Formerly store.h.~2~

1 files changed, 69 insertions, 5 deletions

diff --git a/libstore/store.h b/libstore/store.h
index ce9589d8..5be29b22 100644
--- a/libstore/store.h
+++ b/libstore/store.h
@@ -29,27 +29,91 @@ struct store
      our store.  */
   file_t source;
 
+  /* The type of storage this is (see STORAGE_ in hurd/hurd_types.h).  */
   enum file_storage_class class;
 
+  /* Address ranges in the underlying storage which make up our contiguous
+     address space.  In units of BLOCK_SIZE, below.  */
   off_t *runs;
-  unsigned num_runs;
+  unsigned runs_len;
 
+  /* Handles for the underlying storage.  */
   char *name;
   mach_port_t port;
 
+  /* The size of a `block' on this storage.  */
+  size_t block_size;
+
+  /* The number of blocks in this storage.  */
+  size_t blocks;
+  size_t size;			/* Just BLOCKS * BLOCK_SIZE */
+
+  /* Log_2 (BLOCK_SIZE) or 0 if not a power of 2. */
+  int log2_block_size;
+  /* Log_2 (VM_PAGE_SIZE / BLOCK_SIZE); only valid if LOG2_BLOCK_SIZE is.  */
+  int log2_blocks_per_page;
+
   void *misc;
 
   struct store_meths *meths;
 };
 
+typedef error_t (*store_write_meth_t)(struct store *store,
+				      off_t addr, char *buf, size_t len,
+				      size_t *amount);
+typedef error_t (*store_read_meth_t)(struct store *store,
+				     off_t addr, size_t amount,
+				     char **buf, size_t *len);
+
 struct store_meths
 {
-  error_t (*read)(struct store *store,
-		  off_t addr, size_t amount, char **buf, size_t *len);
-  error_t (*write)(struct store *store,
-		   off_t addr, char *buf, size_t len, size_t *amount);
+  /* Read up to AMOUNT bytes at the underlying address ADDR from the storage
+     into BUF and LEN.  */
+  store_read_meth_t read;
+  /* Write up to LEN bytes from BUF to the storage at the underlying address
+     ADDR.  */
+  store_write_meth_t write;
 };
 
+/* Return a new store in STORE, which refers to the storage underlying
+   SOURCE.  A reference to SOURCE is created (but may be destroyed with
+   store_close_source).  */
 error_t store_create (file_t source, struct store **store);
 
+/* Return a new store in STORE referring to the mach device DEVICE.  */
+error_t store_device_create (device_t device, struct store **store);
+
+/* Return a new store in STORE referring to the file FILE.  Unlike
+   store_create, this will always use file i/o.  */
+error_t store_file_create (file_t file, struct store **store);
+
+error_t store_destroy (struct store *store);
+
+/* If STORE was created using store_create, remove the reference to the
+   source from which it was created.  */
+error_t store_close_source (struct store *store);
+
+error_t store_write (struct store *store,
+		     off_t addr, char *buf, size_t len, size_t *amount);
+error_t store_read (struct store *store,
+		    off_t addr, size_t amount, char **buf, size_t *len);
+
+/* Return a memory object paging on STORE.  [among other reasons,] this may
+   fail because store contains non-contiguous regions on the underlying
+   object.  In such a case you can try calling some of the routines below to
+   get a pager.  */
+error_t store_map (struct store *store, vm_prot_t prot, ...,
+		   mach_port_t *pager);
+
+/* Returns a memory object paging on the file from which STORE was created.
+   If STORE wasn't created using store_create, or the source was destroyed
+   using store_close_source, this will fail.  */
+error_t store_map_source (struct store *store, vm_prot_t prot, ...,
+			  mach_port_t *pager)
+
+/* Create a new pager and paging threads paging on STORE, and return the
+   resulting memory object in PAGER.  */
+error_t store_create_pager (struct store *store, vm_prot_t prot, ...,
+			    mach_port_t *pager)
+
 #endif /* __STORE_H__ */