Formerly stripe.c.~2~

1 files changed, 136 insertions, 51 deletions

diff --git a/libstore/stripe.c b/libstore/stripe.c
index 6058e9d8..485bfd6f 100644
--- a/libstore/stripe.c
+++ b/libstore/stripe.c
@@ -20,74 +20,159 @@
    along with this program; if not, write to the Free Software
    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
 
+#include <stdlib.h>
+
 #include "store.h"
-
-static error_t
-ileave_read (struct store *store,
-	   off_t addr, size_t index, mach_msg_type_number_t amount,
-	   char **buf, mach_msg_type_number_t *len)
-{
-  return io_read (store->port, buf, len, addr * store->block_size, amount);
-}
 
-static error_t
-file_write (struct store *store,
-	   off_t addr, size_t index, char *buf, mach_msg_type_number_t len,
-	   mach_msg_type_number_t *amount)
+struct stripe_info
 {
-  return io_write (store->port, buf, len, addr * store->block_size, amount);
-}
-
-static struct store_meths
-file_meths = {file_read, file_write};
-
+  struct store **stripes;
+  int dealloc : 1;
+};
+
 static error_t
-file_byte_read (struct store *store, off_t addr, mach_msg_type_number_t amount,
-		char **buf, mach_msg_type_number_t *len)
+stripe_read (struct store *store,
+	     off_t addr, size_t index, mach_msg_type_number_t amount,
+	     char **buf, mach_msg_type_number_t *len)
 {
-  return io_read (store->port, buf, len, addr, amount);
+  struct stripe_info *info = store->hook;
+  return store_read (info->stripes[index], addr, amount, buf, len);
 }
 
 static error_t
-file_byte_write (struct store *store,
-		 off_t addr, char *buf, mach_msg_type_number_t len,
-	   mach_msg_type_number_t *amount)
+stripe_write (struct store *store,
+	      off_t addr, size_t index, char *buf, mach_msg_type_number_t len,
+	      mach_msg_type_number_t *amount)
 {
-  return io_write (store->port, buf, len, addr, amount);
+  struct store **stripes = store->hook;
+  return store_write (stripes[index], addr, buf, len, amount);
 }
 
 static struct store_meths
-file_byte_meths = {file_byte_read, file_byte_write};
+stripe_meths = {stripe_read, stripe_write};
 
-/* Return a new store in STORE referring to the mach file FILE.  Consumes
-   the send right FILE.  */
+/* Return a new store in STORE that interleaves all the stores in STRIPES
+   (NUM_STRIPES of them) every INTERLEAVE blocks (every store in STRIPES must
+   have the same block size).  If DEALLOC is true, then the striped stores
+   are freed when this store is (in any case, the array STRIPES is copied,
+   and so should be freed by the caller).  */
 error_t
-store_file_create (file_t file, struct store **store)
+store_ileave_create (struct store **stripes, size_t num_stripes, int dealloc,
+		     off_t interleave, struct store **store)
 {
-  off_t runs[2];
-  struct stat stat;
-  error_t err = io_stat (file, &stat);
-
-  if (err)
-    return err;
-
-  runs[0] = 0;
-  runs[1] = stat.st_size;
-
-  return _store_file_create (file, 1, runs, 2, store);
+  size_t i;
+  error_t err = EINVAL;		/* default error */
+  off_t block_size = 0, min_end = 0;
+  off_t runs[num_stripes * 2];
+  struct stripe_info *info = malloc (sizeof (struct stripe_info));
+
+  if (info == 0)
+    return ENOMEM;
+
+  info->stripes = malloc (sizeof (struct store *) * num_stripes);
+  info->dealloc = dealloc;
+
+  if (info->stripes == 0)
+    {
+      free (info);
+      return ENOMEM;
+    }
+
+  if (interleave == 0)
+    goto barf;
+
+  for (i = 0; i < num_stripes; i++)
+    {
+      runs[i * 2] = 0;
+      runs[i * 2 + 1] = interleave;
+      if (block_size == 0)
+	{
+	  block_size = stripes[i]->block_size;
+	  min_end = stripes[i]->end;
+	}
+      else
+	{
+	  if (block_size != stripes[i]->block_size)
+	    /* Mismatched block sizes; barf.  */
+	    goto barf;
+	  if (min_end > stripes[i]->end)
+	    /* Only use as much space as the smallest stripe has.  */
+	    min_end = stripes[i]->end;
+	}
+    }
+
+  *store = _make_store (0, &stripe_meths, MACH_PORT_NULL, block_size,
+			runs, num_stripes * 2, min_end);
+  if (! *store)
+    {
+      err = ENOMEM;
+      goto barf;
+    }
+
+  (*store)->hook = info;
+  bcopy (stripes, info->stripes, num_stripes * sizeof *stripes);
+
+  return 0;
+
+ barf:
+  free (info->stripes);
+  free (info);
+  return err;
 }
 
-/* Like store_file_create, but doesn't query the file for information.  */
+/* Return a new store in STORE that concatenates all the stores in STORES
+   (NUM_STORES of them) every store in STRIPES must have the same block size.
+   If DEALLOC is true, then the sub-stores are freed when this store is (in
+   any case, the array STORES is copied, and so should be freed by the
+   caller).  */
 error_t
-_store_file_create (file_t file, size_t block_size,
-		    off_t *runs, unsigned runs_len,
-		    struct store **store)
+store_concat_create (struct store **stores, size_t num_stores, int dealloc,
+		     struct store **store)
 {
-  if (block_size == 1)
-    *store = _make_store (STORAGE_HURD_FILE, &file_byte_meths, file, 1,
-			  runs, runs_len);
-  else
-    *store = _make_store (STORAGE_HURD_FILE, &file_meths, file, block_size,
-			  runs, runs_len);
-  return *store ? 0 : ENOMEM;
+  size_t i;
+  error_t err = EINVAL;		/* default error */
+  off_t block_size = 0;
+  off_t runs[num_stores * 2];
+  struct stripe_info *info = malloc (sizeof (struct stripe_info));
+
+  if (info == 0)
+    return ENOMEM;
+
+  info->stripes = malloc (sizeof (struct store *) * num_stores);
+  info->dealloc = dealloc;
+
+  if (info->stripes == 0)
+    {
+      free (info);
+      return ENOMEM;
+    }
+
+  for (i = 0; i < num_stores; i++)
+    {
+      runs[i * 2] = 0;
+      runs[i * 2 + 1] = stores[i]->end;
+      if (block_size == 0)
+	block_size = stores[i]->block_size;
+      else if (block_size != stores[i]->block_size)
+	/* Mismatched block sizes; barf.  */
+	goto barf;
+    }
+
+  *store = _make_store (0, &stripe_meths, MACH_PORT_NULL, block_size,
+			runs, num_stores * 2, 0);
+  if (! *store)
+    {
+      err = ENOMEM;
+      goto barf;
+    }
+
+  (*store)->hook = info;
+  bcopy (stores, info->stripes, num_stores * sizeof *stores);
+
+  return 0;
+
+ barf:
+  free (info->stripes);
+  free (info);
+  return err;
 }