Add a public RevTag.parse() method

Callers might have a canonical tag encoding on hand that they
wish to convert into a clean structure for presentation purposes,
and the object may not be available in a repository.  (E.g. maybe
its a "draft" tag being written in an editor.)

Change-Id: I387a462afb70754aa7ee20891e6c0262438fdf32
Signed-off-by: Shawn O. Pearce <spearce@spearce.org>

diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/RevTagParseTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/RevTagParseTest.java
index b3e62f49e3427d54f331c25664a6719590ae9d83..af70eb5a0d628eabcae9145be72e2cf3a97f82e2 100644 (file)
--- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/RevTagParseTest.java
+++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/revwalk/RevTagParseTest.java
@@ -45,10 +45,13 @@ package org.eclipse.jgit.revwalk;
 
 import java.io.ByteArrayOutputStream;
 
+import org.eclipse.jgit.errors.CorruptObjectException;
 import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.ObjectInserter;
 import org.eclipse.jgit.lib.PersonIdent;
 import org.eclipse.jgit.lib.RepositoryTestCase;
+import org.eclipse.jgit.lib.Tag;
 
 public class RevTagParseTest extends RepositoryTestCase {
        public void testTagBlob() throws Exception {
@@ -395,6 +398,23 @@ public class RevTagParseTest extends RepositoryTestCase {
                assertEquals(shortMsg, c.getShortMessage());
        }
 
+       public void testParse_PublicParseMethod() throws CorruptObjectException {
+               ObjectInserter.Formatter fmt = new ObjectInserter.Formatter();
+               Tag src = new Tag();
+               src.setObjectId(fmt.idFor(Constants.OBJ_TREE, new byte[] {}),
+                               Constants.OBJ_TREE);
+               src.setTagger(committer);
+               src.setTag("a.test");
+               src.setMessage("Test tag\n\nThis is a test.\n");
+
+               RevTag p = RevTag.parse(fmt.format(src));
+               assertEquals(src.getObjectId(), p.getObject());
+               assertEquals(committer, p.getTaggerIdent());
+               assertEquals("a.test", p.getTagName());
+               assertEquals("Test tag", p.getShortMessage());
+               assertEquals(src.getMessage(), p.getFullMessage());
+       }
+
        private static ObjectId id(final String str) {
                return ObjectId.fromString(str);
        }

diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevTag.java b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevTag.java
index dadebe9cb5cc629fb12c663aa5457edaf69963ae..aa33d91a55b10ba498f2ad35c8a4f40bbaf8e7ff 100644 (file)
--- a/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevTag.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/revwalk/RevTag.java
@@ -53,12 +53,65 @@ import org.eclipse.jgit.errors.IncorrectObjectTypeException;
 import org.eclipse.jgit.errors.MissingObjectException;
 import org.eclipse.jgit.lib.AnyObjectId;
 import org.eclipse.jgit.lib.Constants;
+import org.eclipse.jgit.lib.ObjectInserter;
+import org.eclipse.jgit.lib.ObjectReader;
 import org.eclipse.jgit.lib.PersonIdent;
 import org.eclipse.jgit.util.MutableInteger;
 import org.eclipse.jgit.util.RawParseUtils;
 
 /** An annotated tag. */
 public class RevTag extends RevObject {
+       /**
+        * Parse an annotated tag from its canonical format.
+        *
+        * This method constructs a temporary revision pool, parses the tag as
+        * supplied, and returns it to the caller. Since the tag was built inside of
+        * a private revision pool its object pointer will be initialized, but will
+        * not have its headers loaded.
+        *
+        * Applications are discouraged from using this API. Callers usually need
+        * more than one object. Use {@link RevWalk#parseTag(AnyObjectId)} to obtain
+        * a RevTag from an existing repository.
+        *
+        * @param raw
+        *            the canonical formatted tag to be parsed.
+        * @return the parsed tag, in an isolated revision pool that is not
+        *         available to the caller.
+        * @throws CorruptObjectException
+        *             the tag contains a malformed header that cannot be handled.
+        */
+       public static RevTag parse(byte[] raw) throws CorruptObjectException {
+               return parse(new RevWalk((ObjectReader) null), raw);
+       }
+
+       /**
+        * Parse an annotated tag from its canonical format.
+        *
+        * This method inserts the tag directly into the caller supplied revision
+        * pool, making it appear as though the tag exists in the repository, even
+        * if it doesn't. The repository under the pool is not affected.
+        *
+        * @param rw
+        *            the revision pool to allocate the tag within. The tag's object
+        *            pointer will be obtained from this pool.
+        * @param raw
+        *            the canonical formatted tag to be parsed.
+        * @return the parsed tag, in an isolated revision pool that is not
+        *         available to the caller.
+        * @throws CorruptObjectException
+        *             the tag contains a malformed header that cannot be handled.
+        */
+       public static RevTag parse(RevWalk rw, byte[] raw)
+                       throws CorruptObjectException {
+               ObjectInserter.Formatter fmt = new ObjectInserter.Formatter();
+               boolean retain = rw.isRetainBody();
+               rw.setRetainBody(true);
+               RevTag r = rw.lookupTag(fmt.idFor(Constants.OBJ_TAG, raw));
+               r.parseCanonical(rw, raw);
+               rw.setRetainBody(retain);
+               return r;
+       }
+
        private RevObject object;
 
        private byte[] buffer;