From 44a75d9ea8a549d5eb3ab155bcca530b4e0ad595 Mon Sep 17 00:00:00 2001 From: Shawn Pearce Date: Sat, 19 Aug 2017 11:28:34 -0700 Subject: reftable: explicitly store update_index per ref Add an update_index to every reference in a reftable, storing the exact transaction that last modified the reference. This is necessary to fix some merge race conditions. Consider updates at T1, T3 are present in two reftables. Compacting these will create a table with range [T1,T3]. If T2 arrives during or after the compaction its impossible for readers to know how to merge the [T1,T3] table with the T2 table. With an explicit update_index per reference, MergedReftable is able to individually sort each reference, merging individual entries at T3 from [T1,T3] ahead of identically named entries appearing in T2. Change-Id: Ie4065d4176a5a0207dcab9696ae05d086e042140 --- .../storage/reftable/MergedReftableTest.java | 51 +++++++++++++++++++--- .../internal/storage/reftable/ReftableTest.java | 17 ++++---- 2 files changed, 55 insertions(+), 13 deletions(-) (limited to 'org.eclipse.jgit.test/tst/org/eclipse') diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/reftable/MergedReftableTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/reftable/MergedReftableTest.java index f9ebaf6926..adba048e65 100644 --- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/reftable/MergedReftableTest.java +++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/reftable/MergedReftableTest.java @@ -261,6 +261,41 @@ public class MergedReftableTest { } } + @Test + public void missedUpdate() throws IOException { + ByteArrayOutputStream buf = new ByteArrayOutputStream(); + ReftableWriter writer = new ReftableWriter() + .setMinUpdateIndex(1) + .setMaxUpdateIndex(3) + .begin(buf); + writer.writeRef(ref("refs/heads/a", 1), 1); + writer.writeRef(ref("refs/heads/c", 3), 3); + writer.finish(); + byte[] base = buf.toByteArray(); + + byte[] delta = write(Arrays.asList( + ref("refs/heads/b", 2), + ref("refs/heads/c", 4)), + 2); + MergedReftable mr = merge(base, delta); + try (RefCursor rc = mr.allRefs()) { + assertTrue(rc.next()); + assertEquals("refs/heads/a", rc.getRef().getName()); + assertEquals(id(1), rc.getRef().getObjectId()); + assertEquals(1, rc.getUpdateIndex()); + + assertTrue(rc.next()); + assertEquals("refs/heads/b", rc.getRef().getName()); + assertEquals(id(2), rc.getRef().getObjectId()); + assertEquals(2, rc.getUpdateIndex()); + + assertTrue(rc.next()); + assertEquals("refs/heads/c", rc.getRef().getName()); + assertEquals(id(3), rc.getRef().getObjectId()); + assertEquals(3, rc.getUpdateIndex()); + } + } + @Test public void compaction() throws IOException { List delta1 = Arrays.asList( @@ -322,12 +357,18 @@ public class MergedReftableTest { } private byte[] write(Collection refs) throws IOException { + return write(refs, 1); + } + + private byte[] write(Collection refs, long updateIndex) + throws IOException { ByteArrayOutputStream buffer = new ByteArrayOutputStream(); - ReftableWriter writer = new ReftableWriter().begin(buffer); - for (Ref r : RefComparator.sort(refs)) { - writer.writeRef(r); - } - writer.finish(); + new ReftableWriter() + .setMinUpdateIndex(updateIndex) + .setMaxUpdateIndex(updateIndex) + .begin(buffer) + .sortAndWriteRefs(refs) + .finish(); return buffer.toByteArray(); } diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/reftable/ReftableTest.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/reftable/ReftableTest.java index 6809d7b2b2..3ea3061e38 100644 --- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/reftable/ReftableTest.java +++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/internal/storage/reftable/ReftableTest.java @@ -126,7 +126,7 @@ public class ReftableTest { @Test public void estimateCurrentBytesOneRef() throws IOException { Ref exp = ref(MASTER, 1); - int expBytes = 24 + 4 + 5 + 3 + MASTER.length() + 20 + 68; + int expBytes = 24 + 4 + 5 + 4 + MASTER.length() + 20 + 68; byte[] table; ReftableConfig cfg = new ReftableConfig(); @@ -155,7 +155,7 @@ public class ReftableTest { cfg.setIndexObjects(false); cfg.setMaxIndexLevels(1); - int expBytes = 139654; + int expBytes = 147860; byte[] table; ReftableWriter writer = new ReftableWriter().setConfig(cfg); try (ByteArrayOutputStream buf = new ByteArrayOutputStream()) { @@ -174,7 +174,7 @@ public class ReftableTest { public void oneIdRef() throws IOException { Ref exp = ref(MASTER, 1); byte[] table = write(exp); - assertEquals(24 + 4 + 5 + 3 + MASTER.length() + 20 + 68, table.length); + assertEquals(24 + 4 + 5 + 4 + MASTER.length() + 20 + 68, table.length); ReftableReader t = read(table); try (RefCursor rc = t.allRefs()) { @@ -203,7 +203,7 @@ public class ReftableTest { public void oneTagRef() throws IOException { Ref exp = tag(V1_0, 1, 2); byte[] table = write(exp); - assertEquals(24 + 4 + 5 + 2 + V1_0.length() + 40 + 68, table.length); + assertEquals(24 + 4 + 5 + 3 + V1_0.length() + 40 + 68, table.length); ReftableReader t = read(table); try (RefCursor rc = t.allRefs()) { @@ -224,7 +224,7 @@ public class ReftableTest { Ref exp = sym(HEAD, MASTER); byte[] table = write(exp); assertEquals( - 24 + 4 + 5 + 2 + HEAD.length() + 1 + MASTER.length() + 68, + 24 + 4 + 5 + 2 + HEAD.length() + 2 + MASTER.length() + 68, table.length); ReftableReader t = read(table); @@ -281,7 +281,7 @@ public class ReftableTest { String name = "refs/heads/gone"; Ref exp = newRef(name); byte[] table = write(exp); - assertEquals(24 + 4 + 5 + 2 + name.length() + 68, table.length); + assertEquals(24 + 4 + 5 + 3 + name.length() + 68, table.length); ReftableReader t = read(table); try (RefCursor rc = t.allRefs()) { @@ -425,13 +425,14 @@ public class ReftableTest { writer.finish(); byte[] table = buffer.toByteArray(); - assertEquals(245, table.length); + assertEquals(247, table.length); ReftableReader t = read(table); try (RefCursor rc = t.allRefs()) { assertTrue(rc.next()); assertEquals(MASTER, rc.getRef().getName()); assertEquals(id(1), rc.getRef().getObjectId()); + assertEquals(1, rc.getUpdateIndex()); assertTrue(rc.next()); assertEquals(NEXT, rc.getRef().getName()); @@ -636,7 +637,7 @@ public class ReftableTest { writer.finish(); fail("expected BlockSizeTooSmallException"); } catch (BlockSizeTooSmallException e) { - assertEquals(84, e.getMinimumBlockSize()); + assertEquals(85, e.getMinimumBlockSize()); } } -- cgit v1.2.3