--- /dev/null
+/**
+ * ============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'");
+ }
+}
Code Review / ccsdk / apps.git / blobdiff