UploadPack v0: Extract "agent" client capability at parse time

The request receives a list of capabilities and takes out the "agent" to
offer it on its own setter (getAgent).

Do this at parse time: when reading the line if the capability is
"agent" set it directly in the builder.

This makes the treatment of "agent" consistent in v0/v1 and v2.

Change-Id: Ie4f9f2cad8639adeeaef4921df49a30a8ce5b42f
Signed-off-by: Ivan Frade <ifrade@google.com>

org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/transport/parser/FirstWantTest.java

@@ -43,6 +43,7 @@
 package org.eclipse.jgit.internal.transport.parser;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
 import static org.junit.Assert.assertTrue;
 import static org.junit.Assert.fail;
 
@@ -66,9 +67,9 @@ public void testFirstWantWithOptions() throws PackProtocolException {
 				r.getLine());
 		Set<String> capabilities = r.getCapabilities();
 		Set<String> expectedCapabilities = new HashSet<>(
-				Arrays.asList("no-progress", "include-tag", "ofs-delta",
-						"agent=JGit/unknown"));
+				Arrays.asList("no-progress", "include-tag", "ofs-delta"));
 		assertEquals(expectedCapabilities, capabilities);
+		assertEquals("JGit/unknown", r.getAgent());
 	}
 
 	@Test
@@ -79,6 +80,7 @@ public void testFirstWantWithoutOptions() throws PackProtocolException {
 		assertEquals("want b9d4d1eb2f93058814480eae9e1b67550f46ee38",
 				r.getLine());
 		assertTrue(r.getCapabilities().isEmpty());
+		assertNull(r.getAgent());
 	}
 
 	private String makeFirstWantLine(String capability) {
@@ -110,7 +112,7 @@ public void testFirstWantValidCapabilityNames()
 		List<String> validNames = Arrays.asList(
 				"c", "cap", "C", "CAP", "1", "1cap", "cap-64k_test",
 				"-", "-cap",
-				"_", "_cap", "agent=pack.age/Version");
+				"_", "_cap");
 
 		for (String capability: validNames) {
 			FirstWant r = FirstWant.fromLine(makeFirstWantLine(capability));
@@ -118,4 +120,11 @@ public void testFirstWantValidCapabilityNames()
 			assertTrue(r.getCapabilities().contains(capability));
 		}
 	}
+
+	@Test
+	public void testFirstWantValidAgentName() throws PackProtocolException {
+		FirstWant r = FirstWant.fromLine(makeFirstWantLine("agent=pack.age/Version"));
+		assertEquals(r.getCapabilities().size(), 0);
+		assertEquals("pack.age/Version", r.getAgent());
+	}
 }

org.eclipse.jgit/src/org/eclipse/jgit/internal/transport/parser/FirstWant.java

@@ -42,11 +42,13 @@
  */
 package org.eclipse.jgit.internal.transport.parser;
 
-import java.util.Arrays;
+import static org.eclipse.jgit.transport.GitProtocolConstants.OPTION_AGENT;
+
 import java.util.Collections;
 import java.util.HashSet;
 import java.util.Set;
 
+import org.eclipse.jgit.annotations.Nullable;
 import org.eclipse.jgit.errors.PackProtocolException;
 import org.eclipse.jgit.internal.JGitText;
 
@@ -72,6 +74,11 @@ public class FirstWant {
 
 	private final Set<String> capabilities;
 
+	@Nullable
+	private final String agent;
+
+	private static final String AGENT_PREFIX = OPTION_AGENT + '=';
+
 	/**
 	 * Parse the first want line in the protocol v0/v1 pack negotiation.
 	 *
@@ -84,6 +91,7 @@ public class FirstWant {
 	public static FirstWant fromLine(String line) throws PackProtocolException {
 		String wantLine;
 		Set<String> capabilities;
+		String agent = null;
 
 		if (line.length() > 45) {
 			String opt = line.substring(45);
@@ -91,8 +99,15 @@ public static FirstWant fromLine(String line) throws PackProtocolException {
 				throw new PackProtocolException(JGitText.get().wantNoSpaceWithCapabilities);
 			}
 			opt = opt.substring(1);
-			HashSet<String> opts = new HashSet<>(
-					Arrays.asList(opt.split(" "))); //$NON-NLS-1$
+
+			HashSet<String> opts = new HashSet<>();
+			for (String clientCapability : opt.split(" ")) { //$NON-NLS-1$
+				if (clientCapability.startsWith(AGENT_PREFIX)) {
+					agent = clientCapability.substring(AGENT_PREFIX.length());
+				} else {
+					opts.add(clientCapability);
+				}
+			}
 			wantLine = line.substring(0, 45);
 			capabilities = Collections.unmodifiableSet(opts);
 		} else {
@@ -100,12 +115,14 @@ public static FirstWant fromLine(String line) throws PackProtocolException {
 			capabilities = Collections.emptySet();
 		}
 
-		return new FirstWant(wantLine, capabilities);
+		return new FirstWant(wantLine, capabilities, agent);
 	}
 
-	private FirstWant(String line, Set<String> capabilities) {
+	private FirstWant(String line, Set<String> capabilities,
+			@Nullable String agent) {
 		this.line = line;
 		this.capabilities = capabilities;
+		this.agent = agent;
 	}
 
 	/** @return non-capabilities part of the line. */
@@ -113,8 +130,17 @@ public String getLine() {
 		return line;
 	}
 
-	/** @return capabilities parsed from the line as an immutable set. */
+	/**
+	 * @return capabilities parsed from the line as an immutable set (excluding
+	 *         agent).
+	 */
 	public Set<String> getCapabilities() {
 		return capabilities;
 	}
+
+	/** @return client user agent parsed from the line. */
+	@Nullable
+	public String getAgent() {
+		return agent;
+	}
 }

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

@@ -114,14 +114,7 @@ Builder addClientShallowCommit(ObjectId shallowOid) {
 		 * @return this builder
 		 */
 		Builder addClientCapabilities(Collection<String> clientCapabilities) {
-			for (String cap: clientCapabilities) {
-				// TODO(ifrade): Do this is done on parse time
-				if (cap.startsWith("agent=")) { //$NON-NLS-1$
-					agent = cap.substring("agent=".length()); //$NON-NLS-1$
-				} else {
-					clientCaps.add(cap);
-				}
-			}
+			clientCaps.addAll(clientCapabilities);
 			return this;
 		}
 

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

@@ -143,6 +143,7 @@ FetchV0Request recvWants(PacketLineIn pckIn)
 				if (line.length() > 45) {
 					FirstWant firstLine = FirstWant.fromLine(line);
 					reqBuilder.addClientCapabilities(firstLine.getCapabilities());
+					reqBuilder.setAgent(firstLine.getAgent());
 					line = firstLine.getLine();
 				}
 			}

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

@@ -209,6 +209,11 @@ public String getLine() {
 
 		/** @return capabilities parsed from the line. */
 		public Set<String> getOptions() {
+			if (firstWant.getAgent() != null) {
+				Set<String> caps = new HashSet<>(firstWant.getCapabilities());
+				caps.add(OPTION_AGENT + '=' + firstWant.getAgent());
+				return caps;
+			}
 			return firstWant.getCapabilities();
 		}
 	}