{
 "number": 35581,
 "input_hash": "39f636ae2abd6d3d",
 "model": "openrouter/google/gemini-3.8-flash",
 "batch": false,
 "created": "2026-09-17T21:34:06+00:00",
 "provider": "Google",
 "stop_reason": "end_turn",
 "usage": {
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  "display": {
   "goal": [
    "Avoid expensive full block template rebuilds on every waitNext poll by tracking fee inflow via mempool diagrams",
    "Consolidate mining helper state and block submission into a dedicated BlockTemplateManager"
   ],
   "reviewability": [
    "Stacked on #35675; review that PR first",
    "Author split the manager into #35675 following reviewer feedback and is keeping this stacked"
   ],
   "agreement": [
    "Concept support from multiple contributors (w0xlt, pablomartin4btc)",
    "Scoped extraction requested: Sjors asked to isolate BlockTemplateManager into a prerequisite PR, which author created as #35675"
   ],
   "categories": [
    {
     "name": "mining",
     "why": [
      "P2 because it optimizes block template generation latency during waitNext polling without requiring full assembly on every tick",
      "It also unblocks memory tracking improvements for external block templates (#33922)"
     ]
    },
    {
     "name": "mempool",
     "why": [
      "P3 because it caches chunked fee-rate diagrams in ChangeSet and exposes a MempoolUpdated signal for asynchronous fee inflow tracking"
     ]
    },
    {
     "name": "ipc",
     "why": [
      "P3 because it decouples in-process mining RPCs from the IPC interfaces::Mining layer while routing template creation through the manager"
     ]
    },
    {
     "name": "validation",
     "why": [
      "P4 because validation changes are limited to emitting the MempoolUpdated validation signal and passing block height to removeForBlock"
     ]
    }
   ]
  },
  "summary": "This PR introduces `BlockTemplateManager` to encapsulate block template generation, tip tracking, and submission state previously scattered across `src/node/miner.cpp`. It also utilizes cluster mempool fee-rate diagram changes to track fee inflow incrementally, replacing repeated full template rebuilds in `waitNext` with a lightweight staleness check.",
  "problem": "Miners and mining pools polling `waitNext` currently trigger complete block assembly on every tick just to see if mempool fee increases warrant updating the template. In addition, mining and template state is scattered across free functions requiring repetitive parameter plumbing.",
  "discussion": {
   "open_concerns": [],
   "resolved_concerns": [
    "Sjors suggested splitting out the `BlockTemplateManager` introduction into its own PR so other work (such as #33922) can build on it; the author did so in #35675 and addressed related inline comments there.",
    "pablomartin4btc noted implicit preconditions on `IsStale` and missing comments, which the author confirmed addressed in #35675."
   ],
   "author_status": "Active; actively force-pushing rebased commits and maintaining the prerequisite PR #35675."
  },
  "reviewability": {
   "state": "Ready",
   "label": "Review #35675 first",
   "reason": "This PR is stacked on top of #35675, which extracts the core BlockTemplateManager class; reviewers should examine #35675 first."
  },
  "agreement": {
   "participants": [
    {
     "login": "w0xlt",
     "stance": "support",
     "note": "Posted Concept ACK"
    },
    {
     "login": "Sjors",
     "stance": "objection",
     "note": "suggested splitting the PR into BlockTemplateManager first and waitNext followup"
    },
    {
     "login": "pablomartin4btc",
     "stance": "support",
     "note": "Concept ACK and reviewed the BlockTemplateManager design; comments addressed in #35675"
    }
   ],
   "objections": [
    {
     "reviewer": "Sjors",
     "kind": "scope",
     "harm": "combining BlockTemplateManager with the waitNext cluster mempool enhancement makes it harder to review and build dependent work on top",
     "blocking": false,
     "author_replied": true,
     "fix_pushed": false,
     "status": "resolved",
     "evidence": "2026-06-25: \"It would be nice to have a PR focussed on the BlockTemplateManager... The `waitNext()` cluster mempool enhancement would be a natural followup.\"",
     "resolution_evidence": "2026-07-01: \"I will address these comments when I open up a PR that adds the block template manager alone, as @Sjors suggested\"",
     "sources": [
      "thread"
     ]
    }
   ],
   "support": [
    {
     "reviewer": "w0xlt",
     "reason": "Concept ACK",
     "substantive": false
    },
    {
     "reviewer": "pablomartin4btc",
     "reason": "\"The approach of moving free functions onto a class that holds state plus incremental snapshot tracking to avoid full template rebuilds seems clean. The fuzz test catching an actual bug (#35580) is a strong signal.\"",
     "substantive": true
    }
   ],
   "state": "Strong",
   "summary": "Strong concept support; Sjors requested splitting BlockTemplateManager into #35675, which author completed.",
   "reason": "Multiple maintainers and contributors support the concept. The only process criticism was splitting the PR, which the author completed by creating #35675.",
   "evidence": [
    "w0xlt: Concept ACK (2026-06-22)",
    "pablomartin4btc: Concept ACK with positive review of the architecture (2026-07-01)",
    "Sjors: asked to split BlockTemplateManager into a separate PR (2026-07-01)"
   ],
   "model_state": "Strong",
   "derivation": "substantive support, no open objection (pablomartin4btc)",
   "corrections": [],
   "thread_read": {
    "state": "Strong",
    "derived": "Strong",
    "objections": [
     {
      "reviewer": "Sjors",
      "kind": "scope",
      "harm": "combining BlockTemplateManager with the waitNext cluster mempool enhancement makes it harder to review and build dependent work on top",
      "blocking": false,
      "author_replied": true,
      "fix_pushed": false,
      "status": "resolved",
      "evidence": "2026-06-25: \"It would be nice to have a PR focussed on the BlockTemplateManager... The `waitNext()` cluster mempool enhancement would be a natural followup.\"",
      "resolution_evidence": "2026-07-01: \"I will address these comments when I open up a PR that adds the block template manager alone, as @Sjors suggested\""
     }
    ],
    "support": [
     {
      "reviewer": "pablomartin4btc",
      "reason": "The approach of moving free functions onto a state-holding class and incremental snapshot tracking seems clean, and the fuzz test caught a bug",
      "substantive": true
     },
     {
      "reviewer": "w0xlt",
      "reason": "Concept ACK",
      "substantive": false
     }
    ],
    "participants": [
     {
      "login": "w0xlt",
      "stance": "support",
      "note": "Concept ACK"
     },
     {
      "login": "Sjors",
      "stance": "objection",
      "note": "suggested splitting the PR into BlockTemplateManager first and waitNext followup"
     },
     {
      "login": "pablomartin4btc",
      "stance": "support",
      "note": "Concept ACK with substantive support and documentation suggestions"
     }
    ],
    "corrections": [],
    "summary": "Strong; Sjors suggested splitting out BlockTemplateManager which author addressed via #35675; pablomartin4btc gave substantive Concept ACK.",
    "usage": {
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   },
   "first_read": {
    "state": "Strong",
    "model_state": "Strong",
    "objections": [],
    "support": [
     {
      "reviewer": "w0xlt",
      "reason": "Concept ACK",
      "substantive": false
     },
     {
      "reviewer": "pablomartin4btc",
      "reason": "\"The approach of moving free functions onto a class that holds state plus incremental snapshot tracking to avoid full template rebuilds seems clean. The fuzz test catching an actual bug (#35580) is a strong signal.\"",
      "substantive": true
     }
    ]
   }
  },
  "dependencies": {
   "depends_on": [
    35675
   ],
   "enables": [
    "#33922 mining: add getMemoryLoad() and track template non-mempool memory footprint"
   ]
  },
  "categories": [
   {
    "name": "mining",
    "member": true,
    "evidence": "Touches src/node/miner.cpp, introduces BlockTemplateManager, alters waitNext fee inflow detection, and carries the Mining label.",
    "band": "P2",
    "reason_tag": "speedup",
    "score": 0.65,
    "factors": {
     "security_stability": 1,
     "bug_severity": 0,
     "performance": 2,
     "user_value": 2,
     "leverage": 2
    },
    "rationale": "Noticeably improves mining template update efficiency by tracking mempool chunk fee inflow instead of rebuilding entire block templates repeatedly under `waitNext`. Sjors noted it unblocks memory load tracking in #33922."
   },
   {
    "name": "mempool",
    "member": true,
    "evidence": "Modifies txmempool.cpp/h, txgraph.cpp/h, kernel/mempool_entry.h, and implements MempoolUpdated notifications with fee rate diagram caching.",
    "band": "P3",
    "reason_tag": "new feature",
    "score": 0.4,
    "factors": {
     "security_stability": 0,
     "bug_severity": 0,
     "performance": 1,
     "user_value": 0,
     "leverage": 2
    },
    "rationale": "Adds diagram chunk caching to ChangeSet and provides the MemPoolChunksUpdate notification mechanism used by downstream consumers to observe diagram changes asynchronously."
   },
   {
    "name": "ipc",
    "member": true,
    "evidence": "Touches src/node/interfaces.cpp and context.h, removing NodeContext::mining and routing in-process callers directly through BlockTemplateManager.",
    "band": "P3",
    "reason_tag": "cleanup",
    "score": 0.35,
    "factors": {
     "security_stability": 0,
     "bug_severity": 0,
     "performance": 1,
     "user_value": 0,
     "leverage": 1
    },
    "rationale": "Cleans up IPC usage by letting in-process callers bypass the IPC mining interface wrapper and avoiding unnecessary defensive block copying."
   },
   {
    "name": "validation",
    "member": true,
    "evidence": "Touches validationinterface.h/cpp adding MempoolUpdated signal and adjusts removeForBlock in validation.cpp.",
    "band": "P4",
    "reason_tag": "cleanup",
    "score": 0.15,
    "factors": {
     "security_stability": 0,
     "bug_severity": 0,
     "performance": 0,
     "user_value": 0,
     "leverage": 0
    },
    "rationale": "The validation impact is purely incidental plumbing for the new validation interface notification signal and passing height to removeForBlock."
   },
   {
    "name": "build",
    "member": false,
    "evidence": "Only modifies CI IWYU enforcement pattern for the new block_template_manager file.",
    "band": "Unranked",
    "reason_tag": "",
    "score": 0,
    "factors": {
     "security_stability": 0,
     "bug_severity": 0,
     "performance": 0,
     "user_value": 0,
     "leverage": 0
    },
    "rationale": "Mechanical CI IWYU inclusion for a newly added node source file does not constitute a build category change."
   },
   {
    "name": "kernel",
    "member": false,
    "evidence": "Adds MemPoolChunk struct to src/kernel/mempool_entry.h as a data carrier, without altering kernel boundary or API.",
    "band": "Unranked",
    "reason_tag": "",
    "score": 0,
    "factors": {
     "security_stability": 0,
     "bug_severity": 0,
     "performance": 0,
     "user_value": 0,
     "leverage": 0
    },
    "rationale": "Changes to internal kernel headers for mempool chunk structs do not affect libbitcoinkernel API or stability."
   },
   {
    "name": "rpc",
    "member": false,
    "evidence": "Modifies server_util and rpc/mining.cpp to call BlockTemplateManager rather than interfaces::Mining.",
    "band": "Unranked",
    "reason_tag": "",
    "score": 0,
    "factors": {
     "security_stability": 0,
     "bug_severity": 0,
     "performance": 0,
     "user_value": 0,
     "leverage": 0
    },
    "rationale": "Mechanical redirection of internal RPC call sites to the new template manager without RPC behavior or interface changes."
   },
   {
    "name": "tests",
    "member": false,
    "evidence": "Adds tests and a fuzz harness specifically for BlockTemplateManager and mempool updates.",
    "band": "Unranked",
    "reason_tag": "",
    "score": 0,
    "factors": {
     "security_stability": 0,
     "bug_severity": 0,
     "performance": 0,
     "user_value": 0,
     "leverage": 0
    },
    "rationale": "Tests pin the new mining and mempool behaviors rather than improving general test framework infrastructure."
   },
   {
    "name": "utils",
    "member": false,
    "evidence": "Extracts GetHashFromWitnesses helper into hasher.cpp.",
    "band": "Unranked",
    "reason_tag": "",
    "score": 0,
    "factors": {
     "security_stability": 0,
     "bug_severity": 0,
     "performance": 0,
     "user_value": 0,
     "leverage": 0
    },
    "rationale": "Minor refactoring helper in util/hasher is purely supportive of package chunk hashing."
   },
   {
    "name": "wallet",
    "member": false,
    "evidence": "Only updates wallet fee fuzz test setup to reset the template manager.",
    "band": "Unranked",
    "reason_tag": "",
    "score": 0,
    "factors": {
     "security_stability": 0,
     "bug_severity": 0,
     "performance": 0,
     "user_value": 0,
     "leverage": 0
    },
    "rationale": "Incidental fixture adjustment in a wallet test."
   }
  ],
  "confidence": "high",
  "uncertainties": [],
  "needs": [],
  "card": "This PR adds BlockTemplateManager to consolidate mining helper functions and template creation state, and leverages cluster mempool fee-rate diagrams to avoid repeated block assembly during waitNext. Mining clients querying for new templates benefit from reduced CPU overhead and lock contention. The base template manager refactor was split out into #35675, which reviewers should review first. Concept support is strong, with Sjors noting this will unblock template memory footprint tracking in #33922."
 },
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