efl_io_copier: expose pending_size and add debug to done_get.

In some cases the copier isn't done but you know there is not more
data to arrive at it, then you want to know if all pending data was
flushed from the copier's intermediate buffer to the destination, if
so you can call it closed yourself.

src/lib/ecore/efl_io_copier.c

@@ -781,9 +781,26 @@ _efl_io_copier_flush(Eo *o, Efl_Io_Copier_Data *pd, Eina_Bool may_block, Eina_Bo
    return pd->done;
 }
 
-EOLIAN static Eina_Bool
-_efl_io_copier_done_get(Eo *o EINA_UNUSED, Efl_Io_Copier_Data *pd)
+EOLIAN static size_t
+_efl_io_copier_pending_size_get(Eo *o EINA_UNUSED, Efl_Io_Copier_Data *pd)
 {
+   return pd->buf ? eina_binbuf_length_get(pd->buf) : 0;
+}
+
+EOLIAN static Eina_Bool
+_efl_io_copier_done_get(Eo *o, Efl_Io_Copier_Data *pd)
+{
+   DBG("%p done=%d pending=%zd source={%p %s, eos=%d, closed=%d}, destination={%p %s, closed=%d}",
+       o, pd->done,
+       pd->buf ? eina_binbuf_length_get(pd->buf) : 0,
+       pd->source,
+       pd->source ? efl_class_name_get(pd->source) : "",
+       pd->source ? efl_io_reader_eos_get(pd->source) : 1,
+       pd->source ? (efl_isa(pd->source, EFL_IO_CLOSER_MIXIN) ? efl_io_closer_closed_get(pd->source) : 0) : 1,
+       pd->destination,
+       pd->destination ? efl_class_name_get(pd->destination) : "",
+       pd->destination ? (efl_isa(pd->destination, EFL_IO_CLOSER_MIXIN) ? efl_io_closer_closed_get(pd->destination) : 0) : 1);
+
    return pd->done;
 }
 

src/lib/ecore/efl_io_copier.eo

@@ -313,6 +313,23 @@ class Efl.Io.Copier (Efl.Loop_User, Efl.Io.Closer) {
            return: free(own(ptr(Eina.Binbuf)), eina_binbuf_free) @warn_unused; [[Binbuf]]
         }
 
+        @property pending_size {
+            [[Returns the size of the pending buffer.
+
+              The pending buffer is an intermediate buffer where data
+              is read from @.source before it's written to
+              @.destination, if any.
+
+              This is the equivalent of the size of returned by
+              @.binbuf_steal, however it doesn't steal or modify the
+              buffer at all, just query its internal size.
+            ]]
+            get { }
+            values {
+                size: size; [[The pending buffer size, in bytes.]]
+            }
+        }
+
         flush {
             [[Forces reading from source and writing to destination.