Merge "Add in-memory updating support to NoteMap"

4 files changed, 172 insertions, 0 deletions

diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/notes/FanoutBucket.java b/org.eclipse.jgit/src/org/eclipse/jgit/notes/FanoutBucket.java
index 85337c8d15..760528618c 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/notes/FanoutBucket.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/notes/FanoutBucket.java
@@ -84,6 +84,9 @@ class FanoutBucket extends InMemoryNoteBucket {
 	 */
 	private final NoteBucket[] table;
 
+	/** Number of non-null slots in {@link #table}. */
+	private int cnt;
+
 	FanoutBucket(int prefixLen) {
 		super(prefixLen);
 		table = new NoteBucket[256];
@@ -91,6 +94,7 @@ class FanoutBucket extends InMemoryNoteBucket {
 
 	void parseOneEntry(int cell, ObjectId id) {
 		table[cell] = new LazyNoteBucket(id);
+		cnt++;
 	}
 
 	@Override
@@ -99,6 +103,39 @@ class FanoutBucket extends InMemoryNoteBucket {
 		return b != null ? b.get(objId, or) : null;
 	}
 
+	@Override
+	InMemoryNoteBucket set(AnyObjectId noteOn, AnyObjectId noteData,
+			ObjectReader or) throws IOException {
+		int cell = cell(noteOn);
+		NoteBucket b = table[cell];
+
+		if (b == null) {
+			if (noteData == null)
+				return this;
+
+			LeafBucket n = new LeafBucket(prefixLen + 2);
+			table[cell] = n.set(noteOn, noteData, or);
+			cnt++;
+			return this;
+
+		} else {
+			NoteBucket n = b.set(noteOn, noteData, or);
+			if (n == null) {
+				table[cell] = null;
+				cnt--;
+
+				if (cnt == 0)
+					return null;
+
+				return this;
+
+			} else if (n != b) {
+				table[cell] = n;
+			}
+			return this;
+		}
+	}
+
 	private int cell(AnyObjectId id) {
 		return id.getByte(prefixLen >> 1);
 	}
@@ -115,6 +152,12 @@ class FanoutBucket extends InMemoryNoteBucket {
 			return load(objId, or).get(objId, or);
 		}
 
+		@Override
+		InMemoryNoteBucket set(AnyObjectId noteOn, AnyObjectId noteData,
+				ObjectReader or) throws IOException {
+			return load(noteOn, or).set(noteOn, noteData, or);
+		}
+
 		private NoteBucket load(AnyObjectId objId, ObjectReader or)
 				throws IOException {
 			AbbreviatedObjectId p = objId.abbreviate(prefixLen + 2);
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/notes/LeafBucket.java b/org.eclipse.jgit/src/org/eclipse/jgit/notes/LeafBucket.java
index 66d773a05d..ce4feae259 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/notes/LeafBucket.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/notes/LeafBucket.java
@@ -43,6 +43,8 @@
 
 package org.eclipse.jgit.notes;
 
+import java.io.IOException;
+
 import org.eclipse.jgit.lib.AnyObjectId;
 import org.eclipse.jgit.lib.ObjectId;
 import org.eclipse.jgit.lib.ObjectReader;
@@ -96,6 +98,34 @@ class LeafBucket extends InMemoryNoteBucket {
 		return 0 <= idx ? notes[idx].getData() : null;
 	}
 
+	InMemoryNoteBucket set(AnyObjectId noteOn, AnyObjectId noteData,
+			ObjectReader or) throws IOException {
+		int p = search(noteOn);
+		if (0 <= p) {
+			if (noteData != null) {
+				notes[p].setData(noteData.copy());
+				return this;
+
+			} else {
+				System.arraycopy(notes, p + 1, notes, p, cnt - p - 1);
+				cnt--;
+				return 0 < cnt ? this : null;
+			}
+
+		} else if (noteData != null) {
+			growIfFull();
+			p = -(p + 1);
+			if (p < cnt)
+				System.arraycopy(notes, p, notes, p + 1, cnt - p);
+			notes[p] = new Note(noteOn, noteData.copy());
+			cnt++;
+			return this;
+
+		} else {
+			return this;
+		}
+	}
+
 	void parseOneEntry(AnyObjectId noteOn, AnyObjectId noteData) {
 		growIfFull();
 		notes[cnt++] = new Note(noteOn, noteData.copy());
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/notes/NoteBucket.java b/org.eclipse.jgit/src/org/eclipse/jgit/notes/NoteBucket.java
index 286f140847..f75fc1f942 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/notes/NoteBucket.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/notes/NoteBucket.java
@@ -58,4 +58,7 @@ import org.eclipse.jgit.lib.ObjectReader;
 abstract class NoteBucket {
 	abstract ObjectId get(AnyObjectId objId, ObjectReader reader)
 			throws IOException;
+
+	abstract InMemoryNoteBucket set(AnyObjectId noteOn, AnyObjectId noteData,
+			ObjectReader reader) throws IOException;
 }
diff --git a/org.eclipse.jgit/src/org/eclipse/jgit/notes/NoteMap.java b/org.eclipse.jgit/src/org/eclipse/jgit/notes/NoteMap.java
index d2f07279e1..88ab481794 100644
--- a/org.eclipse.jgit/src/org/eclipse/jgit/notes/NoteMap.java
+++ b/org.eclipse.jgit/src/org/eclipse/jgit/notes/NoteMap.java
@@ -51,7 +51,9 @@ import org.eclipse.jgit.errors.LargeObjectException;
 import org.eclipse.jgit.errors.MissingObjectException;
 import org.eclipse.jgit.lib.AbbreviatedObjectId;
 import org.eclipse.jgit.lib.AnyObjectId;
+import org.eclipse.jgit.lib.Constants;
 import org.eclipse.jgit.lib.ObjectId;
+import org.eclipse.jgit.lib.ObjectInserter;
 import org.eclipse.jgit.lib.ObjectReader;
 import org.eclipse.jgit.revwalk.RevCommit;
 import org.eclipse.jgit.revwalk.RevTree;
@@ -66,6 +68,17 @@ import org.eclipse.jgit.revwalk.RevTree;
  */
 public class NoteMap {
 	/**
+	 * Construct a new empty note map.
+	 *
+	 * @return an empty note map.
+	 */
+	public static NoteMap newEmptyMap() {
+		NoteMap r = new NoteMap(null /* no reader */);
+		r.root = new LeafBucket(0);
+		return r;
+	}
+
+	/**
 	 * Load a collection of notes from a branch.
 	 *
 	 * @param reader
@@ -213,6 +226,89 @@ public class NoteMap {
 			return null;
 	}
 
+	/**
+	 * Attach (or remove) a note on an object.
+	 *
+	 * If no note exists, a new note is stored. If a note already exists for the
+	 * given object, it is replaced (or removed).
+	 *
+	 * This method only updates the map in memory.
+	 *
+	 * If the caller wants to attach a UTF-8 encoded string message to an
+	 * object, {@link #set(AnyObjectId, String, ObjectInserter)} is a convenient
+	 * way to encode and update a note in one step.
+	 *
+	 * @param noteOn
+	 *            the object to attach the note to. This same ObjectId can later
+	 *            be used as an argument to {@link #get(AnyObjectId)} or
+	 *            {@link #getCachedBytes(AnyObjectId, int)} to read back the
+	 *            {@code noteData}.
+	 * @param noteData
+	 *            data to associate with the note. This must be the ObjectId of
+	 *            a blob that already exists in the repository. If null the note
+	 *            will be deleted, if present.
+	 * @throws IOException
+	 *             a portion of the note space is not accessible.
+	 */
+	public void set(AnyObjectId noteOn, ObjectId noteData) throws IOException {
+		InMemoryNoteBucket newRoot = root.set(noteOn, noteData, reader);
+		if (newRoot == null) {
+			newRoot = new LeafBucket(0);
+			newRoot.nonNotes = root.nonNotes;
+		}
+		root = newRoot;
+	}
+
+	/**
+	 * Attach a note to an object.
+	 *
+	 * If no note exists, a new note is stored. If a note already exists for the
+	 * given object, it is replaced (or removed).
+	 *
+	 * @param noteOn
+	 *            the object to attach the note to. This same ObjectId can later
+	 *            be used as an argument to {@link #get(AnyObjectId)} or
+	 *            {@link #getCachedBytes(AnyObjectId, int)} to read back the
+	 *            {@code noteData}.
+	 * @param noteData
+	 *            text to store in the note. The text will be UTF-8 encoded when
+	 *            stored in the repository. If null the note will be deleted, if
+	 *            the empty string a note with the empty string will be stored.
+	 * @param ins
+	 *            inserter to write the encoded {@code noteData} out as a blob.
+	 *            The caller must ensure the inserter is flushed before the
+	 *            updated note map is made available for reading.
+	 * @throws IOException
+	 *             the note data could not be stored in the repository.
+	 */
+	public void set(AnyObjectId noteOn, String noteData, ObjectInserter ins)
+			throws IOException {
+		ObjectId dataId;
+		if (noteData != null) {
+			byte[] dataUTF8 = Constants.encode(noteData);
+			dataId = ins.insert(Constants.OBJ_BLOB, dataUTF8);
+		} else {
+			dataId = null;
+		}
+		set(noteOn, dataId);
+	}
+
+	/**
+	 * Remove a note from an object.
+	 *
+	 * If no note exists, no action is performed.
+	 *
+	 * This method only updates the map in memory.
+	 *
+	 * @param noteOn
+	 *            the object to remove the note from.
+	 * @throws IOException
+	 *             a portion of the note space is not accessible.
+	 */
+	public void remove(AnyObjectId noteOn) throws IOException {
+		set(noteOn, null);
+	}
+
 	private void load(ObjectId rootTree) throws MissingObjectException,
 			IncorrectObjectTypeException, CorruptObjectException, IOException {
 		AbbreviatedObjectId none = AbbreviatedObjectId.fromString("");