1 files changed, 180 insertions, 0 deletions
diff --git a/moaSig/moa-asic/src/main/java/at/gv/egiz/asic/impl/ZipCommentReaderStream.java b/moaSig/moa-asic/src/main/java/at/gv/egiz/asic/impl/ZipCommentReaderStream.java
new file mode 100644
index 0000000..93b7651
--- /dev/null
+++ b/moaSig/moa-asic/src/main/java/at/gv/egiz/asic/impl/ZipCommentReaderStream.java
@@ -0,0 +1,180 @@
+package at.gv.egiz.asic.impl;
+
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+
+/**
+ * Created by afitzek on 6/15/16.
+ */
+public class ZipCommentReaderStream extends InputStream {
+
+    private InputStream inputStream;
+
+    private int[] tempBuffer = new int[22];
+
+    private int[] commentBuffer = null;
+
+    private int commentBufferContentLen = 0;
+    private int commentBufferContentOff = 0;
+
+    private int tempBufferContentLen = 0;
+    private int tempBufferContentOff = 0;
+
+    private String fileComment = null;
+
+    private static final byte[] directoryRecord = new byte[] { (byte)0x50, (byte)0x4b, 0x05, 0x06  };
+
+    public ZipCommentReaderStream(InputStream inputStream) {
+        this.inputStream = inputStream;
+    }
+
+    private int readIntIntoBuffer() throws IOException {
+        int tValue = this.inputStream.read();
+
+        if(this.tempBuffer.length <= tempBufferContentOff) {
+            throw new IOException("Temp Buffer is out of space! @ " + tempBufferContentOff);
+        }
+
+        this.tempBuffer[tempBufferContentOff] = tValue;
+        tempBufferContentOff++;
+        tempBufferContentLen++;
+
+        return tValue;
+    }
+
+    private int readIntIntoCommentBuffer() throws IOException {
+        int tValue = this.inputStream.read();
+
+        if(this.commentBuffer.length <= commentBufferContentOff) {
+            throw new IOException("Comment Buffer is out of space! @ " + commentBufferContentOff);
+        }
+
+        this.commentBuffer[commentBufferContentOff] = tValue;
+        commentBufferContentOff++;
+        commentBufferContentLen++;
+
+        return tValue;
+    }
+
+    private void checkMagicBytes() throws IOException {
+        boolean foundMagic = true;
+        tempBufferContentOff = 0;
+        tempBufferContentLen = 0;
+        for(int i = 1; i < directoryRecord.length; i++) {
+            int tValue = readIntIntoBuffer();
+            if(tValue != directoryRecord[i]) {
+                foundMagic = false;
+                break;
+            }
+            if(tValue < 0) {
+                // Found EOF
+                return;
+            }
+        }
+
+        if(foundMagic) {
+            // read input stream until comment length
+            for(int i = 0; i < 16; i++) {
+                int tValue = readIntIntoBuffer();
+
+                if(tValue < 0) {
+                    // Found EOF
+                    return;
+                }
+            }
+
+            int commentlengthHigh = readIntIntoBuffer();
+
+            if(commentlengthHigh < 0) {
+                // Found EOF
+                return;
+            }
+
+            int commentlengthLow = readIntIntoBuffer();
+
+            if(commentlengthLow < 0) {
+                // Found EOF
+                return;
+            }
+
+            int commentLength = commentlengthLow * 255 + commentlengthHigh;
+
+            if(commentLength == 0) {
+                return;
+            }
+
+            this.commentBuffer = new int[commentLength];
+
+            commentBufferContentOff = 0;
+            commentBufferContentLen = 0;
+
+            // read comment buffer string
+            for(int i = 0; i < commentLength; i++) {
+                int tValue = readIntIntoCommentBuffer();
+
+                if(tValue < 0) {
+                    // Found EOF
+                    return;
+                }
+            }
+
+            byte[] stringBuffer = new byte[this.commentBuffer.length];
+
+            for(int i = 0; i < stringBuffer.length; i++) {
+                stringBuffer[i] = (byte)this.commentBuffer[i];
+            }
+
+            this.fileComment = new String(stringBuffer);
+        }
+    }
+
+    @Override
+    public int read() throws IOException {
+        int value = -1;
+        if(tempBufferContentLen > 0) {
+            value = this.tempBuffer[tempBufferContentOff];
+            tempBufferContentOff++;
+
+            // reset temp buffer
+            if(tempBufferContentOff >= tempBufferContentLen) {
+                tempBufferContentOff = 0;
+                tempBufferContentLen = 0;
+            }
+
+            return value;
+        }
+
+        if(this.commentBuffer != null) {
+            value = this.commentBuffer[commentBufferContentOff];
+
+            commentBufferContentOff++;
+
+            // reset comment buffer
+            if(commentBufferContentOff >= commentBufferContentLen) {
+                commentBufferContentOff = 0;
+                commentBufferContentLen = 0;
+                this.commentBuffer = null;
+            }
+
+            return value;
+        }
+
+        value = this.inputStream.read();
+
+        if(value == directoryRecord[0] && this.fileComment == null) {
+            // might have found start of magic bytes
+            checkMagicBytes();
+            // reset buffer offsets
+            tempBufferContentOff = 0;
+            commentBufferContentOff = 0;
+        }
+
+        return value;
+    }
+
+    public String getFileComment() {
+        return this.fileComment;
+    }
+}