Make the logcat fifo size user configurable.

Add a preference where users can set the size of the message list.
Defaults to 1000.

Change-Id: Ia888c3802f07607274bfbdca0ade8fbda009ba55

5 files changed, 88 insertions, 19 deletions

diff --git a/ddms/app/src/com/android/ddms/PrefsDialog.java b/ddms/app/src/com/android/ddms/PrefsDialog.java
index 42ab76c..4745ed7 100644
--- a/ddms/app/src/com/android/ddms/PrefsDialog.java
+++ b/ddms/app/src/com/android/ddms/PrefsDialog.java
@@ -23,6 +23,7 @@ import com.android.ddmlib.Log;
 import com.android.ddmlib.Log.LogLevel;
 import com.android.ddmuilib.DdmUiPreferences;
 import com.android.ddmuilib.PortFieldEditor;
+import com.android.ddmuilib.logcat.LogCatMessageList;
 import com.android.ddmuilib.logcat.LogCatPanel;
 import com.android.sdkstats.SdkStatsPermissionDialog;
 import com.android.sdkstats.SdkStatsService;
@@ -447,6 +448,12 @@ public final class PrefsDialog {
                         "Text output font:",
                         getFieldEditorParent());
                 addField(ffe);
+
+                IntegerFieldEditor maxMessages = new IntegerFieldEditor(
+                        LogCatMessageList.MAX_MESSAGES_PREFKEY,
+                        "Maximum number of logcat messages to buffer",
+                        getFieldEditorParent());
+                addField(maxMessages);
             }
         }
     }
diff --git a/ddms/app/src/com/android/ddms/UIThread.java b/ddms/app/src/com/android/ddms/UIThread.java
index 27a66d1..0bb211b 100644
--- a/ddms/app/src/com/android/ddms/UIThread.java
+++ b/ddms/app/src/com/android/ddms/UIThread.java
@@ -1368,7 +1368,9 @@ public class UIThread implements IUiSelectionListener, IClientChangeListener {
     }
 
     private void createLogCatView(Composite parent) {
-        mLogCatPanel = new LogCatPanel(new LogCatReceiver(), DdmUiPreferences.getStore());
+        IPreferenceStore prefStore = DdmUiPreferences.getStore();
+        LogCatReceiver receiver = new LogCatReceiver(prefStore);
+        mLogCatPanel = new LogCatPanel(receiver, prefStore);
         mLogCatPanel.createPanel(parent);
 
         if (mCurrentDevice != null) {
diff --git a/ddms/libs/ddmuilib/src/com/android/ddmuilib/logcat/LogCatMessageList.java b/ddms/libs/ddmuilib/src/com/android/ddmuilib/logcat/LogCatMessageList.java
index ce9017d..7651250 100644
--- a/ddms/libs/ddmuilib/src/com/android/ddmuilib/logcat/LogCatMessageList.java
+++ b/ddms/libs/ddmuilib/src/com/android/ddmuilib/logcat/LogCatMessageList.java
@@ -16,28 +16,56 @@
 
 package com.android.ddmuilib.logcat;
 
-import java.util.Queue;
 import java.util.concurrent.ArrayBlockingQueue;
+import java.util.concurrent.BlockingQueue;
 
 /**
  * Container for a list of log messages. The list of messages are
  * maintained in a circular buffer (FIFO).
  */
 public final class LogCatMessageList {
-    /** Size of the FIFO.
-     * FIXME: this should be a user preference.
-     */
-    private static final int MAX_MESSAGES = 1000;
+    /** Preference key for size of the FIFO. */
+    public static final String MAX_MESSAGES_PREFKEY =
+            "logcat.messagelist.max.size";
+
+    /** Default value for max # of messages. */
+    public static final int MAX_MESSAGES_DEFAULT = 5000;
 
-    private Queue<LogCatMessage> mQ;
+    private int mFifoSize;
+    private BlockingQueue<LogCatMessage> mQ;
     private LogCatMessage[] mQArray;
 
     /**
      * Construct an empty message list.
+     * @param maxMessages capacity of the circular buffer
+     */
+    public LogCatMessageList(int maxMessages) {
+        mFifoSize = maxMessages;
+
+        mQ = new ArrayBlockingQueue<LogCatMessage>(mFifoSize);
+        mQArray = new LogCatMessage[mFifoSize];
+    }
+
+    /**
+     * Resize the message list.
+     * @param n new size for the list
      */
-    public LogCatMessageList() {
-        mQ = new ArrayBlockingQueue<LogCatMessage>(MAX_MESSAGES);
-        mQArray = new LogCatMessage[MAX_MESSAGES];
+    public synchronized void resize(int n) {
+        mFifoSize = n;
+
+        if (mFifoSize > mQ.size()) {
+            /* if resizing to a bigger fifo, we can copy over all elements from the current mQ */
+            mQ = new ArrayBlockingQueue<LogCatMessage>(mFifoSize, true, mQ);
+        } else {
+            /* for a smaller fifo, copy over the last n entries */
+            LogCatMessage[] curMessages = mQ.toArray(new LogCatMessage[mQ.size()]);
+            mQ = new ArrayBlockingQueue<LogCatMessage>(mFifoSize);
+            for (int i = curMessages.length - mFifoSize; i < curMessages.length; i++) {
+                mQ.offer(curMessages[i]);
+            }
+        }
+
+        mQArray = new LogCatMessage[mFifoSize];
     }
 
     /**
@@ -46,7 +74,7 @@ public final class LogCatMessageList {
      * @param m log to be inserted
      */
     public synchronized void appendMessage(final LogCatMessage m) {
-        if (mQ.size() == MAX_MESSAGES) {
+        if (mQ.remainingCapacity() == 0) {
             /* make space by removing the first entry */
             mQ.poll();
         }
@@ -65,7 +93,7 @@ public final class LogCatMessageList {
      * @return array containing all the log messages
      */
     public Object[] toArray() {
-        if (mQ.size() == MAX_MESSAGES) {
+        if (mQ.size() == mFifoSize) {
             /*
              * Once the queue is full, it stays full until the user explicitly clears
              * all the logs. Optimize for this case by not reallocating the array.
diff --git a/ddms/libs/ddmuilib/src/com/android/ddmuilib/logcat/LogCatPanel.java b/ddms/libs/ddmuilib/src/com/android/ddmuilib/logcat/LogCatPanel.java
index 215bdbd..eda5fe9 100644
--- a/ddms/libs/ddmuilib/src/com/android/ddmuilib/logcat/LogCatPanel.java
+++ b/ddms/libs/ddmuilib/src/com/android/ddmuilib/logcat/LogCatPanel.java
@@ -130,11 +130,13 @@ public final class LogCatPanel extends SelectionDependentPanel
 
         mReceiver.addMessageReceivedEventListener(this);
 
-        initializeFilters(prefStore);
-        initializeFonts(prefStore);
+        initializeFilters();
+
+        setupDefaultPreferences();
+        initializePreferenceUpdateListeners();
     }
 
-    private void initializeFilters(IPreferenceStore prefStore) {
+    private void initializeFilters() {
         mLogCatFilters = new ArrayList<LogCatFilter>();
 
         /* add default filter matching all messages */
@@ -150,15 +152,26 @@ public final class LogCatPanel extends SelectionDependentPanel
         mLogCatFilters.addAll(savedFilters);
     }
 
-    private void initializeFonts(IPreferenceStore prefStore) {
+    private void setupDefaultPreferences() {
         PreferenceConverter.setDefault(mPrefStore, LogCatPanel.LOGCAT_VIEW_FONT_PREFKEY,
                 DEFAULT_LOGCAT_FONT);
+        mPrefStore.setDefault(LogCatMessageList.MAX_MESSAGES_PREFKEY,
+                LogCatMessageList.MAX_MESSAGES_DEFAULT);
+    }
 
+    private void initializePreferenceUpdateListeners() {
         mPrefStore.addPropertyChangeListener(new IPropertyChangeListener() {
             public void propertyChange(PropertyChangeEvent event) {
-                if (event.getProperty().equals(LogCatPanel.LOGCAT_VIEW_FONT_PREFKEY)) {
+                String changedProperty = event.getProperty();
+
+                if (changedProperty.equals(LogCatPanel.LOGCAT_VIEW_FONT_PREFKEY)) {
                     mLogCatMessageLabelProvider.setFont(getFontFromPrefStore());
                     refreshLogCatTable();
+                } else if (changedProperty.equals(
+                        LogCatMessageList.MAX_MESSAGES_PREFKEY)) {
+                    mReceiver.resizeFifo(mPrefStore.getInt(
+                            LogCatMessageList.MAX_MESSAGES_PREFKEY));
+                    refreshLogCatTable();
                 }
             }
         });
diff --git a/ddms/libs/ddmuilib/src/com/android/ddmuilib/logcat/LogCatReceiver.java b/ddms/libs/ddmuilib/src/com/android/ddmuilib/logcat/LogCatReceiver.java
index 0ba0ef6..410fee3 100644
--- a/ddms/libs/ddmuilib/src/com/android/ddmuilib/logcat/LogCatReceiver.java
+++ b/ddms/libs/ddmuilib/src/com/android/ddmuilib/logcat/LogCatReceiver.java
@@ -20,6 +20,8 @@ import com.android.ddmlib.IDevice;
 import com.android.ddmlib.Log;
 import com.android.ddmlib.MultiLineReceiver;
 
+import org.eclipse.jface.preference.IPreferenceStore;
+
 import java.util.ArrayList;
 import java.util.List;
 
@@ -37,11 +39,15 @@ public final class LogCatReceiver {
     private List<ILogCatMessageEventListener> mLogCatMessageListeners;
     private LogCatMessageParser mLogCatMessageParser;
     private LogCatPidToNameMapper mPidToNameMapper;
+    private IPreferenceStore mPrefStore;
 
     /**
      * Construct a LogCat message receiver.
+     * @param prefStore
      */
-    public LogCatReceiver() {
+    public LogCatReceiver(IPreferenceStore prefStore) {
+        mPrefStore = prefStore;
+
         mLogCatMessageListeners = new ArrayList<ILogCatMessageEventListener>();
         mLogCatMessageParser = new LogCatMessageParser();
         mPidToNameMapper = new LogCatPidToNameMapper();
@@ -83,7 +89,7 @@ public final class LogCatReceiver {
         }
 
         mCurrentDevice = device;
-        mLogMessages = new LogCatMessageList();
+        mLogMessages = new LogCatMessageList(getFifoSize());
 
         mLogCatMessageParser.resetState();
         startReceiverThread();
@@ -91,6 +97,11 @@ public final class LogCatReceiver {
         mPidToNameMapper.setDevice(mCurrentDevice);
     }
 
+    private int getFifoSize() {
+        int n = mPrefStore.getInt(LogCatMessageList.MAX_MESSAGES_PREFKEY);
+        return n == 0 ? LogCatMessageList.MAX_MESSAGES_DEFAULT : n;
+    }
+
     private void startReceiverThread() {
         mCurrentLogCatOutputReceiver = new LogCatOutputReceiver();
 
@@ -192,4 +203,12 @@ public final class LogCatReceiver {
             l.messageReceived(messages);
         }
     }
+
+    /**
+     * Resize the internal FIFO.
+     * @param size new size
+     */
+    public void resizeFifo(int size) {
+        mLogMessages.resize(size);
+    }
 }