win32/gwinhttpvfs.c win32/gwinhttpvfs.h win32/gwinhttpfile.c

2008-08-13  Tor Lillqvist  <tml@novell.com>

	* win32/gwinhttpvfs.c
	* win32/gwinhttpvfs.h
	* win32/gwinhttpfile.c
	* win32/gwinhttpfileinputstream.c
	* win32/gwinhttpfileoutputstream.c: Refactor some common code
	snippets into helper functions. Check HTTP response status
	codes. Implement g_winhttp_file_query_info(), looking at
	Content-Length, Content-Type and Last-Modified.

	* win32/winhttp.h: Add some symbolic constants that are not
	publicly documented. Just a handful, so it should be OK to use
	information from the Windows SDK's headers.


svn path=/trunk/; revision=7350

gio/ChangeLog

@@ -1,3 +1,18 @@
+2008-08-13  Tor Lillqvist  <tml@novell.com>
+
+	* win32/gwinhttpvfs.c
+	* win32/gwinhttpvfs.h
+	* win32/gwinhttpfile.c
+	* win32/gwinhttpfileinputstream.c
+	* win32/gwinhttpfileoutputstream.c: Refactor some common code
+	snippets into helper functions. Check HTTP response status
+	codes. Implement g_winhttp_file_query_info(), looking at
+	Content-Length, Content-Type and Last-Modified.
+
+	* win32/winhttp.h: Add some symbolic constants that are not
+	publicly documented. Just a handful, so it should be OK to use
+	information from the Windows SDK's headers.
+
 2008-08-13  Tor Lillqvist  <tml@novell.com>
 
 	Bug 546582 - Callbacks from GFileMonitor present a GFile in the

gio/win32/gwinhttpfile.c

@@ -1,5 +1,5 @@
 /* GIO - GLib Input, Output and Streaming Library
- * 
+ *
  * Copyright (C) 2006-2007 Red Hat, Inc.
  * Copyright (C) 2008 Novell, Inc.
  *
@@ -28,6 +28,7 @@
 
 #include "gfile.h"
 #include "gfileattribute.h"
+#include "gfileinfo.h"
 #include "gwinhttpfile.h"
 #include "gwinhttpfileinputstream.h"
 #include "gwinhttpfileoutputstream.h"
@@ -78,7 +79,7 @@ g_winhttp_file_init (GWinHttpFile *winhttp)
  * _g_winhttp_file_new:
  * @vfs: GWinHttpVfs to use
  * @uri: URI of the GWinHttpFile to create.
- * 
+ *
  * Returns: new winhttp #GFile.
  **/
 GFile *
@@ -129,7 +130,7 @@ _g_winhttp_file_new (GWinHttpVfs *vfs,
       g_free (wuri);
       return NULL;
     }
-  
+
   g_free (wuri);
   return G_FILE (file);
 }
@@ -206,6 +207,17 @@ g_winhttp_file_get_uri (GFile *file)
   retval = g_utf16_to_utf8 (wuri, -1, NULL, NULL, NULL);
   g_free (wuri);
 
+  if (g_str_has_prefix (retval, "http://:@"))
+    {
+      memmove (retval + 7, retval + 9, strlen (retval) - 9);
+      retval[strlen (retval) - 2] = '\0';
+    }
+  else if (g_str_has_prefix (retval, "https://:@"))
+    {
+      memmove (retval + 8, retval + 10, strlen (retval) - 10);
+      retval[strlen (retval) - 2] = '\0';
+    }
+
   return retval;
 }
 
@@ -230,7 +242,7 @@ g_winhttp_file_get_parent (GFile *file)
   uri = g_winhttp_file_get_uri (file);
   if (uri == NULL)
     return NULL;
-    
+
   last_slash = strrchr (uri, '/');
   if (last_slash == NULL || *(last_slash+1) == 0)
     {
@@ -245,7 +257,7 @@ g_winhttp_file_get_parent (GFile *file)
 
   parent = _g_winhttp_file_new (winhttp_file->vfs, uri);
   g_free (uri);
-  
+
   return parent;
 }
 
@@ -282,12 +294,12 @@ g_winhttp_file_equal (GFile *file1,
 
   g_free (uri1);
   g_free (uri2);
-  
+
   return retval;
 }
 
 static const char *
-match_prefix (const char *path, 
+match_prefix (const char *path,
               const char *prefix)
 {
   int prefix_len;
@@ -295,10 +307,10 @@ match_prefix (const char *path,
   prefix_len = strlen (prefix);
   if (strncmp (path, prefix, prefix_len) != 0)
     return NULL;
-  
+
   if (prefix_len > 0 && prefix[prefix_len-1] == '/')
     prefix_len--;
-  
+
   return path + prefix_len;
 }
 
@@ -334,7 +346,7 @@ g_winhttp_file_get_relative_path (GFile *parent,
   char *retval;
 
   remainder = match_prefix (descendant_uri, parent_uri);
-  
+
   if (remainder != NULL && *remainder == '/')
     retval = g_strdup (remainder + 1);
   else
@@ -379,7 +391,7 @@ g_winhttp_file_resolve_relative_path (GFile      *file,
   child->url.dwUrlPathLength = 2*(wcslen (wnew_path)+1);
   child->url.lpszExtraInfo = NULL;
   child->url.dwExtraInfoLength = 0;
-  
+
   return (GFile *) child;
 }
 
@@ -394,15 +406,14 @@ g_winhttp_file_get_child_for_display_name (GFile        *file,
   basename = g_locale_from_utf8 (display_name, -1, NULL, NULL, NULL);
   if (basename == NULL)
     {
-      g_set_error (error, G_IO_ERROR,
+      g_set_error (error, G_IO_ERROR, G_IO_ERROR_INVALID_FILENAME,
-                   G_IO_ERROR_INVALID_FILENAME,
                    _("Invalid filename %s"), display_name);
       return NULL;
     }
 
   new_file = g_file_get_child (file, basename);
   g_free (basename);
-  
+
   return new_file;
 }
 
@@ -412,13 +423,186 @@ g_winhttp_file_set_display_name (GFile         *file,
                                  GCancellable  *cancellable,
                                  GError       **error)
 {
-  g_set_error_literal (error, G_IO_ERROR,
+  g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
-                       G_IO_ERROR_NOT_SUPPORTED,
                        _("Operation not supported"));
 
   return NULL;
 }
 
+static time_t
+mktime_utc (SYSTEMTIME *t)
+{
+  time_t retval;
+
+  static const gint days_before[] =
+  {
+    0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334
+  };
+
+  if (t->wMonth < 1 || t->wMonth > 12)
+    return (time_t) -1;
+
+  retval = (t->wYear - 1970) * 365;
+  retval += (t->wYear - 1968) / 4;
+  retval += days_before[t->wMonth-1] + t->wDay - 1;
+
+  if (t->wYear % 4 == 0 && t->wMonth < 3)
+    retval -= 1;
+
+  retval = ((((retval * 24) + t->wHour) * 60) + t->wMinute) * 60 + t->wSecond;
+
+  return retval;
+}
+
+static GFileInfo *
+g_winhttp_file_query_info (GFile                *file,
+                           const char           *attributes,
+                           GFileQueryInfoFlags   flags,
+                           GCancellable         *cancellable,
+                           GError              **error)
+{
+  GWinHttpFile *winhttp_file = G_WINHTTP_FILE (file);
+  HINTERNET connection, request;
+  const wchar_t *accept_types[] =
+    {
+      L"*/*",
+      NULL,
+    };
+  GFileInfo *info;
+  GFileAttributeMatcher *matcher;
+  char *basename;
+  wchar_t *content_length;
+  wchar_t *content_type;
+  SYSTEMTIME last_modified;
+  DWORD last_modified_len;
+
+  connection = G_WINHTTP_VFS_GET_CLASS (winhttp_file->vfs)->pWinHttpConnect
+    (G_WINHTTP_VFS (winhttp_file->vfs)->session,
+     winhttp_file->url.lpszHostName,
+     winhttp_file->url.nPort,
+     0);
+
+  if (connection == NULL)
+    {
+      _g_winhttp_set_error (error, GetLastError (), "HTTP connection");
+
+      return NULL;
+    }
+
+  request = G_WINHTTP_VFS_GET_CLASS (winhttp_file->vfs)->pWinHttpOpenRequest
+    (connection,
+     L"HEAD",
+     winhttp_file->url.lpszUrlPath,
+     NULL,
+     WINHTTP_NO_REFERER,
+     accept_types,
+     winhttp_file->url.nScheme == INTERNET_SCHEME_HTTPS ? WINHTTP_FLAG_SECURE : 0);
+
+  if (request == NULL)
+    {
+      _g_winhttp_set_error (error, GetLastError (), "HEAD request");
+
+      return NULL;
+    }
+
+  if (!G_WINHTTP_VFS_GET_CLASS (winhttp_file->vfs)->pWinHttpSendRequest
+      (request,
+       NULL, 0,
+       NULL, 0,
+       0,
+       0))
+    {
+      _g_winhttp_set_error (error, GetLastError (), "HEAD request");
+
+      return NULL;
+    }
+
+  if (!_g_winhttp_response (winhttp_file->vfs, request, error, "HEAD request"))
+    return NULL;
+
+  matcher = g_file_attribute_matcher_new (attributes);
+  info = g_file_info_new ();
+  g_file_info_set_attribute_mask (info, matcher);
+
+  basename = g_winhttp_file_get_basename (file);
+  g_file_info_set_name (info, basename);
+  g_free (basename);
+
+  content_length = NULL;
+  if (_g_winhttp_query_header (winhttp_file->vfs,
+                               request,
+                               "HEAD request",
+                               WINHTTP_QUERY_CONTENT_LENGTH,
+                               &content_length,
+                               NULL))
+    {
+      gint64 cl;
+      int n;
+
+      if (swscanf (content_length, L"%I64d%n", &cl, &n) == 1 &&
+          n == wcslen (content_length))
+        g_file_info_set_size (info, cl);
+
+      g_free (content_length);
+    }
+
+  if (matcher == NULL)
+    return info;
+
+  content_type = NULL;
+  if (_g_winhttp_query_header (winhttp_file->vfs,
+                               request,
+                               "HEAD request",
+                               WINHTTP_QUERY_CONTENT_TYPE,
+                               &content_type,
+                               NULL))
+    {
+      char *ct = g_utf16_to_utf8 (content_type, -1, NULL, NULL, NULL);
+
+      if (ct != NULL)
+        {
+          char *p = strchr (ct, ';');
+
+          if (p != NULL)
+            {
+              char *tmp = g_strndup (ct, p - ct);
+
+              g_file_info_set_content_type (info, tmp);
+              g_free (tmp);
+            }
+          else
+            g_file_info_set_content_type (info, ct);
+        }
+
+      g_free (ct);
+    }
+
+  last_modified_len = sizeof (last_modified);
+  if (G_WINHTTP_VFS_GET_CLASS (winhttp_file->vfs)->pWinHttpQueryHeaders
+      (request,
+       WINHTTP_QUERY_LAST_MODIFIED | WINHTTP_QUERY_FLAG_SYSTEMTIME,
+       NULL,
+       &last_modified,
+       &last_modified_len,
+       NULL) &&
+      last_modified_len == sizeof (last_modified) &&
+      /* Don't bother comparing to the exact Y2038 moment */
+      last_modified.wYear >= 1970 &&
+      last_modified.wYear < 2038)
+    {
+      GTimeVal tv;
+
+      tv.tv_sec = mktime_utc (&last_modified);
+      tv.tv_usec = last_modified.wMilliseconds * 1000;
+
+      g_file_info_set_modification_time (info, &tv);
+    }
+
+  g_file_attribute_matcher_unref (matcher);
+
+  return info;
+}
+
 static GFileInputStream *
 g_winhttp_file_read (GFile         *file,
                      GCancellable  *cancellable,
@@ -440,12 +624,7 @@ g_winhttp_file_read (GFile         *file,
 
   if (connection == NULL)
     {
-      char *emsg = _g_winhttp_error_message (GetLastError ());
+      _g_winhttp_set_error (error, GetLastError (), "HTTP connection");
-
-      g_set_error (error, G_IO_ERROR,
-                   G_IO_ERROR_FAILED,
-                   "%s", emsg);
-      g_free (emsg);
 
       return NULL;
     }
@@ -461,12 +640,7 @@ g_winhttp_file_read (GFile         *file,
 
   if (request == NULL)
     {
-      char *emsg = _g_winhttp_error_message (GetLastError ());
+      _g_winhttp_set_error (error, GetLastError (), "GET request");
-
-      g_set_error (error, G_IO_ERROR,
-                   G_IO_ERROR_FAILED,
-                   "%s", emsg);
-      g_free (emsg);
 
       return NULL;
     }
@@ -481,7 +655,7 @@ g_winhttp_file_create (GFile             *file,
                        GError           **error)
 {
   GWinHttpFile *winhttp_file = G_WINHTTP_FILE (file);
-  HINTERNET connection, request;
+  HINTERNET connection;
 
   connection = G_WINHTTP_VFS_GET_CLASS (winhttp_file->vfs)->pWinHttpConnect
     (G_WINHTTP_VFS (winhttp_file->vfs)->session,
@@ -491,12 +665,7 @@ g_winhttp_file_create (GFile             *file,
 
   if (connection == NULL)
     {
-      char *emsg = _g_winhttp_error_message (GetLastError ());
+      _g_winhttp_set_error (error, GetLastError (), "HTTP connection");
-
-      g_set_error (error, G_IO_ERROR,
-                   G_IO_ERROR_FAILED,
-                   "%s", emsg);
-      g_free (emsg);
 
       return NULL;
     }
@@ -550,7 +719,8 @@ g_winhttp_file_copy (GFile                  *source,
                      GError                **error)
 {
   /* Fall back to default copy?? */
-  g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED, "Copy not supported");
+  g_set_error_literal (error, G_IO_ERROR, G_IO_ERROR_NOT_SUPPORTED,
+                       "Copy not supported");
 
   return FALSE;
 }
@@ -590,6 +760,7 @@ g_winhttp_file_file_iface_init (GFileIface *iface)
   iface->resolve_relative_path = g_winhttp_file_resolve_relative_path;
   iface->get_child_for_display_name = g_winhttp_file_get_child_for_display_name;
   iface->set_display_name = g_winhttp_file_set_display_name;
+  iface->query_info = g_winhttp_file_query_info;
   iface->read_fn = g_winhttp_file_read;
   iface->create = g_winhttp_file_create;
 #if 0

gio/win32/gwinhttpfileinputstream.c

@@ -1,5 +1,5 @@
 /* GIO - GLib Input, Output and Streaming Library
- * 
+ *
  * Copyright (C) 2006-2007 Red Hat, Inc.
  * Copyright (C) 2008 Novell, Inc.
  *
@@ -61,7 +61,7 @@ static void
 g_winhttp_file_input_stream_finalize (GObject *object)
 {
   GWinHttpFileInputStream *winhttp_stream;
-  
+
   winhttp_stream = G_WINHTTP_FILE_INPUT_STREAM (object);
 
   if (winhttp_stream->request != NULL)
@@ -77,7 +77,7 @@ g_winhttp_file_input_stream_class_init (GWinHttpFileInputStreamClass *klass)
 {
   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
   GInputStreamClass *stream_class = G_INPUT_STREAM_CLASS (klass);
-  
+
   gobject_class->finalize = g_winhttp_file_input_stream_finalize;
 
   stream_class->read_fn = g_winhttp_file_input_stream_read;
@@ -90,10 +90,10 @@ g_winhttp_file_input_stream_init (GWinHttpFileInputStream *info)
 
 /**
  * g_winhttp_file_input_stream_new:
- * @file: the GWinHttpFile being read 
+ * @file: the GWinHttpFile being read
  * @connection: handle to the HTTP connection, as from WinHttpConnect()
  * @request: handle to the HTTP request, as from WinHttpOpenRequest
- * 
+ *
  * Returns: #GFileInputStream for the given request
  **/
 GFileInputStream *
@@ -109,7 +109,7 @@ _g_winhttp_file_input_stream_new (GWinHttpFile *file,
   stream->request_sent = FALSE;
   stream->connection = connection;
   stream->request = request;
-  
+
   return G_FILE_INPUT_STREAM (stream);
 }
 
@@ -132,39 +132,27 @@ g_winhttp_file_input_stream_read (GInputStream  *stream,
            0,
            0))
         {
-          char *emsg = _g_winhttp_error_message (GetLastError ());
+          _g_winhttp_set_error (error, GetLastError (), "GET request");
-          
-          g_set_error (error, G_IO_ERROR,
-                       G_IO_ERROR_FAILED,
-                       "%s", emsg);
-          g_free (emsg);
-          
-          return -1;
-        }
-  
-      if (!G_WINHTTP_VFS_GET_CLASS (winhttp_stream->file->vfs)->pWinHttpReceiveResponse
-          (winhttp_stream->request, NULL))
-        {
-          char *emsg = _g_winhttp_error_message (GetLastError ());
-          g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
-                       "%s", emsg);
-          g_free (emsg);
 
           return -1;
         }
+
+      if (!_g_winhttp_response (winhttp_stream->file->vfs,
+                                winhttp_stream->request,
+                                error,
+                                "GET request"))
+        return -1;
+
       winhttp_stream->request_sent = TRUE;
     }
-  
+
   if (!G_WINHTTP_VFS_GET_CLASS (winhttp_stream->file->vfs)->pWinHttpReadData
       (winhttp_stream->request, buffer, count, &bytes_read))
     {
-      char *emsg = _g_winhttp_error_message (GetLastError ());
+      _g_winhttp_set_error (error, GetLastError (), "GET request");
-      g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
-                   "%s", emsg);
-      g_free (emsg);
 
       return -1;
     }
-  
+
   return bytes_read;
 }

gio/win32/gwinhttpfileoutputstream.c

@@ -1,5 +1,5 @@
 /* GIO - GLib Input, Output and Streaming Library
- * 
+ *
  * Copyright (C) 2006-2007 Red Hat, Inc.
  * Copyright (C) 2008 Novell, Inc.
  *
@@ -60,7 +60,7 @@ static void
 g_winhttp_file_output_stream_finalize (GObject *object)
 {
   GWinHttpFileOutputStream *winhttp_stream;
-  
+
   winhttp_stream = G_WINHTTP_FILE_OUTPUT_STREAM (object);
 
   if (winhttp_stream->connection != NULL)
@@ -74,7 +74,7 @@ g_winhttp_file_output_stream_class_init (GWinHttpFileOutputStreamClass *klass)
 {
   GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
   GOutputStreamClass *stream_class = G_OUTPUT_STREAM_CLASS (klass);
-  
+
   gobject_class->finalize = g_winhttp_file_output_stream_finalize;
 
   stream_class->write_fn = g_winhttp_file_output_stream_write;
@@ -87,10 +87,10 @@ g_winhttp_file_output_stream_init (GWinHttpFileOutputStream *info)
 
 /**
  * g_winhttp_file_output_stream_new:
- * @file: the GWinHttpFile being read 
+ * @file: the GWinHttpFile being read
  * @connection: handle to the HTTP connection, as from WinHttpConnect()
  * @request: handle to the HTTP request, as from WinHttpOpenRequest
- * 
+ *
  * Returns: #GFileOutputStream for the given request
  **/
 GFileOutputStream *
@@ -132,12 +132,7 @@ g_winhttp_file_output_stream_write (GOutputStream  *stream,
 
   if (request == NULL)
     {
-      char *emsg = _g_winhttp_error_message (GetLastError ());
+      _g_winhttp_set_error (error, GetLastError (), "PUT request");
-
-      g_set_error (error, G_IO_ERROR,
-                   G_IO_ERROR_FAILED,
-                   "%s", emsg);
-      g_free (emsg);
 
       return -1;
     }
@@ -154,47 +149,35 @@ g_winhttp_file_output_stream_write (GOutputStream  *stream,
        count,
        0))
     {
-      char *emsg = _g_winhttp_error_message (GetLastError ());
+      _g_winhttp_set_error (error, GetLastError (), "PUT request");
-      
+
-      g_set_error (error, G_IO_ERROR,
-                   G_IO_ERROR_FAILED,
-                   "%s", emsg);
-      g_free (emsg);
-      
       G_WINHTTP_VFS_GET_CLASS (winhttp_stream->file->vfs)->pWinHttpCloseHandle (request);
       g_free (wheaders);
 
       return -1;
     }
-  
+
   g_free (wheaders);
 
   if (!G_WINHTTP_VFS_GET_CLASS (winhttp_stream->file->vfs)->pWinHttpWriteData
       (request, buffer, count, &bytes_written))
     {
-      char *emsg = _g_winhttp_error_message (GetLastError ());
+      _g_winhttp_set_error (error, GetLastError (), "PUT request");
-      g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
-                   "%s",
-                   emsg);
-      g_free (emsg);
 
       G_WINHTTP_VFS_GET_CLASS (winhttp_stream->file->vfs)->pWinHttpCloseHandle (request);
 
       return -1;
     }
-  
+
   winhttp_stream->offset += bytes_written;
 
-  if (!G_WINHTTP_VFS_GET_CLASS (winhttp_stream->file->vfs)->pWinHttpReceiveResponse
+  if (!_g_winhttp_response (winhttp_stream->file->vfs,
-      (request, NULL))
+                            request,
+                            error,
+                            "PUT request"))
     {
-      char *emsg = _g_winhttp_error_message (GetLastError ());
-      g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
-                   "%s",
-                   emsg);
-      g_free (emsg);
-      
       G_WINHTTP_VFS_GET_CLASS (winhttp_stream->file->vfs)->pWinHttpCloseHandle (request);
+
       return -1;
     }
 

gio/win32/gwinhttpvfs.c

@@ -1,5 +1,5 @@
 /* GIO - GLib Input, Output and Streaming Library
- * 
+ *
  * Copyright (C) 2006-2007 Red Hat, Inc.
  * Copyright (C) 2008 Novell, Inc.
  *
@@ -24,6 +24,9 @@
 
 #include "config.h"
 
+#include <wchar.h>
+
+#include "gioerror.h"
 #include "giomodule.h"
 #include "gvfs.h"
 
@@ -69,7 +72,7 @@ g_winhttp_vfs_init (GWinHttpVfs *vfs)
 
   if (!wagent)
     wagent = g_utf8_to_utf16 ("GWinHttpVfs", -1, NULL, NULL, NULL);
-  
+
   vfs->session = (G_WINHTTP_VFS_GET_CLASS (vfs)->pWinHttpOpen)
     (wagent,
      WINHTTP_ACCESS_TYPE_DEFAULT_PROXY,
@@ -142,7 +145,7 @@ g_winhttp_vfs_get_supported_uri_schemes (GVfs *vfs)
     }
 
   retval[n] = NULL;
-  
+
   return retval;
 }
 
@@ -151,7 +154,7 @@ g_winhttp_vfs_parse_name (GVfs       *vfs,
                           const char *parse_name)
 {
   GWinHttpVfs *winhttp_vfs = G_WINHTTP_VFS (vfs);
-  
+
   g_return_val_if_fail (G_IS_VFS (vfs), NULL);
   g_return_val_if_fail (parse_name != NULL, NULL);
 
@@ -177,7 +180,7 @@ g_winhttp_vfs_class_init (GWinHttpVfsClass *class)
   GObjectClass *object_class;
   GVfsClass *vfs_class;
   HMODULE winhttp;
-  
+
   object_class = (GObjectClass *) class;
 
   object_class->finalize = g_winhttp_vfs_finalize;
@@ -266,9 +269,154 @@ _g_winhttp_error_message (DWORD error_code)
           CASE (UNRECOGNIZED_SCHEME);
           #undef CASE
         default:
-          return g_strdup_printf ("WinHttp error %ld", error_code); 
+          return g_strdup_printf ("WinHttp error %ld", error_code);
         }
     }
   else
     return g_win32_error_message (error_code);
 }
+
+void
+_g_winhttp_set_error (GError     **error,
+                      DWORD        error_code,
+                      const char  *what)
+{
+  char *emsg = _g_winhttp_error_message (error_code);
+
+  g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+               "%s failed: %s", what, emsg);
+  g_free (emsg);
+}
+
+gboolean
+_g_winhttp_response (GWinHttpVfs *vfs,
+                     HINTERNET    request,
+                     GError     **error,
+                     const char  *what)
+{
+  wchar_t *status_code;
+  DWORD status_code_len;
+
+  if (!G_WINHTTP_VFS_GET_CLASS (vfs)->pWinHttpReceiveResponse (request, NULL))
+    {
+      _g_winhttp_set_error (error, GetLastError (), what);
+
+      return FALSE;
+    }
+
+  status_code_len = 0;
+  if (!G_WINHTTP_VFS_GET_CLASS (vfs)->pWinHttpQueryHeaders
+      (request,
+       WINHTTP_QUERY_STATUS_CODE,
+       NULL,
+       NULL,
+       &status_code_len,
+       NULL) &&
+      GetLastError () != ERROR_INSUFFICIENT_BUFFER)
+    {
+      _g_winhttp_set_error (error, GetLastError (), what);
+
+      return FALSE;
+    }
+
+  status_code = g_malloc (status_code_len);
+
+  if (!G_WINHTTP_VFS_GET_CLASS (vfs)->pWinHttpQueryHeaders
+      (request,
+       WINHTTP_QUERY_STATUS_CODE,
+       NULL,
+       status_code,
+       &status_code_len,
+       NULL))
+    {
+      _g_winhttp_set_error (error, GetLastError (), what);
+      g_free (status_code);
+
+      return FALSE;
+    }
+
+  if (status_code[0] != L'2')
+    {
+      wchar_t *status_text = NULL;
+      DWORD status_text_len;
+
+      if (!G_WINHTTP_VFS_GET_CLASS (vfs)->pWinHttpQueryHeaders
+          (request,
+           WINHTTP_QUERY_STATUS_TEXT,
+           NULL,
+           NULL,
+           &status_text_len,
+           NULL) &&
+          GetLastError () == ERROR_INSUFFICIENT_BUFFER)
+        {
+          status_text = g_malloc (status_text_len);
+
+          if (!G_WINHTTP_VFS_GET_CLASS (vfs)->pWinHttpQueryHeaders
+              (request,
+               WINHTTP_QUERY_STATUS_TEXT,
+               NULL,
+               status_text,
+               &status_text_len,
+               NULL))
+            {
+              g_free (status_text);
+              status_text = NULL;
+            }
+        }
+
+      g_set_error (error, G_IO_ERROR, G_IO_ERROR_FAILED,
+                   "%s failed: %S %S",
+                   what, status_code, status_text ? status_text : L"");
+      g_free (status_code);
+      g_free (status_text);
+
+      return FALSE;
+    }
+
+  g_free (status_code);
+
+  return TRUE;
+}
+
+gboolean
+_g_winhttp_query_header (GWinHttpVfs *vfs,
+                         HINTERNET    request,
+                         const char  *request_description,
+                         DWORD        which_header,
+                         wchar_t    **header,
+                         GError     **error)
+{
+  DWORD header_len = 0;
+
+  if (!G_WINHTTP_VFS_GET_CLASS (vfs)->pWinHttpQueryHeaders
+      (request,
+       which_header,
+       NULL,
+       NULL,
+       &header_len,
+       NULL) &&
+      GetLastError () != ERROR_INSUFFICIENT_BUFFER)
+    {
+      _g_winhttp_set_error (error, GetLastError (), request_description);
+
+      return FALSE;
+    }
+
+  *header = g_malloc (header_len);
+  if (!G_WINHTTP_VFS_GET_CLASS (vfs)->pWinHttpQueryHeaders
+      (request,
+       which_header,
+       NULL,
+       *header,
+       &header_len,
+       NULL))
+    {
+      _g_winhttp_set_error (error, GetLastError (), request_description);
+      g_free (*header);
+      *header = NULL;
+
+      return FALSE;
+    }
+
+  return TRUE;
+}

gio/win32/gwinhttpvfs.h

@@ -1,6 +1,6 @@
 /* GIO - GLib Input, Output and Streaming Library
- * 
+ *
- * Copyright (C) 2006-2007 Red Hat, Inc. 
+ * Copyright (C) 2006-2007 Red Hat, Inc.
  * Copyright (C) 2008 Novell, Inc.
  *
  * This library is free software; you can redistribute it and/or
@@ -83,6 +83,22 @@ GVfs *_g_winhttp_vfs_new (void);
 
 char *_g_winhttp_error_message (DWORD error_code);
 
+void _g_winhttp_set_error (GError     **error,
+                           DWORD        error_code,
+                           const char  *what);
+
+gboolean _g_winhttp_response (GWinHttpVfs *vfs,
+                              HINTERNET    request,
+                              GError     **error,
+                              const char  *what);
+
+gboolean _g_winhttp_query_header (GWinHttpVfs *vfs,
+                                  HINTERNET    request,
+                                  const char  *request_description,
+                                  DWORD        which_header,
+                                  wchar_t    **header,
+                                  GError     **error);
+
 G_END_DECLS
 
 #endif /* __G_WINHTTP_VFS_H__ */

gio/win32/winhttp.h

@@ -229,6 +229,18 @@ BOOL        WINAPI WinHttpWriteData(HINTERNET,LPCVOID,DWORD,LPDWORD);
 #define ICU_ESCAPE 0x80000000
 #define ICU_DECODE 0x10000000
 
+/* A few constants I couldn't find publicly documented, so I looked up
+ * their value from the Windows SDK <winhttp.h>. Presumably this falls
+ * under fair use.
+ */
+#define WINHTTP_QUERY_CONTENT_LENGTH 5
+#define WINHTTP_QUERY_CONTENT_TYPE 1
+#define WINHTTP_QUERY_LAST_MODIFIED 11
+#define WINHTTP_QUERY_STATUS_CODE 19
+#define WINHTTP_QUERY_STATUS_TEXT 20
+
+#define WINHTTP_QUERY_FLAG_SYSTEMTIME 0x40000000
+
 #ifdef __cplusplus
 }
 #endif