This test can be useful to determine if the object id at least
begins with an abbreviated id.
Signed-off-by: Shawn O. Pearce <spearce@xxxxxxxxxxx>
---
.../spearce/jgit/lib/AbbreviatedObjectIdTest.java | 58 ++++++++++++++++++++
.../org/spearce/jgit/lib/AbbreviatedObjectId.java | 57 +++++++++++++++++++
.../src/org/spearce/jgit/lib/AnyObjectId.java | 11 ++++
3 files changed, 126 insertions(+), 0 deletions(-)
diff --git a/org.spearce.jgit.test/tst/org/spearce/jgit/lib/AbbreviatedObjectIdTest.java b/org.spearce.jgit.test/tst/org/spearce/jgit/lib/AbbreviatedObjectIdTest.java
index f540f49..3f82d50 100644
--- a/org.spearce.jgit.test/tst/org/spearce/jgit/lib/AbbreviatedObjectIdTest.java
+++ b/org.spearce.jgit.test/tst/org/spearce/jgit/lib/AbbreviatedObjectIdTest.java
@@ -224,4 +224,62 @@ public void testNotEquals_DiffLength() {
assertFalse(a.equals(b));
assertFalse(b.equals(a));
}
+
+ public void testPrefixCompare_Full() {
+ final String s1 = "7b6e8067ec96acef9a4184b43210d583b6d2f99a";
+ final AbbreviatedObjectId a = AbbreviatedObjectId.fromString(s1);
+ final ObjectId i1 = ObjectId.fromString(s1);
+ assertEquals(0, a.prefixCompare(i1));
+ assertTrue(i1.startsWith(a));
+
+ final String s2 = "7b6e8067ec96acef9a4184b43210d583b6d2f99b";
+ final ObjectId i2 = ObjectId.fromString(s2);
+ assertTrue(a.prefixCompare(i2) < 0);
+ assertFalse(i2.startsWith(a));
+
+ final String s3 = "7b6e8067ec96acef9a4184b43210d583b6d2f999";
+ final ObjectId i3 = ObjectId.fromString(s3);
+ assertTrue(a.prefixCompare(i3) > 0);
+ assertFalse(i3.startsWith(a));
+ }
+
+ public void testPrefixCompare_1() {
+ final String sa = "7";
+ final AbbreviatedObjectId a = AbbreviatedObjectId.fromString(sa);
+
+ final String s1 = "7b6e8067ec96acef9a4184b43210d583b6d2f99a";
+ final ObjectId i1 = ObjectId.fromString(s1);
+ assertEquals(0, a.prefixCompare(i1));
+ assertTrue(i1.startsWith(a));
+
+ final String s2 = "8b6e8067ec96acef9a4184b43210d583b6d2f99a";
+ final ObjectId i2 = ObjectId.fromString(s2);
+ assertTrue(a.prefixCompare(i2) < 0);
+ assertFalse(i2.startsWith(a));
+
+ final String s3 = "6b6e8067ec96acef9a4184b43210d583b6d2f99a";
+ final ObjectId i3 = ObjectId.fromString(s3);
+ assertTrue(a.prefixCompare(i3) > 0);
+ assertFalse(i3.startsWith(a));
+ }
+
+ public void testPrefixCompare_17() {
+ final String sa = "7b6e8067ec96acef9";
+ final AbbreviatedObjectId a = AbbreviatedObjectId.fromString(sa);
+
+ final String s1 = "7b6e8067ec96acef9a4184b43210d583b6d2f99a";
+ final ObjectId i1 = ObjectId.fromString(s1);
+ assertEquals(0, a.prefixCompare(i1));
+ assertTrue(i1.startsWith(a));
+
+ final String s2 = "7b6e8067eca6acef9a4184b43210d583b6d2f99a";
+ final ObjectId i2 = ObjectId.fromString(s2);
+ assertTrue(a.prefixCompare(i2) < 0);
+ assertFalse(i2.startsWith(a));
+
+ final String s3 = "7b6e8067ec86acef9a4184b43210d583b6d2f99a";
+ final ObjectId i3 = ObjectId.fromString(s3);
+ assertTrue(a.prefixCompare(i3) > 0);
+ assertFalse(i3.startsWith(a));
+ }
}
diff --git a/org.spearce.jgit/src/org/spearce/jgit/lib/AbbreviatedObjectId.java b/org.spearce.jgit/src/org/spearce/jgit/lib/AbbreviatedObjectId.java
index 1a8d296..206cc2f 100644
--- a/org.spearce.jgit/src/org/spearce/jgit/lib/AbbreviatedObjectId.java
+++ b/org.spearce.jgit/src/org/spearce/jgit/lib/AbbreviatedObjectId.java
@@ -39,6 +39,8 @@
import java.io.UnsupportedEncodingException;
+import org.spearce.jgit.util.NB;
+
/**
* A prefix abbreviation of an {@link ObjectId}.
* <p>
@@ -119,6 +121,24 @@ private static final int hexUInt32(final byte[] bs, int p, final int end) {
return r << (8 - n) * 4;
}
+ static int mask(final int nibbles, final int word, final int v) {
+ final int b = (word - 1) * 8;
+ if (b + 8 <= nibbles) {
+ // We have all of the bits required for this word.
+ //
+ return v;
+ }
+
+ if (nibbles < b) {
+ // We have none of the bits required for this word.
+ //
+ return 0;
+ }
+
+ final int s = 32 - (nibbles - b) * 4;
+ return (v >>> s) << s;
+ }
+
/** Number of half-bytes used by this id. */
final int nibbles;
@@ -157,6 +177,43 @@ public ObjectId toObjectId() {
return isComplete() ? new ObjectId(w1, w2, w3, w4, w5) : null;
}
+ /**
+ * Compares this abbreviation to a full object id.
+ *
+ * @param other
+ * the other object id.
+ * @return <0 if this abbreviation names an object that is less than
+ * <code>other</code>; 0 if this abbreviation exactly matches the
+ * first {@link #length()} digits of <code>other.name()</code>;
+ * >0 if this abbreviation names an object that is after
+ * <code>other</code>.
+ */
+ public int prefixCompare(final AnyObjectId other) {
+ int cmp;
+
+ cmp = NB.compareUInt32(w1, mask(1, other.w1));
+ if (cmp != 0)
+ return cmp;
+
+ cmp = NB.compareUInt32(w2, mask(2, other.w2));
+ if (cmp != 0)
+ return cmp;
+
+ cmp = NB.compareUInt32(w3, mask(3, other.w3));
+ if (cmp != 0)
+ return cmp;
+
+ cmp = NB.compareUInt32(w4, mask(4, other.w4));
+ if (cmp != 0)
+ return cmp;
+
+ return NB.compareUInt32(w5, mask(5, other.w5));
+ }
+
+ private int mask(final int word, final int v) {
+ return mask(nibbles, word, v);
+ }
+
@Override
public int hashCode() {
return w2;
diff --git a/org.spearce.jgit/src/org/spearce/jgit/lib/AnyObjectId.java b/org.spearce.jgit/src/org/spearce/jgit/lib/AnyObjectId.java
index e88e09d..8872017 100644
--- a/org.spearce.jgit/src/org/spearce/jgit/lib/AnyObjectId.java
+++ b/org.spearce.jgit/src/org/spearce/jgit/lib/AnyObjectId.java
@@ -226,6 +226,17 @@ int compareTo(final int[] bs, final int p) {
return NB.compareUInt32(w5, bs[p + 4]);
}
+ /**
+ * Tests if this ObjectId starts with the given abbreviation.
+ *
+ * @param abbr
+ * the abbreviation.
+ * @return true if this ObjectId begins with the abbreviation; else false.
+ */
+ public boolean startsWith(final AbbreviatedObjectId abbr) {
+ return abbr.prefixCompare(this) == 0;
+ }
+
public int hashCode() {
return w2;
}
--
1.6.1.rc2.299.gead4c
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