/*******************************************************************************
* Copyright (c) 2009 The Eclipse Foundation.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* which accompanies this distribution, and is available at
* http://www.eclipse.org/legal/epl-v10.html
*
* Contributors:
* The Eclipse Foundation - initial API and implementation
*******************************************************************************/
package org.eclipse.epp.usagedata.internal.recording;
import java.io.IOException;
import java.io.Reader;
import java.io.StringReader;
import java.io.Writer;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.eclipse.epp.usagedata.internal.gathering.events.UsageDataEvent;
public class UsageDataRecorderUtils {
/**
* Write a header onto the {@link Writer}.
*
* @param writer
* a {@link Writer}. Must not be <code>null</code>.
* @throws IOException
* if writing to the {@link Writer} fails.
*/
public static void writeHeader(Writer writer) throws IOException {
writer.write("what"); //$NON-NLS-1$
writer.write(","); //$NON-NLS-1$
writer.write("kind"); //$NON-NLS-1$
writer.write(","); //$NON-NLS-1$
writer.write("bundleId"); //$NON-NLS-1$
writer.write(","); //$NON-NLS-1$
writer.write("bundleVersion"); //$NON-NLS-1$
writer.write(","); //$NON-NLS-1$
writer.write("description"); //$NON-NLS-1$
writer.write(","); //$NON-NLS-1$
writer.write("time"); //$NON-NLS-1$
writer.write("\n"); //$NON-NLS-1$
}
/**
* Dump the event on the writer. This method assumes exclusive access to the
* writer.
*
* @param writer
* target for the event information. Must not be
* <code>null</code>.
* @param event
* event to write. Must not be <code>null</code>.
*
* @throws IOException
* if writing to the {@link Writer} fails.
*/
public static void writeEvent(Writer writer, UsageDataEvent event) throws IOException {
writer.write(event.what);
writer.write(","); //$NON-NLS-1$
writer.write(event.kind);
writer.write(","); //$NON-NLS-1$
writer.write(event.bundleId != null ? event.bundleId : ""); //$NON-NLS-1$
writer.write(","); //$NON-NLS-1$
writer.write(event.bundleVersion != null ? event.bundleVersion : ""); //$NON-NLS-1$
writer.write(","); //$NON-NLS-1$
writer.write(event.description != null ? encode(event.description) : ""); //$NON-NLS-1$
writer.write(","); //$NON-NLS-1$
writer.write(String.valueOf(event.when));
writer.write("\n"); //$NON-NLS-1$
}
/**
* This method encodes the description so that it can be successfully parsed
* as a single entry by a CSV parser. This takes care of most of the
* escape characters to ensure that the output gets dumped onto a single
* line. We probably take care of more escape characters than we really
* need to, but that's better than the opposite...
* <p>
* The escaped characters should only be an issue in the rare case when
* a status message contains them. Most of our monitors do not generate
* text that contains them.
*
* @param description
* a {@link String}. Must not be <code>null</code>.
*
* @return a {@link String}.
*/
public static String encode(String description) {
StringBuilder builder = new StringBuilder();
builder.append('"');
for(int index=0;index<description.length();index++) {
char next = description.charAt(index);
switch (next) {
case '"' :
builder.append('"');
builder.append(next);
break;
case '\\' :
builder.append("\\\\"); //$NON-NLS-1$
break;
case '\n' :
builder.append("\\n"); //$NON-NLS-1$
break;
case '\r' :
builder.append("\\r"); //$NON-NLS-1$
break;
case '\b' :
builder.append("\\b"); //$NON-NLS-1$
break;
case '\t' :
builder.append("\\t"); //$NON-NLS-1$
break;
case '\f' :
builder.append("\\f"); //$NON-NLS-1$
break;
default :
builder.append(next);
}
}
builder.append('"');
return builder.toString();
}
/**
* Split the String parameter into substrings. The parameter is assumed to
* be in CSV format. Comma separators are assumed. An entry that starts and
* ends with double-quotes may contain commas or escaped double-quotes.
* Double-quotes are escaped by putting two one-after-the-other. This method
* assumes that there are no extraneous white spaces (i.e. leading or
* trailing) in the input.
* <p>
* Note that we don't worry about trying to re-translate escaped characters
* back into their unescaped form. We assume that this method is used exclusively
* for displaying events in a preview pane, or for applying filters; we don't
* need to translate the escaped characters in either of these cases.
* <p>
* The value: "first,\"\"\"second\"\", third\",fourth" will be parsed into
* three strings: "first", "\"second\", third", and "fourth".
* <p>
* Note that callers can safely assume that all entries in the resulting
* array will be non-<code>null</code>.
*
* @param line
* a {@link String}. Must not be <code>null</code>.
*
* @return an array of {@link String}s.
*/
public static String[] splitLine(String line) {
List<String> strings = new java.util.ArrayList<String>();
try {
splitLine(line, strings);
} catch (IOException e) {
// TODO Auto-generated catch block
e.printStackTrace();
}
return (String[]) strings.toArray(new String[strings.size()]);
}
private static void splitLine(String line, List<String> strings) throws IOException {
/*
* There is a potential issue with this implementation in the case
* where a quoted-wrapped field starts with an escaped quote. i.e.
* the string \"\"\"value\"\"\" will be read as escaped-quote, followed
* by quote rather than as quote followed by escaped-quote as is
* intended. The net result is the same (evidenced in the test cases).
*/
Reader reader = new StringReader(line);
int next = 0;
StringBuilder builder = new StringBuilder();
boolean inQuote = false;
while ((next = reader.read()) != -1) {
if (next == '"') {
reader.mark(1);
if (reader.read() == '"') {
builder.append('"');
} else {
reader.reset();
inQuote = !inQuote;
}
} else if (next == ',') {
if (inQuote) {
builder.append(',');
} else {
strings.add(builder.toString());
builder = new StringBuilder();
}
} else {
builder.append((char)next);
}
}
strings.add(builder.toString());
}
}