com.xceptance.xlt.engine.scripting.VariableScope Maven / Gradle / Ivy
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XLT (Xceptance LoadTest) is an extensive load and performance test tool developed and maintained by Xceptance.
/*
* Copyright (c) 2005-2022 Xceptance Software Technologies GmbH
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.xceptance.xlt.engine.scripting;
import java.util.Collections;
import java.util.HashSet;
import java.util.Map;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import org.apache.commons.lang3.StringUtils;
import com.xceptance.common.util.RegExUtils;
/**
* Scope for resolution of variables used by certain commands.
*
* @author Hartmut Arlt (Xceptance Software Technologies GmbH)
*/
public final class VariableScope
{
/** Pattern used to check variable names for validity. */
private static final Pattern VAR_NAME_PATTERN = Pattern.compile("^[A-Za-z_][A-Za-z0-9_]*$");
/** Pattern used to detect quoted dollar-signs. */
private static final Pattern QUOTE_DOLLARSIGN_PATTERN = Pattern.compile("\\$\\$");
/** Pattern used to resolve variable expressions. */
private static final Pattern VAR_EXPR_PATTERN = Pattern.compile("(? _testData;
/**
* Creates a new scope enclosed in the given one.
*
* @param enclosingScope
* the enclosing scope (may be null)
*/
VariableScope(final Map testData, final VariableScope enclosingScope)
{
_enclosingScope = enclosingScope;
_testData = testData != null ? testData : Collections.emptyMap();
}
/**
* Creates a new top-level scope.
*/
VariableScope(final Map testData)
{
this(testData, null);
}
/**
* Returns the enclosing scope.
*/
VariableScope getEnclosingScope()
{
return _enclosingScope;
}
/**
* Returns whether or not this scope is enclosed by another scope.
*
* @return true if this scope is enclosed by another scope, false otherwise
*/
boolean hasEnclosingScope()
{
return _enclosingScope != null;
}
/**
* Resolves the given string.
*
* @param resolvable
* the string to be resolved
* @return the resolved string
*/
String resolve(final String resolvable)
{
if (StringUtils.isBlank(resolvable))
{
return resolvable;
}
final String varResolved = resolveRecursively(resolvable, new HashSet());
return resolveMacros(varResolved);
}
/**
* Resolves the given test data key
*
* @param key
* the key string containing only the name of a test data field
* @return resolved string or null if not found
*/
String resolveKey(final String key)
{
final String resolveKey;
if (StringUtils.isBlank(key))
{
return key;
}
if (RegExUtils.isMatching(key, VAR_EXPR_PATTERN))
{
resolveKey = key;
}
else
{
resolveKey = "${" + key + "}";
}
String resolved = resolve(resolveKey);
if (resolved.equals(resolveKey))
{
return null;
}
else
{
return resolved;
}
}
/**
* Inserts a new test data mapping where the given key is mapped to the given value.
*
* @param key
* the test data variable
* @param value
* the value of the variable
*/
void storeValue(final String key, final String value)
{
if (!isValidVariable(key))
{
throw new ScriptException("Invalid variable name '" + key + "'");
}
if (value != null)
{
synchronized (this)
{
_testData.put(key, value);
}
}
}
/**
* Resolves the given variable.
*
* @param variable
* the test data variable to resolve
* @return the value of the given test data variable or null if there is no such variable known
*/
private String resolveVariable(final String variable)
{
String value = null;
if (_enclosingScope != null)
{
value = _enclosingScope.resolveVariable(variable);
}
if (value == null)
{
value = _testData.get(variable);
}
return value;
}
/**
* Resolves the given string recursively.
*
* @param value
* the value to resolve
* @param hashSet
* set of all variables already resolved
* @return resolved string
*/
private String resolveRecursively(final String value, final HashSet hashSet)
{
String s = value;
if (StringUtils.isNotBlank(s))
{
int iterations = 0;
while (true)
{
if (iterations++ > MAX_ITERATIONS)
{
throw new ScriptException("Failed to resolve '" + value + "'");
}
final String input = s;
final MacroProcessor macroProc = MacroProcessor.getInstance();
for (final String match : RegExUtils.getAllMatches(s, VAR_EXPR_PATTERN))
{
final String exp = match.substring(2, match.length() - 1);
if (isValidVariable(exp) && !hashSet.contains(exp) && !macroProc.isMacro(exp))
{
hashSet.add(exp);
final String resolved = resolveVariable(exp);
if (resolved != null)
{
final String recResolved = resolveRecursively(resolved, new HashSet(hashSet));
s = RegExUtils.replaceAll(s, "(? MAX_ITERATIONS)
{
throw new ScriptException("Failed to resolve macros for '" + value + "'");
}
final String input = s;
final StringBuilder result = new StringBuilder(s);
final Matcher m = MACRO_EXPR_PATTERN.matcher(s);
int offset = 0;
while (m.find())
{
final String match = m.group();
String replacement = match;
if (match.length() == 2 && match.charAt(0) == match.charAt(1))
{
continue;
}
else
{
final String variable = match.substring(2, match.length() - 1);
if (macroProc.isMacro(variable))
{
replacement = macroProc.executeMacro(variable);
}
}
result.replace(m.start() + offset, m.end() + offset, replacement);
offset += replacement.length() - match.length();
}
s = result.toString();
if (s.equals(input))
{
break;
}
}
}
return unescape(s);
}
private static boolean isValidVariable(final String variable)
{
return RegExUtils.isMatching(variable, VAR_NAME_PATTERN);
}
private static String unescape(final String value)
{
String s = value;
if (!StringUtils.isEmpty(s))
{
final StringBuilder result = new StringBuilder(s);
final Matcher m = QUOTE_DOLLARSIGN_PATTERN.matcher(s);
int offset = 0;
while (m.find())
{
result.replace(m.start() + offset, m.end() + offset, "$");
--offset;
}
s = result.toString();
}
return s;
}
}