Move Base64Reader to utils package

Change-Id: Id46898c5cae268f05850d79938929b7707f27320

java/src/com/android/inputmethod/latin/utils/Base64Reader.java

+/*
+ * 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.utils;
+
+import com.android.inputmethod.annotations.UsedForTesting;
+
+import java.io.EOFException;
+import java.io.IOException;
+import java.io.LineNumberReader;
+
+@UsedForTesting
+public class Base64Reader {
+    private final LineNumberReader mReader;
+
+    private String mLine;
+    private int mCharPos;
+    private int mByteCount;
+
+    @UsedForTesting
+    public Base64Reader(final LineNumberReader reader) {
+        mReader = reader;
+        reset();
+    }
+
+    @UsedForTesting
+    public void reset() {
+        mLine = null;
+        mCharPos = 0;
+        mByteCount = 0;
+    }
+
+    @UsedForTesting
+    public int getLineNumber() {
+        return mReader.getLineNumber();
+    }
+
+    @UsedForTesting
+    public int getByteCount() {
+        return mByteCount;
+    }
+
+    private void fillBuffer() throws IOException {
+        if (mLine == null || mCharPos >= mLine.length()) {
+            mLine = mReader.readLine();
+            mCharPos = 0;
+        }
+        if (mLine == null) {
+            throw new EOFException();
+        }
+    }
+
+    private int peekUint8() throws IOException {
+        fillBuffer();
+        final char c = mLine.charAt(mCharPos);
+        if (c >= 'A' && c <= 'Z')
+            return c - 'A' + 0;
+        if (c >= 'a' && c <= 'z')
+            return c - 'a' + 26;
+        if (c >= '0' && c <= '9')
+            return c - '0' + 52;
+        if (c == '+')
+            return 62;
+        if (c == '/')
+            return 63;
+        if (c == '=')
+            return 0;
+        throw new RuntimeException("Unknown character '" + c + "' in base64 at line "
+                + mReader.getLineNumber());
+    }
+
+    private int getUint8() throws IOException {
+        final int value = peekUint8();
+        mCharPos++;
+        return value;
+    }
+
+    @UsedForTesting
+    public int readUint8() throws IOException {
+        final int value1, value2;
+        switch (mByteCount % 3) {
+        case 0:
+            value1 = getUint8() << 2;
+            value2 = value1 | (peekUint8() >> 4);
+            break;
+        case 1:
+            value1 = (getUint8() & 0x0f) << 4;
+            value2 = value1 | (peekUint8() >> 2);
+            break;
+        default:
+            value1 = (getUint8() & 0x03) << 6;
+            value2 = value1 | getUint8();
+            break;
+        }
+        mByteCount++;
+        return value2;
+    }
+
+    @UsedForTesting
+    public short readInt16() throws IOException {
+        final int data = readUint8() << 8;
+        return (short)(data | readUint8());
+    }
+}

tests/src/com/android/inputmethod/latin/utils/Base64ReaderTests.java

+/*
+ * 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.utils;
+
+import android.test.AndroidTestCase;
+import android.test.suitebuilder.annotation.SmallTest;
+
+import java.io.EOFException;
+import java.io.IOException;
+import java.io.LineNumberReader;
+import java.io.StringReader;
+
+@SmallTest
+public class Base64ReaderTests extends AndroidTestCase {
+    private static final String EMPTY_STRING = "";
+    private static final String INCOMPLETE_CHAR1 = "Q";
+    // Encode 'A'.
+    private static final String INCOMPLETE_CHAR2 = "QQ";
+    // Encode 'A', 'B'
+    private static final String INCOMPLETE_CHAR3 = "QUI";
+    // Encode 'A', 'B', 'C'
+    private static final String COMPLETE_CHAR4 = "QUJD";
+    private static final String ALL_BYTE_PATTERN =
+            "AAECAwQFBgcICQoLDA0ODxAREhMUFRYXGBkaGxwdHh8gISIj\n"
+            + "JCUmJygpKissLS4vMDEyMzQ1Njc4OTo7PD0+P0BBQkNERUZH\n"
+            + "SElKS0xNTk9QUVJTVFVWV1hZWltcXV5fYGFiY2RlZmdoaWpr\n"
+            + "bG1ub3BxcnN0dXZ3eHl6e3x9fn+AgYKDhIWGh4iJiouMjY6P\n"
+            + "kJGSk5SVlpeYmZqbnJ2en6ChoqOkpaanqKmqq6ytrq+wsbKz\n"
+            + "tLW2t7i5uru8vb6/wMHCw8TFxsfIycrLzM3Oz9DR0tPU1dbX\n"
+            + "2Nna29zd3t/g4eLj5OXm5+jp6uvs7e7v8PHy8/T19vf4+fr7\n"
+            + "/P3+/w==";
+
+    public void test0CharInt8() {
+        final Base64Reader reader = new Base64Reader(
+                new LineNumberReader(new StringReader(EMPTY_STRING)));
+        try {
+            reader.readUint8();
+            fail("0 char");
+        } catch (final EOFException e) {
+            assertEquals("0 char", 0, reader.getByteCount());
+        } catch (final IOException e) {
+            fail("IOException: " + e);
+        }
+    }
+
+    public void test1CharInt8() {
+        final Base64Reader reader = new Base64Reader(
+                new LineNumberReader(new StringReader(INCOMPLETE_CHAR1)));
+        try {
+            reader.readUint8();
+            fail("1 char");
+        } catch (final EOFException e) {
+            assertEquals("1 char", 0, reader.getByteCount());
+        } catch (final IOException e) {
+            fail("IOException: " + e);
+        }
+    }
+
+    public void test2CharsInt8() {
+        final Base64Reader reader = new Base64Reader(
+                new LineNumberReader(new StringReader(INCOMPLETE_CHAR2)));
+        try {
+            final int v1 = reader.readUint8();
+            assertEquals("2 chars pos 0", 'A', v1);
+            reader.readUint8();
+            fail("2 chars");
+        } catch (final EOFException e) {
+            assertEquals("2 chars", 1, reader.getByteCount());
+        } catch (final IOException e) {
+            fail("IOException: " + e);
+        }
+    }
+
+    public void test3CharsInt8() {
+        final Base64Reader reader = new Base64Reader(
+                new LineNumberReader(new StringReader(INCOMPLETE_CHAR3)));
+        try {
+            final int v1 = reader.readUint8();
+            assertEquals("3 chars pos 0", 'A', v1);
+            final int v2 = reader.readUint8();
+            assertEquals("3 chars pos 1", 'B', v2);
+            reader.readUint8();
+            fail("3 chars");
+        } catch (final EOFException e) {
+            assertEquals("3 chars", 2, reader.getByteCount());
+        } catch (final IOException e) {
+            fail("IOException: " + e);
+        }
+    }
+
+    public void test4CharsInt8() {
+        final Base64Reader reader = new Base64Reader(
+                new LineNumberReader(new StringReader(COMPLETE_CHAR4)));
+        try {
+            final int v1 = reader.readUint8();
+            assertEquals("4 chars pos 0", 'A', v1);
+            final int v2 = reader.readUint8();
+            assertEquals("4 chars pos 1", 'B', v2);
+            final int v3 = reader.readUint8();
+            assertEquals("4 chars pos 2", 'C', v3);
+            reader.readUint8();
+            fail("4 chars");
+        } catch (final EOFException e) {
+            assertEquals("4 chars", 3, reader.getByteCount());
+        } catch (final IOException e) {
+            fail("IOException: " + e);
+        }
+    }
+
+    public void testAllBytePatternInt8() {
+        final Base64Reader reader = new Base64Reader(
+                new LineNumberReader(new StringReader(ALL_BYTE_PATTERN)));
+        try {
+            for (int i = 0; i <= 0xff; i++) {
+                final int v = reader.readUint8();
+                assertEquals("value: all byte pattern: pos " + i, i, v);
+                assertEquals("count: all byte pattern: pos " + i, i + 1, reader.getByteCount());
+            }
+        } catch (final EOFException e) {
+            assertEquals("all byte pattern", 256, reader.getByteCount());
+        } catch (final IOException e) {
+            fail("IOException: " + e);
+        }
+    }
+
+    public void test0CharInt16() {
+        final Base64Reader reader = new Base64Reader(
+                new LineNumberReader(new StringReader(EMPTY_STRING)));
+        try {
+            reader.readInt16();
+            fail("0 char");
+        } catch (final EOFException e) {
+            assertEquals("0 char", 0, reader.getByteCount());
+        } catch (final IOException e) {
+            fail("IOException: " + e);
+        }
+    }
+
+    public void test1CharInt16() {
+        final Base64Reader reader = new Base64Reader(
+                new LineNumberReader(new StringReader(INCOMPLETE_CHAR1)));
+        try {
+            reader.readInt16();
+            fail("1 char");
+        } catch (final EOFException e) {
+            assertEquals("1 char", 0, reader.getByteCount());
+        } catch (final IOException e) {
+            fail("IOException: " + e);
+        }
+    }
+
+    public void test2CharsInt16() {
+        final Base64Reader reader = new Base64Reader(
+                new LineNumberReader(new StringReader(INCOMPLETE_CHAR2)));
+        try {
+            reader.readInt16();
+            fail("2 chars");
+        } catch (final EOFException e) {
+            assertEquals("2 chars", 1, reader.getByteCount());
+        } catch (final IOException e) {
+            fail("IOException: " + e);
+        }
+    }
+
+    public void test3CharsInt16() {
+        final Base64Reader reader = new Base64Reader(
+                new LineNumberReader(new StringReader(INCOMPLETE_CHAR3)));
+        try {
+            final short v1 = reader.readInt16();
+            assertEquals("3 chars pos 0", 'A' << 8 | 'B', v1);
+            reader.readInt16();
+            fail("3 chars");
+        } catch (final EOFException e) {
+            assertEquals("3 chars", 2, reader.getByteCount());
+        } catch (final IOException e) {
+            fail("IOException: " + e);
+        }
+    }
+
+    public void test4CharsInt16() {
+        final Base64Reader reader = new Base64Reader(
+                new LineNumberReader(new StringReader(COMPLETE_CHAR4)));
+        try {
+            final short v1 = reader.readInt16();
+            assertEquals("4 chars pos 0", 'A' << 8 | 'B', v1);
+            reader.readInt16();
+            fail("4 chars");
+        } catch (final EOFException e) {
+            assertEquals("4 chars", 3, reader.getByteCount());
+        } catch (final IOException e) {
+            fail("IOException: " + e);
+        }
+    }
+
+    public void testAllBytePatternInt16() {
+        final Base64Reader reader = new Base64Reader(
+                new LineNumberReader(new StringReader(ALL_BYTE_PATTERN)));
+        try {
+            for (int i = 0; i <= 0xff; i += 2) {
+                final short v = reader.readInt16();
+                final short expected = (short)(i << 8 | (i + 1));
+                assertEquals("value: all byte pattern: pos " + i, expected, v);
+                assertEquals("count: all byte pattern: pos " + i, i + 2, reader.getByteCount());
+            }
+        } catch (final EOFException e) {
+            assertEquals("all byte pattern", 256, reader.getByteCount());
+        } catch (final IOException e) {
+            fail("IOException: " + e);
+        }
+    }
+}