diff options
Diffstat (limited to 'core/src/main/java/com/att/cadi/Capacitor.java')
| -rw-r--r-- | core/src/main/java/com/att/cadi/Capacitor.java | 241 |
1 files changed, 241 insertions, 0 deletions
diff --git a/core/src/main/java/com/att/cadi/Capacitor.java b/core/src/main/java/com/att/cadi/Capacitor.java new file mode 100644 index 0000000..0745875 --- /dev/null +++ b/core/src/main/java/com/att/cadi/Capacitor.java @@ -0,0 +1,241 @@ +/*******************************************************************************
+ * ============LICENSE_START====================================================
+ * * org.onap.aai
+ * * ===========================================================================
+ * * Copyright © 2017 AT&T Intellectual Property. All rights reserved.
+ * * Copyright © 2017 Amdocs
+ * * ===========================================================================
+ * * 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====================================================
+ * *
+ * * ECOMP is a trademark and service mark of AT&T Intellectual Property.
+ * *
+ ******************************************************************************/
+package com.att.cadi;
+
+import java.nio.ByteBuffer;
+import java.util.ArrayList;
+
+/**
+ * Capacitor
+ *
+ * Storage mechanism for read data, specifically designed for InputStreams.
+ *
+ * The Standard BufferedInputStream requires a limit to be set for buffered reading, which is
+ * impractical for reading SOAP headers, which can be quite large.
+ *
+ */
+public class Capacitor {
+ private static final int DEFAULT_CHUNK = 256;
+ private ArrayList<ByteBuffer> bbs = new ArrayList<ByteBuffer>();
+ private ByteBuffer curr = null;
+ private int idx;
+
+ // Maintain a private RingBuffer for Memory, for efficiency
+ private static ByteBuffer[] ring = new ByteBuffer[16];
+ private static int start, end;
+
+
+ public void put(byte b) {
+ if(curr == null || curr.remaining()==0) { // ensure we have a "curr" buffer ready for data
+ curr = ringGet();
+ bbs.add(curr);
+ }
+ curr.put(b);
+ }
+
+ public int read() {
+ if(curr!=null) {
+ if(curr.remaining()>0) { // have a buffer, use it!
+ return curr.get();
+ } else if(idx<bbs.size()){ // Buffer not enough, get next one from array
+ if(idx<bbs.size()) {
+ curr=bbs.get(idx++);
+ return curr.get();
+ }
+ }
+ } // if no curr buffer, treat as end of stream
+ return -1;
+ }
+
+ /**
+ * read into an array like Streams
+ *
+ * @param array
+ * @param offset
+ * @param length
+ * @return
+ */
+ public int read(byte[] array, int offset, int length) {
+ if(curr==null)return -1;
+ int len;
+ int count=0;
+ while(length>0) { // loop through while there's data needed
+ if((len=curr.remaining())>length) { // if enough data in curr buffer, use this code
+ curr.get(array,offset,length);
+ count+=length;
+ length=0;
+ } else { // get data from curr, mark how much is needed to fulfil, and loop for next curr.
+ curr.get(array,offset,len);
+ count+=len;
+ offset+=len;
+ length-=len;
+ if(idx<bbs.size()) {
+ curr=bbs.get(idx++);
+ } else {
+ length=0; // stop, and return the count of how many we were able to load
+ }
+ }
+ }
+ return count;
+ }
+
+ /**
+ * Put an array of data into Capacitor
+ *
+ * @param array
+ * @param offset
+ * @param length
+ */
+ public void put(byte[] array, int offset, int length) {
+ if(curr == null || curr.remaining()==0) {
+ curr = ringGet();
+ bbs.add(curr);
+ }
+
+ int len;
+ while(length>0) {
+ if((len=curr.remaining())>length) {
+ curr.put(array,offset,length);
+ length=0;
+ } else {
+// System.out.println(new String(array));
+ curr.put(array,offset,len);
+ length-=len;
+ offset+=len;
+ curr = ringGet();
+ bbs.add(curr);
+ }
+ }
+ }
+
+ /**
+ * Move state from Storage mode into Read mode, changing all internal buffers to read mode, etc
+ */
+ public void setForRead() {
+ for(ByteBuffer bb : bbs) {
+ bb.flip();
+ }
+ if(bbs.isEmpty()) {
+ curr = null;
+ idx = 0;
+ } else {
+ curr=bbs.get(0);
+ idx=1;
+ }
+ }
+
+ /**
+ * reuse all the buffers
+ */
+ public void done() {
+ for(ByteBuffer bb : bbs) {
+ ringPut(bb);
+ }
+ bbs.clear();
+ curr = null;
+ }
+
+ /**
+ * Declare amount of data available to be read at once.
+ *
+ * @return
+ */
+ public int available() {
+ int count = 0;
+ for(ByteBuffer bb : bbs) {
+ count+=bb.remaining();
+ }
+ return count;
+ }
+
+ /**
+ * Returns how many are left that were not skipped
+ * @param n
+ * @return
+ */
+ public long skip(long n) {
+ long skipped=0L;
+ int skip;
+ while(n>0) {
+ if(n<(skip=curr.remaining())) {
+ curr.position(curr.position()+(int)n);
+ skipped+=skip;
+ n=0;
+ } else {
+ curr.position(curr.limit());
+
+ skipped-=skip;
+ if(idx<bbs.size()) {
+ curr=bbs.get(idx++);
+ n-=skip;
+ } else {
+ n=0;
+ }
+ }
+ }
+ return skipped;
+ }
+ /**
+ * Be able to re-read data that is stored that has already been re-read. This is not a standard Stream behavior, but can be useful
+ * in a standalone mode.
+ */
+ public void reset() {
+ for(ByteBuffer bb : bbs) {
+ bb.position(0);
+ }
+ if(bbs.isEmpty()) {
+ curr = null;
+ idx = 0;
+ } else {
+ curr=bbs.get(0);
+ idx=1;
+ }
+ }
+
+ /*
+ * Ring Functions. Reuse allocated memory
+ */
+ private ByteBuffer ringGet() {
+ ByteBuffer bb = null;
+ synchronized(ring) {
+ bb=ring[start];
+ ring[start]=null;
+ if(bb!=null && ++start>15)start=0;
+ }
+ if(bb==null) {
+ bb=ByteBuffer.allocate(DEFAULT_CHUNK);
+ } else {
+ bb.clear();// refresh reused buffer
+ }
+ return bb;
+ }
+
+ private void ringPut(ByteBuffer bb) {
+ synchronized(ring) {
+ ring[end]=bb; // if null or not, BB will just be Garbage collected
+ if(++end>15)end=0;
+ }
+ }
+
+}
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