tags")
response.raise_for_status()
models = [m["name"] for m in response.json().get("models", [])]
logger.info("Ollama has following models pre-loaded: %s", models)
if (model not in models) and autoload:
logger.warning(
"Model '%s' not yet available in ollama, attempting to pull now...",
model,
)
response = httpx.post(f"{self.base_url}/api/pull", json={"model": model})
response.raise_for_status()
async def close(self) -> None:
"""Close HTTP client."""
await self.client.aclose()