Back again

diff --git a/isam/memory.h b/isam/memory.h
new file mode 100644 (file)
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+++ b/isam/memory.h
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+/*
+ * Copyright (C) 1994, Index Data I/S 
+ * All rights reserved.
+ * Sebastian Hammer, Adam Dickmeiss
+ *
+ * $Log: memory.h,v $
+ * Revision 1.1  1994-09-26 17:12:32  quinn
+ * Back again
+ *
+ * Revision 1.1  1994/09/26  16:07:57  quinn
+ * Most of the functionality in place.
+ *
+ */
+
+#ifndef MEMORY_H
+#define MEMORY_H
+
+#include <isam.h>
+
+extern int is_mbuf_size[3];
+
+/*
+ * Memory buffer. Used to manage records (keys) in memory for
+ * reading and insertion/deletion.
+ */
+typedef struct is_mbuf
+{
+    int refcount;
+    int type;
+#define IS_MBUF_TYPE_SMALL  0
+#define IS_MBUF_TYPE_MEDIUM 1
+#define IS_MBUF_TYPE_LARGE  2 
+    int offset;
+    int num;
+    int cur_record;
+    struct is_mbuf *next;
+    char *data;                 /* dummy */
+} is_mbuf;
+
+/*
+ * Structure describing the virtual image of a disk block.
+ * (these blocks may grow beyond the blocksize during insertion).
+ */
+typedef struct is_mblock
+{
+    int num_records;              /* number of records */
+    int diskpos;                  /* positive if this block is mapped */
+    int nextpos;                  /* pos of nxt blk. Only valid imm aft. rd. */
+    int bread;                    /* number of bytes read */
+    int state;                    /* state of block in rel. to disk block */
+#define IS_MBSTATE_UNREAD  0          /* block hasn't been read */
+#define IS_MBSTATE_PARTIAL 1          /* block has been partially read */
+#define IS_MBSTATE_CLEAN   2          /* block is clean (unmodified) */
+#define IS_MBSTATE_DIRTY   3          /* block has been modified */
+    is_mbuf *cur_mbuf;
+    is_mbuf *data;                /* data contained in block */
+
+    struct is_mblock *next;       /* next diskblock */
+} is_mblock;
+
+/*
+ * Descriptor for a specific table.
+ */
+typedef struct is_mtable
+{
+    int num_records;               /* total number of records */
+    int pos_type;                  /* blocktype */
+    is_mblock *cur_mblock;
+    is_mblock *data;               /* blocks contained in this table */
+    ISAM is;
+} is_mtable;
+
+is_mblock *xmalloc_mblock();
+is_mbuf *xmalloc_mbuf(int type);
+void xfree_mblock(is_mblock *p);
+void xfree_mbuf(is_mblock *p);
+void is_m_establish_tab(ISAM is, is_mtable *tab, ISAM_P pos);
+void is_m_rewind(is_mtable *tab);
+void is_m_replace_record(is_mtable *tab, const void *rec);
+int is_m_write_record(is_mtable *tab, const void *rec);
+void is_m_unread_record(is_mtable *tab);
+int is_m_read_record(is_mtable *tab, void *buf);
+int is_m_seek_record(is_mtable *tab, const void *rec);
+void is_m_delete_record(is_mtable *tab);
+int is_m_peek_record(is_mtable *tab, void *rec);
+int is_m_read_full(is_mtable *tab, is_mblock *mblock);
+
+#endif