Commit b566502a authored by David Dollar's avatar David Dollar

better vendoring, catch lru-cache

parent b6521714
#!/bin/sh
set -ex
VERSION=$1
if [ "$VERSION" == "" ]; then
......@@ -8,8 +11,9 @@ fi
cd vendor/npm
git clone https://github.com/isaacs/npm.git npm-$VERSION
cd npm-$VERSION
git checkout v$VERSION
git submodule init
git submodule update
git submodule update --init --recursive
find . -name ".git" -exec rm -rf {} \;
# lru cache
A cache object that deletes the least-recently-used items.
Usage:
var LRU = require("lru-cache")
, cache = LRU(10) // max 10 items. default = Infinity
cache.set("key", "value")
cache.get("key") // "value"
RTFS for more info.
module.exports = LRUCache
function hOP (obj, key) {
return Object.prototype.hasOwnProperty.call(obj, key)
}
function LRUCache (maxLength) {
if (!(this instanceof LRUCache)) {
return new LRUCache(maxLength)
}
var cache = {} // hash of items by key
, lruList = {} // list of items in order of use recency
, lru = 0 // least recently used
, mru = 0 // most recently used
, length = 0 // number of items in the list
// resize the cache when the maxLength changes.
Object.defineProperty(this, "maxLength",
{ set : function (mL) {
if (!mL || !(typeof mL === "number") || mL <= 0 ) mL = Infinity
maxLength = mL
// if it gets above double maxLength, trim right away.
// otherwise, do it whenever it's convenient.
if (length > maxLength) trim()
}
, get : function () { return maxLength }
, enumerable : true
})
this.maxLength = maxLength
Object.defineProperty(this, "length",
{ get : function () { return length }
, enumerable : true
})
this.set = function (key, value) {
if (hOP(cache, key)) {
this.get(key)
cache[key].value = value
return undefined
}
var hit = {key:key, value:value, lu:mru++}
lruList[hit.lu] = cache[key] = hit
length ++
if (length > maxLength) trim()
}
this.get = function (key) {
if (!hOP(cache, key)) return undefined
var hit = cache[key]
delete lruList[hit.lu]
if (hit.lu === lru) lruWalk()
hit.lu = mru ++
lruList[hit.lu] = hit
return hit.value
}
this.del = function (key) {
if (!hOP(cache, key)) return undefined
var hit = cache[key]
delete cache[key]
delete lruList[hit.lu]
if (hit.lu === lru) lruWalk()
length --
}
function lruWalk () {
// lru has been deleted, hop up to the next hit.
lru = Object.keys(lruList).shift()
}
function trim () {
if (length <= maxLength) return undefined
var prune = Object.keys(lruList).slice(0, length - maxLength)
for (var i = 0, l = (length - maxLength); i < l; i ++) {
delete cache[ lruList[prune[i]].key ]
delete lruList[prune[i]]
}
length = maxLength
lruWalk()
}
}
if (!process || !module || module !== process.mainModule) return undefined
var l = LRUCache(3)
, assert = require("assert")
l.set(1, 1)
l.set(2, 1)
l.set(3, 1)
l.set(4, 1)
l.set(5, 1)
l.set(6, 1)
assert.equal(l.get(1), undefined)
assert.equal(l.get(2), undefined)
assert.equal(l.get(3), undefined)
assert.equal(l.get(4), 1)
assert.equal(l.get(5), 1)
assert.equal(l.get(6), 1)
// now keep re-getting the 6 so it remains the most recently used.
// in this case, we'll have 6, 7, 8, 9, 10, 11, so the ending length = 5
l.set(7, 1)
l.get(6)
l.set(8, 1)
l.get(6)
l.set(9, 1)
l.get(6)
l.set(10, 1)
l.get(6)
l.set(11, 1)
assert.equal(l.length, 3)
assert.equal(l.get(4), undefined)
assert.equal(l.get(5), undefined)
assert.equal(l.get(6), 1)
assert.equal(l.get(7), undefined)
assert.equal(l.get(8), undefined)
assert.equal(l.get(9), undefined)
assert.equal(l.get(10), 1)
assert.equal(l.get(11), 1)
// test changing the maxLength, verify that the LRU items get dropped.
l.maxLength = 100
for (var i = 0; i < 100; i ++) l.set(i, i)
assert.equal(l.length, 100)
for (var i = 0; i < 100; i ++) {
assert.equal(l.get(i), i)
}
l.maxLength = 3
assert.equal(l.length, 3)
for (var i = 0; i < 97; i ++) {
assert.equal(l.get(i), undefined)
}
for (var i = 98; i < 100; i ++) {
assert.equal(l.get(i), i)
}
// now remove the maxLength restriction, and try again.
l.maxLength = "hello"
for (var i = 0; i < 100; i ++) l.set(i, i)
assert.equal(l.length, 100)
for (var i = 0; i < 100; i ++) {
assert.equal(l.get(i), i)
}
// should trigger an immediate resize
l.maxLength = 3
assert.equal(l.length, 3)
for (var i = 0; i < 97; i ++) {
assert.equal(l.get(i), undefined)
}
for (var i = 98; i < 100; i ++) {
assert.equal(l.get(i), i)
}
{ "name" : "lru-cache"
, "description" : "A cache object that deletes the least-recently-used items."
, "version" : "1.0.3"
, "author" : "Isaac Z. Schlueter <i@izs.me>"
, "scripts" : { "test" : "node lib/lru-cache.js" }
, "main" : "lib/lru-cache"
, "repository" : "git://github.com/isaacs/node-lru-cache.git"
}
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