SQLite

  fts5_tokenizer *pTokApi;

  /* Values loaded from the %_config table */
  int iCookie;                    /* Incremented when %_config is modified */
  int pgsz;                       /* Approximate page size used in %_data */
  int nAutomerge;                 /* 'automerge' setting */
  int nCrisisMerge;               /* Maximum allowed segments per level */
  int nUsermerge;                 /* 'usermerge' setting */
  int nHashSize;                  /* Bytes of memory for in-memory hash */
  char *zRank;                    /* Name of rank function */
  char *zRankArgs;                /* Arguments to rank function */

  /* If non-NULL, points to sqlite3_vtab.base.zErrmsg. Often NULL. */
  char **pzErrmsg;

*/


#include "fts5Int.h"

#define FTS5_DEFAULT_PAGE_SIZE   4050
#define FTS5_DEFAULT_AUTOMERGE      4
#define FTS5_DEFAULT_USERMERGE      4
#define FTS5_DEFAULT_CRISISMERGE   16
#define FTS5_DEFAULT_HASHSIZE    (1024*1024)

/* Maximum allowed page size */
#define FTS5_MAX_PAGE_SIZE (128*1024)

static int fts5_iswhitespace(char x){

    if( nAutomerge<0 || nAutomerge>64 ){
      *pbBadkey = 1;
    }else{
      if( nAutomerge==1 ) nAutomerge = FTS5_DEFAULT_AUTOMERGE;
      pConfig->nAutomerge = nAutomerge;
    }
  }

  else if( 0==sqlite3_stricmp(zKey, "usermerge") ){
    int nUsermerge = -1;
    if( SQLITE_INTEGER==sqlite3_value_numeric_type(pVal) ){
      nUsermerge = sqlite3_value_int(pVal);
    }
    if( nUsermerge<2 || nUsermerge>16 ){
      *pbBadkey = 1;
    }else{
      pConfig->nUsermerge = nUsermerge;
    }
  }

  else if( 0==sqlite3_stricmp(zKey, "crisismerge") ){
    int nCrisisMerge = -1;
    if( SQLITE_INTEGER==sqlite3_value_numeric_type(pVal) ){
      nCrisisMerge = sqlite3_value_int(pVal);
    }
    if( nCrisisMerge<0 ){

  sqlite3_stmt *p = 0;
  int rc = SQLITE_OK;
  int iVersion = 0;

  /* Set default values */
  pConfig->pgsz = FTS5_DEFAULT_PAGE_SIZE;
  pConfig->nAutomerge = FTS5_DEFAULT_AUTOMERGE;
  pConfig->nUsermerge = FTS5_DEFAULT_USERMERGE;
  pConfig->nCrisisMerge = FTS5_DEFAULT_CRISISMERGE;
  pConfig->nHashSize = FTS5_DEFAULT_HASHSIZE;

  zSql = sqlite3Fts5Mprintf(&rc, zSelect, pConfig->zDb, pConfig->zName);
  if( zSql ){
    rc = sqlite3_prepare_v2(pConfig->db, zSql, -1, &p, 0);
    sqlite3_free(zSql);

  fts5MultiIterFree(pIter);
  fts5BufferFree(&term);
  if( pnRem ) *pnRem -= writer.nLeafWritten;
}

/*
** Do up to nPg pages of automerge work on the index.
**
** Return true if any changes were actually made, or false otherwise.
*/
static int fts5IndexMerge(
  Fts5Index *p,                   /* FTS5 backend object */
  Fts5Structure **ppStruct,       /* IN/OUT: Current structure of index */
  int nPg,                        /* Pages of work to do */
  int nMin                        /* Minimum number of segments to merge */
){
  int nRem = nPg;
  int bRet = 0;
  Fts5Structure *pStruct = *ppStruct;
  while( nRem>0 && p->rc==SQLITE_OK ){
    int iLvl;                   /* To iterate through levels */
    int iBestLvl = 0;           /* Level offering the most input segments */
    int nBest = 0;              /* Number of input segments on best level */

    /* Set iBestLvl to the level to read input segments from. */

    /* If nBest is still 0, then the index must be empty. */
#ifdef SQLITE_DEBUG
    for(iLvl=0; nBest==0 && iLvl<pStruct->nLevel; iLvl++){
      assert( pStruct->aLevel[iLvl].nSeg==0 );
    }
#endif


    if( nBest<nMin && pStruct->aLevel[iBestLvl].nMerge==0 ){

      break;
    }
    bRet = 1;
    fts5IndexMergeLevel(p, &pStruct, iBestLvl, &nRem);
    if( p->rc==SQLITE_OK && pStruct->aLevel[iBestLvl].nMerge==0 ){
      fts5StructurePromote(p, iBestLvl+1, pStruct);
    }
  }
  *ppStruct = pStruct;
  return bRet;
}

/*
** A total of nLeaf leaf pages of data has just been flushed to a level-0
** segment. This function updates the write-counter accordingly and, if
** necessary, performs incremental merge work.
**

    /* Update the write-counter. While doing so, set nWork. */
    nWrite = pStruct->nWriteCounter;
    nWork = (int)(((nWrite + nLeaf) / p->nWorkUnit) - (nWrite / p->nWorkUnit));
    pStruct->nWriteCounter += nLeaf;
    nRem = (int)(p->nWorkUnit * nWork * pStruct->nLevel);

    fts5IndexMerge(p, ppStruct, nRem, p->pConfig->nAutomerge);
  }
}

static void fts5IndexCrisismerge(
  Fts5Index *p,                   /* FTS5 backend object */
  Fts5Structure **ppStruct        /* IN/OUT: Current structure of index */
){

  if( p->nPendingData ){
    assert( p->pHash );
    p->nPendingData = 0;
    fts5FlushOneHash(p);
  }
}

static Fts5Structure *fts5IndexOptimizeStruct(
  Fts5Index *p, 
  Fts5Structure *pStruct
){
  Fts5Structure *pNew = 0;
  int nByte = sizeof(Fts5Structure);
  int nSeg = pStruct->nSegment;
  int i;



  /* Figure out if this structure requires optimization. A structure does
  ** not require optimization if either:
  **
  **  + it consists of fewer than two segments, or 
  **  + all segments are on the same level, or
  **  + all segments except one are currently inputs to a merge operation.
  **
  ** In the first case, return NULL. In the second, increment the ref-count
  ** on *pStruct and return a copy of the pointer to it.
  */
  if( nSeg<2 ) return 0;
  for(i=0; i<pStruct->nLevel; i++){
    int nThis = pStruct->aLevel[i].nSeg;
    if( nThis==nSeg || (nThis==nSeg-1 && pStruct->aLevel[i].nMerge==nThis) ){
      fts5StructureRef(pStruct);
      return pStruct;
    }
    assert( pStruct->aLevel[i].nMerge<=nThis );
  }




  nByte += (pStruct->nLevel+1) * sizeof(Fts5StructureLevel);
  pNew = (Fts5Structure*)sqlite3Fts5MallocZero(&p->rc, nByte);


  if( pNew ){
    Fts5StructureLevel *pLvl;
    int nByte = nSeg * sizeof(Fts5StructureSegment);
    pNew->nLevel = pStruct->nLevel+1;
    pNew->nRef = 1;
    pNew->nWriteCounter = pStruct->nWriteCounter;
    pLvl = &pNew->aLevel[pStruct->nLevel];

      pNew->nSegment = pLvl->nSeg = nSeg;
    }else{
      sqlite3_free(pNew);
      pNew = 0;
    }
  }

  return pNew;
}

int sqlite3Fts5IndexOptimize(Fts5Index *p){
  Fts5Structure *pStruct;
  Fts5Structure *pNew = 0;
  int nSeg = 0;

  assert( p->rc==SQLITE_OK );
  fts5IndexFlush(p);
  pStruct = fts5StructureRead(p);

  if( pStruct ){
    pNew = fts5IndexOptimizeStruct(p, pStruct);
  }
  fts5StructureRelease(pStruct);

  if( pNew && pNew->nSegment>0 ){
    int iLvl;
    for(iLvl=0; iLvl<pNew->nLevel; iLvl++){
      if( pNew->aLevel[iLvl].nSeg ) break;
    }
    while( p->rc==SQLITE_OK && pNew->aLevel[iLvl].nSeg>0 ){
      int nRem = FTS5_OPT_WORK_UNIT;
      fts5IndexMergeLevel(p, &pNew, iLvl, &nRem);
    }

    fts5StructureWrite(p, pNew);
    fts5StructureRelease(pNew);
  }


  return fts5IndexReturn(p); 
}

/*
** This is called to implement the special "VALUES('merge', $nMerge)"
** INSERT command.
*/
int sqlite3Fts5IndexMerge(Fts5Index *p, int nMerge){
  Fts5Structure *pStruct = fts5StructureRead(p);
  if( pStruct ){
    int nMin = p->pConfig->nUsermerge;
    if( nMerge<0 ){
      Fts5Structure *pNew = fts5IndexOptimizeStruct(p, pStruct);
      fts5StructureRelease(pStruct);
      pStruct = pNew;
      nMin = 2;
      nMerge = nMerge*-1;
    }

    if( pStruct && pStruct->nLevel ){
      if( fts5IndexMerge(p, &pStruct, nMerge, nMin) ){
        fts5StructureWrite(p, pStruct);
      }
    }
    fts5StructureRelease(pStruct);
  }
  return fts5IndexReturn(p);
}

static void fts5AppendRowid(
  Fts5Index *p,
  i64 iDelta,
  Fts5Iter *pUnused,

      pTab->base.zErrMsg = sqlite3_mprintf(
          "cannot %s contentless fts5 table: %s", 
          (nArg>1 ? "UPDATE" : "DELETE from"), pConfig->zName
      );
      rc = SQLITE_ERROR;
    }

    /* DELETE */
    else if( nArg==1 ){
      i64 iDel = sqlite3_value_int64(apVal[0]);  /* Rowid to delete */
      rc = sqlite3Fts5StorageDelete(pTab->pStorage, iDel, 0);
    }

    /* INSERT */
    else if( eType0!=SQLITE_INTEGER ){     
      /* If this is a REPLACE, first remove the current entry (if any) */
      if( eConflict==SQLITE_REPLACE 
       && sqlite3_value_type(apVal[1])==SQLITE_INTEGER 
      ){
        i64 iNew = sqlite3_value_int64(apVal[1]);  /* Rowid to delete */
        rc = sqlite3Fts5StorageDelete(pTab->pStorage, iNew, 0);
      }
      fts5StorageInsert(&rc, pTab, apVal, pRowid);
    }

    /* UPDATE */
    else{
      i64 iOld = sqlite3_value_int64(apVal[0]);  /* Old rowid */
      i64 iNew = sqlite3_value_int64(apVal[1]);  /* New rowid */
      if( iOld!=iNew ){
        if( eConflict==SQLITE_REPLACE ){
          rc = sqlite3Fts5StorageDelete(pTab->pStorage, iOld, 0);
          if( rc==SQLITE_OK ){

/*
** Return a pointer to the fts5_api pointer for database connection db.
** If an error occurs, return NULL and leave an error in the database 
** handle (accessible using sqlite3_errcode()/errmsg()).
*/
static int fts5_api_from_db(sqlite3 *db, fts5_api **ppApi){

  sqlite3_stmt *pStmt = 0;
  int rc;

  *ppApi = 0;
  rc = sqlite3_prepare(db, "SELECT fts5()", -1, &pStmt, 0);
  if( rc==SQLITE_OK ){
    if( SQLITE_ROW==sqlite3_step(pStmt) 
        && sizeof(fts5_api*)==sqlite3_column_bytes(pStmt, 0)
      ){
      memcpy(ppApi, sqlite3_column_blob(pStmt, 0), sizeof(fts5_api*));
    }
    rc = sqlite3_finalize(pStmt);
  }

  return rc;
}


/*
** Argument f should be a flag accepted by matchinfo() (a valid character
** in the string passed as the second argument). If it is not, -1 is 
** returned. Otherwise, if f is a valid matchinfo flag, the value returned

int sqlite3Fts5TestRegisterMatchinfo(sqlite3 *db){
  int rc;                         /* Return code */
  fts5_api *pApi;                 /* FTS5 API functions */

  /* Extract the FTS5 API pointer from the database handle. The 
  ** fts5_api_from_db() function above is copied verbatim from the 
  ** FTS5 documentation. Refer there for details. */
  rc = fts5_api_from_db(db, &pApi);
  if( rc!=SQLITE_OK ) return rc;

  /* If fts5_api_from_db() returns NULL, then either FTS5 is not registered
  ** with this database handle, or an error (OOM perhaps?) has occurred.
  **
  ** Also check that the fts5_api object is version 2 or newer.  
  */ 
  if( pApi==0 || pApi->iVersion<2 ){

    fts5_test_queryphrase
    fts5_test_phrasecount
  } {
    sqlite3_fts5_create_function $db $f $f
  }
}

proc fts5_segcount {tbl} {
  set N 0
  foreach n [fts5_level_segs $tbl] { incr N $n }
  set N
}

proc fts5_level_segs {tbl} {
  set sql "SELECT fts5_decode(rowid,block) aS r FROM ${tbl}_data WHERE rowid=10"
  set ret [list]
  foreach L [lrange [db one $sql] 1 end] {
    lappend ret [expr [llength $L] - 3]
  }

    WITH ii(i) AS (SELECT 1 UNION ALL SELECT i+1 FROM ii WHERE i<$::nRowPerSeg)
      INSERT INTO x8 SELECT repeat('x y ', i % 16) FROM ii;

    WITH ii(i) AS (SELECT 1 UNION ALL SELECT i+1 FROM ii WHERE i<$::nRowPerSeg)
      INSERT INTO x8 SELECT repeat('x y ', i % 16) FROM ii;

    INSERT INTO x8(x8, rank) VALUES('usermerge', 2);
  }

  for {set tn 1} {[lindex [fts5_level_segs x8] 0]>0} {incr tn} {
    do_execsql_test $testname.$tn {
      INSERT INTO x8(x8, rank) VALUES('merge', 1);
      INSERT INTO x8(x8) VALUES('integrity-check');
    }

  set ::nRow $nRow
  do_test $testname.1 {
    for {set i 0} {$i < $::nRow} {incr i} {
      execsql { INSERT INTO x8 VALUES( rnddoc(($i%16) + 5) ) }
      while {[not_merged x8]} {
        execsql {
          INSERT INTO x8(x8, rank) VALUES('usermerge', 2);
          INSERT INTO x8(x8, rank) VALUES('merge', 1);
          INSERT INTO x8(x8, rank) VALUES('usermerge', 16);
          INSERT INTO x8(x8) VALUES('integrity-check');
        }
      }
    }
  } {}
}
proc not_merged {tbl} {
  set segs [fts5_level_segs $tbl]
  foreach s $segs { if {$s>1} { return 1 } }
  return 0
}

do_merge2_test 2.1    5
do_merge2_test 2.2   10
do_merge2_test 2.3   20

#-------------------------------------------------------------------------
# Test that a merge will complete any merge that has already been
# started, even if the number of input segments is less than the current
# value of the 'usermerge' configuration parameter.
#
db func rnddoc fts5_rnddoc

do_execsql_test 3.1 {
  DROP TABLE IF EXISTS x8;
  CREATE VIRTUAL TABLE x8 USING fts5(i);
  INSERT INTO x8(x8, rank) VALUES('pgsz', 32);
  INSERT INTO x8 VALUES(rnddoc(100));
  INSERT INTO x8 VALUES(rnddoc(100));
}
do_test 3.2 {
  execsql {
    INSERT INTO x8(x8, rank) VALUES('usermerge', 4);
    INSERT INTO x8(x8, rank) VALUES('merge', 1);
  }
  fts5_level_segs x8
} {2}

do_test 3.3 {
  execsql {
    INSERT INTO x8(x8, rank) VALUES('usermerge', 2);
    INSERT INTO x8(x8, rank) VALUES('merge', 1);
  }
  fts5_level_segs x8
} {2 1}

do_test 3.4 {
  execsql { INSERT INTO x8(x8, rank) VALUES('usermerge', 4) }
  while {[not_merged x8]} {
    execsql { INSERT INTO x8(x8, rank) VALUES('merge', 1) }
  }
  fts5_level_segs x8
} {0 1}

#-------------------------------------------------------------------------

  }

  do_execsql_test 4.$tn.3 {
    WITH ii(i) AS (SELECT 1 UNION ALL SELECT i+1 FROM ii WHERE i<100)
      INSERT INTO x8 SELECT mydoc() FROM ii;
    WITH ii(i) AS (SELECT 1 UNION ALL SELECT i+1 FROM ii WHERE i<100)
      INSERT INTO x8 SELECT mydoc() FROM ii;
    INSERT INTO x8(x8, rank) VALUES('usermerge', 2);
  }

  set expect [mycount]
    for {set i 0} {$i < 20} {incr i} {
      do_test 4.$tn.4.$i {
        execsql { INSERT INTO x8(x8, rank) VALUES('merge', 1); }
        mycount
      } $expect
      break
    }
#  db eval {SELECT fts5_decode(rowid, block) AS r FROM x8_data} { puts $r }
}

#-------------------------------------------------------------------------
# Test that the 'merge' command does not modify the database if there is
# no work to do. 

do_execsql_test 5.1 {
  CREATE VIRTUAL TABLE x9 USING fts5(one, two);
  INSERT INTO x9(x9, rank) VALUES('pgsz', 32);
  INSERT INTO x9(x9, rank) VALUES('automerge', 2);
  INSERT INTO x9(x9, rank) VALUES('usermerge', 2);
  INSERT INTO x9 VALUES(rnddoc(100), rnddoc(100));
  INSERT INTO x9 VALUES(rnddoc(100), rnddoc(100));
  INSERT INTO x9 VALUES(rnddoc(100), rnddoc(100));
  INSERT INTO x9 VALUES(rnddoc(100), rnddoc(100));
  INSERT INTO x9 VALUES(rnddoc(100), rnddoc(100));
  INSERT INTO x9 VALUES(rnddoc(100), rnddoc(100));
  INSERT INTO x9 VALUES(rnddoc(100), rnddoc(100));
  INSERT INTO x9 VALUES(rnddoc(100), rnddoc(100));
}

do_test 5.2 {
  while 1 {
    set nChange [db total_changes]
    execsql { INSERT INTO x9(x9, rank) VALUES('merge', 1); }
    set nChange [expr [db total_changes] - $nChange]
    #puts $nChange
    if {$nChange<2} break
  }
} {}



finish_test

foreach {tn nStep} {
  1 2
  2 10
  3 50
  4 500
} {

  reset_db
  db func rnddoc rnddoc
  do_execsql_test 1.$tn.1 {
    CREATE VIRTUAL TABLE t1 USING fts5(x, y);
  }
  do_test 1.$tn.2 {
    for {set i 0} {$i < $nStep} {incr i} {

  do_execsql_test 1.$tn.4 {
    INSERT INTO t1(t1) VALUES('optimize');
  }

  do_execsql_test 1.$tn.5 {
    INSERT INTO t1(t1) VALUES('integrity-check');
  }

  do_test 1.$tn.6 { fts5_segcount t1 } 1
}

foreach {tn nStep} {
  1 2
  2 10
  3 50
  4 500
} {
  reset_db
  db func rnddoc rnddoc
  do_execsql_test 1.$tn.1 {
    CREATE VIRTUAL TABLE t1 USING fts5(x, y);
  }
  do_test 2.$tn.2 {
    for {set i 0} {$i < $nStep} {incr i} {
      execsql { INSERT INTO t1 VALUES( rnddoc(5), rnddoc(5) ) }
    }
  } {}

  do_execsql_test 2.$tn.3 {
    INSERT INTO t1(t1) VALUES('integrity-check');
  }

  do_test 2.$tn.4 {
    execsql { INSERT INTO t1(t1, rank) VALUES('merge', -1) }
    while 1 {
      set c [db total_changes]
      execsql { INSERT INTO t1(t1, rank) VALUES('merge', 1) }
      set c [expr [db total_changes]-$c]
      if {$c<2} break
    }
  } {}

  do_execsql_test 2.$tn.5 {
    INSERT INTO t1(t1) VALUES('integrity-check');
  }

  do_test 2.$tn.6 { fts5_segcount t1 } 1
}

finish_test