/usr/local/lib/node_modules/npm/node_modules/@npmcli/arborist/lib
Edit: /usr/local/lib/node_modules/npm/node_modules/@npmcli/arborist/lib/packument-cache.js (2557B)
const { LRUCache } = require('lru-cache')
const { getHeapStatistics } = require('node:v8')
const { log } = require('proc-log')
// This is an in-memory cache that Pacote uses for packuments.
// Packuments are usually cached on disk. This allows for rapid re-requests
// of the same packument to bypass disk reads. The tradeoff here is memory
// usage for disk reads.
class PackumentCache extends LRUCache {
static #heapLimit = Math.floor(getHeapStatistics().heap_size_limit)
#sizeKey
#disposed = new Set()
#log (...args) {
log.silly('packumentCache', ...args)
}
constructor ({
// How much of this.#heapLimit to take up
heapFactor = 0.25,
// How much of this.#maxSize we allow any one packument to take up
// Anything over this is not cached
maxEntryFactor = 0.5,
sizeKey = '_contentLength',
} = {}) {
const maxSize = Math.floor(PackumentCache.#heapLimit * heapFactor)
const maxEntrySize = Math.floor(maxSize * maxEntryFactor)
super({
maxSize,
maxEntrySize,
sizeCalculation: (p) => {
// Don't cache if we don't know the size
// Some versions of pacote set this to `0`, newer versions set it to `null`
if (!p[sizeKey]) {
return maxEntrySize + 1
}
if (p[sizeKey] < 10_000) {
return p[sizeKey] * 2
}
if (p[sizeKey] < 1_000_000) {
return Math.floor(p[sizeKey] * 1.5)
}
// It is less beneficial to store a small amount of super large things
// at the cost of all other packuments.
return maxEntrySize + 1
},
dispose: (v, k) => {
this.#disposed.add(k)
this.#log(k, 'dispose')
},
})
this.#sizeKey = sizeKey
this.#log(`heap:${PackumentCache.#heapLimit} maxSize:${maxSize} maxEntrySize:${maxEntrySize}`)
}
set (k, v, ...args) {
// we use disposed only for a logging signal if we are setting packuments that
// have already been evicted from the cache previously. logging here could help
// us tune this in the future.
const disposed = this.#disposed.has(k)
/* istanbul ignore next - this doesnt happen consistently so hard to test without resorting to unit tests */
if (disposed) {
this.#disposed.delete(k)
}
this.#log(k, 'set', `size:${v[this.#sizeKey]} disposed:${disposed}`)
return super.set(k, v, ...args)
}
has (k, ...args) {
const has = super.has(k, ...args)
this.#log(k, `cache-${has ? 'hit' : 'miss'}`)
return has
}
}
module.exports = PackumentCache