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📄 ExpiringCache.ts

📊 Analysis Summary

Metric	Count
🔧 Functions	3
🧱 Classes	1
📦 Imports	1
📊 Variables & Constants	3
📐 Interfaces	1

📚 Table of Contents

• Imports
• Variables & Constants
• Functions
• Classes
• Interfaces

🛠️ File Location:

📂 packages/typescript-estree/src/parseSettings/ExpiringCache.ts

📦 Imports

Name	Source
CacheDurationSeconds	@typescript-eslint/types

---

Variables & Constants

Name	Type	Kind	Value	Exported
DEFAULT_TSCONFIG_CACHE_DURATION_SECONDS	30	const	30	✓
ZERO_HR_TIME	[number, number]	const	[0, 0]	✗
ageSeconds	number	const	process.hrtime(entry.lastSeen)[0]	✗

---

Functions

ExpiringCache.clear(): void

Code

clear(): void {
    this.#map.clear();
  }

• Return Type: void
• Calls:
• this.#map.clear

ExpiringCache.get(key: Key): Value | undefined

Code

get(key: Key): Value | undefined {
    const entry = this.#map.get(key);
    if (entry?.value != null) {
      if (this.#cacheDurationSeconds === 'Infinity') {
        return entry.value;
      }

      const ageSeconds = process.hrtime(entry.lastSeen)[0];
      if (ageSeconds < this.#cacheDurationSeconds) {
        // cache hit woo!
        return entry.value;
      }
      // key has expired - clean it up to free up memory
      this.#map.delete(key);
    }
    // no hit :'(
    return undefined;
  }

• Parameters:
• key: Key
• Return Type: Value | undefined
• Calls:
• this.#map.get
• process.hrtime
• this.#map.delete
• Internal Comments:

  // cache hit woo!
  // key has expired - clean it up to free up memory (x5)
  // no hit :'(
  

ExpiringCache.set(key: Key, value: Value): this

Code

set(key: Key, value: Value): this {
    this.#map.set(key, {
      lastSeen:
        this.#cacheDurationSeconds === 'Infinity'
          ? // no need to waste time calculating the hrtime in infinity mode as there's no expiry
            ZERO_HR_TIME
          : process.hrtime(),
      value,
    });
    return this;
  }

• Parameters:
• key: Key
• value: Value
• Return Type: this
• Calls:
• this.#map.set
• process.hrtime

---

Classes

ExpiringCache

Class Code

export class ExpiringCache<Key, Value> implements CacheLike<Key, Value> {
  readonly #cacheDurationSeconds: CacheDurationSeconds;

  readonly #map = new Map<
    Key,
    Readonly<{
      lastSeen: [number, number];
      value: Value;
    }>
  >();

  constructor(cacheDurationSeconds: CacheDurationSeconds) {
    this.#cacheDurationSeconds = cacheDurationSeconds;
  }

  clear(): void {
    this.#map.clear();
  }

  get(key: Key): Value | undefined {
    const entry = this.#map.get(key);
    if (entry?.value != null) {
      if (this.#cacheDurationSeconds === 'Infinity') {
        return entry.value;
      }

      const ageSeconds = process.hrtime(entry.lastSeen)[0];
      if (ageSeconds < this.#cacheDurationSeconds) {
        // cache hit woo!
        return entry.value;
      }
      // key has expired - clean it up to free up memory
      this.#map.delete(key);
    }
    // no hit :'(
    return undefined;
  }

  set(key: Key, value: Value): this {
    this.#map.set(key, {
      lastSeen:
        this.#cacheDurationSeconds === 'Infinity'
          ? // no need to waste time calculating the hrtime in infinity mode as there's no expiry
            ZERO_HR_TIME
          : process.hrtime(),
      value,
    });
    return this;
  }
}

Methods

clear(): void

Code

clear(): void {
    this.#map.clear();
  }

get(key: Key): Value | undefined

Code

get(key: Key): Value | undefined {
    const entry = this.#map.get(key);
    if (entry?.value != null) {
      if (this.#cacheDurationSeconds === 'Infinity') {
        return entry.value;
      }

      const ageSeconds = process.hrtime(entry.lastSeen)[0];
      if (ageSeconds < this.#cacheDurationSeconds) {
        // cache hit woo!
        return entry.value;
      }
      // key has expired - clean it up to free up memory
      this.#map.delete(key);
    }
    // no hit :'(
    return undefined;
  }

set(key: Key, value: Value): this

Code

set(key: Key, value: Value): this {
    this.#map.set(key, {
      lastSeen:
        this.#cacheDurationSeconds === 'Infinity'
          ? // no need to waste time calculating the hrtime in infinity mode as there's no expiry
            ZERO_HR_TIME
          : process.hrtime(),
      value,
    });
    return this;
  }

---

Interfaces

CacheLike<Key, Value>

Interface Code

export interface CacheLike<Key, Value> {
  get(key: Key): Value | undefined;
  set(key: Key, value: Value): this;
}

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