The AbbreviatedObjectId class parses an abbreviated SHA-1 string
into a binary format, permitting it to be more efficiently matched
against existing binary ObjectId fields.
Signed-off-by: Shawn O. Pearce <spearce@xxxxxxxxxxx>
---
.../spearce/jgit/lib/AbbreviatedObjectIdTest.java | 227 ++++++++++++++++++++
.../org/spearce/jgit/lib/AbbreviatedObjectId.java | 205 ++++++++++++++++++
.../src/org/spearce/jgit/lib/AnyObjectId.java | 2 +-
3 files changed, 433 insertions(+), 1 deletions(-)
create mode 100644 org.spearce.jgit.test/tst/org/spearce/jgit/lib/AbbreviatedObjectIdTest.java
create mode 100644 org.spearce.jgit/src/org/spearce/jgit/lib/AbbreviatedObjectId.java
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
new file mode 100644
index 0000000..f540f49
--- /dev/null
+++ b/org.spearce.jgit.test/tst/org/spearce/jgit/lib/AbbreviatedObjectIdTest.java
@@ -0,0 +1,227 @@
+/*
+ * Copyright (C) 2008, Google Inc.
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials provided
+ * with the distribution.
+ *
+ * - Neither the name of the Git Development Community nor the
+ * names of its contributors may be used to endorse or promote
+ * products derived from this software without specific prior
+ * written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package org.spearce.jgit.lib;
+
+import junit.framework.TestCase;
+
+public class AbbreviatedObjectIdTest extends TestCase {
+ public void testEmpty_FromByteArray() {
+ final AbbreviatedObjectId i;
+ i = AbbreviatedObjectId.fromString(new byte[] {}, 0, 0);
+ assertNotNull(i);
+ assertEquals(0, i.length());
+ assertFalse(i.isComplete());
+ assertEquals("", i.name());
+ }
+
+ public void testEmpty_FromString() {
+ final AbbreviatedObjectId i = AbbreviatedObjectId.fromString("");
+ assertNotNull(i);
+ assertEquals(0, i.length());
+ assertFalse(i.isComplete());
+ assertEquals("", i.name());
+ }
+
+ public void testFull_FromByteArray() {
+ final String s = "7b6e8067ec96acef9a4184b43210d583b6d2f99a";
+ final byte[] b = Constants.encodeASCII(s);
+ final AbbreviatedObjectId i = AbbreviatedObjectId.fromString(b, 0,
+ b.length);
+ assertNotNull(i);
+ assertEquals(s.length(), i.length());
+ assertTrue(i.isComplete());
+ assertEquals(s, i.name());
+
+ final ObjectId f = i.toObjectId();
+ assertNotNull(f);
+ assertEquals(ObjectId.fromString(s), f);
+ assertEquals(f.hashCode(), i.hashCode());
+ }
+
+ public void testFull_FromString() {
+ final String s = "7b6e8067ec96acef9a4184b43210d583b6d2f99a";
+ final AbbreviatedObjectId i = AbbreviatedObjectId.fromString(s);
+ assertNotNull(i);
+ assertEquals(s.length(), i.length());
+ assertTrue(i.isComplete());
+ assertEquals(s, i.name());
+
+ final ObjectId f = i.toObjectId();
+ assertNotNull(f);
+ assertEquals(ObjectId.fromString(s), f);
+ assertEquals(f.hashCode(), i.hashCode());
+ }
+
+ public void test1_FromString() {
+ final String s = "7";
+ final AbbreviatedObjectId i = AbbreviatedObjectId.fromString(s);
+ assertNotNull(i);
+ assertEquals(s.length(), i.length());
+ assertFalse(i.isComplete());
+ assertEquals(s, i.name());
+ assertNull(i.toObjectId());
+ }
+
+ public void test2_FromString() {
+ final String s = "7b";
+ final AbbreviatedObjectId i = AbbreviatedObjectId.fromString(s);
+ assertNotNull(i);
+ assertEquals(s.length(), i.length());
+ assertFalse(i.isComplete());
+ assertEquals(s, i.name());
+ assertNull(i.toObjectId());
+ }
+
+ public void test3_FromString() {
+ final String s = "7b6";
+ final AbbreviatedObjectId i = AbbreviatedObjectId.fromString(s);
+ assertNotNull(i);
+ assertEquals(s.length(), i.length());
+ assertFalse(i.isComplete());
+ assertEquals(s, i.name());
+ assertNull(i.toObjectId());
+ }
+
+ public void test4_FromString() {
+ final String s = "7b6e";
+ final AbbreviatedObjectId i = AbbreviatedObjectId.fromString(s);
+ assertNotNull(i);
+ assertEquals(s.length(), i.length());
+ assertFalse(i.isComplete());
+ assertEquals(s, i.name());
+ assertNull(i.toObjectId());
+ }
+
+ public void test5_FromString() {
+ final String s = "7b6e8";
+ final AbbreviatedObjectId i = AbbreviatedObjectId.fromString(s);
+ assertNotNull(i);
+ assertEquals(s.length(), i.length());
+ assertFalse(i.isComplete());
+ assertEquals(s, i.name());
+ assertNull(i.toObjectId());
+ }
+
+ public void test6_FromString() {
+ final String s = "7b6e80";
+ final AbbreviatedObjectId i = AbbreviatedObjectId.fromString(s);
+ assertNotNull(i);
+ assertEquals(s.length(), i.length());
+ assertFalse(i.isComplete());
+ assertEquals(s, i.name());
+ assertNull(i.toObjectId());
+ }
+
+ public void test7_FromString() {
+ final String s = "7b6e806";
+ final AbbreviatedObjectId i = AbbreviatedObjectId.fromString(s);
+ assertNotNull(i);
+ assertEquals(s.length(), i.length());
+ assertFalse(i.isComplete());
+ assertEquals(s, i.name());
+ assertNull(i.toObjectId());
+ }
+
+ public void test8_FromString() {
+ final String s = "7b6e8067";
+ final AbbreviatedObjectId i = AbbreviatedObjectId.fromString(s);
+ assertNotNull(i);
+ assertEquals(s.length(), i.length());
+ assertFalse(i.isComplete());
+ assertEquals(s, i.name());
+ assertNull(i.toObjectId());
+ }
+
+ public void test9_FromString() {
+ final String s = "7b6e8067e";
+ final AbbreviatedObjectId i = AbbreviatedObjectId.fromString(s);
+ assertNotNull(i);
+ assertEquals(s.length(), i.length());
+ assertFalse(i.isComplete());
+ assertEquals(s, i.name());
+ assertNull(i.toObjectId());
+ }
+
+ public void test17_FromString() {
+ final String s = "7b6e8067ec96acef9";
+ final AbbreviatedObjectId i = AbbreviatedObjectId.fromString(s);
+ assertNotNull(i);
+ assertEquals(s.length(), i.length());
+ assertFalse(i.isComplete());
+ assertEquals(s, i.name());
+ assertNull(i.toObjectId());
+ }
+
+ public void testEquals_Short() {
+ final String s = "7b6e8067";
+ final AbbreviatedObjectId a = AbbreviatedObjectId.fromString(s);
+ final AbbreviatedObjectId b = AbbreviatedObjectId.fromString(s);
+ assertNotSame(a, b);
+ assertTrue(a.hashCode() == b.hashCode());
+ assertTrue(a.equals(b));
+ assertTrue(b.equals(a));
+ }
+
+ public void testEquals_Full() {
+ final String s = "7b6e8067ec96acef9a4184b43210d583b6d2f99a";
+ final AbbreviatedObjectId a = AbbreviatedObjectId.fromString(s);
+ final AbbreviatedObjectId b = AbbreviatedObjectId.fromString(s);
+ assertNotSame(a, b);
+ assertTrue(a.hashCode() == b.hashCode());
+ assertTrue(a.equals(b));
+ assertTrue(b.equals(a));
+ }
+
+ public void testNotEquals_SameLength() {
+ final String sa = "7b6e8067";
+ final String sb = "7b6e806e";
+ final AbbreviatedObjectId a = AbbreviatedObjectId.fromString(sa);
+ final AbbreviatedObjectId b = AbbreviatedObjectId.fromString(sb);
+ assertFalse(a.equals(b));
+ assertFalse(b.equals(a));
+ }
+
+ public void testNotEquals_DiffLength() {
+ final String sa = "7b6e8067abcd";
+ final String sb = "7b6e8067";
+ final AbbreviatedObjectId a = AbbreviatedObjectId.fromString(sa);
+ final AbbreviatedObjectId b = AbbreviatedObjectId.fromString(sb);
+ assertFalse(a.equals(b));
+ assertFalse(b.equals(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
new file mode 100644
index 0000000..1a8d296
--- /dev/null
+++ b/org.spearce.jgit/src/org/spearce/jgit/lib/AbbreviatedObjectId.java
@@ -0,0 +1,205 @@
+/*
+ * Copyright (C) 2008, Google Inc.
+ *
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or
+ * without modification, are permitted provided that the following
+ * conditions are met:
+ *
+ * - Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * - Redistributions in binary form must reproduce the above
+ * copyright notice, this list of conditions and the following
+ * disclaimer in the documentation and/or other materials provided
+ * with the distribution.
+ *
+ * - Neither the name of the Git Development Community nor the
+ * names of its contributors may be used to endorse or promote
+ * products derived from this software without specific prior
+ * written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
+ * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
+ * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+package org.spearce.jgit.lib;
+
+import java.io.UnsupportedEncodingException;
+
+/**
+ * A prefix abbreviation of an {@link ObjectId}.
+ * <p>
+ * Sometimes Git produces abbreviated SHA-1 strings, using sufficient leading
+ * digits from the ObjectId name to still be unique within the repository the
+ * string was generated from. These ids are likely to be unique for a useful
+ * period of time, especially if they contain at least 6-10 hex digits.
+ * <p>
+ * This class converts the hex string into a binary form, to make it more
+ * efficient for matching against an object.
+ */
+public class AbbreviatedObjectId {
+ /**
+ * Convert an AbbreviatedObjectId from hex characters (US-ASCII).
+ *
+ * @param buf
+ * the US-ASCII buffer to read from.
+ * @param offset
+ * position to read the first character from.
+ * @param end
+ * one past the last position to read (<code>end-offset</code> is
+ * the length of the string).
+ * @return the converted object id.
+ */
+ public static final AbbreviatedObjectId fromString(final byte[] buf,
+ final int offset, final int end) {
+ if (end - offset > AnyObjectId.STR_LEN)
+ throw new IllegalArgumentException("Invalid id");
+ return fromHexString(buf, offset, end);
+ }
+
+ /**
+ * Convert an AbbreviatedObjectId from hex characters.
+ *
+ * @param str
+ * the string to read from. Must be <= 40 characters.
+ * @return the converted object id.
+ */
+ public static final AbbreviatedObjectId fromString(final String str) {
+ if (str.length() > AnyObjectId.STR_LEN)
+ throw new IllegalArgumentException("Invalid id: " + str);
+ final byte[] b = Constants.encodeASCII(str);
+ return fromHexString(b, 0, b.length);
+ }
+
+ private static final AbbreviatedObjectId fromHexString(final byte[] bs,
+ int ptr, final int end) {
+ try {
+ final int a = hexUInt32(bs, ptr, end);
+ final int b = hexUInt32(bs, ptr + 8, end);
+ final int c = hexUInt32(bs, ptr + 16, end);
+ final int d = hexUInt32(bs, ptr + 24, end);
+ final int e = hexUInt32(bs, ptr + 32, end);
+ return new AbbreviatedObjectId(end - ptr, a, b, c, d, e);
+ } catch (ArrayIndexOutOfBoundsException e1) {
+ try {
+ final String str = new String(bs, ptr, end - ptr, "US-ASCII");
+ throw new IllegalArgumentException("Invalid id: " + str);
+ } catch (UnsupportedEncodingException e2) {
+ throw new IllegalArgumentException("Invalid id");
+ }
+ }
+ }
+
+ private static final int hexUInt32(final byte[] bs, int p, final int end) {
+ if (8 <= end - p)
+ return AnyObjectId.hexUInt32(bs, p);
+
+ int r = 0, n = 0;
+ while (n < 8 && p < end) {
+ final int v = AnyObjectId.fromhex[bs[p++]];
+ if (v < 0)
+ throw new ArrayIndexOutOfBoundsException();
+ r <<= 4;
+ r |= v;
+ n++;
+ }
+ return r << (8 - n) * 4;
+ }
+
+ /** Number of half-bytes used by this id. */
+ final int nibbles;
+
+ final int w1;
+
+ final int w2;
+
+ final int w3;
+
+ final int w4;
+
+ final int w5;
+
+ private AbbreviatedObjectId(final int n, final int new_1, final int new_2,
+ final int new_3, final int new_4, final int new_5) {
+ nibbles = n;
+ w1 = new_1;
+ w2 = new_2;
+ w3 = new_3;
+ w4 = new_4;
+ w5 = new_5;
+ }
+
+ /** @return number of hex digits appearing in this id */
+ public int length() {
+ return nibbles;
+ }
+
+ /** @return true if this ObjectId is actually a complete id. */
+ public boolean isComplete() {
+ return length() == AnyObjectId.RAW_LEN * 2;
+ }
+
+ /** @return a complete ObjectId; null if {@link #isComplete()} is false */
+ public ObjectId toObjectId() {
+ return isComplete() ? new ObjectId(w1, w2, w3, w4, w5) : null;
+ }
+
+ @Override
+ public int hashCode() {
+ return w2;
+ }
+
+ @Override
+ public boolean equals(final Object o) {
+ if (o instanceof AbbreviatedObjectId) {
+ final AbbreviatedObjectId b = (AbbreviatedObjectId) o;
+ return nibbles == b.nibbles && w1 == b.w1 && w2 == b.w2
+ && w3 == b.w3 && w4 == b.w4 && w5 == b.w5;
+ }
+ return false;
+ }
+
+ /**
+ * @return string form of the abbreviation, in lower case hexadecimal.
+ */
+ public final String name() {
+ final char[] b = new char[AnyObjectId.STR_LEN];
+
+ AnyObjectId.formatHexChar(b, 0, w1);
+ if (nibbles <= 8)
+ return new String(b, 0, nibbles);
+
+ AnyObjectId.formatHexChar(b, 8, w2);
+ if (nibbles <= 16)
+ return new String(b, 0, nibbles);
+
+ AnyObjectId.formatHexChar(b, 16, w3);
+ if (nibbles <= 24)
+ return new String(b, 0, nibbles);
+
+ AnyObjectId.formatHexChar(b, 24, w4);
+ if (nibbles <= 32)
+ return new String(b, 0, nibbles);
+
+ AnyObjectId.formatHexChar(b, 32, w5);
+ return new String(b, 0, nibbles);
+ }
+
+ @Override
+ public String toString() {
+ return "AbbreviatedObjectId[" + name() + "]";
+ }
+}
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 a534202..e88e09d 100644
--- a/org.spearce.jgit/src/org/spearce/jgit/lib/AnyObjectId.java
+++ b/org.spearce.jgit/src/org/spearce/jgit/lib/AnyObjectId.java
@@ -396,7 +396,7 @@ private void toHexCharArray(final char[] dst) {
private static final char[] hexchar = { '0', '1', '2', '3', '4', '5', '6',
'7', '8', '9', 'a', 'b', 'c', 'd', 'e', 'f' };
- private static void formatHexChar(final char[] dst, final int p, int w) {
+ static void formatHexChar(final char[] dst, final int p, int w) {
int o = p + 7;
while (o >= p && w != 0) {
dst[o--] = hexchar[w & 0xf];
--
1.6.1.rc2.299.gead4c
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