checkin for bug 76293. Moves cache directory aside on startup if disk cache is unable to read or delete files. Cache service disables disk cache device if it fails to initialize, and defaults to using memory cache instead. r=beard, sr=darin.

netwerk/cache/src/nsCacheService.cpp

@@ -433,7 +433,13 @@ nsCacheService::CreateDiskDevice()
 
     nsresult rv = mDiskDevice->Init();
     if (NS_FAILED(rv)) {
-        // XXX log error
+#if DEBUG
+        printf("###\n");
+        printf("### mDiskDevice->Init() failed (0x%.8x)\n", rv);
+        printf("###    - disabling disk cache for this session.\n");
+        printf("###\n");
+#endif        
+        mEnableDiskDevice = PR_FALSE;
         delete mDiskDevice;
         mDiskDevice = nsnull;
     }
@@ -732,28 +738,36 @@ nsCacheService::EnsureEntryHasDevice(nsCacheEntry * entry)
 {
     nsCacheDevice * device = entry->CacheDevice();
     if (device)  return device;
+    nsresult rv = NS_OK;
 
     if (entry->IsStreamData() && entry->IsAllowedOnDisk() && mEnableDiskDevice) {
         // this is the default
         if (!mDiskDevice) {
-            nsresult rv = CreateDiskDevice();
-            if (NS_FAILED(rv))
-                return nsnull;
+            rv = CreateDiskDevice();  // ignore the error (check for mDiskDevice instead)
         }
 
-        device = mDiskDevice;
-    } else if (mEnableMemoryDevice) {
+        if (mDiskDevice) {
+            entry->MarkBinding();  // XXX
+            rv = mDiskDevice->BindEntry(entry);
+            entry->ClearBinding(); // XXX
+            if (NS_SUCCEEDED(rv))
+                device = mDiskDevice;
+        }
+    }
+     
+    // if we can't use mDiskDevice, try mMemoryDevice
+    if (!device && mEnableMemoryDevice) {
         NS_ASSERTION(entry->IsAllowedInMemory(), "oops.. bad flags");
-        device = mMemoryDevice;
+        
+        entry->MarkBinding();  // XXX
+        rv = mMemoryDevice->BindEntry(entry);
+        entry->ClearBinding(); // XXX
+        if (NS_SUCCEEDED(rv))
+            device = mMemoryDevice;
     }
 
     if (device == nsnull)  return nsnull;
 
-	entry->MarkBinding(); // XXX
-    nsresult  rv = device->BindEntry(entry);
-    entry->ClearBinding(); // XXX
-    if (NS_FAILED(rv)) return nsnull;
-
     entry->SetCacheDevice(device);
     return device;
 }

netwerk/cache/src/nsDiskCacheDevice.cpp

@@ -633,6 +633,14 @@ nsDiskCacheDevice::Init()
     gFileTransportService = do_GetService("@mozilla.org/network/file-transport-service;1", &rv);
     if (NS_FAILED(rv)) return rv;
     
+    // delete "Cache.Trash" folder
+    nsCOMPtr<nsIFile> cacheTrashDir;
+    rv = mCacheDirectory->Clone(getter_AddRefs(cacheTrashDir));
+    if (NS_FAILED(rv))  return rv;
+    rv = cacheTrashDir->SetLeafName("Cache.Trash");
+    if (NS_FAILED(rv))  return rv;
+    (void) cacheTrashDir->Delete(PR_TRUE);  // ignore errors, we tried...
+
     // XXX read in persistent information about the cache. this can fail, if
     // no cache directory has ever existed before.
     rv = readCacheMap();
@@ -1502,7 +1510,45 @@ nsresult nsDiskCacheDevice::clobberDiskCache()
     
     // recursively delete the disk cache directory.
     rv = mCacheDirectory->Delete(PR_TRUE);
-    if (NS_FAILED(rv)) return rv;
+    if (NS_FAILED(rv)) {
+        // try moving it aside
+        
+        // get parent directory of cache directory
+        nsCOMPtr<nsIFile> cacheParentDir;
+        rv = mCacheDirectory->GetParent(getter_AddRefs(cacheParentDir));
+        if (NS_FAILED(rv))  return rv;
+        
+        // create "Cache.Trash" directory if necessary
+        nsCOMPtr<nsIFile> oldCacheDir;
+        rv = cacheParentDir->Clone(getter_AddRefs(oldCacheDir));
+        if (NS_FAILED(rv))  return rv;
+        rv = oldCacheDir->Append("Cache.Trash");
+        if (NS_FAILED(rv))  return rv;
+        
+        PRBool exists = PR_FALSE;
+        rv = oldCacheDir->Exists(&exists);
+        if (NS_FAILED(rv))  return rv;
+        
+        if (!exists) {
+            // create the "Cache.Trash" directory
+            rv = oldCacheDir->Create(nsIFile::DIRECTORY_TYPE,0777);
+            if (NS_FAILED(rv))  return rv;
+        }
+        
+        // create a directory with unique name to contain existing cache directory
+        rv = oldCacheDir->Append("Cache");
+        if (NS_FAILED(rv))  return rv;
+        rv = oldCacheDir->CreateUnique(nsnull,nsIFile::DIRECTORY_TYPE, 0777); 
+        if (NS_FAILED(rv))  return rv;
+        
+        // move existing cache directory into profileDir/Cache.Trash/CacheUnique
+        nsCOMPtr<nsIFile> existingCacheDir;
+        rv = mCacheDirectory->Clone(getter_AddRefs(existingCacheDir));
+        if (NS_FAILED(rv))  return rv;
+        rv = existingCacheDir->MoveTo(oldCacheDir, nsnull);
+        if (NS_FAILED(rv))  return rv;
+    }
+    
     rv = mCacheDirectory->Create(nsIFile::DIRECTORY_TYPE, 0777);
     if (NS_FAILED(rv)) return rv;