Bug 1037447 - Introduce nsICacheEntry nsICacheStorage.openTruncate(URL, idEnhance), r=michal

netwerk/cache2/AppCacheStorage.cpp

@@ -84,6 +84,12 @@ NS_IMETHODIMP AppCacheStorage::AsyncOpenURI(nsIURI *aURI,
   return NS_OK;
 }
 
+NS_IMETHODIMP AppCacheStorage::OpenTruncate(nsIURI *aURI, const nsACString & aIdExtension,
+                                            nsICacheEntry **aCacheEntry)
+{
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
 NS_IMETHODIMP AppCacheStorage::Exists(nsIURI *aURI, const nsACString & aIdExtension,
                                       bool *aResult)
 {

netwerk/cache2/CacheStorage.cpp

@@ -105,6 +105,33 @@ NS_IMETHODIMP CacheStorage::AsyncOpenURI(nsIURI *aURI,
 }
 
 
+NS_IMETHODIMP CacheStorage::OpenTruncate(nsIURI *aURI, const nsACString & aIdExtension,
+                                         nsICacheEntry **aCacheEntry)
+{
+  if (!CacheStorageService::Self())
+    return NS_ERROR_NOT_INITIALIZED;
+
+  nsresult rv;
+
+  nsCOMPtr<nsIURI> noRefURI;
+  rv = aURI->CloneIgnoringRef(getter_AddRefs(noRefURI));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  nsRefPtr<CacheEntryHandle> entry;
+  rv = CacheStorageService::Self()->AddStorageEntry(
+    this, noRefURI, aIdExtension,
+    true, // create always
+    true, // replace any existing one
+    getter_AddRefs(entry));
+  NS_ENSURE_SUCCESS(rv, rv);
+
+  // Just open w/o callback, similar to nsICacheEntry.recreate().
+  entry->Entry()->AsyncOpen(nullptr, OPEN_TRUNCATE);
+  entry.forget(aCacheEntry);
+
+  return NS_OK;
+}
+
 NS_IMETHODIMP CacheStorage::Exists(nsIURI *aURI, const nsACString & aIdExtension,
                                    bool *aResult)
 {

netwerk/cache2/OldWrappers.cpp

@@ -944,6 +944,12 @@ NS_IMETHODIMP _OldStorage::AsyncOpenURI(nsIURI *aURI,
   return NS_OK;
 }
 
+NS_IMETHODIMP _OldStorage::OpenTruncate(nsIURI *aURI, const nsACString & aIdExtension,
+                                        nsICacheEntry **aCacheEntry)
+{
+  return NS_ERROR_NOT_IMPLEMENTED;
+}
+
 NS_IMETHODIMP _OldStorage::Exists(nsIURI *aURI, const nsACString & aIdExtension,
                                    bool *aResult)
 {

netwerk/cache2/nsICacheStorage.idl

@@ -5,6 +5,7 @@
 #include "nsISupports.idl"
 
 interface nsIURI;
+interface nsICacheEntry;
 interface nsICacheEntryOpenCallback;
 interface nsICacheEntryDoomCallback;
 interface nsICacheStorageVisitor;
@@ -14,7 +15,7 @@ interface nsICacheStorageVisitor;
  * in-mem+on-disk, in-mem+on-disk+app-cache or just a specific
  * app-cache storage.
  */
-[scriptable, uuid(d9006881-a536-4ce3-bc48-e7f94b40a690)]
+[scriptable, uuid(35d104a6-d252-4fd4-8a56-3c14657cad3b)]
 interface nsICacheStorage : nsISupports
 {
   /**
@@ -77,6 +78,21 @@ interface nsICacheStorage : nsISupports
                     in uint32_t aFlags,
                     in nsICacheEntryOpenCallback aCallback);
 
+  /**
+   * Immediately opens a new and empty cache entry in the storage, any existing
+   * entries are immediately doomed.  This is similar to the recreate() method
+   * on nsICacheEntry.
+   *
+   * Storage may not implement this method and throw NS_ERROR_NOT_IMPLEMENTED.
+   * In that case consumer must use asyncOpen with OPEN_TRUNCATE flag and get
+   * the new entry via a callback.
+   *
+   * @param aURI @see asyncOpenURI
+   * @param aIdExtension @see asyncOpenURI
+   */
+  nsICacheEntry openTruncate(in nsIURI aURI,
+                             in ACString aIdExtension);
+
   /**
    * Synchronously check on existance of an entry.  In case of disk entries
    * this uses information from the cache index.  When the index data are not

netwerk/test/unit/test_cache2-01f-basic-openTruncate.js

@@ -0,0 +1,24 @@
+function run_test()
+{
+  do_get_profile();
+
+  if (!newCacheBackEndUsed()) {
+    do_check_true(true, "This test doesn't run when the old cache back end is used since the behavior is different");
+    return;
+  }
+
+  var storage = getCacheStorage("disk");
+  var entry = storage.openTruncate(createURI("http://new1/"), "");
+  do_check_true(!!entry);
+
+  // Fill the entry, and when done, check it's content
+  (new OpenCallback(NEW, "meta", "data", function() {
+    asyncOpenCacheEntry("http://new1/", "disk", Ci.nsICacheStorage.OPEN_NORMALLY, null,
+      new OpenCallback(NORMAL, "meta", "data", function() {
+        finish_cache2_test();
+      })
+    );
+  })).onCacheEntryAvailable(entry, true, null, 0);
+
+  do_test_pending();
+}

netwerk/test/unit/xpcshell.ini

@@ -26,6 +26,7 @@ support-files =
 [test_cache2-01c-basic-hasmeta-only.js]
 [test_cache2-01d-basic-not-wanted.js]
 [test_cache2-01e-basic-bypass-if-busy.js]
+[test_cache2-01f-basic-openTruncate.js]
 [test_cache2-02-open-non-existing.js]
 [test_cache2-03-oncacheentryavail-throws.js]
 [test_cache2-04-oncacheentryavail-throws2x.js]