Chris Hopman

Add common infrastructure and build scaffolding Summary: Adds the games/ crate with shared infrastructure but no actual games yet: - console.rs: terminal input handling, re-exports superconsole::Stdin - framebuffer.rs: pixel-level framebuffer for sprite rendering - games/mod.rs: Game trait, run_game() loop, HighScores, overlay system - lib.rs: crate root - sprites.png: shared sprite sheet - BUCK: rust_library target only - Cargo.toml: all dependencies, no binary entries - PLAN.md: design notes Reviewed By: JakobDegen Differential Revision: D98707333 fbshipit-source-id: 51e5797d27915a3a4267c0ef0624c7e3442b5189

Add blocks (tetromino color-matching) game Summary: Tetromino color-matching game: pieces fall and lock, runs of 4+ same-color cells in a row/column clear and score (n-3)² points. Unsupported blocks fall as rigid groups with chain-matching. Notable implementation details: - Color-matching mechanic: each cell is randomly colored, matches are 4+ adjacent same-color in a line, scored (n-3)² to reward longer runs - Floating group gravity via disjoint-set (union-find) to identify connected components, with chain re-matching after settling - Seven-bag randomizer for even piece distribution - Lock delay with reset on move/rotate (~0.5s) - Match animation (random color flash for 30 ticks) Reviewed By: JakobDegen Differential Revision: D98824937 fbshipit-source-id: bd2717ccb472a43938854488f7e8bbf2127f1841

Add minesweeper game Summary: Minesweeper with constraint-based solver, no-guess guarantee, and multiple board sizes up to 50×34. Notable implementation details: - Two-phase constraint solver: single-cell propagation + subset elimination between constraint pairs for logical deduction - No-guess guarantee: when no safe moves are deducible, the board is rearranged to make the clicked cell safe while preserving all existing constraints (exact backtracking for small components, randomized for large) - Safe mode (toggle 'g'): blocks provably risky clicks when safe alternatives exist - Auto-chord (toggle 'c'): automatically reveals neighbors of satisfied numbers when flagging, with cascading - Guaranteed large opening on first click via layout regeneration - 4 board sizes: Beginner, Intermediate, Expert, Huge (50×34) - Timer tracking Reviewed By: JakobDegen Differential Revision: D98824934 fbshipit-source-id: c93675bd80ecaf9c34f1867b084ad3dbbf83ac46

Add sokoban puzzle game with level generator Summary: Sokoban box-pushing puzzle with A* solver, procedural level generator, and 600+ pre-generated levels organized by box count. Notable implementation details: - A* solver with state normalization (player position canonicalized to top-left of reachable region), dead-cell pruning via reverse BFS, and greedy Manhattan-distance heuristic - Procedural level generator (sokoban_gen) based on a simplified version of Taylor & Parberry: https://ianparberry.com/pubs/GAMEON-NA_METH_03.pdf Generates rooms via 2x2 templates, searches backward from solved state to find the farthest reachable start position - 600+ levels in separate files by box count (2-6), all guaranteed solvable by construction - Per-level move tracking with lower_is_better scoring - Numbered box mode for following solver solutions - Box-on-target and player-on-target color feedback Reviewed By: JakobDegen Differential Revision: D98828179 fbshipit-source-id: 5f9f1667f9c0afe075e7282773fbfaf1d005993b

Introduce ResultMaybeCompatible Summary: Add `ResultMaybeCompatible<T>`, a three-variant enum that flattens `Result<MaybeCompatible<T>>` into `Compatible(T) | Incompatible(...) | Err(...)`. It implements the `Try` trait so that `?` propagates both errors and incompatibilities, eliminating the common `.await?.require_compatible()?` and `match` boilerplate at callsites. Migrate `get_configured_target_node` and related functions (`gather_deps`, `compute_configured_target_node`, `configure_exec_dep_with_modifiers`, `get_graph_properties`, `ErrorsAndIncompatibilities::finalize`) to return `ResultMaybeCompatible` instead of `Result<MaybeCompatible<...>>`. Also makes `buck2_error::Error::compute_context` public and re-exports `buck2_error::ContextValue` so that `ResultMaybeCompatible` can provide its own `compute_context` method. Reviewed By: JakobDegen Differential Revision: D95148447 fbshipit-source-id: e756146a887e0898b5e6c7c24dd4d4d823f37288

Integrate games into superconsole build overlay Summary: Embeds the games crate into buck2's superconsole as a hidden overlay activated by pressing 'g' three times during any build. Notable implementation details: - Secret 'ggg' activation: three consecutive 'g' presses activate the games overlay during a build, any other key resets the counter - Overlay rendering: games draw above the normal build status output, not replacing it — the build continues underneath - Tick-based escape detection: custom EscapeState machine with a tick-counting timeout (~66ms at 30fps) since buck2's input path delivers characters one at a time without async timeouts - 30fps game tick rate: desired_ticks_per_second switches from the normal build rate to 30fps when games are active - Full state machine: Menu → Playing → GameOver → HighScores with save/load on escape to ~/.buck2_games/ - High scores display matching the standalone menu binary's layout - Escape from menu deactivates the overlay, returning to build view Reviewed By: JakobDegen Differential Revision: D98707326 fbshipit-source-id: 8d770cee9c4aeb26fc8a0445e41869ba04320c2c

Add select_incompatible() Summary: Implement `select_incompatible()`, a new select branch marker that causes the target to be treated as incompatible with the current configuration when that branch is selected. Unlike `select_fail()` which is always an error, `select_incompatible()` causes the target to be skipped gracefully, the same way `target_compatible_with` incompatibility works. This allows expressing conditional incompatibility inline on any attribute: ``` deps = select({ "ovr_config//os:linux": [":linux_dep"], "DEFAULT": select_incompatible("only supports linux"), }) ``` Key changes: - Add `select_incompatible()` starlark function and `StarlarkSelectIncompatible` type, mirroring `select_fail()` / `StarlarkSelectFail`. - Add `CoercedAttr::SelectIncompatible` variant and `IncompatiblePlatformReasonCause::SelectIncompatible` cause. - Implement the `SelectIncompatible` arm in `CoercedAttr::configure_inner` to return `ResultMaybeCompatible::Incompatible`. - Add `incompatible_platform_reason()` method to `AttrConfigurationContext` trait, which constructs an `IncompatiblePlatformReason` from a cause without exposing the `ConfiguredTargetLabel` directly. - `select_map()` preserves `select_incompatible()` values without applying the mapping function, and `select_test()` skips them (same as `select_fail()`). - Incompatibility propagates through the dependency graph: dependents of an incompatible target are also considered incompatible. Reviewed By: JakobDegen Differential Revision: D95148448 fbshipit-source-id: d0330d135ce5db305df35d1cccc8429300ef1c95

Wire up Dice::page_out and worker page-in step Summary: Adds the user-facing `Dice::page_out()` API and the worker's lazy page-in flow: - `Dice::page_out()` sends a new `StateRequest::PageOut` to the core thread, which iterates all `OccupiedGraphNode`s with hydrated values and serializes them to `DiceStorage`. Caller must ensure DICE is idle first (`wait_for_idle().await`). No-op when no `DiceStorage` is configured. Keys whose `value_serialize()` is `NoValueSerialize` (or returns `None`) are silently skipped and stay hydrated. - `DiceTaskWorker` handles the new `MatchPagedOut` / `CheckDepsPagedOut` lookup variants by deserializing the value via `DiceStorage::hydrate` (off the core thread) and sending a `Rehydrate` request to the core thread before continuing. Subsequent lookups for the same key see the rehydrated `NodeValue::Hydrated` and proceed normally — no further hydration needed until the next `page_out`. - Adds 4 e2e tests in `impls/tests/page_out.rs` covering: hydration on next lookup, rehydration persistence across multiple lookups, skip of `NoValueSerialize` keys, and `page_out()` no-op without storage. This completes the page-out / page-in feature stack. Reviewed By: jtbraun Differential Revision: D101759759 fbshipit-source-id: aa2434661fa336ac1b545b3f8b05f704451deb57

Add jump (side-scrolling runner) game Summary: Endless side-scrolling runner with sprite-based parallax rendering, 5 obstacle types, and adaptive difficulty. Notable implementation details: - Multi-layer parallax: 4 layers at different scroll speeds (sky, mountains, trees, ground) with seamless tree wrapping - PNG sprite sheets rendered through FrameBuffer with alpha compositing; 6-frame deer run cycle, 2-frame bird wing flaps - 5 obstacle types: small/large boulders (ground), slow/medium/fast birds (airborne with vertical bobbing and randomized heights) - Adaptive difficulty: gap shrinks 65→45px over 60s, bird probability ramps 30%→75% over 2 minutes - Speed-aware spawn timing: accounts for different obstacle speeds so gaps are correct as they pass the deer - Inset hitbox collision (2px deer, 1px obstacles) for fair near-misses - Airborne animation freeze (legs-together frame while jumping) Reviewed By: JakobDegen Differential Revision: D98824939 fbshipit-source-id: 466108dd25f4e31e709426817f6be5f22c4bf1b2

Check installer child process exit status while waiting on socket Summary: When `buck2 install` spawns an installer process that exits immediately (e.g., due to invalid arguments like passing `--emulator` to an iOS installer), buck2 previously had no mechanism to detect the early exit. It would wait the full 120-second timeout trying to connect to the installer's TCP port, then fail with a confusing timeout error. This change monitors the installer child process while waiting for the TCP connection. If the installer exits before establishing a connection, buck2 immediately reports the failure with the process exit status instead of waiting for the timeout. The fix: - Changed `build_launch_installer` to use `async_background_command` (tokio) and return the `Child` handle instead of discarding it. - Added the child process handle as a parameter to `ConnectedInstaller::connect`. - Used `tokio::select!` to race the connection retry loop against the child process exiting, providing an immediate error when the installer dies early. Reviewed By: JakobDegen Differential Revision: D103760516 fbshipit-source-id: 3ccf85a7ca3af3ef78cd033c3c99da64094881fb

Add breakout game Summary: Breakout with multi-hit bricks, powerups, combos, and level progression. Notable implementation details: - Multi-hit bricks (1-3 health) with color fading as health decreases - 4 powerup types (WidePaddle, MultiBall, FireBall, SplitBall) hidden in ~30% of bricks, visually marked with bold double-line borders - Combo scoring: consecutive breaks without paddle hit multiply points - Border flash feedback in the brick's row color on every break - Paddle hit angle control for directional ball steering - Fine movement (Shift+Arrow for 1-cell precision) - Respawn delay with flashing lives indicator - Level progression with increasing brick health Reviewed By: JakobDegen Differential Revision: D98824945 fbshipit-source-id: 9c0fc757189695368fdd2b6f8ee3e8bce19cb9bd

Add snake game Summary: Classic snake on an 80×40 board with emoji rendering (🦌 and 🍎). Notable implementation details beyond a naive snake: - Distance-biased apple placement using weighted random selection (inverse distance^2.7) so apples spawn near the head - "Last chance" forgiveness tick when about to collide, preventing deaths from input arriving one frame late - Input buffering via VecDeque for rapid cornering sequences - Opposite-direction rejection (silently ignored, not instant death) - Tail-chase allowed since the tail vacates before the head arrives - Full save/load state support via serde Reviewed By: JakobDegen Differential Revision: D98824938 fbshipit-source-id: fe065613f447bf7d9742d444b15e087d76ca208f

Add life (Conway's Game of Life) game Summary: Interactive Game of Life on a 160×80 toroidal grid with framebuffer rendering. Notable features beyond a basic Life implementation: - 8 color visualization schemes (Age, Density, Velocity, Heat, Gradient, Energy, etc.) cycled with 'm', each driven by per-cell auxiliary state - Per-cell age, previous-generation, and heat tracking to power the color schemes without affecting the simulation rules - Interactive editing: cursor to toggle cells, pause, single-step, clear, and re-randomize - Toroidal topology with rem_euclid wrapping - Framebuffer rendering for per-pixel RGB color via half-block characters - Sparse save format (only live cell coordinates) Reviewed By: JakobDegen Differential Revision: D98824935 fbshipit-source-id: a2ccdb60e662ab5e65fc46943ed3aee0e87c459e

Add DiceStorage type backed by sled Summary: Introduces `DiceStorage`, a wrapper around any `pagable::storage::traits::PagableStorage` backend, that exposes (crate-internal) `page_out` and `hydrate` APIs for serializing / deserializing a `DiceValidValue` via its key's `ValueSerialize`. `page_out` accepts a `&mut HashMap<usize, DataKey>` cache so callers in a batch can dedup serialization of arcs reachable from multiple values. Use `DiceStorage::new_page_out_cache()` to construct a fresh cache. Constructors: `DiceStorage::new(Arc<dyn PagableStorage>)` for arbitrary backends, plus `DiceStorage::open(path)` and `DiceStorage::from_sled_db(db)` as sled convenience constructors. `Dice` and `DiceDataBuilder` gain an optional `pagable_storage` field. When `set_pagable_storage` is not called, paging is disabled (the upcoming `Dice::page_out` is a no-op). The storage is wired up but unused — the page-out flow that consumes it lands in a follow-up commit. The new code is annotated `#[allow(dead_code)]` to keep lint clean in the meantime. Reviewed By: jtbraun Differential Revision: D101759760 fbshipit-source-id: f65adc6e43cb5a03f95a858d1435980a71dede51

Add 2048 game Summary: Tile-sliding puzzle on a 4×4 grid with box-drawn tile rendering. Notable implementation details: - Direction-agnostic slide via cell_pos mapping — one function handles all 4 directions without duplicating merge logic - Box-drawn tiles (╭──╮ │val│ ╰──╯) built span-by-span, not just numbers in a grid - Per-value color coding (distinct color for each power of 2) - Bold highlighting on the most recently spawned tile - 90/10 spawn distribution matching the original game Reviewed By: JakobDegen Differential Revision: D98824936 fbshipit-source-id: 1649475ce7be971d1eeaf1197ff9b091adba2ec8

Add 'buck2 debug hydration page-out' command Summary: Hooks the dice paging feature into buck2 with a new debug subcommand: - `configure_dice_for_buck` opens a sled-backed `DiceStorage` when the `BUCK2_DICE_DB_PATH` env var is set, calling `set_pagable_storage` on the builder. Without the env var the storage is unconfigured and `page_out` is a no-op. - New proto `HydrationPageOutRequest` + `DaemonApi::HydrationPageOut` RPC. - Server-side handler waits for DICE to go idle, then calls `dice.page_out()`. - Client-side `oneshot_method!` plus a new `Hydration` debug subcommand with a `PageOut` variant. CLI invocation: `buck2 debug hydration page-out`. To use: start the daemon with `BUCK2_DICE_DB_PATH=/some/path` set in the environment, then run `buck2 debug hydration page-out` to evict every hydrated `OccupiedGraphNode` value to disk. Subsequent lookups hydrate values back on demand off the DICE core thread. Reviewed By: jtbraun Differential Revision: D101759761 fbshipit-source-id: f1e821a5f92df81be59cdff989eea7774f028e81

Extract DiceTaskInternalCritical into its own module Summary: Refactor to encapsulate the mutex-protected critical section of DiceTaskInternal into a separate `mod critical` block. This moves the lock acquisition into methods on the new `DiceTaskInternalCritical` wrapper type, hiding the internal `Data` struct and exposing a cleaner API. No behavioral changes. Reviewed By: JakobDegen Differential Revision: D99415248 fbshipit-source-id: 20ddd675b5c5b2ee5cee4e03968e15132a64776f

Make OccupiedGraphNode value page-able via PagableNodeValue Summary: Introduces a `PagableNodeValue` enum (`Hydrated(DiceValidValue)` / `PagedOut(DataKey)`) and stores it as `OccupiedGraphNode.res`. Adds two new `VersionedGraphResult` variants — `MatchPagedOut(PagedOutMatch)` and `CheckDepsPagedOut(PagedOutMismatch)` — that the graph emits when the node's value is paged out, carrying the `DataKey` the worker needs to hydrate. `OccupiedGraphNode::val()` now returns `&PagableNodeValue`; callers needing the hydrated value call `.expect_hydrated(msg)` with a message explaining why they know the value is hydrated (analogous to `Option::expect`). No code path actually constructs `PagableNodeValue::PagedOut` yet, so the new lookup variants are unreachable in practice. The follow-up commit wires up `Dice::page_out` (which transitions nodes to `PagedOut`) and the worker hydration step (which consumes the new variants). Tests pass unchanged. Reviewed By: jtbraun Differential Revision: D101759758 fbshipit-source-id: 2efd54a402bc01aecc3f3c62d8de7d622c70fc67

Add menu system for game selection Summary: Game selection menu with save/continue support, high score viewing, and animated title. Notable implementation details: - Two-level selection: game list → New Game / Continue sub-menu with greyed-out Continue when no save exists - Animated "BUCK2 GAMES" title with cycling dot animation - High Scores entry in the game list for viewing per-game records - Reusable bordered_line() and hline() helpers shared with the high scores display for consistent box-drawing formatting - Fixed-height rendering via FixedHeight to prevent display jumps when switching between menu and gameplay Reviewed By: JakobDegen Differential Revision: D98828180 fbshipit-source-id: 10b193f6191c319042c4219456dc9c9b8e057fb5

Move cancellation state into the critical section mutex Summary: Move cancellation state from a separate `Cancellations` type on `DiceTask` into the mutex-guarded `Data` in `DiceTaskInternalCritical`. Since it was always accessed under the critical section mutex anyway, the `Arc<UnsafeCell<...>>` wrapper and `MutexGuard` parameter ceremony were redundant. - Replace `Cancellations` with `CancellationState` enum stored directly in `Data`. The Mutex provides all the safety — no more UnsafeCell. - `DiceTask` simplifies to just `{ internal: Arc<DiceTaskInternal> }`. - `DicePromise::Pending` drops its `cancellations` field — `drop_waiter` accesses cancellation state through `task_internal.critical`. - `cancel()` uses `std::mem::replace` on owned state instead of `take_mut` + UnsafeCell. - `CancellationState::Pending` variant bridges the gap between `DiceTaskInternal` creation and `CancellationHandle` availability. Reviewed By: JakobDegen Differential Revision: D99415245 fbshipit-source-id: d94cb875ba1598ed52ff49ad95c8f29d2ac76823