1 files changed, 223 insertions, 0 deletions
diff --git a/cadi/core/src/main/java/org/onap/ccsdk/apps/cadi/BufferedServletInputStream.java b/cadi/core/src/main/java/org/onap/ccsdk/apps/cadi/BufferedServletInputStream.java
new file mode 100644
index 00000000..86ae1900
--- /dev/null
+++ b/cadi/core/src/main/java/org/onap/ccsdk/apps/cadi/BufferedServletInputStream.java
@@ -0,0 +1,223 @@
+/**
+ * ============LICENSE_START====================================================
+ * org.onap.ccsdk
+ * ===========================================================================
+ * Copyright (c) 2023 AT&T Intellectual Property. All rights reserved.
+ * ===========================================================================
+ * 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.
+ * ============LICENSE_END====================================================
+ *
+ */
+
+package org.onap.ccsdk.apps.cadi;
+
+import java.io.IOException;
+import java.io.InputStream;
+
+import jakarta.servlet.ReadListener;
+import jakarta.servlet.ServletInputStream;
+
+/**
+ * BufferedServletInputStream
+ *
+ * There are cases in brain-dead middleware (SOAP) where they store routing information in the content.
+ *
+ * In HTTP, this requires reading the content from the InputStream which, of course, cannot be re-read.
+ *
+ * BufferedInputStream exists to implement the "Mark" protocols for Streaming, which will enable being
+ * re-read.  Unfortunately, J2EE chose to require a "ServletInputStream" as an abstract class, rather than
+ * an interface, which requires we create a delegating pattern, rather than the preferred inheriting pattern.
+ *
+ * Unfortunately, the standard "BufferedInputStream" cannot be used, because it simply creates a byte array
+ * in the "mark(int)" method of that size.  This is not appropriate for this application, because the Header
+ * can be potentially huge, and if a buffer was allocated to accommodate all possibilities, the cost of memory
+ * allocation would be too large for high performance transactions.
+ *
+ *
+ *
+ */
+public class BufferedServletInputStream extends ServletInputStream {
+    private static final int NONE = 0;
+    private static final int STORE = 1;
+    private static final int READ = 2;
+
+    private InputStream is;
+    private int state = NONE;
+    private Capacitor capacitor;
+
+    public BufferedServletInputStream(InputStream is) {
+        this.is = is;
+        capacitor = null;
+    }
+
+
+    public int read() throws IOException {
+        int value=-1;
+        if (capacitor==null) {
+            value=is.read();
+        } else {
+            switch(state) {
+                case STORE:
+                    value = is.read();
+                    if (value>=0) {
+                        capacitor.put((byte)value);
+                    }
+                    break;
+                case READ:
+                    value = capacitor.read();
+                    if (value<0) {
+                        capacitor.done();
+                        capacitor=null; // all done with buffer
+                        value = is.read();
+                    }
+            }
+        }
+        return value;
+    }
+    @Override
+    public int read(byte[] b) throws IOException {
+        return read(b,0,b.length);
+    }
+    
+  @Override
+    public int read(byte[] b, int off, int len) throws IOException {
+        int count = -1;
+        if (capacitor==null) {
+            count = is.read(b,off,len);
+        } else {
+            switch(state) {
+                case STORE:
+                    count = is.read(b, off, len);
+                    if (count>0) {
+                        capacitor.put(b, off, count);
+                    }
+                    break;
+                case READ:
+                    count = capacitor.read(b, off, len);
+                    if (count<=0) {
+                        capacitor.done();
+                        capacitor=null; // all done with buffer
+                    }
+                    if (count<len) {
+                        int temp = is.read(b, count, len-count);
+                        if (temp>0) { // watch for -1
+                            count+=temp;
+                        } else if (count<=0) {
+                            count = temp; // must account for Stream coming back -1
+                        }
+                    }
+                    break;
+            }
+        }
+        return count;
+    }
+
+    public long skip(long n) throws IOException {
+        long skipped = capacitor.skip(n);
+        if (skipped<n) {
+            skipped += is.skip(n-skipped);
+        }
+        return skipped;
+    }
+
+
+    public int available() throws IOException {
+        int count = is.available();
+        if (capacitor!=null)count+=capacitor.available();
+        return count;
+    }
+
+    /**
+     * Return just amount buffered (for debugging purposes, mostly)
+     * @return
+     */
+    public int buffered() {
+        return capacitor.available();
+    }
+
+
+    public void close() throws IOException {
+        if (capacitor!=null) {
+            capacitor.done();
+            capacitor=null;
+        }
+        is.close();
+    }
+
+
+    /**
+     * Note: Readlimit is ignored in this implementation, because the need was for unknown buffer size which wouldn't
+     * require allocating and dumping huge chunks of memory every use, or risk overflow.
+     */
+    public synchronized void mark(int readlimit) {
+        switch(state) {
+            case NONE:
+                capacitor = new Capacitor();
+                break;
+            case READ:
+                capacitor.done();
+                break;
+        }
+        state = STORE;
+    }
+
+
+    /**
+     * Reset Stream
+     *
+     * Calling this twice is not supported in typical Stream situations, but it is allowed in this service.  The caveat is that it can only reset
+     * the data read in since Mark has been called.  The data integrity is only valid if you have not continued to read past what is stored.
+     *
+     */
+    public synchronized void reset() throws IOException {
+        switch(state) {
+            case STORE:
+                capacitor.setForRead();
+                state = READ;
+                break;
+            case READ:
+                capacitor.reset();
+                break;
+            case NONE:
+                throw new IOException("InputStream has not been marked");
+        }
+    }
+
+
+    public boolean markSupported() {
+        return true;
+    }
+
+
+    @Override
+    public boolean isFinished() {
+        
+        try {
+            return (this.is.available() == 0);
+        } catch (IOException e) {
+            return true;
+        }
+    }
+
+
+    @Override
+    public boolean isReady() {
+        return true;
+    }
+
+
+    @Override
+    public void setReadListener(ReadListener arg0) {
+        throw new UnsupportedOperationException("Unimplemented method 'setReadListener'");
+    }
+}