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title: Pantry Push Dedup Verification tags: [pantry, storage, session] created: 2026-05-25 updated: 2026-05-25 status: active related:

• “lemna-data-v2-plan”

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Session: Pantry Push Dedup Verification

Date: 2026-05-25 Scope: src/pantry/src/pantry/cli.py, src/pantry/src/pantry/storage.py

Summary

Verified that pantry push already checks R2 before uploading — the ContentStore.upload() method calls self.exists(key) (a head_object request) and skips if the object exists. No code change needed.

Key Learnings

New Patterns

• Pantry’s content-addressable design (key = namespace/sha256hash) makes push naturally idempotent. Two identical files produce the same key, so dedup happens at two levels: CLI-level filtering (manifest storage_key comparison) and storage-level exists() check.
• When storage_key is None in the manifest (e.g., after pantry add), push still works correctly — it hashes the file, constructs the key, calls upload(), which checks R2 first, and updates the manifest. No redundant upload.

Decisions

• No change to push logic. Current behavior is correct and efficient. The only “waste” is local hashing before upload() discovers the file exists in R2, but that hash is needed anyway to construct the storage key. No real savings from a proactive R2 check.

Pitfalls

• None encountered. The initial concern (does push blindly upload?) was unfounded — the code already handles it.

Skill Updates Needed

• None this session.

Files Modified

• None (investigation only, no code changes)