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Change arguments parsing of CSV module
This commit is contained in:
gwenn
parent
5fa3810a4b
commit
10ba0514e6
@ -1,4 +1,5 @@
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//! CSV Virtual Table
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//! Port of [csv](http://www.sqlite.org/cgi/src/finfo?name=ext/misc/csv.c) C extension.
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extern crate csv;
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use std::fs::File;
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use std::os::raw::{c_char, c_int, c_void};
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@ -9,9 +10,19 @@ use std::str;
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use {Connection, Error, Result};
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use ffi;
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use types::Null;
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use vtab::{declare_vtab, escape_double_quote, Context, IndexInfo, Values, VTab, VTabCursor};
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use vtab::{declare_vtab, dequote, escape_double_quote, parse_boolean, Context, IndexInfo, Values, VTab, VTabCursor};
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/// Register the "csv" module.
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/// ```sql
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/// CREATE VIRTUAL TABLE vtab USING csv(
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/// filename=FILENAME -- Name of file containing CSV content
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/// [, schema=SCHEMA] -- Alternative CSV schema. 'CREATE TABLE x(col1 TEXT NOT NULL, col2 INT, ...);'
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/// [, header=YES|NO] -- First row of CSV defines the names of columns if "yes". Default "no".
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/// [, columns=N] -- Assume the CSV file contains N columns.
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/// [, delimiter=C] -- CSV delimiter. Default ','.
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/// [, quote=C] -- CSV quote. Default '"'. 0 means no quote.
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/// );
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/// ```
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pub fn load_module(conn: &Connection) -> Result<()> {
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let aux: Option<()> = None;
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conn.create_module("csv", &CSV_MODULE, aux)
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@ -55,6 +66,27 @@ impl CSVTab {
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.quote(self.quote)
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})
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}
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fn parameter(c_slice: &[u8]) -> Result<(&str, &str)> {
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let arg = try!(str::from_utf8(c_slice)).trim();
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let mut split = arg.split('=');
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if let Some(key) = split.next() {
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if let Some(value) = split.next() {
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let param = key.trim();
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let value = dequote(value);
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return Ok((param, value));
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}
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}
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Err(Error::ModuleError(format!("illegal argument: '{}'", arg)))
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}
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fn parse_byte(arg: &str) -> Option<u8> {
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if arg.len() == 1 {
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arg.bytes().next()
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} else {
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None
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}
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}
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}
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impl VTab<CSVTabCursor> for CSVTab {
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@ -62,78 +94,124 @@ impl VTab<CSVTabCursor> for CSVTab {
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if args.len() < 4 {
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return Err(Error::ModuleError("no CSV file specified".to_owned()));
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}
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// pull out name of csv file (remove quotes)
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let mut c_filename = args[3];
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if c_filename[0] == b'\'' {
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c_filename = &c_filename[1..c_filename.len() - 1];
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}
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let filename = try!(str::from_utf8(c_filename));
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if !Path::new(filename).exists() {
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return Err(Error::ModuleError(format!("file '{}' does not exist", filename)));
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}
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let mut vtab = CSVTab {
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base: Default::default(),
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filename: String::from(filename),
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filename: "".to_owned(),
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has_headers: false,
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delimiter: b',',
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quote: b'"',
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offset_first_row: 0,
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};
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let mut cols: Vec<String> = Vec::new();
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let mut schema = None;
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let mut n_col = None;
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let args = &args[4..];
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let args = &args[3..];
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for c_slice in args {
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if c_slice.len() == 1 {
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vtab.delimiter = c_slice[0];
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} else if c_slice.len() == 3 && c_slice[0] == b'\'' {
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vtab.delimiter = c_slice[1];
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let (param, value) = try!(CSVTab::parameter(c_slice));
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match param {
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"filename" => {
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if !Path::new(value).exists() {
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return Err(Error::ModuleError(format!("file '{}' does not exist", value)));
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}
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vtab.filename = value.to_owned();
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},
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"schema" => {
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schema = Some(value.to_owned());
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},
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"columns" => {
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if let Ok(n) = value.parse::<u16>() {
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if n_col.is_some() {
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return Err(Error::ModuleError("more than one 'columns' parameter".to_owned()));
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} else if n == 0 {
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return Err(Error::ModuleError("must have at least one column".to_owned()));
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}
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n_col = Some(n);
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} else {
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return Err(Error::ModuleError(format!("unrecognized argument to 'columns': {}", value)));
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}
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},
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"header" => {
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if let Some(b) = parse_boolean(value) {
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vtab.has_headers = b;
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} else {
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return Err(Error::ModuleError(format!("unrecognized argument to 'header': {}", value)));
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}
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},
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"delimiter" => {
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if let Some(b) = CSVTab::parse_byte(value) {
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vtab.delimiter = b;
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} else {
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return Err(Error::ModuleError(format!("unrecognized argument to 'delimiter': {}", value)));
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}
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},
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"quote" => {
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if let Some(b) = CSVTab::parse_byte(value) {
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if b == b'0' {
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vtab.quote = 0;
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} else {
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vtab.quote = b;
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}
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} else {
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return Err(Error::ModuleError(format!("unrecognized argument to 'quote': {}", value)));
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}
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},
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_ => {
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return Err(Error::ModuleError(format!("unrecognized parameter '{}'", param)));
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},
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}
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}
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if vtab.filename.is_empty() {
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return Err(Error::ModuleError("no CSV file specified".to_owned()));
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}
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let mut cols: Vec<String> = Vec::new();
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if vtab.has_headers || (n_col.is_none() && schema.is_none()) {
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let mut reader = try!(vtab.reader());
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if vtab.has_headers {
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let headers = try!(reader.headers());
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vtab.offset_first_row = reader.byte_offset();
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// headers ignored if cols is not empty
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if n_col.is_none() && schema.is_none() {
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cols = headers.into_iter().map(|header| escape_double_quote(&header).into_owned()).collect();
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}
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} else {
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let arg = try!(str::from_utf8(c_slice));
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let uc = arg.to_uppercase();
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if uc.contains("HEADER") {
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vtab.has_headers = true;
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} else if uc.contains("NO_QUOTE") {
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vtab.quote = 0;
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} else {
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cols.push(escape_double_quote(arg).into_owned());
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let mut count = 0;
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while let Some(col) = reader.next_bytes().into_iter_result() {
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try!(col);
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cols.push(format!("c{}", count));
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count+=1;
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}
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}
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}
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if vtab.has_headers {
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let mut reader = try!(vtab.reader());
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let headers = try!(reader.headers());
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vtab.offset_first_row = reader.byte_offset();
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// headers ignored if cols is not empty
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if cols.is_empty() {
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cols = headers;
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}
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if cols.is_empty() && schema.is_none() {
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return Err(Error::ModuleError("no column specified".to_owned()));
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}
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if cols.is_empty() {
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return Err(Error::ModuleError("no column name specified".to_owned()));
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if schema.is_none() {
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let mut sql = String::from("CREATE TABLE x(");
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for (i, col) in cols.iter().enumerate() {
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sql.push('"');
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sql.push_str(col);
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sql.push_str("\" TEXT");
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if i == cols.len() - 1 {
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sql.push_str(");");
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} else {
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sql.push_str(", ");
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}
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}
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schema = Some(sql);
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}
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let mut sql = String::from("CREATE TABLE x(");
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for (i, col) in cols.iter().enumerate() {
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if col.is_empty() {
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return Err(Error::ModuleError("no column name found".to_owned()));
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}
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sql.push('"');
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sql.push_str(col);
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sql.push_str("\" TEXT");
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if i == cols.len() - 1 {
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sql.push_str(");");
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} else {
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sql.push_str(", ");
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}
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}
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try!(declare_vtab(db, &sql));
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try!(declare_vtab(db, &schema.unwrap()));
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Ok(vtab)
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}
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fn best_index(&self, _info: &mut IndexInfo) -> Result<()> {
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// Only a forward full table scan is supported.
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fn best_index(&self, info: &mut IndexInfo) -> Result<()> {
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info.set_estimated_cost(1000000.);
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Ok(())
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}
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@ -149,8 +227,9 @@ struct CSVTabCursor {
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base: ffi::sqlite3_vtab_cursor,
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/// The CSV reader object
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reader: csv::Reader<File>,
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/// Current cursor position
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/// Current cursor position used as rowid
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row_number: usize,
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/// Values of the current row
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cols: Vec<String>,
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eof: bool,
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}
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@ -172,6 +251,8 @@ impl VTabCursor<CSVTab> for CSVTabCursor {
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unsafe { & *(self.base.pVtab as *const CSVTab) }
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}
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// Only a full table scan is supported. So `filter` simply rewinds to
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// the beginning.
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fn filter(&mut self,
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_idx_num: c_int,
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_idx_str: Option<&str>,
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@ -236,7 +317,7 @@ mod test {
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fn test_csv_module() {
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let db = Connection::open_in_memory().unwrap();
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csvtab::load_module(&db).unwrap();
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db.execute_batch("CREATE VIRTUAL TABLE vtab USING csv('test.csv', HAS_HEADERS)").unwrap();
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db.execute_batch("CREATE VIRTUAL TABLE vtab USING csv(filename='test.csv', header=yes)").unwrap();
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{
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let mut s = db.prepare("SELECT rowid, * FROM vtab").unwrap();
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@ -257,7 +338,7 @@ mod test {
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fn test_csv_cursor() {
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let db = Connection::open_in_memory().unwrap();
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csvtab::load_module(&db).unwrap();
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db.execute_batch("CREATE VIRTUAL TABLE vtab USING csv('test.csv', HAS_HEADERS)").unwrap();
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db.execute_batch("CREATE VIRTUAL TABLE vtab USING csv(filename='test.csv', header=yes)").unwrap();
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{
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let mut s =
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@ -331,6 +331,35 @@ pub fn escape_double_quote(identifier: &str) -> Cow<str> {
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Borrowed(identifier)
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}
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}
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/// Dequote string
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pub fn dequote(s: &str) -> &str {
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if s.len() < 2 {
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return s;
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}
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match s.bytes().next() {
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Some(b) if b == b'"' || b == b'\'' => {
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match s.bytes().rev().next() {
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Some(e) if e == b => &s[1..s.len()-1],
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_ => s,
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}
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},
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_ => s,
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}
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}
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/// The boolean can be one of:
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/// ```text
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/// 1 yes true on
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/// 0 no false off
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/// ```
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pub fn parse_boolean(s: &str) -> Option<bool> {
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if s.eq_ignore_ascii_case("yes") || s.eq_ignore_ascii_case("on") || s.eq_ignore_ascii_case("true") || s.eq("1") {
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Some(true)
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} else if s.eq_ignore_ascii_case("no") || s.eq_ignore_ascii_case("off") || s.eq_ignore_ascii_case("false") || s.eq("0") {
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Some(false)
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} else {
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None
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}
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}
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// FIXME copy/paste from function.rs
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unsafe extern "C" fn free_boxed_value<T>(p: *mut c_void) {
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@ -665,3 +694,31 @@ pub mod int_array;
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pub mod csvtab;
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#[cfg(feature = "bundled")]
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pub mod series;
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#[cfg(test)]
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mod test {
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#[test]
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fn test_dequote() {
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assert_eq!("", super::dequote(""));
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assert_eq!("'", super::dequote("'"));
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assert_eq!("\"", super::dequote("\""));
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assert_eq!("'\"", super::dequote("'\""));
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assert_eq!("", super::dequote("''"));
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assert_eq!("", super::dequote("\"\""));
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assert_eq!("x", super::dequote("'x'"));
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assert_eq!("x", super::dequote("\"x\""));
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assert_eq!("x", super::dequote("x"));
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}
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#[test]
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fn test_parse_boolean() {
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assert_eq!(None, super::parse_boolean(""));
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assert_eq!(Some(true), super::parse_boolean("1"));
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assert_eq!(Some(true), super::parse_boolean("yes"));
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assert_eq!(Some(true), super::parse_boolean("on"));
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assert_eq!(Some(true), super::parse_boolean("true"));
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assert_eq!(Some(false), super::parse_boolean("0"));
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assert_eq!(Some(false), super::parse_boolean("no"));
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assert_eq!(Some(false), super::parse_boolean("off"));
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assert_eq!(Some(false), super::parse_boolean("false"));
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}
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}
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