From 995b82cc6ecd741ddc7ff669a75056558b8bbe3e Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?V=C3=ADtor=20Manuel=20de=20Morais=20Santos=20Costa?=
 <vsc@xato.(none)>
Date: Tue, 3 Nov 2009 14:37:12 +0000
Subject: [PATCH] Nuno Fonseca's trie writing updates.

---
 library/itries.yap         |  5 +++-
 library/tries/core_tries.c |  7 ++++--
 library/tries/itries.c     | 48 +++++++++++++++++++++++++++++++++++++-
 3 files changed, 56 insertions(+), 4 deletions(-)

diff --git a/library/itries.yap b/library/itries.yap
index 14f38e83f..323dc2daa 100644
--- a/library/itries.yap
+++ b/library/itries.yap
@@ -31,7 +31,10 @@
 		  itrie_stats/4,
 		  itrie_max_stats/4,
 		  itrie_usage/4,
-		  itrie_print/1
+		  itrie_print/1,
+		  %added by nf
+		  itrie_save2stream/2,
+		  itrie_loadFromstream/2
           ]).
 
 :- load_foreign_files([itries], [], init_itries).
diff --git a/library/tries/core_tries.c b/library/tries/core_tries.c
index dd289539c..424a5f40c 100644
--- a/library/tries/core_tries.c
+++ b/library/tries/core_tries.c
@@ -428,8 +428,11 @@ inline
 TrNode core_trie_load(TrEngine engine, FILE *file, void (*load_function)(TrNode, YAP_Int, FILE *)) {
   TrNode node;
   char version[15];
+  fpos_t curpos;
 
   fscanf(file, "%14s", version);
+  if (fgetpos(file, &curpos) ) return NULL;
+
   if (!strcmp(version, "BEGIN_TRIE_v2")) {
     fseek(file, -11, SEEK_END);
     fscanf(file, "%s", version);
@@ -439,7 +442,7 @@ TrNode core_trie_load(TrEngine engine, FILE *file, void (*load_function)(TrNode,
       fprintf(stderr, "******************************************\n");  
       return NULL;
     }
-    fseek(file, 13, SEEK_SET);
+    if (fsetpos(file, &curpos) ) return NULL;
     CURRENT_LOAD_VERSION = 2;
   } else if (!strcmp(version, "BEGIN_TRIE")) {
     fseek(file, -8, SEEK_END);
@@ -450,7 +453,7 @@ TrNode core_trie_load(TrEngine engine, FILE *file, void (*load_function)(TrNode,
       fprintf(stderr, "******************************************\n");  
       return NULL;
     }
-    fseek(file, 10, SEEK_SET);
+    if (fsetpos(file, &curpos) )  return NULL;
     CURRENT_LOAD_VERSION = 1;
   } else {
     fprintf(stderr, "****************************************\n");
diff --git a/library/tries/itries.c b/library/tries/itries.c
index 72f2b46c9..5a1b66e9e 100644
--- a/library/tries/itries.c
+++ b/library/tries/itries.c
@@ -51,7 +51,9 @@ static int p_itrie_stats(void);
 static int p_itrie_max_stats(void);
 static int p_itrie_usage(void);
 static int p_itrie_print(void);
-
+//nf
+static int p_itrie_loadFromStream(void);
+static int p_itrie_save2stream(void);
 
 
 /* -------------------------- */
@@ -87,6 +89,9 @@ void init_itries(void) {
   YAP_UserCPredicate("itrie_max_stats", p_itrie_max_stats, 4);
   YAP_UserCPredicate("itrie_usage", p_itrie_usage, 4);
   YAP_UserCPredicate("itrie_print", p_itrie_print, 1);
+  // nf
+  YAP_UserCPredicate("itrie_save2stream", p_itrie_save2stream, 2);
+  YAP_UserCPredicate("itrie_loadFromstream", p_itrie_loadFromStream, 2);
   return;
 }
 
@@ -679,3 +684,44 @@ static int p_itrie_print(void) {
   return TRUE;
 }
 #undef arg_itrie
+
+/* added by nf: itrie_save2stream(+Itrie,+Stream) */
+#define arg_itrie   YAP_ARG1
+#define arg_stream  YAP_ARG2
+static int p_itrie_save2stream(void) {
+  FILE *file;
+
+  /* check args */
+  if (!YAP_IsIntTerm(arg_itrie))
+    return FALSE;
+  if ((file=(FILE*)YAP_FileDescriptorFromStream(arg_stream))==NULL)
+    return FALSE;
+
+  /* save itrie and close file */
+  itrie_save((TrEntry) YAP_IntOfTerm(arg_itrie), file);
+  return TRUE;
+}
+#undef arg_itrie
+#undef arg_stream
+
+/* added by nf: itrie_loadFromStream(-Itrie,+Stream) */
+#define arg_itrie YAP_ARG1
+#define arg_stream  YAP_ARG2
+static int p_itrie_loadFromStream(void) {
+  TrEntry itrie;
+  FILE *file;
+
+  /* check args */
+  if (!YAP_IsVarTerm(arg_itrie)) 
+    return FALSE;
+  if (!(file=(FILE*)Yap_FileDescriptorFromStream(arg_stream)))
+    return FALSE;
+
+  /* load itrie and close file */
+  itrie = itrie_load(file);
+  if (!itrie)
+    return FALSE;
+  return YAP_Unify(arg_itrie, YAP_MkIntTerm((YAP_Int) itrie));
+}
+#undef arg_itrie
+#undef arg_stream