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Copyright 2011, Google Inc.
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modification, are permitted provided that the following conditions are
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this software without specific prior written permission.
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LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
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OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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(INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
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*/
package com.google.refine.pcaxis;
import java.io.IOException;
import java.io.LineNumberReader;
import java.util.ArrayList;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.LinkedList;
import java.util.List;
import java.util.Map;
import com.google.refine.importers.TabularImportingParserBase.TableDataReader;
public class PCAxisTableDataReader implements TableDataReader {
final private static class Dimension {
String name;
List<String> values;
int next;
}
final private LineNumberReader _lnReader;
final private List<Exception> exceptions;
String _line = null;
List<Dimension> _dimensions = null;
public PCAxisTableDataReader(LineNumberReader lnReader, List<Exception> exceptions) {
this._lnReader = lnReader;
this.exceptions = exceptions;
}
@Override
public List<Object> getNextRowOfCells() throws IOException {
if (_line == null) {
_line = _lnReader.readLine();
}
if (_line == null) {
return null;
}
if (_dimensions == null) {
return parseMetadataPrologueForColumnNames();
} else {
return parseForNextDataRow();
}
}
private List<Object> parseMetadataPrologueForColumnNames() throws IOException {
_dimensions = new LinkedList<Dimension>();
List<String> dimensionNames = new ArrayList<String>();
while (_line != null) {
int equal = _line.indexOf('=');
if (equal < 0 || _line.startsWith("DATA=")) {
break;
}
// Save the line in case parseValues() changes it.
String savedLine = _line;
List<String> values = parseMetadataValues(equal + 1, exceptions);
if (savedLine.startsWith("VALUES(\"")) {
Dimension dimension = new Dimension();
dimension.name = savedLine.substring(8, equal - 2);
dimension.values = values;
_dimensions.add(dimension);
} else if (savedLine.startsWith("STUB=")) {
dimensionNames.addAll(0, values);
} else if (savedLine.startsWith("HEADING=")) {
dimensionNames.addAll(values);
}
_line = _lnReader.readLine();
}
final Map<String, Integer> dimensionNameToOrder = new HashMap<String, Integer>();
for (int i = 0; i < dimensionNames.size(); i++) {
dimensionNameToOrder.put(dimensionNames.get(i), dimensionNames.size() - i - 1);
}
Collections.sort(_dimensions, new Comparator<Dimension>() {
@Override
public int compare(Dimension d0, Dimension d1) {
return dimensionNameToOrder.get(d0.name)
.compareTo(dimensionNameToOrder.get(d1.name));
}
});
List<Object> columnNames = new LinkedList<Object>();
for (int i = _dimensions.size() - 1; i >= 0; i--) {
columnNames.add(_dimensions.get(i).name);
}
columnNames.add("value");
return columnNames;
}
private List<String> parseMetadataValues(int start, List<Exception> _exceptions) throws IOException {
List<String> values = new ArrayList<String>();
outer:while (_line != null && start < _line.length()) {
char c = _line.charAt(start);
if (c == '"') {
// A string
StringBuffer sb = new StringBuffer();
inner:while (_line != null && start < _line.length()) {
int close = _line.indexOf('"', start + 1);
if (close < 0) {
// Exceptional case of missing closing "
_exceptions.add(new Exception(
"Missing closing quotation mark on line " + _lnReader.getLineNumber()));
sb.append(_line.substring(start + 1));
values.add(sb.toString());
break outer;
} else {
sb.append(_line.substring(start + 1, close));
if (close == _line.length() - 1) {
// String value continues on next line
_line = _lnReader.readLine();
start = 0;
if (_line != null && _line.length() > 0) {
c = _line.charAt(0);
if (c == '"') {
continue inner;
}
}
break;
} else {
start = close + 1;
break;
}
}
}
values.add(sb.toString());
} else {
// A number or identifier
int comma = customIndexOf(_line, ',', start + 1);
int semicolon = customIndexOf(_line, ';', start + 1);
int space = customIndexOf(_line, ' ', start + 1);
int end = Math.min(comma, Math.min(semicolon, space));
values.add(_line.substring(start, end));
start = end;
}
if (start == _line.length()) {
// End of line but no ;. Continue onto next line.
_line = _lnReader.readLine();
start = 0;
} else {
c = _line.charAt(start);
if (c == ';' || c == ')') {
break;
} else if (c == ',' || c == ' ' || c == '-') {
start++;
if (start == _line.length()) {
_line = _lnReader.readLine();
start = 0;
}
} else {
// Exceptional case.
_exceptions.add(new Exception(
"Unrecognized character " + c + " on line " + _lnReader.getLineNumber()));
break;
}
}
}
return values;
}
private List<Object> parseForNextDataRow() throws IOException {
List<Object> cells = getNextBatchOfDataValues(1);
if (cells.size() == 0) {
return null;
}
if (_dimensions.size() > 0) {
for (int i = 0; i < _dimensions.size(); i++) {
Dimension d = _dimensions.get(i);
if (d.next == d.values.size()) {
d.next = 0;
if (i < _dimensions.size() - 1) {
_dimensions.get(i + 1).next++;
}
}
cells.add(0, d.values.get(d.next));
if (i == 0) {
d.next++;
}
}
}
return cells;
}
private List<Object> getNextBatchOfDataValues(int expectedCount) throws IOException {
List<Object> cells = new LinkedList<Object>();
int start = _line.startsWith("DATA=") ? 5 : 0;
while (_line != null) {
int end = Math.min(
customIndexOf(_line, ';', start),
Math.min(
customIndexOf(_line, ' ', start),
customIndexOf(_line, '\t', start)));
if (end > start) {
cells.add(_line.substring(start, end));
}
while (end < _line.length()) {
if (Character.isWhitespace(_line.charAt(end))) {
end++;
} else {
break;
}
}
if (end == _line.length()) {
_line = _lnReader.readLine();
start = 0;
} else if (_line.charAt(end) == ';') {
_line = _lnReader.readLine();
break;
} else {
start = end;
}
if (cells.size() == expectedCount) {
_line = _line.substring(start);
break;
}
}
return cells;
}
static private int customIndexOf(String s, char c, int start) {
int i = s.indexOf(c, start);
return i < 0 ? s.length() : i;
}
}