Extract protocol v2 fetch request parsing to its own class

The parsing code for protocol v2 fetch doesn't have any dependency on
the rest of UploadPack.

Move it to its own class. This makes testing easier (no need to
instantiate the full UploadPack), simplifies the code in UploadPack and
increases modularity.

At the moment, the parser needs to know about the reference database to
validate incoming references. This dependency could be easily removed
moving the validation later in the flow, after the parsing, where other
validations are already happening. Postponing that to keep this patch
about moving unmodified code around.

Change-Id: I7ad29a6b99caa7c12c06f5a7f30ab6a5f6e44dc7
Signed-off-by: Ivan Frade <ifrade@google.com>

1 files changed, 336 insertions, 0 deletions

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/ProtocolV2ParserTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/ProtocolV2ParserTest.java
new file mode 100644
index 0000000000..4d1150844c
--- /dev/null
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/transport/ProtocolV2ParserTest.java
@@ -0,0 +1,336 @@
+/*
+ * Copyright (C) 2018, Google LLC.
+ * and other copyright owners as documented in the project's IP log.
+ *
+ * This program and the accompanying materials are made available
+ * under the terms of the Eclipse Distribution License v1.0 which
+ * accompanies this distribution, is reproduced below, and is
+ * available at http://www.eclipse.org/org/documents/edl-v10.php
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ *   notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ *   copyright notice, this list of conditions and the following
+ *   disclaimer in the documentation and/or other materials provided
+ *   with the distribution.
+ *
+ * - Neither the name of the Eclipse Foundation, Inc. nor the
+ *   names of its contributors may be used to endorse or promote
+ *   products derived from this software without specific prior
+ *   written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+package org.eclipse.jgit.transport;
+
+import static org.hamcrest.Matchers.containsString;
+import static org.hamcrest.Matchers.hasItems;
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertThat;
+import static org.junit.Assert.assertTrue;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.util.Collection;
+import java.util.List;
+import java.util.stream.Collectors;
+
+import org.eclipse.jgit.errors.PackProtocolException;
+import org.eclipse.jgit.internal.storage.dfs.DfsRepositoryDescription;
+import org.eclipse.jgit.internal.storage.dfs.InMemoryRepository;
+import org.eclipse.jgit.junit.TestRepository;
+import org.eclipse.jgit.lib.Config;
+import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.revwalk.RevCommit;
+import org.junit.Before;
+import org.junit.Rule;
+import org.junit.Test;
+import org.junit.rules.ExpectedException;
+
+public class ProtocolV2ParserTest {
+
+	@Rule
+	public ExpectedException thrown = ExpectedException.none();
+
+	private TestRepository<InMemoryRepository> testRepo;
+
+	@Before
+	public void setUp() throws Exception {
+		testRepo = new TestRepository<>(newRepo("protocol-v2-parser-test"));
+	}
+
+	private static InMemoryRepository newRepo(String name) {
+		return new InMemoryRepository(new DfsRepositoryDescription(name));
+	}
+
+	private static class ConfigBuilder {
+
+		private boolean allowRefInWant;
+
+		private boolean allowFilter;
+
+		private ConfigBuilder() {
+		}
+
+		static ConfigBuilder start() {
+			return new ConfigBuilder();
+		}
+
+		static TransferConfig getDefault() {
+			return start().done();
+		}
+
+		ConfigBuilder allowRefInWant() {
+			allowRefInWant = true;
+			return this;
+		}
+
+		ConfigBuilder allowFilter() {
+			allowFilter = true;
+			return this;
+		}
+
+		TransferConfig done() {
+			Config rc = new Config();
+			rc.setBoolean("uploadpack", null, "allowrefinwant", allowRefInWant);
+			rc.setBoolean("uploadpack", null, "allowfilter", allowFilter);
+			return new TransferConfig(rc);
+		}
+	}
+
+	/*
+	 * Convert the input lines to the PacketLine that the parser reads.
+	 */
+	private static PacketLineIn formatAsPacketLine(String... inputLines)
+			throws IOException {
+		ByteArrayOutputStream send = new ByteArrayOutputStream();
+		PacketLineOut pckOut = new PacketLineOut(send);
+		for (String line : inputLines) {
+			if (line == PacketLineIn.END) {
+				pckOut.end();
+			} else if (line == PacketLineIn.DELIM) {
+				pckOut.writeDelim();
+			} else {
+				pckOut.writeString(line);
+			}
+		}
+
+		return new PacketLineIn(new ByteArrayInputStream(send.toByteArray()));
+	}
+
+	private static List<String> objIdsAsStrings(Collection<ObjectId> objIds) {
+		// TODO(ifrade) Translate this to a matcher, so it would read as
+		// assertThat(req.wantsIds(), hasObjectIds("...", "..."))
+		return objIds.stream().map(ObjectId::name).collect(Collectors.toList());
+	}
+
+	/*
+	 * Succesful fetch with the basic core commands of the protocol.
+	 */
+	@Test
+	public void testFetchBasicArguments()
+			throws PackProtocolException, IOException {
+		PacketLineIn pckIn = formatAsPacketLine(
+				PacketLineIn.DELIM,
+				"thin-pack", "no-progress", "include-tag", "ofs-delta",
+				"want 4624442d68ee402a94364191085b77137618633e",
+				"want f900c8326a43303685c46b279b9f70411bff1a4b",
+				"have 554f6e41067b9e3e565b6988a8294fac1cb78f4b",
+				"have abc760ab9ad72f08209943251b36cb886a578f87", "done",
+				PacketLineIn.END);
+		ProtocolV2Parser parser = new ProtocolV2Parser(
+				ConfigBuilder.getDefault());
+		FetchV2Request request = parser.parseFetchRequest(pckIn,
+				testRepo.getRepository().getRefDatabase());
+		assertTrue(request.getOptions()
+				.contains(GitProtocolConstants.OPTION_THIN_PACK));
+		assertTrue(request.getOptions()
+				.contains(GitProtocolConstants.OPTION_NO_PROGRESS));
+		assertTrue(request.getOptions()
+				.contains(GitProtocolConstants.OPTION_INCLUDE_TAG));
+		assertTrue(request.getOptions()
+				.contains(GitProtocolConstants.CAPABILITY_OFS_DELTA));
+		assertThat(objIdsAsStrings(request.getWantsIds()),
+				hasItems("4624442d68ee402a94364191085b77137618633e",
+						"f900c8326a43303685c46b279b9f70411bff1a4b"));
+		assertThat(objIdsAsStrings(request.getPeerHas()),
+				hasItems("554f6e41067b9e3e565b6988a8294fac1cb78f4b",
+						"abc760ab9ad72f08209943251b36cb886a578f87"));
+		assertTrue(request.getWantedRefs().isEmpty());
+		assertTrue(request.wasDoneReceived());
+	}
+
+	@Test
+	public void testFetchWithShallow_deepen() throws IOException {
+		PacketLineIn pckIn = formatAsPacketLine(
+				PacketLineIn.DELIM,
+				"deepen 15",
+				"deepen-relative",
+				"shallow 28274d02c489f4c7e68153056e9061a46f62d7a0",
+				"shallow 145e683b229dcab9d0e2ccb01b386f9ecc17d29d",
+				PacketLineIn.END);
+		ProtocolV2Parser parser = new ProtocolV2Parser(
+				ConfigBuilder.getDefault());
+		FetchV2Request request = parser.parseFetchRequest(pckIn,
+				testRepo.getRepository().getRefDatabase());
+		assertThat(objIdsAsStrings(request.getClientShallowCommits()),
+				hasItems("28274d02c489f4c7e68153056e9061a46f62d7a0",
+						"145e683b229dcab9d0e2ccb01b386f9ecc17d29d"));
+		assertTrue(request.getDeepenNotRefs().isEmpty());
+		assertEquals(15, request.getDepth());
+		assertTrue(request.getOptions()
+				.contains(GitProtocolConstants.OPTION_DEEPEN_RELATIVE));
+	}
+
+	@Test
+	public void testFetchWithShallow_deepenNot() throws IOException {
+		PacketLineIn pckIn = formatAsPacketLine(PacketLineIn.DELIM,
+				"shallow 28274d02c489f4c7e68153056e9061a46f62d7a0",
+				"shallow 145e683b229dcab9d0e2ccb01b386f9ecc17d29d",
+				"deepen-not a08595f76159b09d57553e37a5123f1091bb13e7",
+				PacketLineIn.END);
+		ProtocolV2Parser parser = new ProtocolV2Parser(
+				ConfigBuilder.getDefault());
+		FetchV2Request request = parser.parseFetchRequest(pckIn,
+				testRepo.getRepository().getRefDatabase());
+		assertThat(objIdsAsStrings(request.getClientShallowCommits()),
+				hasItems("28274d02c489f4c7e68153056e9061a46f62d7a0",
+						"145e683b229dcab9d0e2ccb01b386f9ecc17d29d"));
+		assertThat(request.getDeepenNotRefs(),
+				hasItems("a08595f76159b09d57553e37a5123f1091bb13e7"));
+	}
+
+	@Test
+	public void testFetchWithShallow_deepenSince() throws IOException {
+		PacketLineIn pckIn = formatAsPacketLine(PacketLineIn.DELIM,
+				"shallow 28274d02c489f4c7e68153056e9061a46f62d7a0",
+				"shallow 145e683b229dcab9d0e2ccb01b386f9ecc17d29d",
+				"deepen-since 123123123",
+				PacketLineIn.END);
+		ProtocolV2Parser parser = new ProtocolV2Parser(
+				ConfigBuilder.getDefault());
+		FetchV2Request request = parser.parseFetchRequest(pckIn,
+				testRepo.getRepository().getRefDatabase());
+		assertThat(objIdsAsStrings(request.getClientShallowCommits()),
+				hasItems("28274d02c489f4c7e68153056e9061a46f62d7a0",
+						"145e683b229dcab9d0e2ccb01b386f9ecc17d29d"));
+		assertEquals(123123123, request.getDeepenSince());
+	}
+
+	@Test
+	public void testFetchWithNoneFilter() throws IOException {
+		PacketLineIn pckIn = formatAsPacketLine(PacketLineIn.DELIM,
+				"filter blob:none",
+				PacketLineIn.END);
+		ProtocolV2Parser parser = new ProtocolV2Parser(
+				ConfigBuilder.start().allowFilter().done());
+		FetchV2Request request = parser.parseFetchRequest(pckIn,
+				testRepo.getRepository().getRefDatabase());
+		assertEquals(0, request.getFilterBlobLimit());
+	}
+
+	@Test
+	public void testFetchWithBlobSizeFilter() throws IOException {
+		PacketLineIn pckIn = formatAsPacketLine(PacketLineIn.DELIM,
+				"filter blob:limit=15",
+				PacketLineIn.END);
+		ProtocolV2Parser parser = new ProtocolV2Parser(
+				ConfigBuilder.start().allowFilter().done());
+		FetchV2Request request = parser.parseFetchRequest(pckIn,
+				testRepo.getRepository().getRefDatabase());
+		assertEquals(15, request.getFilterBlobLimit());
+	}
+
+	@Test
+	public void testFetchMustNotHaveMultipleFilters() throws IOException {
+		thrown.expect(PackProtocolException.class);
+		PacketLineIn pckIn = formatAsPacketLine(PacketLineIn.DELIM,
+				"filter blob:none",
+				"filter blob:limit=12",
+				PacketLineIn.END);
+		ProtocolV2Parser parser = new ProtocolV2Parser(
+				ConfigBuilder.start().allowFilter().done());
+		FetchV2Request request = parser.parseFetchRequest(pckIn,
+				testRepo.getRepository().getRefDatabase());
+		assertEquals(0, request.getFilterBlobLimit());
+	}
+
+	@Test
+	public void testFetchFilterWithoutAllowFilter() throws IOException {
+		thrown.expect(PackProtocolException.class);
+		PacketLineIn pckIn = formatAsPacketLine(PacketLineIn.DELIM,
+				"filter blob:limit=12", PacketLineIn.END);
+		ProtocolV2Parser parser = new ProtocolV2Parser(
+				ConfigBuilder.getDefault());
+		parser.parseFetchRequest(pckIn,
+				testRepo.getRepository().getRefDatabase());
+	}
+
+	@Test
+	public void testFetchWithRefInWant() throws Exception {
+		RevCommit one = testRepo.commit().message("1").create();
+		RevCommit two = testRepo.commit().message("2").create();
+		testRepo.update("branchA", one);
+		testRepo.update("branchB", two);
+
+		PacketLineIn pckIn = formatAsPacketLine(PacketLineIn.DELIM,
+				"want e4980cdc48cfa1301493ca94eb70523f6788b819",
+				"want-ref refs/heads/branchA",
+				PacketLineIn.END);
+		ProtocolV2Parser parser = new ProtocolV2Parser(
+				ConfigBuilder.start().allowRefInWant().done());
+
+
+		FetchV2Request request = parser.parseFetchRequest(pckIn,
+				testRepo.getRepository().getRefDatabase());
+		assertEquals(1, request.getWantedRefs().size());
+		assertThat(request.getWantedRefs().keySet(),
+				hasItems("refs/heads/branchA"));
+		assertEquals(2, request.getWantsIds().size());
+		assertThat(objIdsAsStrings(request.getWantsIds()),
+				hasItems("e4980cdc48cfa1301493ca94eb70523f6788b819",
+						one.getName()));
+	}
+
+	@Test
+	public void testFetchWithRefInWantUnknownRef() throws Exception {
+		thrown.expect(PackProtocolException.class);
+		thrown.expectMessage(containsString("refs/heads/branchC"));
+
+		PacketLineIn pckIn = formatAsPacketLine(PacketLineIn.DELIM,
+				"want e4980cdc48cfa1301493ca94eb70523f6788b819",
+				"want-ref refs/heads/branchC",
+				PacketLineIn.END);
+		ProtocolV2Parser parser = new ProtocolV2Parser(
+				ConfigBuilder.start().allowRefInWant().done());
+
+		RevCommit one = testRepo.commit().message("1").create();
+		RevCommit two = testRepo.commit().message("2").create();
+		testRepo.update("branchA", one);
+		testRepo.update("branchB", two);
+
+		parser.parseFetchRequest(pckIn,
+				testRepo.getRepository().getRefDatabase());
+	}
+
+}