What does HRESULT 0x00040171 (CACHE_S_SAMECACHE) mean?

CACHE_S_SAMECACHE

Requested OLE cache entry already exists

CACHE_S_SAMECACHE is HRESULT 262513 (0x00040171) from winerror.h. The documented description is “Same cache.” The high-order severity bit is clear, so this is a success result, but it carries more information than plain S_OK.

The cache request succeeded by identifying an existing cache entry equivalent to the requested presentation.

State to verify

The central question is whether the existing cache entry has the aspect, index, medium, and update policy the caller needs.

Where the result is encountered

• This result can appear in repeated IOleCache::Cache calls; record the producing interface and method.
• It can appear in containers rebuilding presentation bookkeeping after load; record the producing interface and method.
• It can appear in objects that deduplicate equivalent cache formats; record the producing interface and method.

Evidence to preserve

• Preserve requested FORMATETC.
• Preserve existing cache connection identifier.
• Preserve ADVF flags.
• Preserve last cache update time.
• Preserve offline rendering result after the server is stopped.

Diagnostic sequence

• Capture the raw HRESULT 0x00040171 immediately after the returning method and record whether the caller used SUCCEEDED, FAILED, equality testing, or exception translation.
• Verify the method-specific state: the existing cache entry has the aspect, index, medium, and update policy the caller needs.

Correct handling, retry, and recovery

Reuse the existing cache entry and avoid duplicate update subscriptions. If policy differs, use the documented cache-management operations rather than assuming a new entry was created.

Practical validation scenario

A document reloads an embedded object and repeats cache setup. It tells it to retain the existing connection instead of adding a second identical presentation and doubling update traffic.

Difference from nearby HRESULT values

CACHE_S_SOMECACHES_NOTUPDATED concerns refresh results; it concerns cache-entry identity at registration time.

References

• Microsoft: COM cache status codes
• Microsoft: IOleCache::Cache
• Microsoft: IOleCache