The R Project SVN R-packages

#include <stdio.h>

#include <string.h>

#include "sqlite_dataframe.h"

/****************************************************************************

 * UTILITY FUNCTIONS

 ****************************************************************************/

/* if user supplied a name, return that name. otherwise, use the 

 * default "data" */

int _check_sdf_name(SEXP name, char **rname, char **iname, int *file_idx) {

    int namelen = 0;

    /* check if arg name is supplied */

    if (IS_CHARACTER(name)) {

        *rname = CHAR_ELT(name,0);

        if (!_is_r_sym(*rname)) { 

            Rprintf("Error: supplied name \"%s\"is not a valid R symbol.\n", 

                    *rname); 

            return FALSE; 

        }

        namelen = strlen(*rname);

        *iname = (char*)R_alloc(namelen + 9, sizeof(char)); /* <name>10000.db\0 */

        sprintf(*iname, "%s.db", *rname);

    } else if (name == R_NilValue) {

        *rname = "data";

        namelen = 5;

        *iname = (char*)R_alloc(13, sizeof(char)); /* data10000.db\0 */

        *file_idx = 1;

        sprintf(*iname, "%s%d.db", *rname, *file_idx);

    } else {

        Rprintf("Error: the supplied value for arg name is not a string.\n");

    }

    return namelen;

}

int _find_free_filename(char *rname, char **iname, int *namelen, int *file_idx) {

    do {

        if (!_file_exists(*iname)) break;

        *namelen = sprintf(*iname, "%s%d.db", rname, ++(*file_idx)) - 3;

    } while (*file_idx < 10000);

    return *file_idx;

}

/* creates an sdf attribute table */

static int _create_sdf_attribute2(const char *iname) {

    sprintf(g_sql_buf[2], "create table [%s].sdf_attributes(attr text, "

            "value text, primary key (attr))", iname);

    int res = _sqlite_exec(g_sql_buf[2]);

    if (res == SQLITE_OK) {

        sprintf(g_sql_buf[2], "insert into [%s].sdf_attributes values ('name',"

                "'%s');", iname, iname);

        res = _sqlite_exec(g_sql_buf[2]);

    }

    return res;

}

/* checks if a column has a corresponding factor|ordered table */

static int _is_factor2(const char *iname, const char *factor_type, const char *colname) {

    sqlite3_stmt *stmt;

    sprintf(g_sql_buf[2], "select * from [%s].[%s %s]", iname, factor_type,

            colname);

    int res = sqlite3_prepare(g_workspace, g_sql_buf[2], -1, &stmt, 0);

    return res == SQLITE_OK;

}

/* create a factor|ordered table */

static int _create_factor_table2(const char *iname, const char *factor_type, 

        const char *colname) {

    sqlite3_stmt *stmt;

    sprintf(g_sql_buf[2], "create table [%s].[%s %s] (level int, label text, "

            "primary key(level), unique(label));", iname, factor_type, colname);

    int res = sqlite3_prepare(g_workspace, g_sql_buf[2], -1, &stmt, 0);

    sqlite3_finalize(stmt);

    return res; /* error on dup name? */

}

/* copy a factor|ordered table from a sdf(db) to another sdf(db) */

static int _copy_factor_levels2(const char *factor_type, const char *iname_src,

        const char *colname_src, const char *iname_dst, const char *colname_dst) {

    sqlite3_stmt *stmt;

    int res;

    res = _create_factor_table2(iname_dst, factor_type, colname_dst);

    if (res == SQLITE_OK) {

        sprintf(g_sql_buf[2], "insert into [%s].[%s %s] select * from [%s].[%s %s]",

                iname_src, factor_type, colname_src, iname_dst, factor_type,

                colname_dst);

        res = sqlite3_prepare(g_workspace, g_sql_buf[2], -1, &stmt, 0);

        sqlite3_finalize(stmt);

    }

    return res; /* error on dup name? */

}

/* assumes stmt has col_cnt + 1 columns, col 0 is [row name]. returned SEXP is 

 * not UNPROTECT-ed, user will have to do that. will create the names &

 * attach factor infos */

static SEXP _setup_df_sexp1(sqlite3_stmt *stmt, const char *iname, 

        int col_cnt, int row_cnt, int *dup_indices) {

    SEXP ret, names, value, class = R_NilValue;

    int i, type;

    const char *colname, *coltype;

    PROTECT(ret = NEW_LIST(col_cnt));

    /* set up names. */

    PROTECT(names = NEW_CHARACTER(col_cnt));

    for (i = 0; i < col_cnt; i++) {

        colname = sqlite3_column_name(stmt, i+1);  /* +1 bec [row name is 0] */

        coltype = sqlite3_column_decltype(stmt, i+1);

        if (dup_indices[i] == 0) {

            strcpy(g_sql_buf[1], colname);

        } else {

            sprintf(g_sql_buf[1], "%s.%d", colname, dup_indices[i]);

        }

        SET_STRING_ELT(names, i, mkChar(g_sql_buf[1]));

        if (strcmp(coltype, "text") == 0) {

            PROTECT(value = NEW_CHARACTER(row_cnt));

        } else if (strcmp(coltype, "double") == 0) {

            PROTECT(value = NEW_NUMERIC(row_cnt));

        } else if (strcmp(coltype, "bit") == 0) {

            PROTECT(value = NEW_LOGICAL(row_cnt));

        } else if (strcmp(coltype, "integer") == 0 || 

                   strcmp(coltype, "int") == 0) {

            PROTECT(value = NEW_INTEGER(row_cnt));

            type = _get_factor_levels1(iname, colname, value);

            if (type == VAR_FACTOR) {

                PROTECT(class = mkString("factor"));

                SET_CLASS(value, class);

                UNPROTECT(1);

            } else if (type == VAR_ORDERED) {

                PROTECT(class = NEW_CHARACTER(2));

                SET_STRING_ELT(class, 0, mkChar("ordered"));

                SET_STRING_ELT(class, 1, mkChar("factor"));

                SET_CLASS(value, class);

                UNPROTECT(1);

            }

        } else {

            Rprintf("Error: not supported type %s for %s\n", coltype, colname);

            UNPROTECT(2); /* unprotect ret, names */

            return R_NilValue;

        }

        SET_VECTOR_ELT(ret, i, value);

        UNPROTECT(1); /* unprotect value */

    }

    SET_NAMES(ret, names);

    UNPROTECT(1); /* unprotect names only */

    return ret;

}

/* expected that 1st col of stmt is [row name], so we start with index 1 */

static int _add_row_to_df(SEXP df, sqlite3_stmt *stmt, int row, int ncols) {

    SEXP vec;

    int type, is_null, i;

    for (i = 1; i <= ncols; i++) {

        vec = VECTOR_ELT(df, i-1);

        type = TYPEOF(vec);

        is_null = (sqlite3_column_type(stmt, row) == SQLITE_NULL);

        if (type == CHARSXP) {

            SET_STRING_ELT(vec, row, mkChar(sqlite3_column_text(stmt, i)));

        } else if (type == INTSXP) {

            INTEGER(vec)[row] = sqlite3_column_int(stmt, i);

        } else if (type == REALSXP) {

            REAL(vec)[row] = sqlite3_column_double(stmt, i);

        } else if (type == LGLSXP) {

            LOGICAL(vec)[row] = sqlite3_column_int(stmt, i);

        }

    }

}

static void _set_rownames2(SEXP df) {

    SEXP value = VECTOR_ELT(df, 0);

    int len = LENGTH(value), i;

    PROTECT(value = NEW_CHARACTER(len));

    for (i = 0; i < len; i++) {

        sprintf(g_sql_buf[2], "%d", i+1);

        SET_STRING_ELT(value, i, mkChar(g_sql_buf[2]));

    }

    SET_ROWNAMES(df, value);

    UNPROTECT(1);

}

/****************************************************************************

 * SDF FUNCTIONS

 ****************************************************************************/

SEXP sdf_create_sdf(SEXP df, SEXP name) {

    SEXP ret;

    char *rname, *iname; 

    int file_idx = 0, namelen, res, i, j;

    namelen = _check_sdf_name(name, &rname, &iname, &file_idx);

    if (!namelen) return R_NilValue;

    /* at this point, iname will contain #{iname}.db */

    _find_free_filename(rname, &iname, &namelen, &file_idx);

    /* found a free number */

    if (file_idx < 10000) {

        /* create a sdf db file by running "attach" statement to non-existent

         * db file

         */

        int sql_len, sql_len2;

        sqlite3_stmt *stmt;

        iname[namelen] = 0;  /* remove ".db" */

        sql_len = sprintf(g_sql_buf[0], "attach '%s.db' as %s", iname, iname);

        res = _sqlite_exec(g_sql_buf[0]);

        if (_sqlite_error(res)) return R_NilValue; /* duplicate dbname */

        /* 

         * create tables for the sdf db

         */

        /* create sdf_attributes table */

        res = _create_sdf_attribute2(iname);

        if (_sqlite_error(res)) return R_NilValue;

        /* create sdf_data table */

        SEXP names = GET_NAMES(df), variable, levels;

        int ncols = GET_LENGTH(names), type, *types;

        char *col_name, *class, *factor;

        /* TODO: put constraints on table after inserting everything? */

        /* 

         * create the create table and insert sql scripts by looping through

         * the columns of df

         */

        types = (int *)R_alloc(ncols, sizeof(int));

        sql_len = sprintf(g_sql_buf[0], "create table [%s].sdf_data ([row name] text", iname);

        sql_len2 = sprintf(g_sql_buf[1], "insert into [%s].sdf_data values(?", iname);

        for (i = 0; i < ncols; i++) {

            col_name = CHAR(STRING_ELT(names, i));

            /* add column definition to the create table sql */

            _expand_buf(0, sql_len+strlen(col_name)+10);

            variable = _getListElement(df, col_name);

            class = CHAR(STRING_ELT(GET_CLASS(variable), 0));

            type = TYPEOF(variable);

            types[i] = type;

            sql_len += sprintf(g_sql_buf[0]+sql_len, ", [%s] %s", col_name, 

                    _get_column_type(class, type));

            /* add handler to insert table sql */

            _expand_buf(1, sql_len+5);

            strcpy(g_sql_buf[1]+sql_len2, ",?");

            sql_len2 += 2; 

            /* create separate table for factors decode */

            if (strcmp(class, "factor") == 0 || strcmp(class, "ordered") == 0){

                if (_create_factor_table2(iname, class, col_name)) 

                    return R_NilValue; /* dup tbl name? */

                levels = GET_LEVELS(variable);

                sprintf(g_sql_buf[2], "insert into [%s].[%s %s] values(?, ?);",

                        iname, class, col_name);

                res = sqlite3_prepare(g_workspace, g_sql_buf[2], -1, &stmt, NULL);

                if (_sqlite_error(res)) return R_NilValue; /* dup tbl name? */

                for (j = 0; j < GET_LENGTH(levels); j++) {

                    sqlite3_reset(stmt);

                    factor = CHAR(STRING_ELT(levels, j));

                    sqlite3_bind_int(stmt, 1, j+1);

                    sqlite3_bind_text(stmt, 2, factor, strlen(factor), SQLITE_STATIC);

                    sqlite3_step(stmt);

                }

                sqlite3_finalize(stmt);

            }

        }

        _expand_buf(0,sql_len+35);

        /* sql_len += sprintf(g_sql_buf[0]+sql_len, ", primary key([row name]));");*/

        sql_len += sprintf(g_sql_buf[0]+sql_len, ");");

        res = _sqlite_exec(g_sql_buf[0]);

        if (_sqlite_error(res)) return R_NilValue; /* why? */

        /*

         * add the data in df to the sdf

         */

        SEXP rownames = getAttrib(df, R_RowNamesSymbol);

        int nrows = GET_LENGTH(rownames);

        char *row_name;

        sprintf(g_sql_buf[1]+sql_len2, ")");

        res = sqlite3_prepare(g_workspace, g_sql_buf[1], -1, &stmt, NULL);

        for (i = 0; i < nrows; i++) {

            row_name = CHAR(STRING_ELT(rownames, i));

            sqlite3_reset(stmt);

            if (*row_name)

                sqlite3_bind_text(stmt, 1, row_name, strlen(row_name), SQLITE_STATIC);

            else

                sqlite3_bind_int(stmt, 1, i);

            for (j = 0; j < ncols; j++) {

                variable = VECTOR_ELT(df, j);

                switch(types[j]) {

                    case INTSXP : 

                        sqlite3_bind_int(stmt, j+2, INTEGER(variable)[i]);

                        break;

                    case REALSXP:

                        sqlite3_bind_double(stmt, j+2, REAL(variable)[i]);

                        break;

                    case CHARSXP:

                        col_name = CHAR(STRING_ELT(variable,i));

                        sqlite3_bind_text(stmt, j+2, col_name, strlen(col_name), SQLITE_STATIC);

                }

                /* TODO: handle NA's & NULL's */

            }

            res = sqlite3_step(stmt);

            if (res != SQLITE_DONE) { 

                sqlite3_finalize(stmt);

                Rprintf("ERROR: %s\n", sqlite3_errmsg(g_workspace));

                return R_NilValue; /* why? */

            }

        }

        sqlite3_finalize(stmt);

        /*

         * add the new sdf to the workspace

         */

        strcpy(g_sql_buf[0], iname);

        iname[namelen] = '.';

        res = _add_sdf1(iname, g_sql_buf[0]);

        if (_sqlite_error(res)) return R_NilValue; /* why? */

        /*

         * create a new object representing the sdf

         */

        ret = _create_sdf_sexp(iname);

    } else {

        Rprintf("ERROR: cannot find a free internal name for %s", rname);

        ret = R_NilValue;

    }

    return ret;

}

SEXP sdf_get_names(SEXP sdf) {

    char *iname = SDF_INAME(sdf);

    int len = sprintf(g_sql_buf[0], "select * from [%s].sdf_data;", iname);

    sqlite3_stmt *stmt;

    int res;

    res = sqlite3_prepare(g_workspace, g_sql_buf[0], len, &stmt, NULL);

    if (_sqlite_error(res)) return R_NilValue;

    SEXP ret;

    len = sqlite3_column_count(stmt)-1;

    PROTECT(ret = NEW_CHARACTER(len));

    for (int i = 0; i < len; i++) {

        SET_STRING_ELT(ret, i, mkChar(sqlite3_column_name(stmt, i+1)));

    }

    sqlite3_finalize(stmt);

    UNPROTECT(1);

    return ret;

}

SEXP sdf_get_length(SEXP sdf) {

    char *iname = CHAR(STRING_ELT(_getListElement(sdf, "iname"),0));

    int len = sprintf(g_sql_buf[0], "select * from [%s].sdf_data;", iname);

    sqlite3_stmt *stmt;

    int res;

    res = sqlite3_prepare(g_workspace, g_sql_buf[0], len, &stmt, NULL);

    if (_sqlite_error(res)) return R_NilValue;

    SEXP ret;

    len = sqlite3_column_count(stmt)-1;

    PROTECT(ret = NEW_INTEGER(1));

    INTEGER(ret)[0] = len;

    sqlite3_finalize(stmt);

    UNPROTECT(1);

    return ret;

}

/* get row count */

SEXP sdf_get_row_count(SEXP sdf) {

    char *iname = CHAR(STRING_ELT(_getListElement(sdf, "iname"),0));

    char **out;

    int res, ncol, nrow;

    SEXP ret;

    sprintf(g_sql_buf[0], "select count(*) from [%s].sdf_data;", iname);

    res = sqlite3_get_table(g_workspace, g_sql_buf[0], &out, &nrow, &ncol, NULL);

    if (_sqlite_error(res)) return R_NilValue;

    if (nrow != 1) ret = R_NilValue;

    else {

        PROTECT(ret = NEW_INTEGER(1));

        INTEGER(ret)[0] = atoi(out[1]);

        UNPROTECT(1);

    }

    sqlite3_free_table(out);

    return ret;

}

SEXP sdf_import_table(SEXP _filename, SEXP _name, SEXP _sep, SEXP _quote, 

        SEXP _rownames, SEXP _colnames) {

    char *filename = CHAR_ELT(_filename, 0);

    FILE *f = fopen(filename, "r");

    if (f == NULL) {

        Rprintf("Error: File %s does not exist.", filename);

        return R_NilValue;

    }

    char *sep = CHAR_ELT(_sep, 0), *quote = CHAR_ELT(_quote,0);

    char *name = CHAR_ELT(_name, 0);

    /* create the table */

    /* insert the stuffs */

    /* register to workspace */

    return R_NilValue;

}

SEXP sdf_get_index(SEXP sdf, SEXP row, SEXP col) {

    SEXP ret, *df;

    char *iname = SDF_INAME(sdf);

    sqlite3_stmt *stmt, *stmt2;

    int buflen = 0, idxlen, col_cnt, row_cnt, index;

    int i, j,res;

    int *col_indices, col_index_len, *dup_indices;

    int row_index_len;

    sprintf(g_sql_buf[0], "select * from [%s].sdf_data ", iname);

    res = sqlite3_prepare(g_workspace, g_sql_buf[0], -1, &stmt, 0);

    if (_sqlite_error(res)) return R_NilValue;

    buflen = sprintf(g_sql_buf[0], "select [row name]");

    idxlen = LENGTH(col);

    col_cnt = sqlite3_column_count(stmt) - 1;

    /*

     * PROCESS COLUMN INDEX

     */

    if (col == R_NilValue) {

        for (i = 1; i < col_cnt+1; i++) {

            buflen += sprintf(g_sql_buf[0]+buflen, ",[%s]", 

                    sqlite3_column_name(stmt, i)); 

        }

        _expand_buf(0, buflen+20+strlen(iname));

        buflen += sprintf(g_sql_buf[0]+buflen, " from [%s].sdf_data", iname);

        col_index_len = col_cnt;

        col_indices = (int *)R_alloc(idxlen, sizeof(int));

        dup_indices = (int *)R_alloc(idxlen, sizeof(int));

        for (i = 0; i < col_cnt; i++) { col_indices[i] = i; dup_indices[i] = 0; }

    } else if (col == R_NilValue || idxlen < 1) {

        sqlite3_finalize(stmt);

        return R_NilValue;

    } else if (IS_NUMERIC(col)) {

        col_indices = (int *)R_alloc(idxlen, sizeof(int));

        dup_indices = (int *)R_alloc(idxlen, sizeof(int));

        col_index_len = 0;

        for (i = 0; i < idxlen; i++) {

            /* no need to correct for 0 base because col 0 is [row name] */

            index = ((int) REAL(col)[i]); 

            if (index > col_cnt) {

                sqlite3_finalize(stmt);

                Rprintf("Error: undefined columns selected\n");

                return R_NilValue;

            } else if (index > 0) {

                buflen += sprintf(g_sql_buf[0]+buflen, ",[%s]", 

                        sqlite3_column_name(stmt,index));

                dup_indices[col_index_len] = 0;

                for (j = 0; j < col_index_len; j++) {

                    if (col_indices[j] == index) dup_indices[col_index_len]++;

                }

                col_indices[col_index_len++] = index;

            } else if (index < 0) {

                sqlite3_finalize(stmt);

                Rprintf("Error: negative indices not supported.\n");

                return R_NilValue;

            }

        }

        if (col_index_len == 0) {

            sqlite3_finalize(stmt);

            Rprintf("Error: no indices detected??\n");

            return R_NilValue;

        } else { 

            _expand_buf(0, buflen+20+strlen(iname));

            buflen += sprintf(g_sql_buf[0]+buflen, " from [%s].sdf_data", iname);

        }

    } else if (IS_INTEGER(col)) {

        /* identical logic with IS_NUMERIC, except that we don't have to cast

         * stuffs from SEXP col. the alternative is doing if idxlen times. */

        col_indices = (int *)R_alloc(idxlen, sizeof(int));

        dup_indices = (int *)R_alloc(idxlen, sizeof(int));

        col_index_len = 0;

        for (i = 0; i < idxlen; i++) {

            /* no need to correct for 0 base because col 0 is [row name] */

            index = INTEGER(col)[i];

            if (index > col_cnt) {

                sqlite3_finalize(stmt);

                Rprintf("Error: undefined columns selected\n");

                return R_NilValue;

            } else if (index > 0) {

                buflen += sprintf(g_sql_buf[0]+buflen, ",[%s]", 

                        sqlite3_column_name(stmt,index));

                dup_indices[col_index_len] = 0;

                for (j = 0; j < col_index_len; j++) {

                    if (col_indices[j] == index) dup_indices[col_index_len]++;

                }

                col_indices[col_index_len++] = index;

            } else if (index < 0) {

                sqlite3_finalize(stmt);

                Rprintf("Error: negative indices not supported.\n");

                return R_NilValue;

            }

        }

        if (col_index_len == 0) {

            sqlite3_finalize(stmt);

            Rprintf("Error: no indices detected??\n");

            return R_NilValue;

        } else { 

            _expand_buf(0, buflen+20+strlen(iname));

            buflen += sprintf(g_sql_buf[0]+buflen, " from [%s].sdf_data", iname);

        }

    } else if (IS_LOGICAL(col)) {

        /* recycling stuff, so max column output is the # of cols in the df */

        col_indices = (int *)R_alloc(col_cnt, sizeof(int));

        dup_indices = (int *)R_alloc(col_cnt, sizeof(int));

        col_index_len = 0;

        for (i = 0; i < col_cnt; i++) {

            if (LOGICAL(col)[i%idxlen]) {

                buflen += sprintf(g_sql_buf[0]+buflen, ",[%s]", 

                        sqlite3_column_name(stmt,i+1));

                dup_indices[col_index_len] = 0;

                col_indices[col_index_len++] = i;

            }

        }

        if (col_index_len == 0) {

            sqlite3_finalize(stmt);

            Rprintf("Warning: no column selected.\n");

            return R_NilValue;

        } else { 

            _expand_buf(0, buflen+20+strlen(iname));

            buflen += sprintf(g_sql_buf[0]+buflen, " from [%s].sdf_data", iname);

        }

    } else {

        sqlite3_finalize(stmt);

        Rprintf("Error: don't know how to handle column index.\n");

        return R_NilValue;

    }

    /* 

     * PROCESS ROW INDEX

     */

    idxlen = LENGTH(row);

    if (row == R_NilValue) {

        if (col_index_len == 1) {

            ret = sdf_get_variable(sdf, mkString(sqlite3_column_name(stmt,col_indices[0])));

            sqlite3_finalize(stmt);

            return ret;

        } if (col_index_len > 1) {

            /* create a new SDF, logic similar to sdf_create_sdf */

            /* we have to close the current statement so we can do

             * edits in the db */

            /* sqlite3_finalize(stmt); */

            /* find a new name. data<n> ? */

            char *iname2, *rname2;

            const char *colname;

            int namelen, file_idx = 0, sql_len, sql_len2, dup_idx;

            namelen = _check_sdf_name(R_NilValue, &rname2, &iname2, &file_idx);

            if (!namelen) return R_NilValue; 

            _find_free_filename(rname2, &iname2, &namelen, &file_idx);

            if (file_idx >= 10000) { 

                Rprintf("Error: cannot find free SDF name.\n");

                return R_NilValue;

            }

            /* create new db by attaching a non-existent file */

            iname2[namelen] = 0; /* remove ".db" */

            sprintf(g_sql_buf[1], "attach '%s.db' as %s", iname2, iname2);

            res = _sqlite_exec(g_sql_buf[1]);

            if (_sqlite_error(res)) return R_NilValue; 

            /* create attributes table */

            res = _create_sdf_attribute2(iname2);

            if (_sqlite_error(res)) return R_NilValue; 

            /* create sdf_data table */

            sql_len = sprintf(g_sql_buf[1], "create table [%s].sdf_data ([row name] text", iname2);

            sql_len2 = 0;

            for (i = 0; i < col_index_len; i++) {

                colname = sqlite3_column_name(stmt, col_indices[i]);

                if (dup_indices[i] == 0) {

                    sql_len += sprintf(g_sql_buf[1]+sql_len, ", [%s] %s", colname,

                            sqlite3_column_decltype(stmt, col_indices[i]));

                } else {

                    /* un-duplicate col names by appending num, just like R */

                    sql_len += sprintf(g_sql_buf[1]+sql_len, ", [%s.%d] %s", colname,

                            dup_indices[i], 

                            sqlite3_column_decltype(stmt, col_indices[i]));

                }

                /* deal with possibly factor columns */

                if (_is_factor2(iname, "factor", colname)) {

                    /* found a factor column */

                    if (dup_indices[i] == 0)  {

                        _copy_factor_levels2("factor", iname, colname, iname2, colname);

                    } else {

                        sprintf(g_sql_buf[3], "%s.%d", colname, dup_indices[i]);

                        _copy_factor_levels2("factor", iname, colname, iname2, 

                                g_sql_buf[3]);

                    }

                }

                /* and deal with ordered factors too... life is hard, then you die */

                if (_is_factor2(iname, "ordered", colname)) {

                    if (dup_indices[i] == 0)  {

                        _copy_factor_levels2("ordered", iname, colname, iname2, 

                                colname);

                    } else {

                        sprintf(g_sql_buf[3], "%s.%d", colname, dup_indices[i]);

                        _copy_factor_levels2("ordered", iname, colname, iname2, 

                                g_sql_buf[3]);

                    }

                }

            }

            /* don't need it anymore */

            sqlite3_finalize(stmt);

            /* no table index created, that's for v2 I hope*/

            sql_len += sprintf(g_sql_buf[1]+sql_len, ");");

            res = _sqlite_exec(g_sql_buf[1]);

            if (_sqlite_error(res)) { Rprintf("here? %s\n", g_sql_buf[1]); return R_NilValue; }

            /* insert data (with row names). buf[0] contains a select */

            sprintf(g_sql_buf[1], "insert into [%s].sdf_data %s", iname2,

                    g_sql_buf[0]);

            res = _sqlite_exec(g_sql_buf[1]);

            if (_sqlite_error(res)) return R_NilValue;

            /* add new sdf to workspace */

            sprintf(g_sql_buf[0], "%s.db", iname2);

            res = _add_sdf1(g_sql_buf[0], iname2);

            if (_sqlite_error(res)) return R_NilValue;

            /* create SEXP for the SDF */

            ret = _create_sdf_sexp(iname2);

            return ret;

        } else { sqlite3_finalize(stmt); return R_NilValue; }

    } else if (row == R_NilValue || idxlen < 1) {

        sqlite3_finalize(stmt);

        return R_NilValue;

    } else if (IS_NUMERIC(row)) {

        sqlite3_finalize(stmt);

        sprintf(g_sql_buf[1], "[%s].sdf_data", iname);

        row_cnt = _get_row_count2(g_sql_buf[1]);

        /* append " limit ?,1" to the formed select statement */

        _expand_buf(0, buflen+10);

        buflen += sprintf(g_sql_buf[0]+buflen, " limit ?,1");

        /*Rprintf("sql [%d]: %s\n", buflen, g_sql_buf[0]); */

        index = ((int) REAL(row)[0]) - 1;

        if (idxlen < 0 && idxlen == 1) return R_NilValue;

        res = sqlite3_prepare(g_workspace, g_sql_buf[0], -1, &stmt, 0);

        if (_sqlite_error(res)) return R_NilValue;

        sqlite3_bind_int(stmt, 1, index);

        res = sqlite3_step(stmt);

        /* create data frame */

        ret = _setup_df_sexp1(stmt, iname, col_index_len, idxlen, dup_indices);

        if (ret == R_NilValue) { sqlite3_finalize(stmt); return R_NilValue; }

        /* put data in it */

        row_index_len = 0;

        if (index >= 0 && index < row_cnt) {

            _add_row_to_df(ret, stmt, row_index_len++, col_index_len);

        }

        for (i = 1; i < idxlen; i++) {

            sqlite3_reset(stmt);

            index = ((int) REAL(row)[i]) - 1;

            if (index >= 0 && index < row_cnt) {

                sqlite3_bind_int(stmt, 1, index);

                res = sqlite3_step(stmt);

                _add_row_to_df(ret, stmt, row_index_len++, col_index_len);

            }

        }

        sqlite3_finalize(stmt);

        /* shrink vectors */

        if (row_index_len < idxlen) {

            for (i = 0; i < col_index_len; i++) {

                SET_VECTOR_ELT(ret, i, 

                        _shrink_vector(VECTOR_ELT(ret, i), row_index_len));

            }

        }

        UNPROTECT(1); /* for the ret from _setup_df_sexp1 */

    } else if (IS_INTEGER(row)) {

        /* same stuff as with IS_INTEGER, except for setting of var index*/

        sqlite3_finalize(stmt);

        sprintf(g_sql_buf[1], "[%s].sdf_data", iname);

        row_cnt = _get_row_count2(g_sql_buf[1]);

        /* append " limit ?,1" to the formed select statement */

        _expand_buf(0, buflen+10);

        buflen += sprintf(g_sql_buf[0]+buflen, " limit ?,1");

        index = INTEGER(row)[0] - 1;

        if (idxlen < 0 && idxlen == 1) return R_NilValue;

        res = sqlite3_prepare(g_workspace, g_sql_buf[0], -1, &stmt, 0);

        if (_sqlite_error(res)) return R_NilValue;

        sqlite3_bind_int(stmt, 1, index);

        res = sqlite3_step(stmt);

        /* create data frame */

        ret = _setup_df_sexp1(stmt, iname, col_index_len, idxlen, dup_indices);

        if (ret == R_NilValue) { sqlite3_finalize(stmt); return R_NilValue; }

        /* put data in it */

        row_index_len = 0;

        if (index >= 0 && index < row_cnt) {

            _add_row_to_df(ret, stmt, row_index_len++, col_index_len);

        }

        for (i = 1; i < idxlen; i++) {

            sqlite3_reset(stmt);

            index = INTEGER(row)[i] - 1;

            if (index >= 0 && index < row_cnt) {

                sqlite3_bind_int(stmt, 1, index);

                res = sqlite3_step(stmt); 

                _add_row_to_df(ret, stmt, row_index_len++, col_index_len);

            }

        }

        sqlite3_finalize(stmt);

        /* shrink vectors */

        if (row_index_len < idxlen) {

            for (i = 0; i < col_index_len; i++) {

                SET_VECTOR_ELT(ret, i, 

                        _shrink_vector(VECTOR_ELT(ret, i), row_index_len));

            }

        }

        UNPROTECT(1); /* for the ret from _setup_df_sexp1 */

    } else if (IS_LOGICAL(row)) {

        /* */

        sqlite3_finalize(stmt);

        int est_row_cnt = 0;

        sprintf(g_sql_buf[1], "[%s].sdf_data", iname);

        row_cnt = _get_row_count2(g_sql_buf[1]);

        /* append " limit ?,1" to the formed select statement */

        _expand_buf(0, buflen+10);

        buflen += sprintf(g_sql_buf[0]+buflen, " limit ?,1");

        /* find if there is any TRUE element in the vector */

        for (i = 0; i < idxlen & i < row_cnt; i++) {

            if (LOGICAL(row)[i]) break;

        }

        if (i < idxlen & i < row_cnt) {

            est_row_cnt = (idxlen-i) * (row_cnt/idxlen);

            if (row_cnt%idxlen > i) est_row_cnt += (row_cnt%idxlen - i);

            res = sqlite3_prepare(g_workspace, g_sql_buf[0], -1, &stmt, 0);

            if (_sqlite_error(res)) return R_NilValue;

            sqlite3_bind_int(stmt, 1, i);

            sqlite3_step(stmt);

            ret = _setup_df_sexp1(stmt, iname, col_index_len, est_row_cnt, dup_indices);

            row_index_len = 0;

            _add_row_to_df(ret, stmt, row_index_len++, col_index_len);

            for (i++ ; i < row_cnt; i++) {

                if (LOGICAL(row)[i%idxlen]) {

                    sqlite3_reset(stmt);

                    sqlite3_bind_int(stmt, 1, i);

                    sqlite3_step(stmt);

                    _add_row_to_df(ret, stmt, row_index_len++, col_index_len);

                }

            }

        }

        sqlite3_finalize(stmt);

        /* shrink vectors */

        if (est_row_cnt > 0 && row_index_len < est_row_cnt) {

            for (i = 0; i < col_index_len; i++) {

                SET_VECTOR_ELT(ret, i, 

                        _shrink_vector(VECTOR_ELT(ret, i), row_index_len));

            }

        }

        UNPROTECT(1); /* for the ret from _setup_df_sexp1 */

    }

    if (ret != R_NilValue && col_index_len > 1) {

        SEXP class = mkString("data.frame");

        SET_CLASS(ret, class);

        _set_rownames2(ret);

    } else if (ret != R_NilValue && col_index_len == 1) {

        ret = VECTOR_ELT(ret, 0);

    }

    return ret;

}

SEXP sopen(SEXP name) {

    char *filename;

    if (IS_CHARACTER(name)) {

        filename = CHAR(STRING_ELT(name,0));

        Rprintf("%s\n", filename);

    }

    /* sqlite3 *db;

    int res = sqlite3_open(filename, &db); */

    SEXP ret;

    PROTECT(ret = NEW_LOGICAL(1));

    LOGICAL(ret)[0] = IS_CHARACTER(name);

    /* sqlite3_close(db); */ 

    UNPROTECT(1);

    return ret;

}