X-Git-Url: http://mj.ucw.cz/gitweb/?a=blobdiff_plain;f=lib%2Fsorter.h;h=d1f059fccec58f0240748dc7dc0777cb78eaa27d;hb=9fbdf10b4915874aad2eb98087293e5c721d3eb2;hp=be2e80a33b12dade3daffafc9683626998d7b5c0;hpb=78d7afe64ca18c0cf679aec89d611641f5cbe872;p=libucw.git

diff --git a/lib/sorter.h b/lib/sorter.h
index be2e80a3..d1f059fc 100644
--- a/lib/sorter.h
+++ b/lib/sorter.h
@@ -21,6 +21,8 @@
  *			deleted as soon as possible
  *  SORT_INPUT_FILE	input is a file with this name
  *  SORT_INPUT_FB	input is a fastbuf stream
+ *			(can be safely NULL if you want to treat original
+ *			input in a different way by file read functions)
  *  SORT_INPUT_FBPAIR	input is a pair of fastbuf streams
  *			(not supported by the presorter)
  *  SORT_OUTPUT_FILE	output is a file with this name
@@ -46,9 +48,11 @@
  *			fetch data belonging to a just fetched key and store
  *			them to memory following the key, but not over limit.
  *			Returns a pointer to first byte after the data
- *			or NULL if the data don't fit.
- *			Important: keys carrying no data must be position
- *			independent.
+ *			or NULL if the data don't fit. For variable-length
+ *			keys, it can use the rest of SORT_KEY and even return
+ *			pointer before end of the key.
+ *			Important: before PREFIX_fetch_item() succeeds, the key
+ *			must be position independent, the sorter can copy it.
  *  void PREFIX_store_item(struct fastbuf *f, SORT_KEY *k)
  *			[used only with SORT_PRESORT]
  *			write key and all its data read with PREFIX_fetch_data
@@ -159,7 +163,7 @@ P(pass)(struct fastbuf **fb1, struct fastbuf **fb2)
 	{
 	  P(merge_data)(in1, in2, out1, kin1, kin2);
 	  SWAP(kin1, kprev1, ktmp);
-	  next1 = P(fetch_key)(in1, kin1); /* FIXME: Re-use other code? */
+	  next1 = P(fetch_key)(in1, kin1);
 	  run1 = next1 && (P(compare)(kprev1, kin1) LESS 0);
 	  SWAP(kin2, kprev2, ktmp);
 	  next2 = P(fetch_key)(in2, kin2);
@@ -372,14 +376,14 @@ struct fastbuf *fb1, struct fastbuf *fb2
 #ifdef SORT_INPUT_FILE
   struct fastbuf *fb1, *fb2;
   fb1 = bopen(inname, O_RDONLY, sorter_stream_bufsize);
-#ifdef SORT_DELETE_INPUT
-  fb1->is_temp_file = SORT_DELETE_INPUT;
-#endif
   fb2 = NULL;
 #elif defined(SORT_INPUT_FB)
   struct fastbuf *fb2 = NULL;
 #endif
 
+#ifdef SORT_DELETE_INPUT
+  fb1->is_temp_file = SORT_DELETE_INPUT;
+#endif
   sorter_pass_counter = 1;
 #ifdef SORT_PRESORT
   P(presort)(&fb1, &fb2);