Don't share tmp repos between artifacts [#541]

lein-module based projects will share an aether session when deploying,
but we want each module to have it's own session, so they will each have
their own atomic deploy. Without this change, the second and all
subsequent module deploys will fail.

The fix here is to store the tmp repos as a seq, and find the existing
one that matches the current upload, or creating a new one if none
match. This would allow interleaving files for different artifacts in
the same session, which none of the existing tooling does, but who knows
what craziness exists out there?

src/clojars/routes/repo.clj

@@ -45,24 +45,35 @@
   (let [filename (if (string? file) file (.getName file))]
     (.endsWith filename ".pom")))
 
-(defn find-upload-dir [{:keys [upload-dir]}]
-  (let [dir (io/file upload-dir)]
-    (if (and dir (.exists dir))
-      dir
-      (let [dir' (io/file (FileUtils/getTempDirectory)
-                   (str "upload-" (UUID/randomUUID)))]
-        (FileUtils/forceMkdir dir')
-        dir'))))
-
-(defn upload-request [db groupname session f]
+(def metadata-edn "_metadata.edn")
+
+(defn read-metadata [dir]
+  (let [md-file (io/file dir metadata-edn)]
+    (when (.exists md-file)
+      (read-string (slurp md-file)))))
+
+(defn find-upload-dir [group artifact {:keys [upload-dirs]}]
+  (if-let [dir (some (fn [dir]
+                       (let [dir (io/file dir)]
+                         (when (and dir (.exists dir)
+                                 (= [group artifact] ((juxt :group :name) (read-metadata dir))))
+                           dir)))
+                 upload-dirs)]
+    dir
+    (doto (io/file (FileUtils/getTempDirectory)
+            (str "upload-" (UUID/randomUUID)))
+      (FileUtils/forceMkdir))))
+
+(defn upload-request [db groupname artifact session f]
   (with-account
     (fn [account]
-      (let [upload-dir (find-upload-dir session)]
+      (let [upload-dir (find-upload-dir groupname artifact session)]
         (require-authorization db account groupname (partial f account upload-dir))
         ;; should we only do 201 if the file didn't already exist?
         {:status 201
          :headers {}
-         :session (assoc session :upload-dir (.getAbsolutePath upload-dir))
+         :session (update session
+                    :upload-dirs #((fnil conj []) % (.getAbsolutePath upload-dir)))
          :body nil}))))
 
 (defn find-pom [dir]
@@ -77,8 +88,6 @@
       (= match name)
       (re-find match name))))
 
-(def metadata-edn "_metadata.edn")
-
 (defn find-artifacts
   ([dir]
    (find-artifacts dir true))
@@ -219,7 +228,7 @@
                   (throw-invalid (str "invalid pom file: " (.getMessage e))
                     {:file pom-file}
                     e)))
-          {:keys [group group-path name] :as posted-metadata} (read-string (slurp (io/file dir metadata-edn)))]
+          {:keys [group group-path name] :as posted-metadata} (read-metadata dir)]
 
       ;; since we trigger on maven-metadata.xml, we don't actually
       ;; have the sums for it because they are uploaded *after* the
@@ -263,6 +272,7 @@
     (upload-request
       db
       groupname
+      artifact
       session
       (fn [_ upload-dir]
         (spit (io/file upload-dir metadata-edn)
@@ -296,6 +306,7 @@
               (upload-request
                 db
                 groupname
+                artifact
                 session
                 (fn [account upload-dir]
                   (let [file (io/file upload-dir group artifact file)]