diff options
Diffstat (limited to 'src/main/java/org/pdfbox/io/ASCII85InputStream.java')
| -rw-r--r-- | src/main/java/org/pdfbox/io/ASCII85InputStream.java | 269 |
1 files changed, 269 insertions, 0 deletions
diff --git a/src/main/java/org/pdfbox/io/ASCII85InputStream.java b/src/main/java/org/pdfbox/io/ASCII85InputStream.java new file mode 100644 index 0000000..863d64d --- /dev/null +++ b/src/main/java/org/pdfbox/io/ASCII85InputStream.java @@ -0,0 +1,269 @@ +/**
+ * Copyright (c) 2003, www.pdfbox.org
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ * this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ * this list of conditions and the following disclaimer in the documentation
+ * and/or other materials provided with the distribution.
+ * 3. Neither the name of pdfbox; nor the names of its
+ * contributors may be used to endorse or promote products derived from this
+ * software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
+ * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ * http://www.pdfbox.org
+ *
+ */
+package org.pdfbox.io;
+
+import java.io.FilterInputStream;
+import java.io.InputStream;
+import java.io.IOException;
+
+/**
+ * This class represents an ASCII85 stream.
+ *
+ * @author Ben Litchfield
+ * @version $Revision: 1.5 $
+ */
+public class ASCII85InputStream extends FilterInputStream
+{
+ private int index;
+ private int n;
+ private boolean eof;
+
+ private byte[] ascii;
+ private byte[] b;
+
+ /**
+ * Constructor.
+ *
+ * @param is The input stream to actually read from.
+ */
+ public ASCII85InputStream( InputStream is )
+ {
+ super(is);
+ index = 0;
+ n = 0;
+ eof = false;
+ ascii = new byte[5];
+ b = new byte[4];
+ }
+
+ /**
+ * This will read the next byte from the stream.
+ *
+ * @return The next byte read from the stream.
+ *
+ * @throws IOException If there is an error reading from the wrapped stream.
+ */
+ public final int read() throws IOException
+ {
+ if( index >= n )
+ {
+ if(eof)
+ {
+ return -1;
+ }
+ index = 0;
+ int k;
+ byte z;
+ do
+ {
+ int zz=(byte)in.read();
+ if(zz==-1)
+ {
+ eof=true;
+ return -1;
+ }
+ z = (byte)zz;
+ } while( z=='\n' || z=='\r' || z==' ');
+
+ if (z == '~' || z=='x')
+ {
+ eof=true;
+ ascii=b=null;
+ n = 0;
+ return -1;
+ }
+ else if (z == 'z')
+ {
+ b[0]=b[1]=b[2]=b[3]=0;
+ n = 4;
+ }
+ else
+ {
+ ascii[0]=z; // may be EOF here....
+ for (k=1;k<5;++k)
+ {
+ do
+ {
+ int zz=(byte)in.read();
+ if(zz==-1)
+ {
+ eof=true;
+ return -1;
+ }
+ z=(byte)zz;
+ } while ( z=='\n' || z=='\r' || z==' ' );
+ ascii[k]=z;
+ if (z == '~' || z=='x')
+ {
+ break;
+ }
+ }
+ n = k - 1;
+ if ( n==0 )
+ {
+ eof = true;
+ ascii = null;
+ b = null;
+ return -1;
+ }
+ if ( k < 5 )
+ {
+ for (++k; k < 5; ++k )
+ {
+ ascii[k] = 0x21;
+ }
+ eof=true;
+ }
+ // decode stream
+ long t=0;
+ for ( k=0; k<5; ++k)
+ {
+ z=(byte)(ascii[k] - 0x21);
+ if (z < 0 || z > 93)
+ {
+ n = 0;
+ eof = true;
+ ascii = null;
+ b = null;
+ throw new IOException("Invalid data in Ascii85 stream");
+ }
+ t = (t * 85L) + z;
+ }
+ for ( k = 3; k>=0; --k)
+ {
+ b[k] = (byte)(t & 0xFFL);
+ t>>>=8;
+ }
+ }
+ }
+ return b[index++] & 0xFF;
+ }
+
+ /**
+ * This will read a chunk of data.
+ *
+ * @param data The buffer to write data to.
+ * @param offset The offset into the data stream.
+ * @param len The number of byte to attempt to read.
+ *
+ * @return The number of bytes actually read.
+ *
+ * @throws IOException If there is an error reading data from the underlying stream.
+ */
+ public final int read(byte[] data, int offset, int len) throws IOException
+ {
+ if(eof && index>=n)
+ {
+ return -1;
+ }
+ for(int i=0;i<len;i++)
+ {
+ if(index<n)
+ {
+ data[i+offset]=b[index++];
+ }
+ else
+ {
+ int t = read();
+ if ( t == -1 )
+ {
+ return i;
+ }
+ data[i+offset]=(byte)t;
+ }
+ }
+ return len;
+ }
+
+ /**
+ * This will close the underlying stream and release any resources.
+ *
+ * @throws IOException If there is an error closing the underlying stream.
+ */
+ public void close() throws IOException
+ {
+ ascii = null;
+ eof = true;
+ b = null;
+ super.close();
+ }
+
+ /**
+ * non supported interface methods.
+ *
+ * @return False always.
+ */
+ public boolean markSupported()
+ {
+ return false;
+ }
+
+ /**
+ * Unsupported.
+ *
+ * @param nValue ignored.
+ *
+ * @return Always zero.
+ */
+ public long skip(long nValue)
+ {
+ return 0;
+ }
+
+ /**
+ * Unsupported.
+ *
+ * @return Always zero.
+ */
+ public int available()
+ {
+ return 0;
+ }
+
+ /**
+ * Unsupported.
+ *
+ * @param readlimit ignored.
+ */
+ public void mark(int readlimit)
+ {
+ }
+
+ /**
+ * Unsupported.
+ *
+ * @throws IOException telling that this is an unsupported action.
+ */
+ public void reset() throws IOException
+ {
+ throw new IOException("Reset is not supported");
+ }
+}
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