/*

  * Copyright (c) 1997, 2008, Oracle and/or its affiliates. All rights reserved.

  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

  *

  * This code is free software; you can redistribute it and/or modify it

  * under the terms of the GNU General Public License version 2 only, as

  * published by the Free Software Foundation.  Oracle designates this

  * particular file as subject to the "Classpath" exception as provided

  * by Oracle in the LICENSE file that accompanied this code.

  *

  * This code is distributed in the hope that it will be useful, but WITHOUT

  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

  * version 2 for more details (a copy is included in the LICENSE file that

  * accompanied this code).

  *

  * You should have received a copy of the GNU General Public License version

  * 2 along with this work; if not, write to the Free Software Foundation,

  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

  *

  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

  * or visit www.oracle.com if you need additional information or have any

  * questions.

  */

 package org.apidesign.bck2brwsr.emul.lang;

 import java.io.FilterInputStream;

 import java.io.IOException;

 import java.io.InputStream;

 /*

  * A fast buffered input stream for parsing manifest files.

  * 

  * Taken from java.util.jar.Manifest.FastInputStream and modified to be

  * independent of other Manifest functionality.

  */

 public abstract class ManifestInputStream extends FilterInputStream {

     private byte[] buf;

     private int count = 0;

     private int pos = 0;

     protected ManifestInputStream(InputStream in) {

         this(in, 8192);

     }

     protected ManifestInputStream(InputStream in, int size) {

         super(in);

         buf = new byte[size];

     }

     public int read() throws IOException {

         if (pos >= count) {

             fill();

             if (pos >= count) {

                 return -1;

             }

         }

         return buf[pos++] & 0xff;

     }

     public int read(byte[] b, int off, int len) throws IOException {

         int avail = count - pos;

         if (avail <= 0) {

             if (len >= buf.length) {

                 return in.read(b, off, len);

             }

             fill();

             avail = count - pos;

             if (avail <= 0) {

                 return -1;

             }

         }

         if (len > avail) {

             len = avail;

         }

         System.arraycopy(buf, pos, b, off, len);

         pos += len;

         return len;

     }

     /*

      * Reads 'len' bytes from the input stream, or until an end-of-line

      * is reached. Returns the number of bytes read.

      */

     public int readLine(byte[] b, int off, int len) throws IOException {

         byte[] tbuf = this.buf;

         int total = 0;

         while (total < len) {

             int avail = count - pos;

             if (avail <= 0) {

                 fill();

                 avail = count - pos;

                 if (avail <= 0) {

                     return -1;

                 }

             }

             int n = len - total;

             if (n > avail) {

                 n = avail;

             }

             int tpos = pos;

             int maxpos = tpos + n;

             while (tpos < maxpos && tbuf[tpos++] != '\n') {

                 ;

             }

             n = tpos - pos;

             System.arraycopy(tbuf, pos, b, off, n);

             off += n;

             total += n;

             pos = tpos;

             if (tbuf[tpos - 1] == '\n') {

                 break;

             }

         }

         return total;

     }

     public byte peek() throws IOException {

         if (pos == count) {

             fill();

         }

         if (pos == count) {

             return -1; // nothing left in buffer

         }

         return buf[pos];

     }

     public int readLine(byte[] b) throws IOException {

         return readLine(b, 0, b.length);

     }

     public long skip(long n) throws IOException {

         if (n <= 0) {

             return 0;

         }

         long avail = count - pos;

         if (avail <= 0) {

             return in.skip(n);

         }

         if (n > avail) {

             n = avail;

         }

         pos += n;

         return n;

     }

     public int available() throws IOException {

         return (count - pos) + in.available();

     }

     public void close() throws IOException {

         if (in != null) {

             in.close();

             in = null;

             buf = null;

         }

     }

     private void fill() throws IOException {

         count = pos = 0;

         int n = in.read(buf, 0, buf.length);

         if (n > 0) {

             count = n;

         }

     }

     protected abstract String putValue(String key, String value);

     public void readAttributes(byte[] lbuf) throws IOException {

         ManifestInputStream is = this;

         String name = null;

         String value = null;

         byte[] lastline = null;

         int len;

         while ((len = is.readLine(lbuf)) != -1) {

             boolean lineContinued = false;

             if (lbuf[--len] != '\n') {

                 throw new IOException("line too long");

             }

             if (len > 0 && lbuf[len - 1] == '\r') {

                 --len;

             }

             if (len == 0) {

                 break;

             }

             int i = 0;

             if (lbuf[0] == ' ') {

                 if (name == null) {

                     throw new IOException("misplaced continuation line");

                 }

                 lineContinued = true;

                 byte[] buf = new byte[lastline.length + len - 1];

                 System.arraycopy(lastline, 0, buf, 0, lastline.length);

                 System.arraycopy(lbuf, 1, buf, lastline.length, len - 1);

                 if (is.peek() == ' ') {

                     lastline = buf;

                     continue;

                 }

                 value = new String(buf, 0, buf.length, "UTF8");

                 lastline = null;

             } else {

                 while (lbuf[i++] != ':') {

                     if (i >= len) {

                         throw new IOException("invalid header field");

                     }

                 }

                 if (lbuf[i++] != ' ') {

                     throw new IOException("invalid header field");

                 }

                 name = new String(lbuf, 0, 0, i - 2);

                 if (is.peek() == ' ') {

                     lastline = new byte[len - i];

                     System.arraycopy(lbuf, i, lastline, 0, len - i);

                     continue;

                 }

                 value = new String(lbuf, i, len - i, "UTF8");

             }

             try {

                 if ((putValue(name, value) != null) && (!lineContinued)) {

                     throw new IOException("Duplicate name in Manifest: " + name + ".\n" + "Ensure that the manifest does not " + "have duplicate entries, and\n" + "that blank lines separate " + "individual sections in both your\n" + "manifest and in the META-INF/MANIFEST.MF " + "entry in the jar file.");

                 }

             } catch (IllegalArgumentException e) {

                 throw new IOException("invalid header field name: " + name);

             }

         }

     }

 }