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| Source at commit 1322 created 12 years 8 months ago. By meklort, Add doxygen to utils folder | |
|---|---|
| 1 | /******************************************************************************␊ |
| 2 | *␊ |
| 3 | * $Id: $␊ |
| 4 | *␊ |
| 5 | * Copyright (C) 1997-2011 by Dimitri van Heesch.␊ |
| 6 | *␊ |
| 7 | * Permission to use, copy, modify, and distribute this software and its␊ |
| 8 | * documentation under the terms of the GNU General Public License is hereby ␊ |
| 9 | * granted. No representations are made about the suitability of this software ␊ |
| 10 | * for any purpose. It is provided "as is" without express or implied warranty.␊ |
| 11 | * See the GNU General Public License for more details.␊ |
| 12 | *␊ |
| 13 | * Documents produced by Doxygen are derivative works derived from the␊ |
| 14 | * input used in their production; they are not affected by this license.␊ |
| 15 | *␊ |
| 16 | */␊ |
| 17 | ␊ |
| 18 | #ifndef STORE_H␊ |
| 19 | #define STORE_H␊ |
| 20 | ␊ |
| 21 | #include <qglobal.h>␊ |
| 22 | #include <stdio.h>␊ |
| 23 | ␊ |
| 24 | #include "portable.h"␊ |
| 25 | ␊ |
| 26 | /*! @brief Abstract interface for file based memory storage operations */␊ |
| 27 | class StorageIntf␊ |
| 28 | {␊ |
| 29 | public:␊ |
| 30 | /*! Required by gcc */␊ |
| 31 | virtual ~StorageIntf() {}␊ |
| 32 | /*! Read \a size bytes from the store into \a buf. */␊ |
| 33 | virtual int read(char *buf,uint size) = 0;␊ |
| 34 | /*! Write \a size bytes from \a buf into the store. */␊ |
| 35 | virtual int write(const char *buf,uint size) = 0;␊ |
| 36 | };␊ |
| 37 | ␊ |
| 38 | /*! @brief The Store is a file based memory manager.␊ |
| 39 | *␊ |
| 40 | * You can open the store using open(). Then obtain a handle via alloc()␊ |
| 41 | * followed by a sequence of write() commands to store information,␊ |
| 42 | * and finalize it using end(). ␊ |
| 43 | * ␊ |
| 44 | * Later on you locate the information␊ |
| 45 | * with seek() using the handle obtained with alloc(), and then use a␊ |
| 46 | * sequence of read() calls to read the information back. ␊ |
| 47 | *␊ |
| 48 | * If no longer needed the storage space can be freed using release().␊ |
| 49 | * ␊ |
| 50 | * The store will dynamically grow the file on disk if needed.␊ |
| 51 | */␊ |
| 52 | class Store : public StorageIntf␊ |
| 53 | {␊ |
| 54 | public:␊ |
| 55 | /*! Creates a store. */␊ |
| 56 | Store();␊ |
| 57 | ␊ |
| 58 | /*! Releases the store object. Will close the underlying file if opened. */␊ |
| 59 | ~Store();␊ |
| 60 | ␊ |
| 61 | /*! Opens the file underlying the store using \a name as the file name. ␊ |
| 62 | * Returns 0 upon success, or -1 otherwise.␊ |
| 63 | */␊ |
| 64 | int open(const char *name);␊ |
| 65 | ␊ |
| 66 | /*! Allocates a handle to write to and read from. */␊ |
| 67 | portable_off_t alloc();␊ |
| 68 | ␊ |
| 69 | /*! Writes \a size bytes in array \a buf to the store. ␊ |
| 70 | * First alloc() has to be called.␊ |
| 71 | * \note The information can only be read after end() has been called.␊ |
| 72 | */␊ |
| 73 | int write(const char *buf,uint size);␊ |
| 74 | ␊ |
| 75 | /*! Ends the sequence of writes. ␊ |
| 76 | * \note After this call, first alloc() has to be called␊ |
| 77 | * before new writes can be done.␊ |
| 78 | */␊ |
| 79 | void end();␊ |
| 80 | ␊ |
| 81 | /*! Releases the memory corresponding to the handle returned with alloc() */␊ |
| 82 | void release(portable_off_t handle);␊ |
| 83 | ␊ |
| 84 | /*! Closes the store */␊ |
| 85 | void close();␊ |
| 86 | ␊ |
| 87 | /*! Goes to the start of information corresponding to handle \a pos */␊ |
| 88 | void seek(portable_off_t handle);␊ |
| 89 | ␊ |
| 90 | /*! Reads \a size bytes from the store into the array pointed to be \a buf.␊ |
| 91 | * \note Before reading seek() has to be called to set the right start of the store.␊ |
| 92 | */␊ |
| 93 | int read(char *buf,uint size);␊ |
| 94 | ␊ |
| 95 | void printStats();␊ |
| 96 | ␊ |
| 97 | private:␊ |
| 98 | enum State␊ |
| 99 | {␊ |
| 100 | Init,␊ |
| 101 | Reading,␊ |
| 102 | Writing␊ |
| 103 | };␊ |
| 104 | struct Node␊ |
| 105 | {␊ |
| 106 | portable_off_t pos;␊ |
| 107 | struct Node *next;␊ |
| 108 | };␊ |
| 109 | void printFreeList();␊ |
| 110 | FILE *m_file;␊ |
| 111 | portable_off_t m_front;␊ |
| 112 | Node *m_head;␊ |
| 113 | State m_state;␊ |
| 114 | int m_reads;␊ |
| 115 | int m_writes;␊ |
| 116 | };␊ |
| 117 | ␊ |
| 118 | #endif␊ |
| 119 | |
