Added special mode for sorting of regular files.

[libucw.git] / lib / sorter.h

diff --git a/lib/sorter.h b/lib/sorter.h
index be2e80a33b12dade3daffafc9683626998d7b5c0..4c42d7788d90b04771e8ed31840705acdd25ef7a 100644 (file)
--- a/lib/sorter.h
+++ b/lib/sorter.h
@@ -1,7 +1,10 @@
 /*
  *     Sherlock Library -- Universal Sorter
  *
- *     (c) 2001 Martin Mares <mj@ucw.cz>
+ *     (c) 2001--2003 Martin Mares <mj@ucw.cz>
+ *
+ *     This software may be freely distributed and used according to the terms
+ *     of the GNU Lesser General Public License.
  */
 
 /*
@@ -17,10 +20,16 @@
  *                     defined by the sorter)
  *  SORT_PRESORT       include an in-core presorting pass
  *  SORT_UNIFY         merge items with identical keys
+ *  SORT_REGULAR       all items are equally long and they don't contain
+ *                     anything else than the key. In this case, the sorter
+ *                     automatically supplies fetch_key, copy_data, fetch_item
+ *                     and store_item functions.
  *  SORT_DELETE_INPUT  a C expression, if true, the input files are
  *                     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 +55,11 @@
  *                     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
@@ -60,6 +71,9 @@
  *                     from the list of items, but not deallocated, so
  *                     the remaining item can freely reference data of the
  *                     other one.
+ *
+ *  After including this file, all parameter macros are automatically
+ *  undef'd.
  */
 
 /* Declarations of externals from sorter.c */
@@ -71,8 +85,7 @@ extern uns sorter_trace;
 extern uns sorter_presort_bufsize;
 extern uns sorter_stream_bufsize;
 
-extern uns sorter_pass_counter, sorter_file_counter;
-struct fastbuf *sorter_open_tmp(void);
+extern uns sorter_pass_counter;
 
 #endif         /* !SORT_DECLS_READ */
 
@@ -98,6 +111,34 @@ struct fastbuf *sorter_open_tmp(void);
 #define LESS <=
 #endif
 
+#ifdef SORT_REGULAR
+
+static inline int
+P(fetch_key)(struct fastbuf *in, SORT_KEY *x)
+{
+  return breadb(in, x, sizeof(*x));
+}
+
+static inline void
+P(copy_data)(struct fastbuf *in UNUSED, struct fastbuf *out, SORT_KEY *x)
+{
+  bwrite(out, x, sizeof(*x));
+}
+
+static inline byte *
+P(fetch_item)(struct fastbuf *in UNUSED, SORT_KEY *x UNUSED, byte *limit UNUSED)
+{
+  return (byte *)(x+1);
+}
+
+static inline void
+P(store_item)(struct fastbuf *out, SORT_KEY *x)
+{
+  bwrite(out, x, sizeof(*x));
+}
+
+#endif
+
 static struct fastbuf *
 P(flush_out)(struct fastbuf *out)
 {
@@ -143,7 +184,7 @@ P(pass)(struct fastbuf **fb1, struct fastbuf **fb2)
          struct fastbuf *t;
          SWAP(out1, out2, t);
          if (!out1)
-           out1 = sorter_open_tmp();
+           out1 = bopen_tmp(sorter_stream_bufsize);
          run_count++;
        }
       if (comp LESS 0)
@@ -159,7 +200,7 @@ 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);
@@ -269,7 +310,7 @@ P(presort)(struct fastbuf **fb1, struct fastbuf **fb2)
     {
       SWAP(out1, out2, tbuf);
       if (!out1)
-       out1 = sorter_open_tmp();
+       out1 = bopen_tmp(sorter_stream_bufsize);
       current = buffer;
       last = &first;
       if (leftover)
@@ -342,6 +383,7 @@ P(presort)(struct fastbuf **fb1, struct fastbuf **fb2)
        (out2 ? (int)((btell(out2) + 1023) / 1024) : 0));
   *fb1 = P(flush_out)(out1);
   *fb2 = P(flush_out)(out2);
+  xfree(buffer);
 }
 
 #endif         /* SORT_PRESORT */
@@ -372,14 +414,14 @@ 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
+  bconfig(fb1, BCONFIG_IS_TEMP_FILE, SORT_DELETE_INPUT);
+#endif
   sorter_pass_counter = 1;
 #ifdef SORT_PRESORT
   P(presort)(&fb1, &fb2);
@@ -387,12 +429,12 @@ struct fastbuf *fb1, struct fastbuf *fb2
 #endif
     do P(pass)(&fb1, &fb2); while (fb1 && fb2);
   if (!fb1)
-    fb1 = sorter_open_tmp();
+    fb1 = bopen_tmp(sorter_stream_bufsize);
 
 #ifdef SORT_OUTPUT_FB
   return fb1;
 #else
-  fb1->is_temp_file = 0;
+  bconfig(fb1, BCONFIG_IS_TEMP_FILE, 0);
   if (rename(fb1->name, outname) < 0)
     die("rename(%s,%s): %m", fb1->name, outname);
   bclose(fb1);
@@ -403,5 +445,15 @@ struct fastbuf *fb1, struct fastbuf *fb2
 #undef LESS
 #undef SWAP
 #undef SORT_NODE
+#undef SORT_KEY
+#undef SORT_PREFIX
+#undef SORT_UNIFY
+#undef SORT_REGULAR
+#undef SORT_DELETE_INPUT
+#undef SORT_INPUT_FILE
+#undef SORT_INPUT_FB
+#undef SORT_INPUT_FBPAIR
+#undef SORT_OUTPUT_FILE
+#undef SORT_OUTPUT_FB
 
 #endif         /* !SORT_DECLARE_ONLY */