SQLite

#include "fts1.h"
#include "fts1_hash.h"
#include "fts1_tokenizer.h"
#include "sqlite3.h"
#include "sqlite3ext.h"
SQLITE_EXTENSION_INIT1


#if 0
# define TRACE(A)  printf A; fflush(stdout)
#else
# define TRACE(A)
#endif

/* utility functions */

/* We encode variable-length integers in little-endian order using seven bits
 * per byte as follows:
**
** KEY:
**         A = 0xxxxxxx    7 bits of data and one flag bit

  *r++ = '\0';
  assert( r == result + len );
  return result;
}

static int sql_exec(sqlite3 *db, const char *zName, const char *zFormat){
  char *zCommand = string_format(zFormat, zName);
  TRACE(("FTS1 sql: %s\n", zCommand));
  int rc = sqlite3_exec(db, zCommand, NULL, 0, NULL);
  free(zCommand);
  return rc;
}

static int sql_prepare(sqlite3 *db, const char *zName, sqlite3_stmt **ppStmt,
                const char *zFormat){
  char *zCommand = string_format(zFormat, zName);
  TRACE(("FTS1 prepare: %s\n", zCommand));
  int rc = sqlite3_prepare(db, zCommand, -1, ppStmt, NULL);
  free(zCommand);
  return rc;
}

/* end utility functions */

  return sql_single_step_statement(v, TERM_DELETE_STMT, &s);
}

static void fulltext_vtab_destroy(fulltext_vtab *v){
  int iStmt;

  TRACE(("FTS1 Destroy %p\n", v));
  for( iStmt=0; iStmt<MAX_STMT; iStmt++ ){
    if( v->pFulltextStatements[iStmt]!=NULL ){
      sqlite3_finalize(v->pFulltextStatements[iStmt]);
      v->pFulltextStatements[iStmt] = NULL;
    }
  }

  rc = sqlite3_declare_vtab(db, "create table x(content text)");
  if( rc!=SQLITE_OK ) return rc;

  memset(v->pFulltextStatements, 0, sizeof(v->pFulltextStatements));

  *ppVTab = &v->base;
  TRACE(("FTS1 Connect %p\n", v));
  return SQLITE_OK;
}

static int fulltextCreate(sqlite3 *db, void *pAux, int argc, char **argv,
                          sqlite3_vtab **ppVTab){
  int rc;
  assert( argc>=3 );
  TRACE(("FTS1 Create\n"));

  /* The %_content table holds the text of each full-text item, with
  ** the rowid used as the docid.
  **
  ** The %_term table maps each term to a document list blob
  ** containing elements sorted by ascending docid, each element
  ** encoded as:

      pInfo->aConstraintUsage[i].omit = 1;
      pInfo->idxNum = QUERY_FULLTEXT;
      pInfo->estimatedCost = 1.0;   /* an arbitrary value for now */
      return SQLITE_OK;
    }
  }
  pInfo->idxNum = QUERY_GENERIC;
  TRACE(("FTS1 BestIndex\n"));
  return SQLITE_OK;
}

static int fulltextDisconnect(sqlite3_vtab *pVTab){
  TRACE(("FTS1 Disconnect %p\n", pVTab));
  fulltext_vtab_destroy((fulltext_vtab *)pVTab);
  return SQLITE_OK;
}

static int fulltextDestroy(sqlite3_vtab *pVTab){
  fulltext_vtab *v = (fulltext_vtab *)pVTab;

  TRACE(("FTS1 Destroy %p\n", pVTab));
  int rc = sql_exec(v->db, v->zName,
                    "drop table %_content; drop table %_term");
  if( rc!=SQLITE_OK ) return rc;

  fulltext_vtab_destroy((fulltext_vtab *)pVTab);
  return SQLITE_OK;
}

static int fulltextOpen(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor){
  fulltext_cursor *c;

  c = (fulltext_cursor *) calloc(sizeof(fulltext_cursor), 1);
  /* sqlite will initialize c->base */
  *ppCursor = &c->base;
  TRACE(("FTS1 Open %p: %p\n", pVTab, c));

  return SQLITE_OK;
}

static int fulltextClose(sqlite3_vtab_cursor *pCursor){
  fulltext_cursor *c = (fulltext_cursor *) pCursor;
  TRACE(("FTS1 Close %p\n", c));
  sqlite3_finalize(c->pStmt);
  if( c->result.pDoclist!=NULL ){
    docListDelete(c->result.pDoclist);
  }
  free(c);
  return SQLITE_OK;
}

static int fulltextNext(sqlite3_vtab_cursor *pCursor){
  fulltext_cursor *c = (fulltext_cursor *) pCursor;
  sqlite_int64 iDocid;
  int rc;

  TRACE(("FTS1 Next %p\n", pCursor));
  switch( c->iCursorType ){
    case QUERY_GENERIC:
      /* TODO(shess) Handle SQLITE_SCHEMA AND SQLITE_BUSY. */
      rc = sqlite3_step(c->pStmt);
      switch( rc ){
        case SQLITE_ROW:
          c->eof = 0;

                          int idxNum, const char *idxStr,
                          int argc, sqlite3_value **argv){
  fulltext_cursor *c = (fulltext_cursor *) pCursor;
  fulltext_vtab *v = cursor_vtab(c);
  int rc;
  const char *zStatement;

  TRACE(("FTS1 Filter %p\n",pCursor));
  c->iCursorType = idxNum;
  switch( idxNum ){
    case QUERY_GENERIC:
      zStatement = "select rowid, content from %_content";
      break;

    case QUERY_FULLTEXT:   /* full-text search */

  return content_delete(v, iRow);
}

static int fulltextUpdate(sqlite3_vtab *pVtab, int nArg, sqlite3_value **ppArg,
                   sqlite_int64 *pRowid){
  fulltext_vtab *v = (fulltext_vtab *) pVtab;

  TRACE(("FTS1 Update %p\n", pVtab));
  if( nArg<2 ){
    return index_delete(v, sqlite3_value_int64(ppArg[0]));
  }

  if( sqlite3_value_type(ppArg[0]) != SQLITE_NULL ){
    return SQLITE_ERROR;   /* an update; not yet supported */
  }