diff --git a/java/src/com/android/inputmethod/latin/makedict/BinaryDictEncoderUtils.java b/java/src/com/android/inputmethod/latin/makedict/BinaryDictEncoderUtils.java
index 3b1d2427b0535ccaa1fb25d17daead0990e0208f..6cc0bfb7656e0b23e8962ac26d5389128964d1d4 100644
--- a/java/src/com/android/inputmethod/latin/makedict/BinaryDictEncoderUtils.java
+++ b/java/src/com/android/inputmethod/latin/makedict/BinaryDictEncoderUtils.java
@@ -225,6 +225,26 @@ public class BinaryDictEncoderUtils {
return position;
}
+ static void writeUIntToStream(final OutputStream stream, final int value, final int size)
+ throws IOException {
+ switch(size) {
+ case 4:
+ stream.write((value >> 24) & 0xFF);
+ /* fall through */
+ case 3:
+ stream.write((value >> 16) & 0xFF);
+ /* fall through */
+ case 2:
+ stream.write((value >> 8) & 0xFF);
+ /* fall through */
+ case 1:
+ stream.write(value & 0xFF);
+ break;
+ default:
+ /* nop */
+ }
+ }
+
// End utility methods
// This method is responsible for finding a nice ordering of the nodes that favors run-time
diff --git a/java/src/com/android/inputmethod/latin/makedict/SparseTable.java b/java/src/com/android/inputmethod/latin/makedict/SparseTable.java
new file mode 100644
index 0000000000000000000000000000000000000000..0b9cf91d2bb33c4ae37e4652db14ca8559415350
--- /dev/null
+++ b/java/src/com/android/inputmethod/latin/makedict/SparseTable.java
@@ -0,0 +1,150 @@
+/*
+ * Copyright (C) 2013 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.inputmethod.latin.makedict;
+
+import com.android.inputmethod.annotations.UsedForTesting;
+
+import java.io.IOException;
+import java.io.OutputStream;
+import java.util.ArrayList;
+import java.util.Collections;
+
+/**
+ * SparseTable is an extensible map from integer to integer.
+ * This holds one value for every mBlockSize keys, so it uses 1/mBlockSize'th of the full index
+ * memory.
+ */
+@UsedForTesting
+public class SparseTable {
+
+ /**
+ * mLookupTable is indexed by terminal ID, containing exactly one entry for every mBlockSize
+ * terminals.
+ * It contains at index i = j / mBlockSize the index in mContentsTable where the values for
+ * terminals with IDs j to j + mBlockSize - 1 are stored as an mBlockSize-sized integer array.
+ */
+ private final ArrayList<Integer> mLookupTable;
+ private final ArrayList<Integer> mContentTable;
+
+ private final int mBlockSize;
+ public static final int NOT_EXIST = -1;
+
+ @UsedForTesting
+ public SparseTable(final int initialCapacity, final int blockSize) {
+ mBlockSize = blockSize;
+ final int lookupTableSize = initialCapacity / mBlockSize
+ + (initialCapacity % mBlockSize > 0 ? 1 : 0);
+ mLookupTable = new ArrayList<Integer>(Collections.nCopies(lookupTableSize, NOT_EXIST));
+ mContentTable = new ArrayList<Integer>();
+ }
+
+ @UsedForTesting
+ public SparseTable(final int[] lookupTable, final int[] contentTable, final int blockSize) {
+ mBlockSize = blockSize;
+ mLookupTable = new ArrayList<Integer>(lookupTable.length);
+ for (int i = 0; i < lookupTable.length; ++i) {
+ mLookupTable.add(lookupTable[i]);
+ }
+ mContentTable = new ArrayList<Integer>(contentTable.length);
+ for (int i = 0; i < contentTable.length; ++i) {
+ mContentTable.add(contentTable[i]);
+ }
+ }
+
+ /**
+ * Converts an byte array to an int array considering each set of 4 bytes is an int stored in
+ * big-endian.
+ * The length of byteArray must be a multiple of four.
+ * Otherwise, IndexOutOfBoundsException will be raised.
+ */
+ @UsedForTesting
+ private static void convertByteArrayToIntegerArray(final byte[] byteArray,
+ final ArrayList<Integer> integerArray) {
+ for (int i = 0; i < byteArray.length; i += 4) {
+ int value = 0;
+ for (int j = i; j < i + 4; ++j) {
+ value <<= 8;
+ value |= byteArray[j] & 0xFF;
+ }
+ integerArray.add(value);
+ }
+ }
+
+ @UsedForTesting
+ public SparseTable(final byte[] lookupTable, final byte[] contentTable, final int blockSize) {
+ mBlockSize = blockSize;
+ mLookupTable = new ArrayList<Integer>(lookupTable.length / 4);
+ mContentTable = new ArrayList<Integer>(contentTable.length / 4);
+ convertByteArrayToIntegerArray(lookupTable, mLookupTable);
+ convertByteArrayToIntegerArray(contentTable, mContentTable);
+ }
+
+ @UsedForTesting
+ public int get(final int index) {
+ if (index < 0 || index / mBlockSize >= mLookupTable.size()
+ || mLookupTable.get(index / mBlockSize) == NOT_EXIST) {
+ return NOT_EXIST;
+ }
+ return mContentTable.get(mLookupTable.get(index / mBlockSize) + (index % mBlockSize));
+ }
+
+ @UsedForTesting
+ public void set(final int index, final int value) {
+ if (mLookupTable.get(index / mBlockSize) == NOT_EXIST) {
+ mLookupTable.set(index / mBlockSize, mContentTable.size());
+ for (int i = 0; i < mBlockSize; ++i) {
+ mContentTable.add(NOT_EXIST);
+ }
+ }
+ mContentTable.set(mLookupTable.get(index / mBlockSize) + (index % mBlockSize), value);
+ }
+
+ public void remove(final int index) {
+ set(index, NOT_EXIST);
+ }
+
+ @UsedForTesting
+ public int size() {
+ return mLookupTable.size() * mBlockSize;
+ }
+
+ @UsedForTesting
+ /* package */ int getContentTableSize() {
+ return mContentTable.size();
+ }
+
+ @UsedForTesting
+ /* package */ int getLookupTableSize() {
+ return mLookupTable.size();
+ }
+
+ public boolean contains(final int index) {
+ return get(index) != NOT_EXIST;
+ }
+
+ @UsedForTesting
+ public void write(final OutputStream lookupOutStream, final OutputStream contentOutStream)
+ throws IOException {
+ for (final int index : mLookupTable) {
+ BinaryDictEncoderUtils.writeUIntToStream(lookupOutStream, index, 4);
+ }
+
+ for (final int index : mContentTable) {
+ BinaryDictEncoderUtils.writeUIntToStream(contentOutStream, index, 4);
+ }
+ }
+}
diff --git a/tests/src/com/android/inputmethod/latin/makedict/SparseTableTests.java b/tests/src/com/android/inputmethod/latin/makedict/SparseTableTests.java
new file mode 100644
index 0000000000000000000000000000000000000000..132483d5e6852a9136528532a63acc290378b936
--- /dev/null
+++ b/tests/src/com/android/inputmethod/latin/makedict/SparseTableTests.java
@@ -0,0 +1,160 @@
+/*
+ * Copyright (C) 2013 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.inputmethod.latin.makedict;
+
+import android.test.AndroidTestCase;
+import android.test.suitebuilder.annotation.LargeTest;
+import android.util.Log;
+
+import java.io.File;
+import java.io.FileInputStream;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.util.ArrayList;
+import java.util.Random;
+
+/**
+ * Unit tests for SparseTable.
+ */
+@LargeTest
+public class SparseTableTests extends AndroidTestCase {
+ private static final String TAG = SparseTableTests.class.getSimpleName();
+
+ private static final int[] SMALL_INDEX = { SparseTable.NOT_EXIST, 0 };
+ private static final int[] BIG_INDEX = { SparseTable.NOT_EXIST, 1, 2, 3, 4, 5, 6, 7};
+
+ private final Random mRandom;
+ private final ArrayList<Integer> mRandomIndex;
+
+ private static final int DEFAULT_SIZE = 10000;
+ private static final int BLOCK_SIZE = 8;
+
+ public SparseTableTests() {
+ this(System.currentTimeMillis(), DEFAULT_SIZE);
+ }
+
+ public SparseTableTests(final long seed, final int tableSize) {
+ super();
+ Log.d(TAG, "Seed for test is " + seed + ", size is " + tableSize);
+ mRandom = new Random(seed);
+ mRandomIndex = new ArrayList<Integer>(tableSize);
+ for (int i = 0; i < tableSize; ++i) {
+ mRandomIndex.add(SparseTable.NOT_EXIST);
+ }
+ }
+
+ public void testInitializeWithArray() {
+ final SparseTable table = new SparseTable(SMALL_INDEX, BIG_INDEX, BLOCK_SIZE);
+ for (int i = 0; i < 8; ++i) {
+ assertEquals(SparseTable.NOT_EXIST, table.get(i));
+ }
+ assertEquals(SparseTable.NOT_EXIST, table.get(8));
+ for (int i = 9; i < 16; ++i) {
+ assertEquals(i - 8, table.get(i));
+ }
+ }
+
+ public void testSet() {
+ final SparseTable table = new SparseTable(16, BLOCK_SIZE);
+ table.set(3, 6);
+ table.set(8, 16);
+ for (int i = 0; i < 16; ++i) {
+ if (i == 3 || i == 8) {
+ assertEquals(i * 2, table.get(i));
+ } else {
+ assertEquals(SparseTable.NOT_EXIST, table.get(i));
+ }
+ }
+ }
+
+ private void generateRandomIndex(final int size, final int prop) {
+ for (int i = 0; i < DEFAULT_SIZE; ++i) {
+ if (mRandom.nextInt(100) < prop) {
+ mRandomIndex.set(i, mRandom.nextInt());
+ } else {
+ mRandomIndex.set(i, SparseTable.NOT_EXIST);
+ }
+ }
+ }
+
+ private void runTestRandomSet() {
+ final SparseTable table = new SparseTable(DEFAULT_SIZE, BLOCK_SIZE);
+ int elementCount = 0;
+ for (int i = 0; i < DEFAULT_SIZE; ++i) {
+ if (mRandomIndex.get(i) != SparseTable.NOT_EXIST) {
+ table.set(i, mRandomIndex.get(i));
+ elementCount++;
+ }
+ }
+
+ Log.d(TAG, "table size = " + table.getLookupTableSize() + " + "
+ + table.getContentTableSize());
+ Log.d(TAG, "the table has " + elementCount + " elements");
+ for (int i = 0; i < DEFAULT_SIZE; ++i) {
+ assertEquals(table.get(i), (int)mRandomIndex.get(i));
+ }
+
+ // flush and reload
+ OutputStream lookupOutStream = null;
+ OutputStream contentOutStream = null;
+ InputStream lookupInStream = null;
+ InputStream contentInStream = null;
+ try {
+ final File lookupIndexFile = File.createTempFile("testRandomSet", ".small");
+ final File contentFile = File.createTempFile("testRandomSet", ".big");
+ lookupOutStream = new FileOutputStream(lookupIndexFile);
+ contentOutStream = new FileOutputStream(contentFile);
+ table.write(lookupOutStream, contentOutStream);
+ lookupInStream = new FileInputStream(lookupIndexFile);
+ contentInStream = new FileInputStream(contentFile);
+ final byte[] lookupArray = new byte[(int) lookupIndexFile.length()];
+ final byte[] contentArray = new byte[(int) contentFile.length()];
+ lookupInStream.read(lookupArray);
+ contentInStream.read(contentArray);
+ final SparseTable newTable = new SparseTable(lookupArray, contentArray, BLOCK_SIZE);
+ for (int i = 0; i < DEFAULT_SIZE; ++i) {
+ assertEquals(table.get(i), newTable.get(i));
+ }
+ } catch (IOException e) {
+ Log.d(TAG, "IOException while flushing and realoding", e);
+ } finally {
+ if (lookupOutStream != null) {
+ try {
+ lookupOutStream.close();
+ } catch (IOException e) {
+ Log.d(TAG, "IOException while closing the stream", e);
+ }
+ }
+ if (contentOutStream != null) {
+ try {
+ contentOutStream.close();
+ } catch (IOException e) {
+ Log.d(TAG, "IOException while closing contentStream.", e);
+ }
+ }
+ }
+ }
+
+ public void testRandomSet() {
+ for (int i = 0; i <= 100; i += 10) {
+ generateRandomIndex(DEFAULT_SIZE, i);
+ runTestRandomSet();
+ }
+ }
+}