/* ** 2011 March 18 ** ** The author disclaims copyright to this source code. In place of ** a legal notice, here is a blessing: ** ** May you do good and not evil. ** May you find forgiveness for yourself and forgive others. ** May you share freely, never taking more than you give. ** ************************************************************************* ** ** This file contains a VFS "shim" - a layer that sits in between the ** pager and the real VFS. ** ** This particular shim enforces a multiplex system on DB files. ** This shim shards/partitions a single DB file into smaller ** "chunks" such that the total DB file size may exceed the maximum ** file size of the underlying file system. ** */ #ifndef _TEST_MULTIPLEX_H #define _TEST_MULTIPLEX_H /* ** CAPI: File-control Operations Supported by Multiplex VFS ** ** Values interpreted by the xFileControl method of a Multiplex VFS db file-handle. ** ** MULTIPLEX_CTRL_ENABLE: ** This file control is used to enable or disable the multiplex ** shim. ** ** MULTIPLEX_CTRL_SET_CHUNK_SIZE: ** This file control is used to set the maximum allowed chunk ** size for a multiplex file set. The chunk size should be ** a multiple of SQLITE_MAX_PAGE_SIZE, and will be rounded up ** if not. ** ** MULTIPLEX_CTRL_SET_MAX_CHUNKS: ** This file control is used to set the maximum number of chunks ** allowed to be used for a mutliplex file set. */ #define MULTIPLEX_CTRL_ENABLE 214014 #define MULTIPLEX_CTRL_SET_CHUNK_SIZE 214015 #define MULTIPLEX_CTRL_SET_MAX_CHUNKS 214016 /* ** CAPI: Initialize the multiplex VFS shim - sqlite3_multiplex_initialize() ** ** Use the VFS named zOrigVfsName as the VFS that does the actual work. ** Use the default if zOrigVfsName==NULL. ** ** The multiplex VFS shim is named "multiplex". It will become the default ** VFS if makeDefault is non-zero. ** ** An auto-extension is registered which will make the function ** multiplex_control() available to database connections. This ** function gives access to the xFileControl interface of the ** multiplex VFS shim. ** ** SELECT multiplex_control(<op>,<val>); ** ** <op>=1 MULTIPLEX_CTRL_ENABLE ** <val>=0 disable ** <val>=1 enable ** ** <op>=2 MULTIPLEX_CTRL_SET_CHUNK_SIZE ** <val> int, chunk size ** ** <op>=3 MULTIPLEX_CTRL_SET_MAX_CHUNKS ** <val> int, max chunks ** ** THIS ROUTINE IS NOT THREADSAFE. Call this routine exactly once ** during start-up. */ extern int sqlite3_multiplex_initialize(const char *zOrigVfsName, int makeDefault); /* ** CAPI: Shutdown the multiplex system - sqlite3_multiplex_shutdown() ** ** All SQLite database connections must be closed before calling this ** routine. ** ** THIS ROUTINE IS NOT THREADSAFE. Call this routine exactly once while ** shutting down in order to free all remaining multiplex groups. */ extern int sqlite3_multiplex_shutdown(void); #endif