X-Git-Url: http://git.indexdata.com/?a=blobdiff_plain;f=isam%2Fmemory.c;h=8079f22e46d1c45b3fcf4faabffe0771137c8ab4;hb=8ddf739043beb068cac9287afa88ea92bf4d3ed6;hp=afb788775211a8948906f62cd72d5a9d119dedda;hpb=06cef3aac0230e856f36e61533e2a4e60f299a02;p=idzebra-moved-to-github.git

diff --git a/isam/memory.c b/isam/memory.c
index afb7887..8079f22 100644
--- a/isam/memory.c
+++ b/isam/memory.c
@@ -1,10 +1,32 @@
 /*
- * Copyright (C) 1994, Index Data I/S 
+ * Copyright (C) 1994-1999, Index Data
  * All rights reserved.
  * Sebastian Hammer, Adam Dickmeiss
  *
  * $Log: memory.c,v $
- * Revision 1.9  1995-12-06 15:48:46  quinn
+ * Revision 1.16  1999-02-02 14:51:20  adam
+ * Updated WIN32 code specific sections. Changed header.
+ *
+ * Revision 1.15  1997/09/09 13:38:11  adam
+ * Partial port to WIN95/NT.
+ *
+ * Revision 1.14  1996/10/29 13:56:56  adam
+ * Include of zebrautl.h instead of alexutil.h.
+ *
+ * Revision 1.13  1996/03/20 13:29:16  quinn
+ * Bug-fix
+ *
+ * Revision 1.12  1996/03/11  14:52:23  quinn
+ * Fixed update bug. Repeated insertion in the same area sometimes caused
+ * problems.
+ *
+ * Revision 1.11  1996/02/10  12:20:58  quinn
+ * *** empty log message ***
+ *
+ * Revision 1.10  1995/12/12  14:12:47  quinn
+ * *** empty log message ***
+ *
+ * Revision 1.9  1995/12/06  15:48:46  quinn
  * Fixed update-problem.
  *
  * Revision 1.8  1995/12/06  14:48:27  quinn
@@ -40,8 +62,10 @@
 
 #include <assert.h>
 #include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
 
-#include <alexutil.h>
+#include <zebrautl.h>
 #include <isam.h>
 
 int is_mbuf_size[3] = { 0, 1024, 4096 };
@@ -148,6 +172,7 @@ void is_m_establish_tab(ISAM is, is_mtable *tab, ISAM_P pos)
 	tab->data->data = 0;
 	tab->cur_mblock = tab->data;
 	tab->cur_mblock->cur_mbuf = 0;
+	tab->last_mbuf = 0;
     }
     else /* new block */
     {
@@ -160,6 +185,7 @@ void is_m_establish_tab(ISAM is, is_mtable *tab, ISAM_P pos)
 	tab->cur_mblock = tab->data;
 	tab->cur_mblock->cur_mbuf = tab->data->data;
 	tab->cur_mblock->cur_mbuf->cur_record = 0;
+	tab->last_mbuf = 0;
     }
     tab->is = is;
 }
@@ -230,18 +256,28 @@ void is_m_delete_record(is_mtable *tab)
     	mbuf->num--;
     	mbuf->cur_record--;
     }
-    else /* middle of a block */
+    else if (mbuf->cur_record == 1) /* beginning of mbuf */
     {
+	mbuf->num--;
+	mbuf->offset +=is_keysize(tab->is);
+	mbuf->cur_record = 0;
+    }
+    else /* middle of mbuf */
+    {
+	/* insert block after current one */
 	new = xmalloc_mbuf(IS_MBUF_TYPE_SMALL);
 	new->next = mbuf->next;
 	mbuf->next = new;
+
+	/* virtually transfer everything after current record to new one. */
 	new->data = mbuf->data;
 	mbuf->refcount++;
 	new->offset = mbuf->offset + mbuf->cur_record * is_keysize(tab->is);
 	new->num = mbuf->num - mbuf->cur_record;
+	
+	/* old buf now only contains stuff before current record */
 	mbuf->num = mbuf->cur_record -1;
-	mbuf = mbuf->next;
-	mbuf->cur_record = 0;
+	tab->cur_mblock->cur_mbuf = new;
     }
     tab->num_records--;
     tab->cur_mblock->num_records--;
@@ -285,7 +321,9 @@ int is_m_write_record(is_mtable *tab, const void *rec)
 	mbuf = tab->cur_mblock->cur_mbuf = mbuf->next;
 	mbuf->cur_record = 0;
     }
+    /*
     logf (LOG_DEBUG, "is_m_write_rec(rec == %d)", mbuf->cur_record);
+    */
     memcpy(mbuf->data + mbuf->offset + mbuf->cur_record * is_keysize(tab->is),
 	rec, is_keysize(tab->is));
     mbuf->num++;
@@ -299,7 +337,10 @@ int is_m_write_record(is_mtable *tab, const void *rec)
 void is_m_unread_record(is_mtable *tab)
 {
     assert(tab->cur_mblock->cur_mbuf->cur_record);
-    tab->cur_mblock->cur_mbuf->cur_record--;
+    if (tab->last_mbuf)
+	tab->cur_mblock->cur_mbuf = tab->last_mbuf;
+    else
+	tab->cur_mblock->cur_mbuf->cur_record--;
 }
 
 /*
@@ -367,14 +408,20 @@ int is_m_read_record(is_mtable *tab, void *buf, int keep)
 		    if (read_current_full(tab, tab->cur_mblock) < 0)
 			return -1;
 		tab->cur_mblock->cur_mbuf = mbuf = tab->cur_mblock->data;
+		tab->last_mbuf = 0;
 	    }
 	    else
 	    	return 0;   /* EOTable */
 	}
 	else
+	{
+	    tab->last_mbuf = mbuf;
 	    tab->cur_mblock->cur_mbuf = mbuf = mbuf->next;
+	}
 	mbuf->cur_record = 0;
     }
+    else
+	tab->last_mbuf = 0;
     memcpy(buf, mbuf->data + mbuf->offset + mbuf->cur_record *
 	is_keysize(tab->is), is_keysize(tab->is));
     mbuf->cur_record++;
@@ -396,7 +443,7 @@ int is_m_seek_record(is_mtable *tab, const void *rec)
 	if ((rs = (*tab->is->cmp)(peek, rec)) > 0)
 	{
 	    is_m_unread_record(tab);
-	    return 1;
+	    return rs;
 	}
 	else if (rs == 0)
 	    return 0;