C++ compilation.

[idzebra-moved-to-github.git] / isam / memory.c

diff --git a/isam/memory.c b/isam/memory.c
index d7a327c..d6e3a62 100644 (file)
--- 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 1.10  1995-12-12 14:12:47  quinn
+ * Revision 1.17  1999-05-26 07:49:14  adam
+ * C++ compilation.
+ *
+ * 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
@@ -43,8 +65,10 @@
 
 #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 };
@@ -61,7 +85,8 @@ is_mblock *xmalloc_mblock()
 
     if (!mblock_freelist)
     {
-       mblock_freelist = xmalloc(sizeof(is_mblock) * MALLOC_CHUNK);
+       mblock_freelist = (is_mblock *)
+           xmalloc(sizeof(is_mblock) * MALLOC_CHUNK);
        for (i = 0; i < MALLOC_CHUNK - 1; i++)
            mblock_freelist[i].next = &mblock_freelist[i+1];
        mblock_freelist[i].next = 0;
@@ -85,7 +110,7 @@ is_mbuf *xmalloc_mbuf(int type)
     }
     else
     {
-       tmp = xmalloc(sizeof(is_mbuf) + is_mbuf_size[type]);
+       tmp = (is_mbuf*) xmalloc(sizeof(is_mbuf) + is_mbuf_size[type]);
        tmp->type = type;
     }
     tmp->refcount = type ? 1 : 0;
@@ -151,6 +176,7 @@ 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 */
     {
@@ -163,6 +189,7 @@ 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;
 }
@@ -225,7 +252,7 @@ void is_m_replace_record(is_mtable *tab, const void *rec)
  */
 void is_m_delete_record(is_mtable *tab)
 {
-    is_mbuf *mbuf, *new;
+    is_mbuf *mbuf, *inew;
 
     mbuf = tab->cur_mblock->cur_mbuf;
     if (mbuf->cur_record >= mbuf->num)  /* top of mbuf */
@@ -233,18 +260,28 @@ 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 */
     {
-       new = xmalloc_mbuf(IS_MBUF_TYPE_SMALL);
-       new->next = mbuf->next;
-       mbuf->next = new;
-       new->data = mbuf->data;
+       mbuf->num--;
+       mbuf->offset +=is_keysize(tab->is);
+       mbuf->cur_record = 0;
+    }
+    else /* middle of mbuf */
+    {
+       /* insert block after current one */
+       inew = xmalloc_mbuf(IS_MBUF_TYPE_SMALL);
+       inew->next = mbuf->next;
+       mbuf->next = inew;
+
+       /* virtually transfer everything after current record to new one. */
+       inew->data = mbuf->data;
        mbuf->refcount++;
-       new->offset = mbuf->offset + mbuf->cur_record * is_keysize(tab->is);
-       new->num = mbuf->num - mbuf->cur_record;
+       inew->offset = mbuf->offset + mbuf->cur_record * is_keysize(tab->is);
+       inew->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 = inew;
     }
     tab->num_records--;
     tab->cur_mblock->num_records--;
@@ -288,7 +325,9 @@ 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++;
@@ -302,7 +341,10 @@ 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--;
 }
 
 /*
@@ -370,14 +412,20 @@ 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++;