Add support for alpha versions

Elasticsearch 5.0 will come with alpha versions which is not supported
in the current version scheme. This commit adds support for aplpha starting
with es 5.0.0 in a backwards compatible way.

core/src/main/java/org/elasticsearch/Version.java

@@ -35,8 +35,8 @@ import java.io.IOException;
 @SuppressWarnings("deprecation")
 public class Version {
 
-    // The logic for ID is: XXYYZZAA, where XX is major version, YY is minor version, ZZ is revision, and AA is Beta/RC indicator
-    // AA values below 50 are beta builds, and below 99 are RC builds, with 99 indicating a release
+    // The logic for ID is: XXYYZZAA, where XX is major version, YY is minor version, ZZ is revision, and AA is alpha/beta/rc indicator
+    // AA values below 25 are fro alpha builder (since 5.0), and above 25 and below 50 are beta builds, and below 99 are RC builds, with 99 indicating a release
     // the (internal) format of the id is there so we can easily do after/before checks on the id
 
 
@@ -143,9 +143,10 @@ public class Version {
         }
 
         try {
-
+            final int rawMajor = Integer.parseInt(parts[0]);
+            final int betaOffset = rawMajor < 5 ? 0 : 25;
             //we reverse the version id calculation based on some assumption as we can't reliably reverse the modulo
-            final int major = Integer.parseInt(parts[0]) * 1000000;
+            final int major = rawMajor * 1000000;
             final int minor = Integer.parseInt(parts[1]) * 10000;
             final int revision = Integer.parseInt(parts[2]) * 100;
 
@@ -153,11 +154,17 @@ public class Version {
             int build = 99;
             if (parts.length == 4) {
                 String buildStr = parts[3];
-                if (buildStr.startsWith("Beta") || buildStr.startsWith("beta")) {
-                    build = Integer.parseInt(buildStr.substring(4));
-                }
-                if (buildStr.startsWith("RC") || buildStr.startsWith("rc")) {
+                if (buildStr.startsWith("alpha")) {
+                    assert rawMajor >= 5 : "major must be >= 5 but was " + major;
+                    build = Integer.parseInt(buildStr.substring(5));
+                    assert build < 25 : "expected a beta build but " + build + " >= 25";
+                } else if (buildStr.startsWith("Beta") || buildStr.startsWith("beta")) {
+                    build = betaOffset + Integer.parseInt(buildStr.substring(4));
+                    assert build < 50 : "expected a beta build but " + build + " >= 50";
+                } else if (buildStr.startsWith("RC") || buildStr.startsWith("rc")) {
                     build = Integer.parseInt(buildStr.substring(2)) + 50;
+                } else {
+                    throw new IllegalArgumentException("unable to parse version " + version);
                 }
             }
 
@@ -220,13 +227,16 @@ public class Version {
     public String toString() {
         StringBuilder sb = new StringBuilder();
         sb.append(major).append('.').append(minor).append('.').append(revision);
-        if (isBeta()) {
+        if (isAlpha()) {
+            sb.append("-alpha");
+            sb.append(build);
+        } else if (isBeta()) {
             if (major >= 2) {
                 sb.append("-beta");
             } else {
                 sb.append(".Beta");
             }
-            sb.append(build);
+            sb.append(major < 5 ? build : build-25);
         } else if (build < 99) {
             if (major >= 2) {
                 sb.append("-rc");
@@ -262,7 +272,16 @@ public class Version {
     }
 
     public boolean isBeta() {
-        return build < 50;
+        return major < 5 ? build < 50 : build >= 25 && build < 50;
+    }
+
+    /**
+     * Returns true iff this version is an alpha version
+     * Note: This has been introduced in elasticsearch version 5. Previous versions will never
+     * have an alpha version.
+     */
+    public boolean isAlpha() {
+        return major < 5 ? false :  build < 25;
     }
 
     public boolean isRC() {

core/src/test/java/org/elasticsearch/VersionTests.java

@@ -57,6 +57,12 @@ public class VersionTests extends ESTestCase {
         assertThat(V_2_2_0.onOrAfter(V_5_0_0), is(false));
         assertThat(V_2_2_0.onOrAfter(V_2_2_0), is(true));
         assertThat(V_5_0_0.onOrAfter(V_2_2_0), is(true));
+
+        assertTrue(Version.fromString("5.0.0-alpha2").onOrAfter(Version.fromString("5.0.0-alpha1")));
+        assertTrue(Version.fromString("5.0.0").onOrAfter(Version.fromString("5.0.0-beta2")));
+        assertTrue(Version.fromString("5.0.0-rc1").onOrAfter(Version.fromString("5.0.0-beta24")));
+        assertTrue(Version.fromString("5.0.0-alpha24").before(Version.fromString("5.0.0-beta0")));
+
     }
 
     public void testVersionConstantPresent() {
@@ -144,12 +150,40 @@ public class VersionTests extends ESTestCase {
         assertEquals("2.0.0-beta1", Version.V_2_0_0_beta1.toString());
         assertEquals("5.0.0", Version.V_5_0_0.toString());
         assertEquals("2.3.0", Version.V_2_3_0.toString());
+        assertEquals("0.90.0.Beta1", Version.fromString("0.90.0.Beta1").toString());
+        assertEquals("1.0.0.Beta1", Version.fromString("1.0.0.Beta1").toString());
+        assertEquals("2.0.0-beta1", Version.fromString("2.0.0-beta1").toString());
+        assertEquals("5.0.0-beta1", Version.fromString("5.0.0-beta1").toString());
+        assertEquals("5.0.0-alpha1", Version.fromString("5.0.0-alpha1").toString());
     }
 
     public void testIsBeta() {
         assertTrue(Version.V_2_0_0_beta1.isBeta());
+        assertTrue(Version.fromString("1.0.0.Beta1").isBeta());
+        assertTrue(Version.fromString("0.90.0.Beta1").isBeta());
     }
 
+
+    public void testIsAlpha() {
+        assertTrue(new Version(5000001, org.apache.lucene.util.Version.LUCENE_6_0_0).isAlpha());
+        assertFalse(new Version(4000002, org.apache.lucene.util.Version.LUCENE_6_0_0).isAlpha());
+        assertTrue(new Version(4000002, org.apache.lucene.util.Version.LUCENE_6_0_0).isBeta());
+        assertTrue(Version.fromString("5.0.0-alpha14").isAlpha());
+        assertEquals(5000014, Version.fromString("5.0.0-alpha14").id);
+        assertTrue(Version.fromId(5000015).isAlpha());
+
+        for (int i = 0 ; i < 25; i++) {
+            assertEquals(Version.fromString("5.0.0-alpha" + i).id, Version.fromId(5000000 + i).id);
+            assertEquals("5.0.0-alpha" + i, Version.fromId(5000000 + i).toString());
+        }
+
+        for (int i = 0 ; i < 25; i++) {
+            assertEquals(Version.fromString("5.0.0-beta" + i).id, Version.fromId(5000000 + i + 25).id);
+            assertEquals("5.0.0-beta" + i, Version.fromId(5000000 + i + 25).toString());
+        }
+    }
+
+
     public void testParseVersion() {
         final int iters = scaledRandomIntBetween(100, 1000);
         for (int i = 0; i < iters; i++) {
@@ -160,6 +194,10 @@ public class VersionTests extends ESTestCase {
             Version parsedVersion = Version.fromString(version.toString());
             assertEquals(version, parsedVersion);
         }
+
+        expectThrows(IllegalArgumentException.class, () -> {
+            Version.fromString("5.0.0-alph2");
+        });
     }
 
     public void testParseLenient() {