support servers that don't handle a Range request

panda/src/downloader/httpChannel.I

@@ -518,6 +518,70 @@ is_file_size_known() const {
   return _got_file_size;
 }
 
+////////////////////////////////////////////////////////////////////
+//     Function: HTTPChannel::get_first_byte_requested
+//       Access: Published
+//  Description: Returns the first byte of the file requested by the
+//               request.  This will normally be 0 to indicate that
+//               the file is being requested from the beginning, but
+//               if the file was requested via a get_subdocument()
+//               call, this will contain the first_byte parameter from
+//               that call.
+////////////////////////////////////////////////////////////////////
+INLINE size_t HTTPChannel::
+get_first_byte_requested() const {
+  return _first_byte_requested;
+}
+
+////////////////////////////////////////////////////////////////////
+//     Function: HTTPChannel::get_last_byte_requested
+//       Access: Published
+//  Description: Returns the last byte of the file requested by the
+//               request.  This will normally be 0 to indicate that
+//               the file is being requested to its last byte, but if
+//               the file was requested via a get_subdocument() call,
+//               this will contain the last_byte parameter from that
+//               call.
+////////////////////////////////////////////////////////////////////
+INLINE size_t HTTPChannel::
+get_last_byte_requested() const {
+  return _last_byte_requested;
+}
+
+////////////////////////////////////////////////////////////////////
+//     Function: HTTPChannel::get_first_byte_delivered
+//       Access: Published
+//  Description: Returns the first byte of the file (that will be)
+//               delivered by the server in response to the current
+//               request.  Normally, this is the same as
+//               get_first_byte_requested(), but some servers will
+//               ignore a subdocument request and always return the
+//               whole file, in which case this value will be 0,
+//               regardless of what was requested to
+//               get_subdocument().
+////////////////////////////////////////////////////////////////////
+INLINE size_t HTTPChannel::
+get_first_byte_delivered() const {
+  return _first_byte_delivered;
+}
+
+////////////////////////////////////////////////////////////////////
+//     Function: HTTPChannel::get_last_byte_delivered
+//       Access: Published
+//  Description: Returns the last byte of the file (that will be)
+//               delivered by the server in response to the current
+//               request.  Normally, this is the same as
+//               get_last_byte_requested(), but some servers will
+//               ignore a subdocument request and always return the
+//               whole file, in which case this value will be 0,
+//               regardless of what was requested to
+//               get_subdocument().
+////////////////////////////////////////////////////////////////////
+INLINE size_t HTTPChannel::
+get_last_byte_delivered() const {
+  return _last_byte_delivered;
+}
+
 ////////////////////////////////////////////////////////////////////
 //     Function: HTTPChannel::reset
 //       Access: Published

panda/src/downloader/httpChannel.cxx

@@ -621,7 +621,7 @@ download_to_file(const Filename &filename, bool subdocument_resumes) {
   _download_to_file.close();
   _download_to_file.clear();
 
-  _subdocument_resumes = (subdocument_resumes && _first_byte_requested != 0);
+  _subdocument_resumes = (subdocument_resumes && _first_byte_delivered != 0);
 
   if (!_download_to_filename.open_write(_download_to_file, !_subdocument_resumes)) {
     downloader_cat.info()
@@ -630,7 +630,7 @@ download_to_file(const Filename &filename, bool subdocument_resumes) {
   }
 
   _download_dest = DD_file;
-  if (!reset_download_position(_first_byte_requested)) {
+  if (!reset_download_position(_first_byte_delivered)) {
     reset_download_to();
     return false;
   }
@@ -684,9 +684,9 @@ download_to_ram(Ramfile *ramfile, bool subdocument_resumes) {
   ramfile->_pos = 0;
   _download_to_ramfile = ramfile;
   _download_dest = DD_ram;
-  _subdocument_resumes = (subdocument_resumes && _first_byte_requested != 0);
+  _subdocument_resumes = (subdocument_resumes && _first_byte_delivered != 0);
 
-  if (!reset_download_position(_first_byte_requested)) {
+  if (!reset_download_position(_first_byte_delivered)) {
     reset_download_to();
     return false;
   }
@@ -1685,6 +1685,17 @@ run_reading_header() {
     _first_byte_delivered = 0;
     _last_byte_delivered = 0;
   }
+  if (downloader_cat.is_debug()) {
+    if (_first_byte_requested != 0 || _last_byte_requested != 0 ||
+        _first_byte_delivered != 0 || _last_byte_delivered != 0) {
+      downloader_cat.debug()
+        << "Requested byte range " << _first_byte_requested
+        << " to " << _last_byte_delivered
+        << "; server delivers range " << _first_byte_delivered
+        << " to " << _last_byte_delivered
+        << "\n";
+    }
+  }
 
   // Set the _document_spec to reflect what we just retrieved.
   _document_spec = DocumentSpec(_request.get_url());

panda/src/downloader/httpChannel.h

@@ -150,6 +150,11 @@ PUBLISHED:
   virtual off_t get_file_size() const;
   INLINE bool is_file_size_known() const;
 
+  INLINE size_t get_first_byte_requested() const;
+  INLINE size_t get_last_byte_requested() const;
+  INLINE size_t get_first_byte_delivered() const;
+  INLINE size_t get_last_byte_delivered() const;
+
   void write_headers(ostream &out) const;
 
   INLINE void reset();