ExtentManager.h

   1 /*
   2  * Copyright (c) 2008 Computer, Inc. All rights reserved.
   3  *
   4  * @APPLE_LICENSE_HEADER_START@
   5  *
   6  * This file contains Original Code and/or Modifications of Original Code
   7  * as defined in and that are subject to the Apple Public Source License
   8  * Version 2.0 (the 'License'). You may not use this file except in
   9  * compliance with the License. Please obtain a copy of the License at
  10  * http://www.opensource.apple.com/apsl/ and read it before using this
  11  * file.
  12  *
  13  * The Original Code and all software distributed under the License are
  14  * distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
  15  * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
  16  * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
  18  * Please see the License for the specific language governing rights and
  19  * limitations under the License.
  20  *
  21  * @APPLE_LICENSE_HEADER_END@
  22  */
  23 //
  24 //      ExtentManager.h
  25 //
  26 #ifndef EXTENTMANAGER_H
  27 #define EXTENTMANAGER_H
  28
  29 #include <list>
  30 #include <vector>
  31 #include <algorithm>
  32 #include <sys/types.h>
  33 #include <sys/errno.h>
  34 #include <cstdio>
  35 #include <cassert>
  36 using namespace std;
  37
  38 struct ExtentInfo {
  39         off_t blockAddr;
  40         off_t numBlocks;
  41 };
  42
  43 inline bool BeforeExtent(const ExtentInfo &a, const ExtentInfo &b)
  44 {
  45                 return (a.blockAddr + a.numBlocks) < b.blockAddr;
  46 }
  47
  48 typedef list<ExtentInfo>::iterator ListExtIt;
  49
  50 class ExtentManager {
  51 public:
  52         ExtentManager() : blockSize(0), totalBytes(0), totalBlocks(0) {};
  53         ~ExtentManager() {};
  54
  55         void Init(uint32_t theBlockSize, uint32_t theNativeBlockSize, off_t theTotalBytes);
  56
  57         void AddBlockRangeExtent(off_t blockAddr, off_t numBlocks);
  58         void AddByteRangeExtent(off_t byteAddr, off_t numBytes);
  59         void RemoveBlockRangeExtent(off_t blockAddr, off_t numBlocks);
  60
  61         void DebugPrint();
  62
  63 protected:
  64         void MergeExtent(const ExtentInfo &a, const ExtentInfo &b, ExtentInfo *c);
  65
  66 public:
  67         size_t blockSize;
  68         size_t nativeBlockSize;
  69         off_t totalBytes;
  70         off_t totalBlocks;
  71         list<ExtentInfo> extentList;
  72 };
  73
  74 #endif // #ifndef EXTENTMANAGER_H