bug 240920 - document nsIStreamLoader, document nsISimpleStreamListener some

more, and a bit of cleanup
r+sr=darin

netwerk/base/public/nsISimpleStreamListener.idl

@@ -49,7 +49,8 @@ interface nsISimpleStreamListener : nsIStreamListener
     /**
      * Initialize the simple stream listener.
      *
-     * @param aSink data will be read from the channel to this output stream
+     * @param aSink data will be read from the channel to this output stream.
+     *              Must implement writeFrom.
      * @param aObserver optional stream observer (can be NULL)
      */
     void init(in nsIOutputStream aSink,

netwerk/base/public/nsIStreamLoader.idl

@@ -54,9 +54,25 @@ interface nsIStreamLoaderObserver : nsISupports
                           [size_is(resultLength)] in string result);
 };
 
+/**
+ * Asynchronously loads a channel into a memory buffer.
+ */
 [scriptable, uuid(31d37360-8e5a-11d3-93ad-00104ba0fd40)]
 interface nsIStreamLoader : nsISupports
 {
+    /**
+     * Initialize this stream loader, and start loading the data.
+     *
+     * @param aChannel
+     *        A Channel to load data from. This must not be asyncOpen'd yet!
+     * @param aObserver
+     *        An observer that will be notified when the data is complete.
+     * @param aContext
+     *        May be null. Will be passed to the observer.
+     *
+     * @note Failure to open the channel will be indicated by an async callback
+     *       to the observer.
+     */
     void init(in nsIChannel aChannel,
               in nsIStreamLoaderObserver aObserver,
               in nsISupports aContext);
@@ -67,7 +83,8 @@ interface nsIStreamLoader : nsISupports
     readonly attribute unsigned long numBytesRead;
 
     /**
-     * Gets the request that loaded this file
+     * Gets the request that loaded this file.
+     * null after the request has finished loading.
      */
     readonly attribute nsIRequest request;
 };

netwerk/base/src/nsStreamLoader.cpp

@@ -37,10 +37,7 @@
 
 #include "nsStreamLoader.h"
 #include "nsIInputStream.h"
-#include "nsIURL.h"
-#include "nsNetUtil.h"
 #include "nsIChannel.h"
-//#include "nsIHttpChannel.h"
 #include "nsProxiedService.h"
 
 static NS_DEFINE_CID(kProxyObjectManagerCID, NS_PROXYEVENT_MANAGER_CID);
@@ -98,13 +95,7 @@ NS_IMPL_ISUPPORTS3(nsStreamLoader, nsIStreamLoader,
 NS_IMETHODIMP 
 nsStreamLoader::GetNumBytesRead(PRUint32* aNumBytes)
 {
-  if (!mData.IsEmpty()) {
-    *aNumBytes = mData.Length();
-  }
-  else {
-    *aNumBytes = 0;
-  }
-
+  *aNumBytes = mData.Length();
   return NS_OK;
 }
 

netwerk/base/src/nsStreamLoader.h

@@ -52,8 +52,8 @@ public:
   NS_DECL_NSIREQUESTOBSERVER
   NS_DECL_NSISTREAMLISTENER
 
-  nsStreamLoader() { };
-  virtual ~nsStreamLoader() {};
+  nsStreamLoader() { }
+  ~nsStreamLoader() {}
 
   static NS_METHOD
   Create(nsISupports *aOuter, REFNSIID aIID, void **aResult);

netwerk/base/src/nsURLHelperUnix.cpp

@@ -93,7 +93,7 @@ net_GetFileFromURLSpec(const nsACString &aURL, nsIFile **result)
     nsresult rv;
 
     nsCOMPtr<nsILocalFile> localFile;
-    rv = NS_NewNativeLocalFile(nsCString(), PR_TRUE, getter_AddRefs(localFile));
+    rv = NS_NewNativeLocalFile(EmptyCString(), PR_TRUE, getter_AddRefs(localFile));
     if (NS_FAILED(rv))
       return rv;