Put filter spec information in a dedicated object

This increases type-safety and is ground work for support of the
"tree:<depth>" filter.

Change-Id: Id19eacdcdaddb9132064c642f6d554b1060efe9f
Signed-off-by: Matthew DeVore <matvore@gmail.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/ProtocolV0ParserTest.java

 		assertThat(request.getWantIds(),
 				hasOnlyObjectIds("4624442d68ee402a94364191085b77137618633e",
 						"f900c8326a43303685c46b279b9f70411bff1a4b"));
-		assertEquals(13000, request.getFilterBlobLimit());
+		assertEquals(13000, request.getFilterSpec().getBlobLimit());
 	}
 
 }

org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/ProtocolV2ParserTest.java

 		ProtocolV2Parser parser = new ProtocolV2Parser(
 				ConfigBuilder.start().allowFilter().done());
 		FetchV2Request request = parser.parseFetchRequest(pckIn);
-		assertEquals(0, request.getFilterBlobLimit());
+		assertEquals(0, request.getFilterSpec().getBlobLimit());
 	}
 
 	@Test
 		ProtocolV2Parser parser = new ProtocolV2Parser(
 				ConfigBuilder.start().allowFilter().done());
 		FetchV2Request request = parser.parseFetchRequest(pckIn);
-		assertEquals(15, request.getFilterBlobLimit());
+		assertEquals(15, request.getFilterSpec().getBlobLimit());
 	}
 
 	@Test

org.eclipse.jgit/src/org/eclipse/jgit/transport/FetchRequest.java

 
 	final Set<ObjectId> clientShallowCommits;
 
-	final long filterBlobLimit;
+	final FilterSpec filterSpec;
 
 	final Set<String> clientCapabilities;
 
 	 *            how deep to go in the tree
 	 * @param clientShallowCommits
 	 *            commits the client has without history
-	 * @param filterBlobLimit
-	 *            to exclude blobs on certain conditions
+	 * @param filterSpec
+	 *            the filter spec
 	 * @param clientCapabilities
 	 *            capabilities sent in the request
 	 * @param deepenNotRefs
 	 *            agent as reported by the client in the request body
 	 */
 	FetchRequest(@NonNull Set<ObjectId> wantIds, int depth,
-			@NonNull Set<ObjectId> clientShallowCommits, long filterBlobLimit,
+			@NonNull Set<ObjectId> clientShallowCommits,
+			@NonNull FilterSpec filterSpec,
 			@NonNull Set<String> clientCapabilities, int deepenSince,
 			@NonNull List<String> deepenNotRefs, @Nullable String agent) {
 		this.wantIds = requireNonNull(wantIds);
 		this.depth = depth;
 		this.clientShallowCommits = requireNonNull(clientShallowCommits);
-		this.filterBlobLimit = filterBlobLimit;
+		this.filterSpec = requireNonNull(filterSpec);
 		this.clientCapabilities = requireNonNull(clientCapabilities);
 		this.deepenSince = deepenSince;
 		this.deepenNotRefs = requireNonNull(deepenNotRefs);
 	}
 
 	/**
-	 * @return the blob limit set in a "filter" line (-1 if not set)
+	 * @return the filter spec given in a "filter" line
 	 */
-	long getFilterBlobLimit() {
-		return filterBlobLimit;
+	@NonNull
+	FilterSpec getFilterSpec() {
+		return filterSpec;
 	}
 
 	/**
 	String getAgent() {
 		return agent;
 	}
-}
+}

org.eclipse.jgit/src/org/eclipse/jgit/transport/FetchV0Request.java

  */
 package org.eclipse.jgit.transport;
 
+import static java.util.Objects.requireNonNull;
+
 import java.util.Collection;
 import java.util.Collections;
 import java.util.HashSet;
 final class FetchV0Request extends FetchRequest {
 
 	FetchV0Request(@NonNull Set<ObjectId> wantIds, int depth,
-			@NonNull Set<ObjectId> clientShallowCommits, long filterBlobLimit,
+			@NonNull Set<ObjectId> clientShallowCommits,
+			@NonNull FilterSpec filterSpec,
 			@NonNull Set<String> clientCapabilities, @Nullable String agent) {
-		super(wantIds, depth, clientShallowCommits, filterBlobLimit,
-				clientCapabilities, 0, Collections.emptyList(), agent);
+		super(wantIds, depth, clientShallowCommits, filterSpec,
+				clientCapabilities, 0, Collections.emptyList(),	agent);
 	}
 
 	static final class Builder {
 
 		final Set<ObjectId> clientShallowCommits = new HashSet<>();
 
-		long filterBlobLimit = -1;
+		FilterSpec filterSpec = FilterSpec.NO_FILTER;
 
 		final Set<String> clientCaps = new HashSet<>();
 
 		}
 
 		/**
-		 * @param filterBlobLim
-		 *            blob limit set in a "filter" line
+		 * @param filter
+		 *            the filter set in a filter line
 		 * @return this builder
 		 */
-		Builder setFilterBlobLimit(long filterBlobLim) {
-			filterBlobLimit = filterBlobLim;
+		Builder setFilterSpec(@NonNull FilterSpec filter) {
+			filterSpec = requireNonNull(filter);
 			return this;
 		}
 
 		FetchV0Request build() {
 			return new FetchV0Request(wantIds, depth, clientShallowCommits,
-					filterBlobLimit, clientCaps, agent);
+					filterSpec, clientCaps, agent);
 		}
 
 	}

org.eclipse.jgit/src/org/eclipse/jgit/transport/FetchV2Request.java

 			@NonNull Set<ObjectId> wantIds,
 			@NonNull Set<ObjectId> clientShallowCommits, int deepenSince,
 			@NonNull List<String> deepenNotRefs, int depth,
-			long filterBlobLimit,
+			@NonNull FilterSpec filterSpec,
 			boolean doneReceived, @NonNull Set<String> clientCapabilities,
 			@Nullable String agent, @NonNull List<String> serverOptions) {
-		super(wantIds, depth, clientShallowCommits, filterBlobLimit,
-				clientCapabilities, deepenSince, deepenNotRefs, agent);
+		super(wantIds, depth, clientShallowCommits, filterSpec,
+				clientCapabilities, deepenSince,
+				deepenNotRefs, agent);
 		this.peerHas = requireNonNull(peerHas);
 		this.wantedRefs = requireNonNull(wantedRefs);
 		this.doneReceived = doneReceived;
 
 		int deepenSince;
 
-		long filterBlobLimit = -1;
+		FilterSpec filterSpec = FilterSpec.NO_FILTER;
 
 		boolean doneReceived;
 
 		}
 
 		/**
-		 * @param filterBlobLim
-		 *            set in a "filter" line
+		 * @param filter
+		 *            spec set in a "filter" line
 		 * @return this builder
 		 */
-		Builder setFilterBlobLimit(long filterBlobLim) {
-			filterBlobLimit = filterBlobLim;
+		Builder setFilterSpec(@NonNull FilterSpec filter) {
+			filterSpec = requireNonNull(filter);
 			return this;
 		}
 
 		FetchV2Request build() {
 			return new FetchV2Request(peerHas, wantedRefs, wantIds,
 					clientShallowCommits, deepenSince, deepenNotRefs,
-					depth, filterBlobLimit, doneReceived, clientCapabilities,
+					depth, filterSpec, doneReceived, clientCapabilities,
 					agent, Collections.unmodifiableList(serverOptions));
 		}
 	}

org.eclipse.jgit/src/org/eclipse/jgit/transport/FilterSpec.java

 import org.eclipse.jgit.internal.JGitText;
 
 /**
- * Utility code for dealing with filter lines.
+ * Represents either a filter specified in a protocol "filter" line, or a
+ * placeholder to indicate no filtering.
+ *
+ * @since 5.4
  */
-final class FilterSpec {
+public final class FilterSpec {
+
+	private final long blobLimit;
 
-	private FilterSpec() {}
+	private FilterSpec(long blobLimit) {
+		this.blobLimit = blobLimit;
+	}
 
-	/*
+	/**
 	 * Process the content of "filter" line from the protocol. It has a shape
 	 * like "blob:none" or "blob:limit=N", with limit a positive number.
 	 *
 	 * @param filterLine
 	 *            the content of the "filter" line in the protocol
-	 * @return N, the limit, defaulting to 0 if "none"
+	 * @return a FilterSpec representing the given filter
 	 * @throws PackProtocolException
 	 *             invalid filter because due to unrecognized format or
 	 *             negative/non-numeric filter.
 	 */
-	static long parseFilterLine(String filterLine)
+	public static FilterSpec fromFilterLine(String filterLine)
 			throws PackProtocolException {
 		long blobLimit = -1;
 
 							JGitText.get().invalidFilter, filterLine));
 		}
 
+		return new FilterSpec(blobLimit);
+	}
+
+	/**
+	 * @param blobLimit
+	 *            the blob limit in a "blob:[limit]" or "blob:none" filter line
+	 * @return a filter spec which filters blobs above a certain size
+	 */
+	static FilterSpec withBlobLimit(long blobLimit) {
+		if (blobLimit < 0) {
+			throw new IllegalArgumentException(
+					"blobLimit cannot be negative: " + blobLimit); //$NON-NLS-1$
+		}
+		return new FilterSpec(blobLimit);
+	}
+
+	/**
+	 * A placeholder that indicates no filtering.
+	 */
+	public static final FilterSpec NO_FILTER = new FilterSpec(-1);
+
+	/**
+	 * @return -1 if this filter does not filter blobs based on size, or a
+	 *         non-negative integer representing the max size of blobs to allow
+	 */
+	public long getBlobLimit() {
 		return blobLimit;
 	}
 
+	/**
+	 * @return true if this filter doesn't filter out anything
+	 */
+	public boolean isNoOp() {
+		return blobLimit == -1;
+	}
+
 }

org.eclipse.jgit/src/org/eclipse/jgit/transport/ProtocolV0Parser.java

 				}
 				filterReceived = true;
 
-				reqBuilder.setFilterBlobLimit(FilterSpec.parseFilterLine(arg));
+				reqBuilder.setFilterSpec(FilterSpec.fromFilterLine(arg));
 				continue;
 			}
 

org.eclipse.jgit/src/org/eclipse/jgit/transport/ProtocolV2Parser.java

 							JGitText.get().tooManyFilters);
 				}
 				filterReceived = true;
-				reqBuilder.setFilterBlobLimit(FilterSpec.parseFilterLine(
+				reqBuilder.setFilterSpec(FilterSpec.fromFilterLine(
 						line.substring(OPTION_FILTER.length() + 1)));
 			} else {
 				throw new PackProtocolException(MessageFormat

org.eclipse.jgit/src/org/eclipse/jgit/transport/UploadPack.java

 		if (currentRequest == null) {
 			throw new RequestNotYetReadException();
 		}
-		return currentRequest.getFilterBlobLimit();
+		return currentRequest.getFilterSpec().getBlobLimit();
 	}
 
 	/**
 				accumulator);
 		try {
 			pw.setIndexDisabled(true);
-			if (req.getFilterBlobLimit() >= 0) {
-				pw.setFilterBlobLimit(req.getFilterBlobLimit());
-				pw.setUseCachedPacks(false);
-			} else {
+			if (req.getFilterSpec().isNoOp()) {
 				pw.setUseCachedPacks(true);
+			} else {
+				pw.setFilterBlobLimit(req.getFilterSpec().getBlobLimit());
+				pw.setUseCachedPacks(false);
 			}
 			pw.setUseBitmaps(
 					req.getDepth() == 0