DeviceInfoUtils: add class and helper for three-part version number

Add a class Version and string helper for handling a three-part
kernel version number.

Test: atest com.android.testutils.DeviceInfoUtilsTest
Bug: 232332847
Change-Id: I0f229e935bd8332ef2ef93fc910a576df9c054ae
diff --git a/staticlibs/tests/unit/src/com/android/testutils/DeviceInfoUtilsTest.java b/staticlibs/tests/unit/src/com/android/testutils/DeviceInfoUtilsTest.java
index f99700a..6f603d5 100644
--- a/staticlibs/tests/unit/src/com/android/testutils/DeviceInfoUtilsTest.java
+++ b/staticlibs/tests/unit/src/com/android/testutils/DeviceInfoUtilsTest.java
@@ -17,6 +17,9 @@
 package com.android.testutils;
 
 import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotEquals;
+import static org.junit.Assert.assertTrue;
 
 import androidx.test.filters.SmallTest;
 
@@ -42,4 +45,65 @@
         assertEquals(-1, DeviceInfoUtils.compareMajorMinorVersion("3.10", "4.8.0"));
         assertEquals(-1, DeviceInfoUtils.compareMajorMinorVersion("4.7.10.10", "4.8"));
     }
+
+    @Test
+    public void testGetMajorMinorSubminorVersion() throws Exception {
+        final DeviceInfoUtils.KVersion expected = new DeviceInfoUtils.KVersion(4, 19, 220);
+        assertEquals(expected, DeviceInfoUtils.getMajorMinorSubminorVersion("4.19.220"));
+        assertEquals(expected, DeviceInfoUtils.getMajorMinorSubminorVersion("4.19.220.50"));
+        assertEquals(expected, DeviceInfoUtils.getMajorMinorSubminorVersion(
+                "4.19.220-g500ede0aed22-ab8272303"));
+
+        final DeviceInfoUtils.KVersion expected2 = new DeviceInfoUtils.KVersion(5, 17, 0);
+        assertEquals(expected2, DeviceInfoUtils.getMajorMinorSubminorVersion("5.17"));
+        assertEquals(expected2, DeviceInfoUtils.getMajorMinorSubminorVersion("5.17."));
+        assertEquals(expected2, DeviceInfoUtils.getMajorMinorSubminorVersion("5.17.beta"));
+        assertEquals(expected2, DeviceInfoUtils.getMajorMinorSubminorVersion(
+                "5.17-rc6-g52099515ca00-ab8032400"));
+
+        final DeviceInfoUtils.KVersion invalid = new DeviceInfoUtils.KVersion(0, 0, 0);
+        assertEquals(invalid, DeviceInfoUtils.getMajorMinorSubminorVersion(""));
+        assertEquals(invalid, DeviceInfoUtils.getMajorMinorSubminorVersion("4"));
+        assertEquals(invalid, DeviceInfoUtils.getMajorMinorSubminorVersion("4."));
+        assertEquals(invalid, DeviceInfoUtils.getMajorMinorSubminorVersion("4-beta"));
+        assertEquals(invalid, DeviceInfoUtils.getMajorMinorSubminorVersion("1.x.1"));
+        assertEquals(invalid, DeviceInfoUtils.getMajorMinorSubminorVersion("x.1.1"));
+    }
+
+    @Test
+    public void testVersion() throws Exception {
+        final DeviceInfoUtils.KVersion v1 = new DeviceInfoUtils.KVersion(4, 8, 1);
+        final DeviceInfoUtils.KVersion v2 = new DeviceInfoUtils.KVersion(4, 8, 1);
+        final DeviceInfoUtils.KVersion v3 = new DeviceInfoUtils.KVersion(4, 8, 2);
+        final DeviceInfoUtils.KVersion v4 = new DeviceInfoUtils.KVersion(4, 9, 1);
+        final DeviceInfoUtils.KVersion v5 = new DeviceInfoUtils.KVersion(5, 8, 1);
+
+        assertEquals(v1, v2);
+        assertNotEquals(v1, v3);
+        assertNotEquals(v1, v4);
+        assertNotEquals(v1, v5);
+
+        assertEquals(0, v1.compareTo(v2));
+        assertEquals(-1, v1.compareTo(v3));
+        assertEquals(1, v3.compareTo(v1));
+        assertEquals(-1, v1.compareTo(v4));
+        assertEquals(1, v4.compareTo(v1));
+        assertEquals(-1, v1.compareTo(v5));
+        assertEquals(1, v5.compareTo(v1));
+
+        assertTrue(v2.isInRange(v1, v5));
+        assertTrue(v3.isInRange(v1, v5));
+        assertTrue(v4.isInRange(v1, v5));
+        assertFalse(v5.isInRange(v1, v5));
+        assertFalse(v1.isInRange(v3, v5));
+        assertFalse(v5.isInRange(v2, v4));
+
+        assertTrue(v2.isAtLeast(v1));
+        assertTrue(v3.isAtLeast(v1));
+        assertTrue(v4.isAtLeast(v1));
+        assertTrue(v5.isAtLeast(v1));
+        assertFalse(v1.isAtLeast(v3));
+        assertFalse(v1.isAtLeast(v4));
+        assertFalse(v1.isAtLeast(v5));
+    }
 }
diff --git a/staticlibs/testutils/devicetests/com/android/testutils/DeviceInfoUtils.java b/staticlibs/testutils/devicetests/com/android/testutils/DeviceInfoUtils.java
index 69cb5f8..1925b55 100644
--- a/staticlibs/testutils/devicetests/com/android/testutils/DeviceInfoUtils.java
+++ b/staticlibs/testutils/devicetests/com/android/testutils/DeviceInfoUtils.java
@@ -26,7 +26,78 @@
  * Utilities for device information.
  */
 public class DeviceInfoUtils {
-    private static Pair<Integer, Integer> getVersionFromString(String version) {
+    /**
+     * Class for a three-part kernel version number.
+     */
+    public static class KVersion {
+        public final int major;
+        public final int minor;
+        public final int sub;
+
+        public KVersion(int major, int minor, int sub) {
+            this.major = major;
+            this.minor = minor;
+            this.sub = sub;
+        }
+
+        /**
+         * Compares with other version numerically.
+         *
+         * @param  other the other version to compare
+         * @return the value 0 if this == other;
+         *         a value less than 0 if this < other and
+         *         a value greater than 0 if this > other.
+         */
+        public int compareTo(final KVersion other) {
+            int res = Integer.compare(this.major, other.major);
+            if (res == 0) {
+                res = Integer.compare(this.minor, other.minor);
+            }
+            if (res == 0) {
+                res = Integer.compare(this.sub, other.sub);
+            }
+            return res;
+        }
+
+        /**
+         * At least satisfied with the given version.
+         *
+         * @param  from the start version to compare
+         * @return return true if this version is at least satisfied with the given version.
+         *         otherwise, return false.
+         */
+        public boolean isAtLeast(final KVersion from) {
+            return compareTo(from) >= 0;
+        }
+
+        /**
+         * Falls within the given range [from, to).
+         *
+         * @param  from the start version to compare
+         * @param  to   the end version to compare
+         * @return return true if this version falls within the given range.
+         *         otherwise, return false.
+         */
+        public boolean isInRange(final KVersion from, final KVersion to) {
+            return isAtLeast(from) && !isAtLeast(to);
+        }
+
+        @Override
+        public boolean equals(Object o) {
+            if (!(o instanceof KVersion)) return false;
+            KVersion that = (KVersion) o;
+            return this.major == that.major
+                    && this.minor == that.minor
+                    && this.sub == that.sub;
+        }
+    };
+
+    /**
+     * Get a two-part kernel version number (major and minor) from a given string.
+     *
+     * TODO: use class KVersion.
+     */
+    private static Pair<Integer, Integer> getMajorMinorVersion(String version) {
         // Only gets major and minor number of the version string.
         final Pattern versionPattern = Pattern.compile("^(\\d+)(\\.(\\d+))?.*");
         final Matcher m = versionPattern.matcher(version);
@@ -49,10 +120,12 @@
      * @return the value 0 if s1 == s2;
      *         a value less than 0 if s1 < s2 and
      *         a value greater than 0 if s1 > s2.
+     *
+     * TODO: use class KVersion.
      */
     public static int compareMajorMinorVersion(final String s1, final String s2) {
-        final Pair<Integer, Integer> v1 = getVersionFromString(s1);
-        final Pair<Integer, Integer> v2 = getVersionFromString(s2);
+        final Pair<Integer, Integer> v1 = getMajorMinorVersion(s1);
+        final Pair<Integer, Integer> v2 = getMajorMinorVersion(s2);
 
         if (v1.first == v2.first) {
             return Integer.compare(v1.second, v2.second);
@@ -60,4 +133,28 @@
             return Integer.compare(v1.first, v2.first);
         }
     }
+
+    /**
+     * Get a three-part kernel version number (major, minor and subminor) from a given string.
+     * Any version string must at least have major and minor number. If the subminor number can't
+     * be parsed from string. Assign zero as subminor number. Invalid version is treated as
+     * version 0.0.0.
+     */
+    public static KVersion getMajorMinorSubminorVersion(final String version) {
+        // The kernel version is a three-part version number (major, minor and subminor). Get
+        // the three-part version numbers and discard the remaining stuff if any.
+        // For example:
+        //   4.19.220-g500ede0aed22-ab8272303 --> 4.19.220
+        //   5.17-rc6-g52099515ca00-ab8032400 --> 5.17.0
+        final Pattern versionPattern = Pattern.compile("^(\\d+)\\.(\\d+)(\\.(\\d+))?.*");
+        final Matcher m = versionPattern.matcher(version);
+        if (m.matches()) {
+            final int major = Integer.parseInt(m.group(1));
+            final int minor = Integer.parseInt(m.group(2));
+            final int sub = TextUtils.isEmpty(m.group(4)) ? 0 : Integer.parseInt(m.group(4));
+            return new KVersion(major, minor, sub);
+        } else {
+            return new KVersion(0, 0, 0);
+        }
+    }
 }