SQLite

} QueryType;

typedef enum fulltext_statement {
  CONTENT_INSERT_STMT,
  CONTENT_SELECT_STMT,
  CONTENT_UPDATE_STMT,
  CONTENT_DELETE_STMT,
  CONTENT_EXISTS_STMT,

  BLOCK_INSERT_STMT,
  BLOCK_SELECT_STMT,
  BLOCK_DELETE_STMT,
  BLOCK_DELETE_ALL_STMT,

  SEGDIR_MAX_INDEX_STMT,
  SEGDIR_SET_STMT,
  SEGDIR_SELECT_LEVEL_STMT,
  SEGDIR_SPAN_STMT,
  SEGDIR_DELETE_STMT,
  SEGDIR_SELECT_SEGMENT_STMT,
  SEGDIR_SELECT_ALL_STMT,
  SEGDIR_DELETE_ALL_STMT,

  MAX_STMT                     /* Always at end! */
} fulltext_statement;

/* These must exactly match the enum above. */
/* TODO(shess): Is there some risk that a statement will be used in two
** cursors at once, e.g.  if a query joins a virtual table to itself?
** If so perhaps we should move some of these to the cursor object.
*/
static const char *const fulltext_zStatement[MAX_STMT] = {
  /* CONTENT_INSERT */ NULL,  /* generated in contentInsertStatement() */
  /* CONTENT_SELECT */ NULL,  /* generated in contentSelectStatement() */
  /* CONTENT_UPDATE */ NULL,  /* generated in contentUpdateStatement() */
  /* CONTENT_DELETE */ "delete from %_content where docid = ?",
  /* CONTENT_EXISTS */ "select docid from %_content limit 1",

  /* BLOCK_INSERT */
  "insert into %_segments (blockid, block) values (null, ?)",
  /* BLOCK_SELECT */ "select block from %_segments where blockid = ?",
  /* BLOCK_DELETE */ "delete from %_segments where blockid between ? and ?",
  /* BLOCK_DELETE_ALL */ "delete from %_segments",

  /* SEGDIR_MAX_INDEX */ "select max(idx) from %_segdir where level = ?",
  /* SEGDIR_SET */ "insert into %_segdir values (?, ?, ?, ?, ?, ?)",
  /* SEGDIR_SELECT_LEVEL */
  "select start_block, leaves_end_block, root from %_segdir "
  " where level = ? order by idx",
  /* SEGDIR_SPAN */
  "select min(start_block), max(end_block) from %_segdir "
  " where level = ? and start_block <> 0",
  /* SEGDIR_DELETE */ "delete from %_segdir where level = ?",

  /* NOTE(shess): The first three results of the following two
  ** statements must match.
  */
  /* SEGDIR_SELECT_SEGMENT */
  "select start_block, leaves_end_block, root from %_segdir "
  " where level = ? and idx = ?",
  /* SEGDIR_SELECT_ALL */
  "select start_block, leaves_end_block, root from %_segdir "
  " order by level desc, idx asc",
  /* SEGDIR_DELETE_ALL */ "delete from %_segdir",
};

/*
** A connection to a fulltext index is an instance of the following
** structure.  The xCreate and xConnect methods create an instance
** of this structure and xDestroy and xDisconnect free that instance.
** All other methods receive a pointer to the structure as one of their

  if( rc!=SQLITE_OK ) return rc;

  rc = sqlite3_bind_int64(s, 1, iDocid);
  if( rc!=SQLITE_OK ) return rc;

  return sql_single_step(s);
}

/* Returns SQLITE_ROW if any rows exist in %_content, SQLITE_DONE if
** no rows exist, and any error in case of failure.
*/
static int content_exists(fulltext_vtab *v){
  sqlite3_stmt *s;
  int rc = sql_get_statement(v, CONTENT_EXISTS_STMT, &s);
  if( rc!=SQLITE_OK ) return rc;

  rc = sqlite3_step(s);
  if( rc!=SQLITE_ROW ) return rc;

  /* We expect only one row.  We must execute another sqlite3_step()
   * to complete the iteration; otherwise the table will remain locked. */
  rc = sqlite3_step(s);
  if( rc==SQLITE_DONE ) return SQLITE_ROW;
  if( rc==SQLITE_ROW ) return SQLITE_ERROR;
  return rc;
}

/* insert into %_segments values ([pData])
**   returns assigned blockid in *piBlockid
*/
static int block_insert(fulltext_vtab *v, const char *pData, int nData,
                        sqlite_int64 *piBlockid){
  sqlite3_stmt *s;

  /* Delete the segment directory itself. */
  rc = sql_get_statement(v, SEGDIR_DELETE_STMT, &s);
  if( rc!=SQLITE_OK ) return rc;

  rc = sqlite3_bind_int64(s, 1, iLevel);
  if( rc!=SQLITE_OK ) return rc;

  return sql_single_step(s);
}

/* Delete entire fts index, SQLITE_OK on success, relevant error on
** failure.
*/
static int segdir_delete_all(fulltext_vtab *v){
  sqlite3_stmt *s;
  int rc = sql_get_statement(v, SEGDIR_DELETE_ALL_STMT, &s);
  if( rc!=SQLITE_OK ) return rc;

  rc = sql_single_step(s);
  if( rc!=SQLITE_OK ) return rc;

  rc = sql_get_statement(v, BLOCK_DELETE_ALL_STMT, &s);
  if( rc!=SQLITE_OK ) return rc;

  return sql_single_step(s);
}

/* TODO(shess) clearPendingTerms() is far down the file because
** writeZeroSegment() is far down the file because LeafWriter is far
** down the file.  Consider refactoring the code to move the non-vtab
** code above the vtab code so that we don't need this forward

  fulltext_vtab *v = (fulltext_vtab *) pVtab;
  int rc;

  FTSTRACE(("FTS3 Update %p\n", pVtab));

  if( nArg<2 ){
    rc = index_delete(v, sqlite3_value_int64(ppArg[0]));
    if( rc==SQLITE_OK ){
      /* If we just deleted the last row in the table, clear out the
      ** index data.
      */
      rc = content_exists(v);
      if( rc==SQLITE_ROW ){
        rc = SQLITE_OK;
      }else if( rc==SQLITE_DONE ){
        /* Clear the pending terms so we don't flush a useless level-0
        ** segment when the transaction closes.
        */
        rc = clearPendingTerms(v);
        if( rc==SQLITE_OK ){
          rc = segdir_delete_all(v);
        }
      }
    }
  } else if( sqlite3_value_type(ppArg[0]) != SQLITE_NULL ){
    /* An update:
     * ppArg[0] = old rowid
     * ppArg[1] = new rowid
     * ppArg[2..2+v->nColumn-1] = values
     * ppArg[2+v->nColumn] = value for magic column (we ignore this)
     * ppArg[2+v->nColumn+1] = value for docid

# 2008 June 26
#
# 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 implements regression tests for SQLite library.  The focus
# of this script is testing the FTS3 module's optimize() function.
#
# $Id: fts3d.test,v 1.1 2008/07/14 20:43:15 shess Exp $
#

set testdir [file dirname $argv0]
source $testdir/tester.tcl

# If SQLITE_ENABLE_FTS3 is not defined, omit this file.
ifcapable !fts3 {
  finish_test
  return
}

#*************************************************************************
# Probe to see if support for the FTS3 dump_* functions is compiled in.
# TODO(shess): Change main.mk to do the right thing and remove this test.
db eval {
  DROP TABLE IF EXISTS t1;
  CREATE VIRTUAL TABLE t1 USING fts3(c);
  INSERT INTO t1 (docid, c) VALUES (1, 'x');
}

set s {SELECT dump_terms(t1, 1) FROM t1 LIMIT 1}
set r {1 {unable to use function dump_terms in the requested context}}
if {[catchsql $s]==$r} {
  finish_test
  return
}

#*************************************************************************
# Utility function to check for the expected terms in the segment
# level/index.  _all version does same but for entire index.
proc check_terms {test level index terms} {
  # TODO(shess): Figure out why uplevel in do_test can't catch
  # $level and $index directly.
  set ::level $level
  set ::index $index
  do_test $test.terms {
    execsql {
      SELECT dump_terms(t1, $::level, $::index) FROM t1 LIMIT 1;
    }
  } [list $terms]
}
proc check_terms_all {test terms} {
  do_test $test.terms {
    execsql {
      SELECT dump_terms(t1) FROM t1 LIMIT 1;
    }
  } [list $terms]
}

# Utility function to check for the expected doclist for the term in
# segment level/index.  _all version does same for entire index.
proc check_doclist {test level index term doclist} {
  # TODO(shess): Again, why can't the non-:: versions work?
  set ::term $term
  set ::level $level
  set ::index $index
  do_test $test {
    execsql {
      SELECT dump_doclist(t1, $::term, $::level, $::index) FROM t1 LIMIT 1;
    }
  } [list $doclist]
}
proc check_doclist_all {test term doclist} {
  set ::term $term
  do_test $test {
    execsql {
      SELECT dump_doclist(t1, $::term) FROM t1 LIMIT 1;
    }
  } [list $doclist]
}

#*************************************************************************
# Test results when all rows are deleted and one is added back.
# Previously older segments would continue to exist, but now the index
# should be dropped when the table is empty.  The results should look
# exactly like we never added the earlier rows in the first place.
db eval {
  DROP TABLE IF EXISTS t1;
  CREATE VIRTUAL TABLE t1 USING fts3(c);
  INSERT INTO t1 (docid, c) VALUES (1, 'This is a test');
  INSERT INTO t1 (docid, c) VALUES (2, 'That was a test');
  INSERT INTO t1 (docid, c) VALUES (3, 'This is a test');
  DELETE FROM t1 WHERE 1=1; -- Delete each row rather than dropping table.
  INSERT INTO t1 (docid, c) VALUES (1, 'This is a test');
}

# Should be a single initial segment.
do_test fts3d-1.segments {
  execsql {
    SELECT level, idx FROM t1_segdir ORDER BY level, idx;
  }
} {0 0}
do_test fts3d-1.matches {
  execsql {
    SELECT OFFSETS(t1) FROM t1
     WHERE t1 MATCH 'this OR that OR was OR a OR is OR test' ORDER BY docid;
  }
} {{0 0 0 4 0 4 5 2 0 3 8 1 0 5 10 4}}

check_terms_all fts3d-1.1 {a is test this}
check_doclist_all fts3d-1.1.1 a {[1 0[2]]}
check_doclist_all fts3d-1.1.2 is {[1 0[1]]}
check_doclist_all fts3d-1.1.3 test {[1 0[3]]}
check_doclist_all fts3d-1.1.4 this {[1 0[0]]}

check_terms   fts3d-1.2   0 0 {a is test this}
check_doclist fts3d-1.2.1 0 0 a {[1 0[2]]}
check_doclist fts3d-1.2.2 0 0 is {[1 0[1]]}
check_doclist fts3d-1.2.3 0 0 test {[1 0[3]]}
check_doclist fts3d-1.2.4 0 0 this {[1 0[0]]}

# TODO(shess): optimize() tests here.

finish_test