Anthropic「Introducing Contextual Retrieval」

<document> 
{{WHOLE_DOCUMENT}} 
</document> 
ドキュメント全体に配置したいチャンクは次のとおりです。
<chunk> 
{{CHUNK_CONTENT}} 
</chunk> 
このチャンクを検索でより適切に取得できるように、ドキュメント全体におけるこのチャンクの位置づけを簡潔に説明してください。簡潔な説明のみを回答としてください。それ以外は回答しないでください。

//! Executor for differential fuzzing.
//! It wraps two executors that will be run after each other with the same input.
//! In comparison to the [`crate::executors::CombinedExecutor`] it also runs the secondary executor in `run_target`.
//!
use core::{cell::UnsafeCell, fmt::Debug, ptr};

use libafl_bolts::{ownedref::OwnedMutPtr, tuples::MatchName};
use serde::{Deserialize, Serialize};

use crate::{
    executors::{Executor, ExitKind, HasObservers},
    inputs::UsesInput,
    observers::{DifferentialObserversTuple, ObserversTuple, UsesObservers},
    state::UsesState,
    Error,
};

/// A [`DiffExecutor`] wraps a primary executor, forwarding its methods, and a secondary one
#[derive(Debug)]
pub struct DiffExecutor<A, B, OTA, OTB, DOT> {
    primary: A,
    secondary: B,
    observers: UnsafeCell<ProxyObserversTuple<OTA, OTB, DOT>>,
}

impl<A, B, OTA, OTB, DOT> DiffExecutor<A, B, OTA, OTB, DOT> {
    /// Create a new `DiffExecutor`, wrapping the given `executor`s.
    pub fn new(primary: A, secondary: B, observers: DOT) -> Self
    where
        A: UsesState + HasObservers<Observers = OTA>,
        B: UsesState<State = A::State> + HasObservers<Observers = OTB>,
        DOT: DifferentialObserversTuple<OTA, OTB, A::State>,
        OTA: ObserversTuple<A::State>,
        OTB: ObserversTuple<A::State>,
    {
        Self {
            primary,
            secondary,
            observers: UnsafeCell::new(ProxyObserversTuple {
                primary: OwnedMutPtr::Ptr(ptr::null_mut()),
                secondary: OwnedMutPtr::Ptr(ptr::null_mut()),
                differential: observers,
            }),
        }
    }
(snip)

--------- Index: 0, Length: 847, Lines: 26 Words: 90 ----------
//! Executor for differential fuzzing.
//! It wraps two executors that will be run after each other with the same input.
//! In comparison to the [`crate::executors::CombinedExecutor`] it also runs the secondary executor in `run_target`.
//!
use core::{cell::UnsafeCell, fmt::Debug, ptr};

use libafl_bolts::{ownedref::OwnedMutPtr, tuples::MatchName};
use serde::{Deserialize, Serialize};

use crate::{
    executors::{Executor, ExitKind, HasObservers},
    inputs::UsesInput,
    observers::{DifferentialObserversTuple, ObserversTuple, UsesObservers},
    state::UsesState,
    Error,
};

/// A [`DiffExecutor`] wraps a primary executor, forwarding its methods, and a secondary one
#[derive(Debug)]
pub struct DiffExecutor<A, B, OTA, OTB, DOT> {
    primary: A,
    secondary: B,
    observers: UnsafeCell<ProxyObserversTuple<OTA, OTB, DOT>>,
}


--------- Index: 1, Length: 793, Lines: 22 Words: 70 ----------
impl<A, B, OTA, OTB, DOT> DiffExecutor<A, B, OTA, OTB, DOT> {
    /// Create a new `DiffExecutor`, wrapping the given `executor`s.
    pub fn new(primary: A, secondary: B, observers: DOT) -> Self
    where
        A: UsesState + HasObservers<Observers = OTA>,
        B: UsesState<State = A::State> + HasObservers<Observers = OTB>,
        DOT: DifferentialObserversTuple<OTA, OTB, A::State>,
        OTA: ObserversTuple<A::State>,
        OTB: ObserversTuple<A::State>,
    {
        Self {
            primary,
            secondary,
            observers: UnsafeCell::new(ProxyObserversTuple {
                primary: OwnedMutPtr::Ptr(ptr::null_mut()),
                secondary: OwnedMutPtr::Ptr(ptr::null_mut()),
                differential: observers,
            }),
        }
    }