OutOfMemoryError: Java heap space when compiling unwanted source maps

[fnicollet]

Hello,

We are running into an error, here is the stack trace:

Caused by: java.lang.OutOfMemoryError: Java heap space
	at java.util.Arrays.copyOf(Arrays.java:2367)
	at java.lang.AbstractStringBuilder.expandCapacity(AbstractStringBuilder.java:130)
	at java.lang.AbstractStringBuilder.ensureCapacityInternal(AbstractStringBuilder.java:114)
	at java.lang.AbstractStringBuilder.append(AbstractStringBuilder.java:415)
	at java.lang.StringBuilder.append(StringBuilder.java:132)
	at java.lang.StringBuilder.append(StringBuilder.java:179)
	at java.lang.StringBuilder.append(StringBuilder.java:72)
	at com.github.sommeri.sourcemap.SourceMapGeneratorV3.addValuesList(SourceMapGeneratorV3.java:367)
	at com.github.sommeri.sourcemap.SourceMapGeneratorV3.addSourceContentMap(SourceMapGeneratorV3.java:339)
	at com.github.sommeri.sourcemap.SourceMapGeneratorV3.appendTo(SourceMapGeneratorV3.java:314)
	at com.github.sommeri.less4j.core.output.SourceMapBuilder.toSourceMap(SourceMapBuilder.java:135)
	at com.github.sommeri.less4j.utils.CssPrinter.toSourceMap(CssPrinter.java:1052)
	at com.github.sommeri.less4j.core.ThreadUnsafeLessCompiler.createCompilationResult(ThreadUnsafeLessCompiler.java:120)
	at com.github.sommeri.less4j.core.ThreadUnsafeLessCompiler.doCompile(ThreadUnsafeLessCompiler.java:88)
	at com.github.sommeri.less4j.core.ThreadUnsafeLessCompiler.compile(ThreadUnsafeLessCompiler.java:76)
	at com.github.sommeri.less4j.core.ThreadUnsafeLessCompiler.compile(ThreadUnsafeLessCompiler.java:65)
	at com.github.sommeri.less4j.core.DefaultLessCompiler.compile(DefaultLessCompiler.java:44)
	at utils.applications.ThemeCompiler.compileThemeContent(ThemeCompiler.java:186)

We don't really care about source map, we don't actually have any, we are just compiling a lot of tiny less files. I tried disabling the source map altogether:

      LessCompiler.Configuration configuration = new LessCompiler.Configuration();
      configuration.getSourceMapConfiguration().setLinkSourceMap(false);
      LessCompiler.CompilationResult result = lessCompiler.compile(source, configuration);

But when I read the code, the option is read in "handleSourceMapLink":

less4j/src/main/java/com/github/sommeri/less4j/core/ThreadUnsafeLessCompiler.java

Line 201 in bca5cb2

if (!sourceMapConfiguration.shouldLinkSourceMap() && !sourceMapConfiguration.isInline())

Which is right after the "toSourceMap" line where it crashes:

less4j/src/main/java/com/github/sommeri/less4j/core/ThreadUnsafeLessCompiler.java

Lines 177 to 179 in bca5cb2

	String sourceMap = builder.toSourceMap();
	handleSourceMapLink(cssStyleSheet, css, options, lessSource, sourceMap);

Is it an error in less4j? Should the option be read earlier so that it doesn't concatenate Strings that won't be used later?

Fabien