[PATCH 1/4] Cache tree ObjectId's too
- From
Robin Rosenberg <robin.rosenberg@dewire.com>
- Date
- Mar 18, 2007, 22:15 UTC
- Message-ID
- <20070318221555.24742.93993.stgit@lathund.dewire.com>
- In-Reply-To
- <20070318220711.24742.90943.stgit@lathund.dewire.com>
The caching part is experimental. We explicitly leave it up to the garbage collector when to recycle git objects. After trying this practically we will se what is best. The upside is that rescanning the history for a certain resource is very quick when data is still in the cache (tens of milliseconds), which is very good for interactivity. When memory is tight we go to disk and fetch the data, which could take a couple of seconds on a large repo.
Signed-off-by: Robin Rosenberg <robin.rosenberg@dewire.com> ---
.../src/org/spearce/jgit/lib/Repository.java | 18 +++++++++++++----- 1 files changed, 13 insertions(+), 5 deletions(-)
diff --git a/org.spearce.jgit/src/org/spearce/jgit/lib/Repository.java b/org.spearce.jgit/src/org/spearce/jgit/lib/Repository.java index 8b1f42c..d3b2178 100644 --- a/org.spearce.jgit/src/org/spearce/jgit/lib/Repository.java +++ b/org.spearce.jgit/src/org/spearce/jgit/lib/Repository.java @@ -47,7 +47,8 @@ public class Repository { private WindowCache windows; - private Map cache = new WeakHashMap(30000); + private Map treeCache = new WeakHashMap(30000); + private Map commitCache = new WeakHashMap(30000); public Repository(final File d) throws IOException { gitDir = d.getAbsoluteFile(); @@ -189,7 +190,7 @@ public class Repository { } public Commit mapCommit(final ObjectId id) throws IOException { - Commit ret = (Commit)cache.get(id); + Commit ret = (Commit)commitCache.get(id); if (ret != null) return ret; @@ -201,7 +202,7 @@ public class Repository { ret = new Commit(this, id, raw); // The key must not be the referenced strongly // by the value in WeakHashMaps - cache.put(new ObjectId(id.getBytes()), ret); + commitCache.put(new ObjectId(id.getBytes()), ret); return ret; } throw new IncorrectObjectTypeException(id, Constants.TYPE_COMMIT); @@ -213,12 +214,19 @@ public class Repository { } public Tree mapTree(final ObjectId id) throws IOException { + Tree ret = (Tree)treeCache.get(id); + if (ret != null) + return ret; + final ObjectLoader or = openObject(id); if (or == null) return null; final byte[] raw = or.getBytes(); - if (Constants.TYPE_TREE.equals(or.getType())) - return new Tree(this, id, raw); + if (Constants.TYPE_TREE.equals(or.getType())) { + ret = new Tree(this, id, raw); + treeCache.put(new ObjectId(id.getBytes()), ret); + return ret; + } if (Constants.TYPE_COMMIT.equals(or.getType())) return mapTree(ObjectId.fromString(raw, 5)); throw new IncorrectObjectTypeException(id, Constants.TYPE_TREE);