SQLite

** dlwAdd - construct doclist element and append to buffer.
**    Only apply dlwAdd() to DL_DOCIDS doclists (else use PLWriter).
*/
typedef struct DLWriter {
  DocListType iType;
  DataBuffer *b;
  sqlite_int64 iPrevDocid;
#ifndef NDEBUG
  int has_iPrevDocid;
#endif
} DLWriter;

static void dlwInit(DLWriter *pWriter, DocListType iType, DataBuffer *b){
  pWriter->b = b;
  pWriter->iType = iType;
  pWriter->iPrevDocid = 0;
#ifndef NDEBUG
  pWriter->has_iPrevDocid = 0;
#endif
}
static void dlwDestroy(DLWriter *pWriter){
  SCRAMBLE(pWriter);
}
/* iFirstDocid is the first docid in the doclist in pData.  It is
** needed because pData may point within a larger doclist, in which
** case the first item would be delta-encoded.

  dlwAppend(pWriter, dlrDocData(pReader), dlrDocDataBytes(pReader),
            dlrDocid(pReader), dlrDocid(pReader));
}
static void dlwAdd(DLWriter *pWriter, sqlite_int64 iDocid){
  char c[VARINT_MAX];
  int n = putVarint(c, iDocid-pWriter->iPrevDocid);

  /* Docids must ascend. */
  assert( !pWriter->has_iPrevDocid || iDocid>pWriter->iPrevDocid );
  assert( pWriter->iType==DL_DOCIDS );

  dataBufferAppend(pWriter->b, c, n);
  pWriter->iPrevDocid = iDocid;
#ifndef NDEBUG
  pWriter->has_iPrevDocid = 1;
#endif
}

/*******************************************************************/
/* PLReader is used to read data from a document's position list.  As
** the caller steps through the list, data is cached so that varints
** only need to be decoded once.
**

}
static void plwInit(PLWriter *pWriter, DLWriter *dlw, sqlite_int64 iDocid){
  char c[VARINT_MAX];
  int n;

  pWriter->dlw = dlw;

  /* Docids must ascend. */
  assert( !pWriter->dlw->has_iPrevDocid || iDocid>pWriter->dlw->iPrevDocid );
  n = putVarint(c, iDocid-pWriter->dlw->iPrevDocid);
  dataBufferAppend(pWriter->dlw->b, c, n);
  pWriter->dlw->iPrevDocid = iDocid;
#ifndef NDEBUG
  pWriter->dlw->has_iPrevDocid = 1;
#endif

  pWriter->iColumn = 0;
  pWriter->iPos = 0;
  pWriter->iOffset = 0;
}
/* TODO(shess) Should plwDestroy() also terminate the doclist?  But
** then plwDestroy() would no longer be just a destructor, it would

# 2006 September 9
#
# 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 FTS2 module.
#
# $Id: fts2a.test,v 1.2 2007/05/21 21:59:18 shess Exp $
#

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

# If SQLITE_ENABLE_FTS2 is defined, omit this file.
ifcapable !fts2 {

  set rowid [db last_insert_rowid]
  execsql {SELECT content FROM t1 WHERE rowid=$rowid}
} {{}}
do_test fts2a-5.3 {
  execsql {SELECT rowid FROM t1 WHERE content MATCH NULL}
} {}

# Test the ability to handle non-positive rowids
#
do_test fts2a-6.0 {
  execsql {INSERT INTO t1(rowid, content) VALUES(0, 'four five')}
} {}
do_test fts2a-6.1 {
  execsql {SELECT content FROM t1 WHERE rowid = 0}
} {{four five}}
do_test fts2a-6.2 {
  execsql {INSERT INTO t1(rowid, content) VALUES(-1, 'three four')}
} {}
do_test fts2a-6.3 {
  execsql {SELECT content FROM t1 WHERE rowid = -1}
} {{three four}}
do_test fts2a-6.4 {
  execsql {SELECT rowid FROM t1 WHERE t1 MATCH 'four'}
} {-1 0 8 9 10 11 12 13 14 15 24 25 26 27 28 29 30 31}

finish_test