arlad/blocks.h

   1 /*
   2  * Copyright (c) 2005-2006, Stockholms Universitet
   3  * (Stockholm University, Stockholm Sweden)
   4  * All rights reserved.
   5  *
   6  * Redistribution and use in source and binary forms, with or without
   7  * modification, are permitted provided that the following conditions
   8  * are met:
   9  *
  10  * 1. Redistributions of source code must retain the above copyright
  11  *    notice, this list of conditions and the following disclaimer.
  12  *
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  *
  17  * 3. Neither the name of the university nor the names of its contributors
  18  *    may be used to endorse or promote products derived from this software
  19  *    without specific prior written permission.
  20  *
  21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
  22  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
  25  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
  26  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
  27  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
  28  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
  29  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
  30  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
  31  * POSSIBILITY OF SUCH DAMAGE.
  32  */
  33
  34 /* $Id$ */
  35
  36 #ifndef _BLOCKS_H_
  37 #define _BLOCKS_H_
  38
  39 #include <nnpfs/nnpfs_blocks.h>
  40 #include <fcache.h>
  41
  42 struct block {
  43     uint64_t offset;
  44     struct FCacheEntry *node;
  45
  46     Listitem *lru_le;        /* block lru */
  47     Listitem *block_le;      /* node's block list, make it a tree?  */
  48
  49     struct {
  50         unsigned kernelp : 1;
  51         unsigned busy : 1;
  52     } flags;
  53 };
  54
  55 typedef enum {
  56     BLOCK_NONE   = 0x0,
  57     BLOCK_GOT    = 0x01,
  58     BLOCK_BUSY   = 0x02
  59 } BlockState;
  60
  61 typedef void (*block_callback_t)(struct block *block, void *data);
  62
  63 /*
  64  * get block offset of data offset 'off'
  65  */
  66
  67 static inline uint64_t
  68 block_offset(uint64_t off) {
  69     return off - (off & (fcache_getblocksize() - 1));
  70 }
  71
  72 /*
  73  * get next block offset after data offset 'off'
  74  *
  75  * This actually gives the same block if it is aligned on a block
  76  * boundary.  Current users depend on that.
  77  */
  78
  79 static inline uint64_t
  80 block_next_offset(uint64_t off) {
  81     return block_offset(off + fcache_getblocksize() - 1);
  82 }
  83
  84 /*
  85  * get last block offset for file length 'len'
  86  * Result may not be what is expected for zero.
  87  */
  88
  89 static inline uint64_t
  90 block_end_offset(uint64_t len) {
  91     return len ? block_offset(len - 1) : len;
  92 }
  93
  94 struct block *
  95 block_get(FCacheEntry *node, uint64_t offset);
  96
  97 struct block *
  98 block_add(FCacheEntry *node, uint64_t offset);
  99
 100 void
 101 block_foreach(FCacheEntry *node,
 102               block_callback_t fun,
 103               void *data);
 104
 105 void
 106 block_free(struct block *block);
 107
 108 BlockState
 109 block_any(FCacheEntry *node);
 110
 111 Bool
 112 block_emptyp(FCacheEntry *node);
 113
 114 #endif /* _BLOCKS_H_ */