Ensure DiskSpaceMonitor is initialised on each Queue instantiation

[tgd]

Previously, the disk space monitor was only instantiated when acquiring a store file. This meant that disk space monitor only monitored queue paths that had been appended to by the current Queue API instance. After this change the disk space monitor will monitor each queue path even if an appender was never instantiated or used. For test coverage please see:

Chronicle-Queue/src/test/java/net/openhft/chronicle/queue/DiskSpaceMonitoringIntegrationTest.java

Lines 23 to 109 in cdc10d6

	class DiskSpaceMonitoringIntegrationTest extends QueueTestCommon {
	/**
	* Stores which paths are being monitored by the {@link net.openhft.chronicle.threads.DiskSpaceMonitor}.
	*/
	private Map<String, FileStore> monitoredPaths;
	@SuppressWarnings("unchecked")
	@BeforeEach
	public void beforeEach() throws NoSuchFieldException, IllegalAccessException {
	Field fileStoreCacheMap = DiskSpaceMonitor.class.getDeclaredField("fileStoreCacheMap");
	fileStoreCacheMap.setAccessible(true);
	monitoredPaths = (Map<String, FileStore>) fileStoreCacheMap.get(DiskSpaceMonitor.INSTANCE);
	}
	@Nested
	class EnsureThatPollIsCalledInDifferentScenarioTests {
	@Test
	void newQueueNoWrite() {
	File tmpDir = getTmpDir();
	try (SingleChronicleQueue queue = SingleChronicleQueueBuilder.builder().path(tmpDir).build();
	ExcerptAppender appender = queue.createAppender()) {
	assertMapped(tmpDir);
	} finally {
	IOTools.deleteDirWithFiles(tmpDir);
	}
	}
	@Test
	void newQueueWithWrite() {
	File tmpDir = getTmpDir();
	try (SingleChronicleQueue queue = SingleChronicleQueueBuilder.builder().path(tmpDir).build();
	ExcerptAppender appender = queue.createAppender()) {
	appender.writeText("Test");
	assertMapped(tmpDir);
	} finally {
	IOTools.deleteDirWithFiles(tmpDir);
	}
	}
	@Test
	void newQueueJustTail() {
	File tmpDir = getTmpDir();
	try (SingleChronicleQueue queue = SingleChronicleQueueBuilder.builder().path(tmpDir).build();
	ExcerptTailer tailer = queue.createTailer()) {
	assertMapped(tmpDir);
	} finally {
	IOTools.deleteDirWithFiles(tmpDir);
	}
	}
	@Test
	void existingQueueNoWrite() {
	File tmpDir = getTmpDir();
	try (SingleChronicleQueue queue = SingleChronicleQueueBuilder.builder().path(tmpDir).build();
	ExcerptAppender appender = queue.createAppender()) {
	// Intentional no-op
	}
	try (SingleChronicleQueue queue = SingleChronicleQueueBuilder.builder().path(tmpDir).build();
	ExcerptAppender appender = queue.createAppender()) {
	assertMapped(tmpDir);
	}
	}
	@Test
	void existingQueueWithWrite() {
	File tmpDir = getTmpDir();
	try (SingleChronicleQueue queue = SingleChronicleQueueBuilder.builder().path(tmpDir).build();
	ExcerptAppender appender = queue.createAppender()) {
	// Intentional no-op
	}
	try (SingleChronicleQueue queue = SingleChronicleQueueBuilder.builder().path(tmpDir).build();
	ExcerptAppender appender = queue.createAppender()) {
	appender.writeText("Test");
	assertMapped(tmpDir);
	}
	}
	}
	private void assertMapped(File queuePath) {
	String path = queuePath.getAbsolutePath().toString();
	assertTrue(monitoredPaths.containsKey(path), () -> "Expected that the following queue path should be monitored by the disk space monitor, but it was not. Path: " + path);
	}