i*dZddlmZddlZddlmZmZddlmZm Z eje Z Gdde ZeGdd ZGd d Zy) u core/merge/compensating_transaction.py CompensatingTransaction — Partial-Fail Recovery for failed saga deltas. Generates inverse RFC 6902 patches for failed agent deltas and applies rollback operations so that the shared state can be wound back to a consistent pre-saga baseline. Supported inverse mapping (RFC 6902): add -> remove (delete the key that was inserted) remove -> add (re-insert with original value from current_state) replace -> replace (restore original value from current_state) move -> move (swap path and from) copy -> IrreversibleOperationError (cannot determine original) unknown -> IrreversibleOperationError Design notes: - Patch operations are inverted in REVERSE order so the rollback correctly undoes each step starting from the most recent. - If a cold_ledger is supplied, a "compensation_applied" event is appended to the ledger after collecting all inverse ops. - Partial compensation (some ops irreversible) sets success=False and final_status="partial_compensation" but still returns the reversible ops so callers can apply best-effort rollback. # VERIFICATION_STAMP # Story: 7.06 # Verified By: parallel-builder # Verified At: 2026-02-25 # Tests: 9/9 # Coverage: 100% ) annotationsN) dataclassfield)AnyOptionalceZdZdZy)IrreversibleOperationErrorue Raised when an RFC 6902 operation cannot be reliably inverted. Currently applies to: - 'copy' — we cannot know what was at the destination before the copy - unknown — unrecognised op type Callers should catch this during compensation and record partial-compensation status rather than aborting the entire rollback. N)__name__ __module__ __qualname____doc__ remove (same path) remove -> add (same path, value restored from original_state) replace -> replace (same path, value restored from original_state) move -> move (swap path and from) copy -> IrreversibleOperationError other -> IrreversibleOperationError rCpathaddremove)rCrG)rCrGvaluereplacemovefrom)rCrGrMcopyzCannot invert 'copy' at path u. — destination state before copy is unknown.zUnknown RFC 6902 op type z at path .)get_get_value_at_pathr )r!rCrAop_typerGoriginal_value from_paths rr@z)CompensatingTransaction._invert_single_ops&&r"vvfb! e "D1 1  !44^TJNG G  !!44^TJN#TNK K  vr*I!)TB B  ,/x8<<  -+G;ixqI rct|dr |j}n%t|tr|j dg}ng}t|t t fr t |SgS)z Return the patch list from *delta*, normalising both StateDelta objects (which store patch as a frozen tuple) and plain dicts. Returns an empty list if no patch can be extracted. r:)hasattrr: isinstancedictrPrtuple)r9r:s rr,z&CompensatingTransaction._extract_patchsS 5' "KKE t $IIgr*EE edE] +;  rc|jdDcgc]}|s| }}|}|D]%}t|tr|j|}%y|Scc}w)u Navigate a nested dict by RFC 6902 JSON Pointer path and return the value found at that location. Examples: path="/config/mode" -> state["config"]["mode"] path="/name" -> state["name"] Returns None if any key along the path is missing or if *state* is not a dict (fail-safe for compensation — we still emit the inverse op, just with None as the restore value). /N)splitrWrXrP)staterGppartscurrentparts rrQz*CompensatingTransaction._get_value_at_paths\!JJsO1qq11 D'4(!++d+   2s AAr)r"z Optional[Any]returnNone)r5rr6rXrbr)r:rrArXrbr)rCrXrArXrbrX)r9rrbr)r]rXrGrrbr) r r r r r#r=r-r@ staticmethodr,rQrrrrr[se""B B B   B H>)V$rr)r __future__rlogging dataclassesrrtypingrr getLoggerr r/r4r rrrrrrjs\ D#(   8 $  $ "" ".OOr