[sql] Import reference version of SQLite 3.17..

third_party/sqlite/sqlite-src-3170000/src/test_multiplex.h

+/*
+** 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 SQLITE_TEST_MULTIPLEX_H
+#define SQLITE_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
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/*
+** 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(int eForce);
+
+#ifdef __cplusplus
+}  /* End of the 'extern "C"' block */
+#endif
+
+#endif /* SQLITE_TEST_MULTIPLEX_H */