pt 1 in reviving the android build (copied from pm 28a1, wish me luck)

mobile/android/thirdparty/com/jakewharton/disklrucache/StrictLineReader.java

@@ -0,0 +1,196 @@
+/*
+ * Copyright (C) 2012 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.jakewharton.disklrucache;
+
+import java.io.ByteArrayOutputStream;
+import java.io.Closeable;
+import java.io.EOFException;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.UnsupportedEncodingException;
+import java.nio.charset.Charset;
+
+/**
+ * Buffers input from an {@link InputStream} for reading lines.
+ *
+ * <p>This class is used for buffered reading of lines. For purposes of this class, a line ends
+ * with "\n" or "\r\n". End of input is reported by throwing {@code EOFException}. Unterminated
+ * line at end of input is invalid and will be ignored, the caller may use {@code
+ * hasUnterminatedLine()} to detect it after catching the {@code EOFException}.
+ *
+ * <p>This class is intended for reading input that strictly consists of lines, such as line-based
+ * cache entries or cache journal. Unlike the {@link java.io.BufferedReader} which in conjunction
+ * with {@link java.io.InputStreamReader} provides similar functionality, this class uses different
+ * end-of-input reporting and a more restrictive definition of a line.
+ *
+ * <p>This class supports only charsets that encode '\r' and '\n' as a single byte with value 13
+ * and 10, respectively, and the representation of no other character contains these values.
+ * We currently check in constructor that the charset is one of US-ASCII, UTF-8 and ISO-8859-1.
+ * The default charset is US_ASCII.
+ */
+class StrictLineReader implements Closeable {
+  private static final byte CR = (byte) '\r';
+  private static final byte LF = (byte) '\n';
+
+  private final InputStream in;
+  private final Charset charset;
+
+  /*
+   * Buffered data is stored in {@code buf}. As long as no exception occurs, 0 <= pos <= end
+   * and the data in the range [pos, end) is buffered for reading. At end of input, if there is
+   * an unterminated line, we set end == -1, otherwise end == pos. If the underlying
+   * {@code InputStream} throws an {@code IOException}, end may remain as either pos or -1.
+   */
+  private byte[] buf;
+  private int pos;
+  private int end;
+
+  /**
+   * Constructs a new {@code LineReader} with the specified charset and the default capacity.
+   *
+   * @param in the {@code InputStream} to read data from.
+   * @param charset the charset used to decode data. Only US-ASCII, UTF-8 and ISO-8859-1 are
+   * supported.
+   * @throws NullPointerException if {@code in} or {@code charset} is null.
+   * @throws IllegalArgumentException if the specified charset is not supported.
+   */
+  public StrictLineReader(InputStream in, Charset charset) {
+    this(in, 8192, charset);
+  }
+
+  /**
+   * Constructs a new {@code LineReader} with the specified capacity and charset.
+   *
+   * @param in the {@code InputStream} to read data from.
+   * @param capacity the capacity of the buffer.
+   * @param charset the charset used to decode data. Only US-ASCII, UTF-8 and ISO-8859-1 are
+   * supported.
+   * @throws NullPointerException if {@code in} or {@code charset} is null.
+   * @throws IllegalArgumentException if {@code capacity} is negative or zero
+   * or the specified charset is not supported.
+   */
+  public StrictLineReader(InputStream in, int capacity, Charset charset) {
+    if (in == null || charset == null) {
+      throw new NullPointerException();
+    }
+    if (capacity < 0) {
+      throw new IllegalArgumentException("capacity <= 0");
+    }
+    if (!(charset.equals(Util.US_ASCII))) {
+      throw new IllegalArgumentException("Unsupported encoding");
+    }
+
+    this.in = in;
+    this.charset = charset;
+    buf = new byte[capacity];
+  }
+
+  /**
+   * Closes the reader by closing the underlying {@code InputStream} and
+   * marking this reader as closed.
+   *
+   * @throws IOException for errors when closing the underlying {@code InputStream}.
+   */
+  public void close() throws IOException {
+    synchronized (in) {
+      if (buf != null) {
+        buf = null;
+        in.close();
+      }
+    }
+  }
+
+  /**
+   * Reads the next line. A line ends with {@code "\n"} or {@code "\r\n"},
+   * this end of line marker is not included in the result.
+   *
+   * @return the next line from the input.
+   * @throws IOException for underlying {@code InputStream} errors.
+   * @throws EOFException for the end of source stream.
+   */
+  public String readLine() throws IOException {
+    synchronized (in) {
+      if (buf == null) {
+        throw new IOException("LineReader is closed");
+      }
+
+      // Read more data if we are at the end of the buffered data.
+      // Though it's an error to read after an exception, we will let {@code fillBuf()}
+      // throw again if that happens; thus we need to handle end == -1 as well as end == pos.
+      if (pos >= end) {
+        fillBuf();
+      }
+      // Try to find LF in the buffered data and return the line if successful.
+      for (int i = pos; i != end; ++i) {
+        if (buf[i] == LF) {
+          int lineEnd = (i != pos && buf[i - 1] == CR) ? i - 1 : i;
+          String res = new String(buf, pos, lineEnd - pos, charset.name());
+          pos = i + 1;
+          return res;
+        }
+      }
+
+      // Let's anticipate up to 80 characters on top of those already read.
+      ByteArrayOutputStream out = new ByteArrayOutputStream(end - pos + 80) {
+        @Override
+        public String toString() {
+          int length = (count > 0 && buf[count - 1] == CR) ? count - 1 : count;
+          try {
+            return new String(buf, 0, length, charset.name());
+          } catch (UnsupportedEncodingException e) {
+            throw new AssertionError(e); // Since we control the charset this will never happen.
+          }
+        }
+      };
+
+      while (true) {
+        out.write(buf, pos, end - pos);
+        // Mark unterminated line in case fillBuf throws EOFException or IOException.
+        end = -1;
+        fillBuf();
+        // Try to find LF in the buffered data and return the line if successful.
+        for (int i = pos; i != end; ++i) {
+          if (buf[i] == LF) {
+            if (i != pos) {
+              out.write(buf, pos, i - pos);
+            }
+            pos = i + 1;
+            return out.toString();
+          }
+        }
+      }
+    }
+  }
+
+  public boolean hasUnterminatedLine() {
+    return end == -1;
+  }
+
+  /**
+   * Reads new input data into the buffer. Call only with pos == end or end == -1,
+   * depending on the desired outcome if the function throws.
+   */
+  private void fillBuf() throws IOException {
+    int result = in.read(buf, 0, buf.length);
+    if (result == -1) {
+      throw new EOFException();
+    }
+    pos = 0;
+    end = result;
+  }
+}
+