tiny.reducer.bytes

1//! The search deletes bytes from an input that reproduces a defect until a2//! smaller input still reproduces it, carrying out *test-case reduction* over3//! byte sequences. It works on any `[]const u8`, and it finds a shorter4//! *subsequence* of the input (a sequence obtained from another by deleting5//! bytes and keeping the order of the rest) that still reproduces the failure.6//! Two properties bound a run. First, the *attempt budget*, the ceiling on the7//! number of oracle calls (`Settings.max_attempts`), caps the work. Second, a8//! given input with a given *oracle*, the caller's function (`InterestingFn`)9//! that answers whether one candidate still reproduces the defect, yields the10//! same result every time. The search works on the raw bytes of the input.11//!12//! ## Module Organization13//!14//! Four internal modules divide the work:15//! - `capacity` works out the upper bound on the memory a run needs and catches16//!   arithmetic overflow in that sum.17//! - `model` declares the error sets, the oracle type `InterestingFn`, the18//!   status flag the search reports, and the settings a run reads.19//! - `storage` holds the *workspace* (the one byte allocation `Storage` makes20//!   and reuses for every run), allocated up front and double-buffered, and21//!   checks each lifecycle step against the *phase* recorded for `alloc_phase`.22//! - `reduction` runs the search itself, deleting a *chunk* at a time (the23//!   number of adjacent bytes one candidate deletes) and halving the chunk24//!   greedily.25//!26//! ## Dataflow Pipeline27//!28//! The five calls of a run connect in one order:29//! 1. `Storage.init(allocator, limits)` takes the caller's *limits* (the30//!    longest input it will submit), derives the layout *capacity* itself, and31//!    allocates the backing memory once.32//! 2. `storage.activate()` seals the workspace into steady state.33//! 3. `reduce()` acquires the workspace regions, runs the search with no34//!    backing allocation of its own, and returns a `Result` borrowing from the35//!    workspace (`Result.bytes` points into the workspace without owning36//!    memory).37//! 4. `Result.deinit()` gives up the *lease* (one run's exclusive hold on the38//!    workspace, recorded by `in_use`), returning the workspace to steady and39//!    *idle* so the next run can acquire it.40//! 5. `storage.deinit(allocator)` tears down the idle workspace and frees the41//!    backing memory.4243/// Module holding the capacity derivation and the limits type.44pub const capacity = @import("capacity.zig");4546/// Module holding the data types, the oracle function interface, the error47/// sets, and the execution settings.48pub const model = @import("model.zig");4950/// Module holding the reduction loop, the execution counters, and the borrowed51/// result.52pub const reduction = @import("reduce.zig");5354/// Module holding the workspace, allocated up front and double-buffered, and55/// the phase-checked lifecycle around it.56pub const storage = @import("storage.zig");5758/// Workspace layout derived from the caller's limits, sized so that a run in59/// steady state needs no further allocation.60pub const Capacity = capacity.Capacity;6162/// Stopping condition that ended the search, `one_minimal` or63/// `budget_exhausted`.64pub const Completion = model.Completion;6566/// Sizing constraint the caller supplies for the byte reduction workspace.67pub const Limits = capacity.Limits;6869/// Set of errors the reduction framework produces while acquiring the workspace70/// or checking the input.71pub const Error = model.Error;7273/// Set of errors raised when the input exceeds the workspace bounds or another74/// run already holds the workspace.75pub const Exhaustion = model.Exhaustion;7677/// Oracle's answer about one candidate, `interesting` or `uninteresting`.78pub const Interesting = model.Interesting;7980/// Type of the caller's oracle function pointer.81pub const InterestingFn = model.InterestingFn;8283/// Options that control how a run executes.84pub const Settings = model.Settings;8586/// Outcome of a run, with bytes borrowed from the acquired workspace.87pub const Result = reduction.Result;8889/// Snapshot of one workspace's state, taken by value at the moment of the call.90pub const Status = storage.Status;9192/// Workspace, allocated up front and double-buffered, that carries reduction in93/// steady state.94pub const Storage = storage.Storage;9596/// Shortens an initial byte sequence against the caller's oracle.97pub const reduce = reduction.reduce;

1/// Namespace holding the byte-oriented implementation.2pub const bytes = @import("bytes/root.zig");