SQLite

**
** If the page size is not changed, either because one of the enumerated
** conditions above is not true, the pager was in error state when this
** function was called, or because the memory allocation attempt failed, 
** then *pPageSize is set to the old, retained page size before returning.
*/
int sqlite3PagerSetPagesize(Pager *pPager, u32 *pPageSize, int nReserve){
  int rc = SQLITE_OK;

  /* It is not possible to do a full assert_pager_state() here, as this
  ** function may be called from within PagerOpen(), before the state
  ** of the Pager object is internally consistent.
  **
  ** At one point this function returned an error if the pager was in 
  ** PAGER_ERROR state. But since PAGER_ERROR state guarantees that
  ** there is at least one outstanding page reference, this function
  ** is a no-op for that case anyhow.
  */

  u32 pageSize = *pPageSize;
  assert( pageSize==0 || (pageSize>=512 && pageSize<=SQLITE_MAX_PAGE_SIZE) );
  if( (pPager->memDb==0 || pPager->dbSize==0)
   && sqlite3PcacheRefCount(pPager->pPCache)==0 
   && pageSize && pageSize!=pPager->pageSize 
  ){
    char *pNew;                 /* New temp space */
    i64 nByte = 0;

    if( pPager->eState>PAGER_OPEN && isOpen(pPager->fd) ){
      rc = sqlite3OsFileSize(pPager->fd, &nByte);

    }
    if( rc==SQLITE_OK ){
      pNew = (char *)sqlite3PageMalloc(pageSize);
      if( !pNew ) rc = SQLITE_NOMEM;
    }

    if( rc==SQLITE_OK ){

      pager_reset(pPager);
      pPager->dbSize = nByte/pageSize;
      pPager->pageSize = pageSize;
      sqlite3PageFree(pPager->pTmpSpace);
      pPager->pTmpSpace = pNew;
      sqlite3PcacheSetPageSize(pPager->pPCache, pageSize);
    }
  }

  *pPageSize = pPager->pageSize;
  if( rc==SQLITE_OK ){
    if( nReserve<0 ) nReserve = pPager->nReserve;
    assert( nReserve>=0 && nReserve<1000 );
    pPager->nReserve = (i16)nReserve;
    pagerReportSize(pPager);
  }
  return rc;
}

/*
** Return a pointer to the "temporary page" buffer held internally
** by the pager.  This is a buffer that is big enough to hold the
** entire content of a database page.  This buffer is used internally
** during rollback and will be overwritten whenever a rollback

  do_test pager1-28.$tn.17 { file exists test.db-journal } 1

  do_test pager1-28.$tn.17 { csql2 { COMMIT } } {1 {database is locked}}
  do_test pager1-28-$tn.18 { code1 { read $channel } } c
  do_test pager1-28-$tn.19 { code1 { close $channel } } {}
  do_test pager1-28.$tn.20 { sql2 { COMMIT } } {}
}

do_test pager1-29.1 {
  faultsim_delete_and_reopen
  execsql {
    PRAGMA page_size = 1024;
    PRAGMA auto_vacuum = full;
    PRAGMA locking_mode=exclusive;
    CREATE TABLE t1(a, b);
    INSERT INTO t1 VALUES(1, 2);
  }
  file size test.db
} [expr 1024*3]
do_test pager1-29.2 {
  execsql {
    PRAGMA page_size = 4096;
    VACUUM;
  }
  file size test.db
} [expr 4096*3]


finish_test

proc a_string {n} {
  global a_string_counter
  incr a_string_counter
  string range [string repeat "${a_string_counter}." $n] 1 $n
}
db func a_string a_string



#-------------------------------------------------------------------------
# Test fault-injection while rolling back a hot-journal file.
#
do_test pagerfault-1-pre1 {
  execsql {
    PRAGMA journal_mode = DELETE;
    PRAGMA cache_size = 10;

} -test {
  faultsim_test_result {0 {}} \
    {1 {unable to open a temporary database file for storing temporary tables}}
  set ic [db eval { PRAGMA temp.integrity_check }]
  if {$ic != "ok"} { error "Integrity check: $ic" }
}



proc lockrows {n} {
  if {$n==0} { return "" }
  db eval { SELECT * FROM t1 WHERE oid = $n } { 
    return [lockrows [expr {$n-1}]]
  }
}


do_test pagerfault-25-pre1 {
  faultsim_delete_and_reopen
  db func a_string a_string
  execsql {
    PRAGMA page_size = 1024;
    PRAGMA auto_vacuum = 0;
    CREATE TABLE t1(a);
    INSERT INTO t1 VALUES(a_string(500));
    INSERT INTO t1 SELECT a_string(500) FROM t1;
    INSERT INTO t1 SELECT a_string(500) FROM t1;
    INSERT INTO t1 SELECT a_string(500) FROM t1;
    INSERT INTO t1 SELECT a_string(500) FROM t1;
    INSERT INTO t1 SELECT a_string(500) FROM t1;
  }
  faultsim_save_and_close
} {}
do_faultsim_test pagerfault-25 -prep {
  faultsim_restore_and_reopen
  db func a_string a_string
  set ::channel [db incrblob -readonly t1 a 1]
  execsql { 
    PRAGMA cache_size = 10;
    BEGIN;
      INSERT INTO t1 VALUES(a_string(3000));
      INSERT INTO t1 VALUES(a_string(3000));
  }
} -body {
  lockrows 30
} -test {
  catch { lockrows 30 }
  catch { db eval COMMIT }
  close $::channel
  faultsim_test_result {0 {}} 
}

do_faultsim_test pagerfault-26 -prep {
  faultsim_delete_and_reopen
  execsql {
    PRAGMA page_size = 1024;
    PRAGMA journal_mode = truncate;
    PRAGMA auto_vacuum = full;
    PRAGMA locking_mode=exclusive;
    CREATE TABLE t1(a, b);
    INSERT INTO t1 VALUES(1, 2);
    PRAGMA page_size = 4096;
  }
} -body {
  execsql {
    VACUUM;
  }
} -test {
  faultsim_test_result {0 {}}

  set contents [db eval {SELECT * FROM t1}]
  if {$contents != "1 2"} { error "Bad database contents ($contents)" }

  set sz [file size test.db]
  if {$testrc!=0 && $sz!=1024*3 && $sz!=4096*3} { 
    error "Expected file size to be 3072 or 12288 bytes - actual size $sz bytes"
  }
  if {$testrc==0 && $sz!=4096*3} { 
    error "Expected file size to be 12288 bytes - actual size $sz bytes"
  }
} 


finish_test