1 files changed, 106 insertions, 0 deletions
diff --git a/s2storage/src/readonly/java/com/android/storage/io/read/TypedInputStream.java b/s2storage/src/readonly/java/com/android/storage/io/read/TypedInputStream.java
new file mode 100644
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+++ b/s2storage/src/readonly/java/com/android/storage/io/read/TypedInputStream.java
@@ -0,0 +1,106 @@
+/*
+ * Copyright (C) 2020 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.storage.io.read;
+
+import com.android.storage.block.read.BlockData;
+
+import java.io.BufferedInputStream;
+import java.io.Closeable;
+import java.io.DataInputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * A typed stream-based typed data accessor.
+ *
+ * See {@link BlockData} for a random-access equivalent.
+ */
+public final class TypedInputStream implements Closeable {
+
+    private final DataInputStream mDataInputStream;
+
+    /** Wraps an InputStream. */
+    public TypedInputStream(InputStream is) {
+        mDataInputStream = new DataInputStream(new BufferedInputStream(is, 8192));
+    }
+
+    /** Skip forward the specified number of bytes. */
+    public int skipBytes(int n) throws IOException {
+        return mDataInputStream.skipBytes(n);
+    }
+
+    /** Reads the next byte as an unsigned value. */
+    public int readUnsignedByte() throws IOException {
+        return mDataInputStream.readByte() & 0xFF;
+    }
+
+    /** Reads the next byte as a signed value. */
+    public byte readSignedByte() throws IOException {
+        return mDataInputStream.readByte();
+    }
+
+    /**
+     * Reads a tiny (<= 255 entries) array of signed bytes where the length is encoded in the
+     * data.
+     */
+    public byte[] readTinyVarByteArray() throws IOException {
+        int arraySize = readUnsignedByte();
+        byte[] bytes = new byte[arraySize];
+        for (int i = 0; i < bytes.length; i++) {
+            bytes[i] = (byte) mDataInputStream.readUnsignedByte();
+        }
+        return bytes;
+    }
+
+    /**
+     * Reads a tiny (<= 255 entries) array of chars where the length is encoded in the data.
+     */
+    public char[] readTinyVarCharArray() throws IOException {
+        int arraySize = readUnsignedByte();
+        char[] chars = new char[arraySize];
+        for (int i = 0; i < chars.length; i++) {
+            chars[i] = mDataInputStream.readChar();
+        }
+        return chars;
+    }
+
+    /**
+     * Reads a char in network byte order.
+     */
+    public char readChar() throws IOException {
+        return mDataInputStream.readChar();
+    }
+
+    /**
+     * Reads a signed int in network byte order.
+     */
+    public int readInt() throws IOException {
+        return mDataInputStream.readInt();
+    }
+
+    /**
+     * Reads a signed long in network byte order.
+     */
+    public long readLong() throws IOException {
+        return mDataInputStream.readLong();
+    }
+
+    @Override
+    public void close() throws IOException {
+        mDataInputStream.close();
+    }
+}