diff --git a/common/util/src/com/android/compatibility/common/util/MetricsReportLog.java b/common/util/src/com/android/compatibility/common/util/MetricsReportLog.java
new file mode 100644
index 0000000..4675231
--- /dev/null
+++ b/common/util/src/com/android/compatibility/common/util/MetricsReportLog.java
@@ -0,0 +1,42 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+
+package com.android.compatibility.common.util;
+
+/**
+ * A {@link ReportLog} that can be used with the in memory metrics store used for host side metrics.
+ */
+public final class MetricsReportLog extends ReportLog {
+    private final String mDeviceSerial;
+    private final String mAbi;
+    private final String mClassMethodName;
+
+    /**
+     * @param deviceSerial serial number of the device
+     * @param abi abi the test was run on
+     * @param classMethodName class name and method name of the test in class#method format.
+     *        Note that ReportLog.getClassMethodNames() provide this.
+     */
+    public MetricsReportLog(String deviceSerial, String abi, String classMethodName) {
+        mDeviceSerial = deviceSerial;
+        mAbi = abi;
+        mClassMethodName = classMethodName;
+    }
+
+    public void submit() {
+        MetricsStore.storeResult(mDeviceSerial, mAbi, mClassMethodName, this);
+    }
+}
diff --git a/common/util/src/com/android/compatibility/common/util/MetricsStore.java b/common/util/src/com/android/compatibility/common/util/MetricsStore.java
new file mode 100644
index 0000000..9eeb94a
--- /dev/null
+++ b/common/util/src/com/android/compatibility/common/util/MetricsStore.java
@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+
+package com.android.compatibility.common.util;
+
+import java.util.concurrent.ConcurrentHashMap;
+
+/**
+ * A simple in-memory store for metrics results. This should be used for hostside metrics reporting.
+ */
+public class MetricsStore {
+
+    // needs concurrent version as there can be multiple client accessing this.
+    // But there is no additional protection for the same key as that should not happen.
+    private static final ConcurrentHashMap<String, ReportLog> mMap =
+            new ConcurrentHashMap<String, ReportLog>();
+
+    /**
+     * Stores a result. Existing result with the same key will be replaced.
+     * Note that key is generated in the form of device_serial#class#method name.
+     * So there should be no concurrent test for the same (serial, class, method).
+     * @param deviceSerial
+     * @param abi
+     * @param classMethodName
+     * @param reportLog Contains the result to be stored
+     */
+    public static void storeResult(
+            String deviceSerial, String abi, String classMethodName, ReportLog reportLog) {
+        mMap.put(generateTestKey(deviceSerial, abi, classMethodName), reportLog);
+    }
+
+    /**
+     * retrieves a metric result for the given condition and remove it from the internal
+     * storage. If there is no result for the given condition, it will return null.
+     */
+    public static ReportLog removeResult(String deviceSerial, String abi, String classMethodName) {
+        return mMap.remove(generateTestKey(deviceSerial, abi, classMethodName));
+    }
+
+    /**
+     * @return test key in the form of device_serial#abi#class_name#method_name
+     */
+    private static String generateTestKey(String deviceSerial, String abi, String classMethodName) {
+        return String.format("%s#%s#%s", deviceSerial, abi, classMethodName);
+    }
+}
diff --git a/common/util/src/com/android/compatibility/common/util/ReportLog.java b/common/util/src/com/android/compatibility/common/util/ReportLog.java
index 8cfc086..7209ac8 100644
--- a/common/util/src/com/android/compatibility/common/util/ReportLog.java
+++ b/common/util/src/com/android/compatibility/common/util/ReportLog.java
@@ -16,28 +16,37 @@
 
 package com.android.compatibility.common.util;
 
-import org.xmlpull.v1.XmlSerializer;
-
-import java.io.IOException;
 import java.io.Serializable;
 import java.util.ArrayList;
 import java.util.List;
+import java.util.StringTokenizer;
+import java.util.regex.Pattern;
 
 /**
  * Utility class to add results to the report.
  */
-public abstract class ReportLog implements Serializable {
+public class ReportLog implements Serializable {
 
+    private static final String LOG_SEPARATOR = "+++";
+    private static final String SUMMARY_SEPARATOR = "++++";
+    private static final String LOG_ELEM_SEPARATOR = "|";
+    private static final String EMPTY_CHAR = " ";
     private Result mSummary;
     private final List<Result> mDetails = new ArrayList<Result>();
 
-    class Result implements Serializable {
-        private static final int CALLER_STACKTRACE_DEPTH = 5;
+    static class Result implements Serializable {
         private String mLocation;
         private String mMessage;
         private double[] mValues;
         private ResultType mType;
         private ResultUnit mUnit;
+        private Double mTarget;
+
+
+        private Result(String location, String message, double[] values,
+                ResultType type, ResultUnit unit) {
+            this(location, message, values, null /*target*/, type, unit);
+        }
 
         /**
          * Creates a result object to be included in the report. Each object has a message
@@ -47,23 +56,22 @@
          *
          * @param message A string describing the values
          * @param values An array of the values
+         * @param target Nullable. The target value.
          * @param type Represents how to interpret the values (eg. A lower score is better)
          * @param unit Represents the unit in which the values are (eg. Milliseconds)
-         * @param depth A number used to increase the depth the stack is queried. This should only
-         * be given in the case that the report is populated by a helper function, in which case it
-         * would be 1, or else 0.
          */
-        private Result(String message, double[] values, ResultType type,
-                ResultUnit unit, int depth) {
-            final StackTraceElement[] trace = Thread.currentThread().getStackTrace();
-            final StackTraceElement e =
-                    trace[Math.min(CALLER_STACKTRACE_DEPTH + depth, trace.length - 1)];
-            mLocation = String.format(
-                    "%s#%s:%d", e.getClassName(), e.getMethodName(), e.getLineNumber());
+        private Result(String location, String message, double[] values,
+                Double target, ResultType type, ResultUnit unit) {
+            mLocation = location;
             mMessage = message;
             mValues = values;
             mType = type;
             mUnit = unit;
+            mTarget = target;
+        }
+
+        public double getTarget() {
+            return mTarget;
         }
 
         public String getLocation() {
@@ -85,51 +93,89 @@
         public ResultUnit getUnit() {
             return mUnit;
         }
+
+        /**
+         * Format:
+         * location|message|target|type|unit|value[s], target can be " " if there is no target set.
+         * log for array = classMethodName:line_number|message|unit|type|space separated values
+         */
+        String toEncodedString() {
+            StringBuilder builder = new StringBuilder()
+                    .append(mLocation)
+                    .append(LOG_ELEM_SEPARATOR)
+                    .append(mMessage)
+                    .append(LOG_ELEM_SEPARATOR)
+                    .append(mTarget != null ? mTarget : EMPTY_CHAR)
+                    .append(LOG_ELEM_SEPARATOR)
+                    .append(mType.name())
+                    .append(LOG_ELEM_SEPARATOR)
+                    .append(mUnit.name())
+                    .append(LOG_ELEM_SEPARATOR);
+            for (double value : mValues) {
+                builder.append(value).append(" ");
+            }
+            return builder.toString();
+        }
+
+        static Result fromEncodedString(String encodedString) {
+            String[] elems = encodedString.split(Pattern.quote(LOG_ELEM_SEPARATOR));
+            if (elems.length < 5) {
+                return null;
+            }
+
+            String[] valueStrArray = elems[5].split(" ");
+            double[] valueArray = new double[valueStrArray.length];
+            for (int i = 0; i < valueStrArray.length; i++) {
+                valueArray[i] = Double.parseDouble(valueStrArray[i]);
+            }
+            return new Result(
+                    elems[0], /*location*/
+                    elems[1], /*message*/
+                    valueArray, /*values*/
+                    elems[2].equals(EMPTY_CHAR) ? null : Double.parseDouble(elems[2]), /*target*/
+                    ResultType.valueOf(elems[3]), /*type*/
+                    ResultUnit.valueOf(elems[4])  /*unit*/);
+        }
     }
 
     /**
      * Adds an array of values to the report.
      */
     public void addValues(String message, double[] values, ResultType type, ResultUnit unit) {
-        mDetails.add(new Result(message, values, type, unit, 0));
+        mDetails.add(new Result(Stacktrace.getTestCallerClassMethodNameLineNumber(),
+                message, values, type, unit));
     }
 
     /**
      * Adds an array of values to the report.
      */
-    public void addValues(String message, double[] values, ResultType type,
-            ResultUnit unit, int depth) {
-        mDetails.add(new Result(message, values, type, unit, depth));
+    public void addValues(
+            String message, double[] values, ResultType type, ResultUnit unit, String location) {
+        mDetails.add(new Result(location, message, values, type, unit));
     }
 
     /**
      * Adds a value to the report.
      */
     public void addValue(String message, double value, ResultType type, ResultUnit unit) {
-        mDetails.add(new Result(message, new double[] {value}, type, unit, 0));
+        mDetails.add(new Result(Stacktrace.getTestCallerClassMethodNameLineNumber(), message,
+                new double[] {value}, type, unit));
     }
 
     /**
      * Adds a value to the report.
      */
     public void addValue(String message, double value, ResultType type,
-            ResultUnit unit, int depth) {
-        mDetails.add(new Result(message, new double[] {value}, type, unit, depth));
+            ResultUnit unit, String location) {
+        mDetails.add(new Result(location, message, new double[] {value}, type, unit));
     }
 
     /**
      * Sets the summary of the report.
      */
     public void setSummary(String message, double value, ResultType type, ResultUnit unit) {
-        mSummary = new Result(message, new double[] {value}, type, unit, 0);
-    }
-
-    /**
-     * Sets the summary of the report.
-     */
-    public void setSummary(String message, double value, ResultType type,
-            ResultUnit unit, int depth) {
-        mSummary = new Result(message, new double[] {value}, type, unit, depth);
+        mSummary = new Result(Stacktrace.getTestCallerClassMethodNameLineNumber(),
+                message, new double[] {value}, type, unit);
     }
 
     public Result getSummary() {
@@ -139,4 +185,46 @@
     public List<Result> getDetailedMetrics() {
         return new ArrayList<Result>(mDetails);
     }
+
+    /**
+     * Parse a String encoded {@link com.android.compatibility.common.util.ReportLog}
+     */
+    public static ReportLog fromEncodedString(String encodedString) {
+        ReportLog reportLog = new ReportLog();
+        StringTokenizer tok = new StringTokenizer(encodedString, SUMMARY_SEPARATOR);
+        if (tok.hasMoreTokens()) {
+            // Extract the summary
+            reportLog.mSummary = Result.fromEncodedString(tok.nextToken());
+        }
+        if (tok.hasMoreTokens()) {
+            // Extract the detailed results
+            StringTokenizer detailedTok = new StringTokenizer(tok.nextToken(), LOG_SEPARATOR);
+            while (detailedTok.hasMoreTokens()) {
+                reportLog.mDetails.add(Result.fromEncodedString(detailedTok.nextToken()));
+            }
+        }
+        return reportLog;
+    }
+
+    /**
+     * @return a String representation of this report or null if not collected
+     */
+    protected String toEncodedString() {
+        if ((mSummary == null) && mDetails.isEmpty()) {
+            // just return empty string
+            return null;
+        }
+        StringBuilder builder = new StringBuilder();
+        builder.append(mSummary.toEncodedString());
+        builder.append(SUMMARY_SEPARATOR);
+        for (Result result : mDetails) {
+            builder.append(result.toEncodedString());
+            builder.append(LOG_SEPARATOR);
+        }
+        // delete the last separator
+        if (builder.length() >= LOG_SEPARATOR.length()) {
+            builder.delete(builder.length() - LOG_SEPARATOR.length(), builder.length());
+        }
+        return builder.toString();
+    }
 }
diff --git a/common/util/src/com/android/compatibility/common/util/Stacktrace.java b/common/util/src/com/android/compatibility/common/util/Stacktrace.java
new file mode 100644
index 0000000..27bf9ca
--- /dev/null
+++ b/common/util/src/com/android/compatibility/common/util/Stacktrace.java
@@ -0,0 +1,70 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+
+package com.android.compatibility.common.util;
+
+/**
+ * Helper methods for dealing with stack traces
+ */
+public class Stacktrace {
+
+    private static final int SAFETY_DEPTH = 4;
+    private static final String TEST_POSTFIX = "Test";
+
+    private Stacktrace() {}
+
+    /**
+     * @return classname#methodname from call stack of the current thread
+     */
+    public static String getTestCallerClassMethodName() {
+        return getTestCallerClassMethodName(false /*includeLineNumber*/);
+    }
+
+    /**
+     * @return classname#methodname from call stack of the current thread
+     */
+    public static String getTestCallerClassMethodNameLineNumber() {
+        return getTestCallerClassMethodName(true /*includeLineNumber*/);
+    }
+
+    /**
+     * @return classname#methodname from call stack of the current thread
+     */
+    private static String getTestCallerClassMethodName(boolean includeLineNumber) {
+        StackTraceElement[] elements = Thread.currentThread().getStackTrace();
+        // Look for the first class name in the elements array that ends with Test
+        for (int i = 0; i < elements.length; i++) {
+            if (elements[i].getClassName().endsWith(TEST_POSTFIX)) {
+                return buildClassMethodName(elements, i, includeLineNumber);
+            }
+        }
+
+        // Use a reasonable default if the test name isn't found
+        return buildClassMethodName(elements, SAFETY_DEPTH, includeLineNumber);
+    }
+
+    private static String buildClassMethodName(
+            StackTraceElement[] elements, int depth, boolean includeLineNumber) {
+        depth = Math.min(depth, elements.length - 1);
+        StringBuilder builder = new StringBuilder();
+        builder.append(elements[depth].getClassName()).append("#")
+                .append(elements[depth].getMethodName());
+        if (includeLineNumber) {
+            builder.append(":").append(elements[depth].getLineNumber());
+        }
+        return builder.toString();
+    }
+}
diff --git a/common/util/tests/src/com/android/compatibility/common/util/MetricsStoreTest.java b/common/util/tests/src/com/android/compatibility/common/util/MetricsStoreTest.java
new file mode 100644
index 0000000..944cc43
--- /dev/null
+++ b/common/util/tests/src/com/android/compatibility/common/util/MetricsStoreTest.java
@@ -0,0 +1,49 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+
+package com.android.compatibility.common.util;
+
+import junit.framework.TestCase;
+
+/**
+ * Unit tests for {@link MetricsStore}
+ */
+public class MetricsStoreTest extends TestCase {
+
+    private static final String DEVICE_SERIAL = "DEVICE_SERIAL";
+    private static final String ABI = "ABI";
+    private static final String CLASSMETHOD_NAME = "CLASSMETHOD_NAME";
+
+    private static final double[] VALUES = new double[] {1, 11, 21, 1211, 111221};
+
+    private ReportLog mReportLog;
+
+    @Override
+    protected void setUp() throws Exception {
+        this.mReportLog = new ReportLog();
+    }
+
+    public void testStoreAndRemove() {
+        mReportLog.setSummary("Sample Summary", 1.0, ResultType.HIGHER_BETTER, ResultUnit.BYTE);
+        mReportLog.addValues("Details", VALUES, ResultType.NEUTRAL, ResultUnit.FPS);
+        MetricsStore.storeResult(DEVICE_SERIAL, ABI, CLASSMETHOD_NAME, mReportLog);
+
+        ReportLog reportLog = MetricsStore.removeResult(DEVICE_SERIAL, ABI, CLASSMETHOD_NAME);
+        assertSame(mReportLog, reportLog);
+        assertNull(MetricsStore.removeResult("blah", ABI, CLASSMETHOD_NAME));
+    }
+
+}
diff --git a/common/util/tests/src/com/android/compatibility/common/util/MetricsXmlSerializerTest.java b/common/util/tests/src/com/android/compatibility/common/util/MetricsXmlSerializerTest.java
index 70da820..05e69d8 100644
--- a/common/util/tests/src/com/android/compatibility/common/util/MetricsXmlSerializerTest.java
+++ b/common/util/tests/src/com/android/compatibility/common/util/MetricsXmlSerializerTest.java
@@ -36,7 +36,8 @@
             HEADER
             + "<Summary message=\"Sample\" scoreType=\"higher_better\" unit=\"byte\">1.0</Summary>"
             + "<Details>"
-                    + "<ValueArray source=\"sun.reflect.NativeMethodAccessorImpl#invoke0:-2\""
+                    + "<ValueArray source=\"com.android.compatibility.common.util."
+                    + "MetricsXmlSerializerTest#testSerialize:84\""
                     + " message=\"Details\" scoreType=\"neutral\" unit=\"fps\">"
                         + "<Value>1.0</Value>"
                         + "<Value>11.0</Value>"
diff --git a/common/util/tests/src/com/android/compatibility/common/util/ReportLogTest.java b/common/util/tests/src/com/android/compatibility/common/util/ReportLogTest.java
new file mode 100644
index 0000000..a5f3306
--- /dev/null
+++ b/common/util/tests/src/com/android/compatibility/common/util/ReportLogTest.java
@@ -0,0 +1,68 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License
+ */
+
+package com.android.compatibility.common.util;
+
+import junit.framework.TestCase;
+
+import java.util.Arrays;
+
+/**
+ * Unit tests for {@link ReportLog}
+ */
+public class ReportLogTest extends TestCase {
+
+    private static final double[] VALUES = new double[] {1, 11, 21, 1211, 111221};
+
+    private static final String EXPECTED_ENCODED_REPORT_LOG =
+            "com.android.compatibility.common.util.ReportLogTest#testEncodeDecode:44|" +
+            "Sample Summary| |HIGHER_BETTER|BYTE|1.0 ++++" +
+            "com.android.compatibility.common.util.ReportLogTest#testEncodeDecode:45|" +
+            "Details| |NEUTRAL|FPS|1.0 11.0 21.0 1211.0 111221.0 ";
+    private ReportLog reportLog;
+
+    @Override
+    protected void setUp() throws Exception {
+        this.reportLog = new ReportLog();
+    }
+
+    public void testEncodeDecode() {
+
+        reportLog.setSummary("Sample Summary", 1.0, ResultType.HIGHER_BETTER, ResultUnit.BYTE);
+        reportLog.addValues("Details", VALUES, ResultType.NEUTRAL, ResultUnit.FPS);
+
+        String encodedReportLog = reportLog.toEncodedString();
+        assertEquals(EXPECTED_ENCODED_REPORT_LOG, encodedReportLog);
+
+        ReportLog decodedReportLog = ReportLog.fromEncodedString(encodedReportLog);
+        ReportLog.Result summary = reportLog.getSummary();
+        assertEquals("Sample Summary", summary.getMessage());
+        assertFalse(summary.getLocation().isEmpty());
+        assertEquals(ResultType.HIGHER_BETTER, summary.getType());
+        assertEquals(ResultUnit.BYTE, summary.getUnit());
+        assertTrue(Arrays.equals(new double[] {1.0}, summary.getValues()));
+
+        assertEquals(1, decodedReportLog.getDetailedMetrics().size());
+        ReportLog.Result detail = decodedReportLog.getDetailedMetrics().get(0);
+        assertEquals("Details", detail.getMessage());
+        assertFalse(detail.getLocation().isEmpty());
+        assertEquals(ResultType.NEUTRAL, detail.getType());
+        assertEquals(ResultUnit.FPS, detail.getUnit());
+        assertTrue(Arrays.equals(VALUES, detail.getValues()));
+
+        assertEquals(encodedReportLog, decodedReportLog.toEncodedString());
+    }
+}
diff --git a/common/util/tests/src/com/android/compatibility/common/util/UnitTests.java b/common/util/tests/src/com/android/compatibility/common/util/UnitTests.java
index b9a17e1..348c680 100644
--- a/common/util/tests/src/com/android/compatibility/common/util/UnitTests.java
+++ b/common/util/tests/src/com/android/compatibility/common/util/UnitTests.java
@@ -26,6 +26,8 @@
     public UnitTests() {
         super();
 
+        addTestSuite(MetricsStoreTest.class);
         addTestSuite(MetricsXmlSerializerTest.class);
+        addTestSuite(ReportLogTest.class);
     }
 }