In the current Pulsar codebase, the logic to parse CLI arguments for measurement units like time and bytes is scattered across various CLI classes. Each value read has its distinct parsing implementation, leading to a lack of code reuse.
This PIP is to refactor the argument parsing logic to leverage the @Parameter.converter
functionality provided by JCommander [link 3]. This will isolate the measurement-specific parsing logic and increase code reusability.
Cmd
classes to utilize the converter functionality of JCommander. This will streamline the parsing logic and simplify the codebase.CmdNamespaces.java
CmdTopics.java
,CmdTopicPolicies.java
.Consider the code snippet from CmdNamespaces.java for example. The existing code uses a local variable maxBlockSizeStr
to temporarily store the value of --maxBlockSize
or -mbs
. This is then parsed and validated in a separate section of the code.
@Parameter( names = {"--maxBlockSize", "-mbs"}, description = "Max block size (eg: 32M, 64M), default is 64MB s3 and google-cloud-storage requires this parameter", required = false) private String maxBlockSizeStr;
parsing like below ....
// parsing like.... int maxBlockSizeInBytes=OffloadPoliciesImpl.DEFAULT_MAX_BLOCK_SIZE_IN_BYTES; if(StringUtils.isNotEmpty(maxBlockSizeStr)){ long maxBlockSize=validateSizeString(maxBlockSizeStr); if(positiveCheck("MaxBlockSize",maxBlockSize) &&maxValueCheck("MaxBlockSize",maxBlockSize,Integer.MAX_VALUE)) { maxBlockSizeInBytes=Long.valueOf(maxBlockSize).intValue(); } }
@Parameter( names = {"--maxBlockSize", "-mbs"}, description = "Max block size (eg: 32M, 64M), default is 64MB s3 and google-cloud-storage requires this parameter", required = false, converter = MemoryUnitToByteConverter.class) // <--- parsing logic "inline" easy to follow private long maxBlockSizeStr=DEFAULT_MAX_BLOCK_SIZE_IN_BYTES; // <---- default value in line
... and actual parsing in isolation, ready for reuse like...
class MemoryUnitToByteConverter implements IStringConverter<Long> { private static Set<Character> sizeUnit = Sets.newHashSet('k', 'K', 'm', 'M', 'g', 'G', 't', 'T'); private final long defaultValue; public MemoryUnitToByteConverter(long defaultValue) { this.defaultValue = defaultValue; } @Override public Long convert(String memoryLimitArgument) { parseBytes(memoryLimitArgument); } long parseBytes(String memoryLimitArgument) { if (StringUtils.isNotEmpty(memoryLimitArgument)) { long memoryLimitArg = validateSizeString(memoryLimitArgument); if (positiveCheckStatic("memory-limit", memoryLimitArg)) { return memoryLimitArg; } } return defaultValue; } ... more internal helper methods }