[CRUNCH-369] Crunch doesn't use custom getSplits functions of FileInputFormat subclasses

• Type: Bug
• Status: Closed
• Priority: Minor
• Resolution: Duplicate
• Affects Version/s: 0.9.0
• Component/s: IO
• Assignee: Unassigned
• Reporter: Jeremy Lewi
• Created: 23/Mar/14 03:33
• Updated: 19/Sep/14 00:07
• Resolved: 23/Mar/14 19:41

Description

Suppose I create a source for a custom InputFormat which is a subclass of FileInputFormat; e.g.

TableSource<LongWritable, FastQWritable> source = From.formattedFile(
inputFile, FastQInputFormatNew.class, LongWritable.class,
FastQWritable.class);

where FastQInputFormat is a subclass of FileInputFormat.

This won't work as expected because by default CrunchInputFormat.getSplits will end up using CrunchCombineFileInputFormat to split the file. This doesn't work because my custom FIleInputFormat uses a custom file splitter.

I can work around this by explicitly disabling the combining: e.g

source.inputConf(RuntimeParameters.DISABLE_COMBINE_FILE, Boolean.TRUE.toString());

but this doesn't strike me as the best solution. If I tell Crunch to use a custom InputFormat I shouldn't have to specify a second config option in order to tell Crunch to respect the getSplits function in my custom InputFormat.

I think CrunchInputFormat.getSplits should check that the format class exactly matches FileInputFormat; i.e. it isn't a subclass. For subclasses Crunch should use the getsplits function in the custom InputFormat class. I think changing the check to the following might work

if (format.getClass().equals(FileInputFormat.class) &&
!conf.getBoolean(RuntimeParameters.DISABLE_COMBINE_FILE, true)

Issue Links

• duplicates: CRUNCH-331 Change default settings for CombineFileInputFormat