From 3ecc389e6632fb16efce39ecc02fbec2b489fb49 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Greg=20Berg=C3=A9?= <neoziro@gmail.com>
Date: Mon, 27 Jan 2014 23:42:19 +0100
Subject: [PATCH] Fix concurrent renaming.

We stock the renaming promise in cache to ensure that there is not concurrent renaming.
---
 lib/core/ResolveCache.js  | 22 +++++++++++++++++-----
 test/core/resolveCache.js | 24 ++++++++++++++++++++++++
 2 files changed, 41 insertions(+), 5 deletions(-)

diff --git a/lib/core/ResolveCache.js b/lib/core/ResolveCache.js
index 0bf503dd..5730278a 100644
--- a/lib/core/ResolveCache.js
+++ b/lib/core/ResolveCache.js
@@ -124,7 +124,18 @@ ResolveCache.prototype.store = function (canonicalDir, pkgMeta) {
         })
         // Move the canonical to sourceId/target
         .then(function () {
-            return Q.nfcall(fs.rename, canonicalDir, dir)
+            // We store the renaming in cache.
+            var key = 'moving:' + dir;
+            var promise;
+            if (that._cache.has(key)) {
+                promise = that._cache.get(key);
+            }
+            else {
+                promise = Q.nfcall(fs.rename, canonicalDir, dir);
+                that._cache.set(key, promise);
+            }
+
+            return promise
             .fail(function (err) {
                 // If error is EXDEV it means that we are trying to rename
                 // across different drives, so we copy and remove it instead
@@ -132,10 +143,11 @@ ResolveCache.prototype.store = function (canonicalDir, pkgMeta) {
                     throw err;
                 }
 
-                return copy.copyDir(canonicalDir, dir)
-                .then(function () {
-                    return Q.nfcall(rimraf, canonicalDir);
-                });
+                return copy.copyDir(canonicalDir, dir);
+            })
+            // To match all case, we remove the directory.
+            .then(function () {
+                return Q.nfcall(rimraf, canonicalDir);
             });
         });
     })
diff --git a/test/core/resolveCache.js b/test/core/resolveCache.js
index 5ebb82f9..102879c5 100644
--- a/test/core/resolveCache.js
+++ b/test/core/resolveCache.js
@@ -310,6 +310,30 @@ describe('ResolveCache', function () {
             })
             .done();
         });
+
+        it('should be possible to store two package at same time', function (next) {
+            var store = resolveCache.store.bind(resolveCache, tempPackage, {
+                name: 'foo',
+                _source: 'foo',
+                _target: 'foo/bar'
+            });
+            var store2 = resolveCache.store.bind(resolveCache, tempPackage2, {
+                name: 'foo',
+                _source: 'foo',
+                _target: 'foo/bar'
+            });
+
+            Q.all([store(), store2()]).then(function (dirs) {
+                var dir = dirs[0];
+                expect(dir).to.equal(path.join(cacheDir, md5('foo'), 'foo%2Fbar'));
+                expect(fs.existsSync(dir)).to.be(true);
+                expect(fs.existsSync(path.join(dir, 'baz'))).to.be(true);
+                expect(fs.existsSync(tempPackage)).to.be(false);
+                expect(fs.existsSync(tempPackage2)).to.be(false);
+
+                next();
+            }).done();
+        });
     });
 
     describe('.versions', function () {