modernc.org/cc@v1.0.1/v2/testdata/_sqlite/src/test_multiplex.h (about)

     1  /*
     2  ** 2011 March 18
     3  **
     4  ** The author disclaims copyright to this source code.  In place of
     5  ** a legal notice, here is a blessing:
     6  **
     7  **    May you do good and not evil.
     8  **    May you find forgiveness for yourself and forgive others.
     9  **    May you share freely, never taking more than you give.
    10  **
    11  *************************************************************************
    12  **
    13  ** This file contains a VFS "shim" - a layer that sits in between the
    14  ** pager and the real VFS.
    15  **
    16  ** This particular shim enforces a multiplex system on DB files.  
    17  ** This shim shards/partitions a single DB file into smaller 
    18  ** "chunks" such that the total DB file size may exceed the maximum
    19  ** file size of the underlying file system.
    20  **
    21  */
    22  
    23  #ifndef SQLITE_TEST_MULTIPLEX_H
    24  #define SQLITE_TEST_MULTIPLEX_H
    25  
    26  /*
    27  ** CAPI: File-control Operations Supported by Multiplex VFS
    28  **
    29  ** Values interpreted by the xFileControl method of a Multiplex VFS db file-handle.
    30  **
    31  ** MULTIPLEX_CTRL_ENABLE:
    32  **   This file control is used to enable or disable the multiplex
    33  **   shim.
    34  **
    35  ** MULTIPLEX_CTRL_SET_CHUNK_SIZE:
    36  **   This file control is used to set the maximum allowed chunk 
    37  **   size for a multiplex file set.  The chunk size should be 
    38  **   a multiple of SQLITE_MAX_PAGE_SIZE, and will be rounded up
    39  **   if not.
    40  **
    41  ** MULTIPLEX_CTRL_SET_MAX_CHUNKS:
    42  **   This file control is used to set the maximum number of chunks
    43  **   allowed to be used for a mutliplex file set.
    44  */
    45  #define MULTIPLEX_CTRL_ENABLE          214014
    46  #define MULTIPLEX_CTRL_SET_CHUNK_SIZE  214015
    47  #define MULTIPLEX_CTRL_SET_MAX_CHUNKS  214016
    48  
    49  #ifdef __cplusplus
    50  extern "C" {
    51  #endif
    52  
    53  /*
    54  ** CAPI: Initialize the multiplex VFS shim - sqlite3_multiplex_initialize()
    55  **
    56  ** Use the VFS named zOrigVfsName as the VFS that does the actual work.  
    57  ** Use the default if zOrigVfsName==NULL.  
    58  **
    59  ** The multiplex VFS shim is named "multiplex".  It will become the default
    60  ** VFS if makeDefault is non-zero.
    61  **
    62  ** An auto-extension is registered which will make the function 
    63  ** multiplex_control() available to database connections.  This
    64  ** function gives access to the xFileControl interface of the 
    65  ** multiplex VFS shim.
    66  **
    67  ** SELECT multiplex_control(<op>,<val>);
    68  ** 
    69  **   <op>=1 MULTIPLEX_CTRL_ENABLE
    70  **   <val>=0 disable
    71  **   <val>=1 enable
    72  ** 
    73  **   <op>=2 MULTIPLEX_CTRL_SET_CHUNK_SIZE
    74  **   <val> int, chunk size
    75  ** 
    76  **   <op>=3 MULTIPLEX_CTRL_SET_MAX_CHUNKS
    77  **   <val> int, max chunks
    78  **
    79  ** THIS ROUTINE IS NOT THREADSAFE.  Call this routine exactly once
    80  ** during start-up.
    81  */
    82  extern int sqlite3_multiplex_initialize(const char *zOrigVfsName, int makeDefault);
    83  
    84  /*
    85  ** CAPI: Shutdown the multiplex system - sqlite3_multiplex_shutdown()
    86  **
    87  ** All SQLite database connections must be closed before calling this
    88  ** routine.
    89  **
    90  ** THIS ROUTINE IS NOT THREADSAFE.  Call this routine exactly once while
    91  ** shutting down in order to free all remaining multiplex groups.
    92  */
    93  extern int sqlite3_multiplex_shutdown(int eForce);
    94  
    95  #ifdef __cplusplus
    96  }  /* End of the 'extern "C"' block */
    97  #endif
    98  
    99  #endif /* SQLITE_TEST_MULTIPLEX_H */