Initial revision

From-SVN: r26263

libjava/java/io/LineNumberInputStream.java

@@ -0,0 +1,143 @@
+/* Copyright (C) 1998, 1999  Cygnus Solutions
+
+   This file is part of libgcj.
+
+This software is copyrighted work licensed under the terms of the
+Libgcj License.  Please consult the file "LIBGCJ_LICENSE" for
+details.  */
+ 
+package java.io;
+
+/**
+ * @author Warren Levy <warrenl@cygnus.com>
+ * @date November 11, 1998.
+ * @deprecated 
+ */
+/* Written using "Java Class Libraries", 2nd edition, ISBN 0-201-31002-3
+ * "The Java Language Specification", ISBN 0-201-63451-1
+ * plus online API docs for JDK 1.2 beta from http://www.javasoft.com.
+ * Status:  Believed complete and correct.  Deprecated in JDK 1.1.
+ */
+ 
+public class LineNumberInputStream extends FilterInputStream
+{
+  /* The current line number. */
+  private int lineNumber = 0;
+
+  /* The line number when the stream was marked. */
+  private int markLineNumber = 0;
+
+  /* Flag to indicate a '\r' was just read so that an immediately subsequent
+   * '\n' can be ignored. */
+  private boolean justReadReturnChar = false;
+
+  public LineNumberInputStream(InputStream in)
+  {
+    super(in);
+  }
+
+  public int available() throws IOException
+  {
+    // We can only guarantee half the characters that might be available
+    // without blocking because "\r\n" is treated as a single character.
+    return in.available() / 2;
+  }
+
+  public int getLineNumber()
+  {
+    return lineNumber;
+  }
+
+  public void mark(int readlimit)
+  {
+    in.mark(readlimit);
+    markLineNumber = lineNumber;
+  }
+
+  public int read() throws IOException
+  {
+    // Treat "\r\n" as a single character.  A '\r' may have been read by
+    // a previous call to read so we keep an internal flag to avoid having
+    // to read ahead.
+
+    int ch = in.read();
+
+    if (ch == '\n')
+      if (justReadReturnChar)
+	{
+	  ch = in.read();
+          justReadReturnChar = false;
+	}
+      else
+	lineNumber++;
+    else if (ch == '\r')
+      {
+	ch = '\n';
+	justReadReturnChar = true;
+	lineNumber++;
+      }
+    else
+      justReadReturnChar = false;
+
+    return ch;
+  }
+
+  public int read(byte[] b, int off, int len) throws IOException
+  {
+    if (off < 0 || len < 0 || off + len > b.length)
+      throw new ArrayIndexOutOfBoundsException();
+
+    // This case always succeeds.
+    if (len == 0)
+      return 0;
+
+    // The simplest, though not necessarily the most time efficient thing
+    // to do is simply call read(void) len times.  Since this is a deprecated
+    // class, that should be ok.
+    final int origOff = off;
+    while (len-- > 0)
+      {
+	int ch = read();
+	if (ch < 0)
+	  break;
+
+	b[off++] = (byte) ch;
+      }
+
+    // This is safe since we already know that some bytes were
+    // actually requested.
+    return off == origOff ? -1 : off - origOff;
+  }
+
+  public void reset() throws IOException
+  {
+    in.reset();
+    lineNumber = markLineNumber;
+    justReadReturnChar = false;
+  }
+
+  public void setLineNumber(int lineNumber)
+  {
+    this.lineNumber = lineNumber;
+  }
+
+  public long skip(long n) throws IOException
+  {
+    if (n <= 0)
+      return 0L;
+
+    final long origN = n;
+
+    do
+      {
+	int ch = read();
+	if (ch < 0)
+	  break;
+	if (ch == '\n' || ch == '\r')
+	  lineNumber++;
+      }
+    while (--n > 0);
+
+    return origN - n;
+  }
+}