** Merged from IBEX_DISK branch to head.

2000-09-19  Not Zed  <NotZed@HelixCode.com>

	** Merged from IBEX_DISK branch to head.

svn path=/trunk/; revision=5500

1 files changed, 102 insertions, 0 deletions

diff --git a/libibex/block.h b/libibex/block.h
new file mode 100644
index 0000000000..40262de6e2
--- /dev/null
+++ b/libibex/block.h
@@ -0,0 +1,102 @@
+
+/* public interfaces for block io routines */
+
+#ifndef _BLOCK_H
+#define _BLOCK_H
+
+/*#define IBEX_STATS*/		/* define to get/dump block access stats */
+
+#include <glib.h>
+
+typedef guint32 nameid_t;
+typedef guint32 blockid_t;
+
+#define BLOCK_BITS (8)
+#define BLOCK_SIZE (1<<BLOCK_BITS)
+#define CACHE_SIZE 256		/* blocks in disk cache */
+
+/* root block */
+struct _root {
+	char version[4];
+
+	blockid_t free;		/* list of free blocks */
+	blockid_t roof;		/* top of allocated space, everything below is in a free or used list */
+	blockid_t tail;		/* list of 'tail' blocks */
+
+	blockid_t words;	/* root of words index */
+	blockid_t names;	/* root of names index */
+};
+
+/* basic disk structure for (data) blocks */
+struct _block {
+	unsigned int next:32-BLOCK_BITS;	/* next block */
+	unsigned int used:BLOCK_BITS;		/* number of elements used */
+
+	nameid_t bl_data[(BLOCK_SIZE-4)/4];	/* references */
+};
+
+/* custom list structure, for a simple/efficient cache */
+struct _listnode {
+	struct _listnode *next;
+	struct _listnode *prev;
+};
+struct _list {
+	struct _listnode *head;
+	struct _listnode *tail;
+	struct _listnode *tailpred;
+};
+
+void ibex_list_new(struct _list *v);
+struct _listnode *ibex_list_addhead(struct _list *l, struct _listnode *n);
+struct _listnode *ibex_list_addtail(struct _list *l, struct _listnode *n);
+struct _listnode *ibex_list_remove(struct _listnode *n);
+
+/* in-memory structure for block cache */
+struct _memblock {
+	struct _memblock *next;
+	struct _memblock *prev;
+
+	blockid_t block;
+	int flags;
+
+	struct _block data;
+};
+#define BLOCK_DIRTY (1<<0)
+
+struct _memcache {
+	struct _list nodes;
+	int count;		/* nodes in cache */
+
+	GHashTable *index;	/* blockid->memblock mapping */
+	int fd;			/* file fd */
+
+#ifdef IBEX_STATS
+	GHashTable *stats;
+#endif
+	/* temporary here */
+	struct _IBEXWord *words; /* word index */
+};
+
+#ifdef IBEX_STATS
+struct _stat_info {
+	int read;
+	int write;
+	int cache_hit;
+	int cache_miss;
+};
+#endif /* IBEX_STATS */
+
+struct _memcache *ibex_block_cache_open(const char *name, int flags, int mode);
+void ibex_block_cache_close(struct _memcache *block_cache);
+void ibex_block_cache_sync(struct _memcache *block_cache);
+void ibex_block_cache_flush(struct _memcache *block_cache);
+
+blockid_t ibex_block_get(struct _memcache *block_cache);
+void ibex_block_free(struct _memcache *block_cache, blockid_t blockid);
+void ibex_block_dirty(struct _block *block);
+struct _block *ibex_block_read(struct _memcache *block_cache, blockid_t blockid);
+
+#define block_number(x) ((x)>>BLOCK_BITS)
+#define block_location(x) ((x)<<BLOCK_BITS)
+
+#endif /* ! _BLOCK_H */