SQLite

/*
** 2004 April 6
**
** 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.
**
*************************************************************************
** $Id: btree.c,v 1.227 2005/01/08 12:42:39 danielk1977 Exp $
**
** This file implements a external (disk-based) database using BTrees.
** For a detailed discussion of BTrees, refer to
**
**     Donald E. Knuth, THE ART OF COMPUTER PROGRAMMING, Volume 3:
**     "Sorting And Searching", pages 473-480. Addison-Wesley
**     Publishing Company, Reading, Massachusetts.

        releasePage(pRoot);
        return rc;
      }
    }else{
      pRoot = pPageMove;
    } 

    /* Update the pointer-map and meta-data with the new root-page number. */
    rc = ptrmapPut(pBt, pgnoRoot, PTRMAP_ROOTPAGE, 0);
    if( rc ){
      releasePage(pRoot);
      return rc;
    }
    rc = sqlite3BtreeUpdateMeta(pBt, 4, pgnoRoot);
    if( rc ){
      releasePage(pRoot);
      return rc;
    }

  }else{
    rc = allocatePage(pBt, &pRoot, &pgnoRoot, 1, 0);
    if( rc ) return rc;
  }
#endif
  assert( sqlite3pager_iswriteable(pRoot->aData) );
  zeroPage(pRoot, flags | PTF_LEAF);

** The pager is used to access a database disk file.  It implements
** atomic commit and rollback through the use of a journal file that
** is separate from the database file.  The pager also implements file
** locking to prevent two processes from writing the same database
** file simultaneously, or one process from reading the database while
** another is writing.
**
** @(#) $Id: pager.c,v 1.180 2005/01/08 12:42:39 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"
#include "pager.h"
#include <assert.h>
#include <string.h>

  void (*xReiniter)(void*,int);   /* Call this routine when reloading pages */
  int pageSize;               /* Number of bytes in a page */
  int psAligned;              /* pageSize rounded up to a multiple of 8 */
  int nPage;                  /* Total number of in-memory pages */
  int nRef;                   /* Number of in-memory pages with PgHdr.nRef>0 */
  int mxPage;                 /* Maximum number of pages to hold in cache */
  int nHit, nMiss, nOvfl;     /* Cache hits, missing, and LRU overflows */
  int nRead,nWrite;           /* Database pages read/written */
  void (*xCodec)(void*,void*,Pgno,int); /* Routine for en/decoding data */
  void *pCodecArg;            /* First argument to xCodec() */
  u8 journalOpen;             /* True if journal file descriptors is valid */
  u8 journalStarted;          /* True if header of journal is synced */
  u8 useJournal;              /* Use a rollback journal on this file */
  u8 stmtOpen;                /* True if the statement subjournal is open */
  u8 stmtInUse;               /* True we are in a statement subtransaction */

    ** any such pages to the file.
    */
    if( pList->pgno<=pPager->dbSize ){
      CODEC(pPager, PGHDR_TO_DATA(pList), pList->pgno, 6);
      TRACE3("STORE %d page %d\n", PAGERID(pPager), pList->pgno);
      rc = sqlite3OsWrite(&pPager->fd, PGHDR_TO_DATA(pList), pPager->pageSize);
      CODEC(pPager, PGHDR_TO_DATA(pList), pList->pgno, 0);
      pPager->nWrite++;
    }
#ifndef NDEBUG
    else{
      TRACE3("NOSTORE %d page %d\n", PAGERID(pPager), pList->pgno);
    }
#endif
    if( rc ) return rc;

        if( sqlite3OsFileSize(&pPager->fd,&fileSize)!=SQLITE_OK
               || fileSize>=pgno*pPager->pageSize ){
          sqlite3pager_unref(PGHDR_TO_DATA(pPg));
          return rc;
        }else{
          memset(PGHDR_TO_DATA(pPg), 0, pPager->pageSize);
        }
      }else{
        pPager->nRead++;
      }
    }
  }else{
    /* The requested page is in the page cache. */
    pPager->nHit++;
    page_ref(pPg);
  }

  return pPager->readOnly;
}

/*
** This routine is used for testing and analysis only.
*/
int *sqlite3pager_stats(Pager *pPager){
  static int a[11];
  a[0] = pPager->nRef;
  a[1] = pPager->nPage;
  a[2] = pPager->mxPage;
  a[3] = pPager->dbSize;
  a[4] = pPager->state;
  a[5] = pPager->errMask;
  a[6] = pPager->nHit;
  a[7] = pPager->nMiss;
  a[8] = pPager->nOvfl;
  a[9] = pPager->nRead;
  a[10] = pPager->nWrite;
  return a;
}

/*
** Set the statement rollback point.
**
** This routine should be called with the transaction journal already

**    May you share freely, never taking more than you give.
**
*************************************************************************
** Code for testing the btree.c module in SQLite.  This code
** is not included in the SQLite library.  It is used for automated
** testing of the SQLite library.
**
** $Id: test3.c,v 1.58 2005/01/08 12:42:39 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "pager.h"
#include "btree.h"
#include "tcl.h"
#include <stdlib.h>
#include <string.h>

  if( argc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " ID\"", 0);
    return TCL_ERROR;
  }
  pBt = sqlite3TextToPtr(argv[1]);
  a = sqlite3pager_stats(sqlite3BtreePager(pBt));
  for(i=0; i<11; i++){
    static char *zName[] = {
      "ref", "page", "max", "size", "state", "err",
      "hit", "miss", "ovfl", "read", "write"
    };
    char zBuf[100];
    Tcl_AppendElement(interp, zName[i]);
    sqlite3_snprintf(sizeof(zBuf), zBuf,"%d",a[i]);
    Tcl_AppendElement(interp, zBuf);
  }
  return TCL_OK;

    for(j=0; j<19; j++){
      sqlite3GetVarint(zBuf, &out);
    }
    in += incr;
  }
  return TCL_OK;
}

/*
** usage:   btree_from_db  DB-HANDLE
**
** This command returns the btree handle for the main database associated
** with the database-handle passed as the argument. Example usage:
**
** sqlite3 db test.db
** set bt [btree_from_db db]
*/
static int btree_from_db(
  void *NotUsed,
  Tcl_Interp *interp,    /* The TCL interpreter that invoked this command */
  int argc,              /* Number of arguments */
  const char **argv      /* Text of each argument */
){
  char zBuf[100];
  Tcl_CmdInfo info;
  sqlite3 *db;
  Btree *pBt;

  if( argc!=2 ){
    Tcl_AppendResult(interp, "wrong # args: should be \"", argv[0],
       " DB-HANDLE\"", 0);
    return TCL_ERROR;
  }

  if( 1!=Tcl_GetCommandInfo(interp, argv[1], &info) ){
    Tcl_AppendResult(interp, "No such db-handle: \"", argv[1], "\"", 0);
    return TCL_ERROR;
  }
  db = *((sqlite3 **)info.objClientData);
  assert( db );

  pBt = db->aDb[0].pBt;
  sqlite3_snprintf(sizeof(zBuf), zBuf, "%p", pBt);
  Tcl_SetResult(interp, zBuf, TCL_VOLATILE);
  return TCL_OK;
}

/*
** Register commands with the TCL interpreter.
*/
int Sqlitetest3_Init(Tcl_Interp *interp){
  extern int sqlite3_btree_trace;
  static struct {

     { "btree_cursor_list",        (Tcl_CmdProc*)btree_cursor_list        },
     { "btree_integrity_check",    (Tcl_CmdProc*)btree_integrity_check    },
     { "btree_breakpoint",         (Tcl_CmdProc*)btree_breakpoint         },
     { "btree_varint_test",        (Tcl_CmdProc*)btree_varint_test        },
     { "btree_begin_statement",    (Tcl_CmdProc*)btree_begin_statement    },
     { "btree_commit_statement",   (Tcl_CmdProc*)btree_commit_statement   },
     { "btree_rollback_statement", (Tcl_CmdProc*)btree_rollback_statement },
     { "btree_from_db",            (Tcl_CmdProc*)btree_from_db            },
  };
  int i;

  for(i=0; i<sizeof(aCmd)/sizeof(aCmd[0]); i++){
    Tcl_CreateCommand(interp, aCmd[i].zName, aCmd[i].xProc, 0, 0);
  }
  Tcl_LinkVar(interp, "pager_refinfo_enable", (char*)&pager3_refinfo_enable,

**
*************************************************************************
** This file contains code used to implement the VACUUM command.
**
** Most of the code in this file may be omitted by defining the
** SQLITE_OMIT_VACUUM macro.
**
** $Id: vacuum.c,v 1.36 2005/01/08 12:42:40 danielk1977 Exp $
*/
#include "sqliteInt.h"
#include "os.h"

#ifndef SQLITE_OMIT_VACUUM
/*
** Generate a random name of 20 character in length.

  if( rc!=SQLITE_OK ) goto end_of_vacuum;
  assert( strcmp(db->aDb[db->nDb-1].zName,"vacuum_db")==0 );
  pTemp = db->aDb[db->nDb-1].pBt;
  sqlite3BtreeSetPageSize(pTemp, sqlite3BtreeGetPageSize(pMain),
     sqlite3BtreeGetReserve(pMain));
  assert( sqlite3BtreeGetPageSize(pTemp)==sqlite3BtreeGetPageSize(pMain) );
  execSql(db, "PRAGMA vacuum_db.synchronous=OFF");

#ifndef SQLITE_OMIT_AUTOVACUUM
  sqlite3BtreeSetAutoVacuum(pTemp, sqlite3BtreeGetAutoVacuum(pMain));
#endif

  /* Begin a transaction */
  rc = execSql(db, "BEGIN;");
  if( rc!=SQLITE_OK ) goto end_of_vacuum;

  /* Query the schema of the main database. Create a mirror schema
  ** in the temporary database.