Some write optimizations for buffers and lazy initialization of heade…

…rs. Fixed problem in FixedBufferData constructor.

Signed-off-by: Santiago Pericasgeertsen <santiago.pericasgeertsen@oracle.com>

common/buffers/src/main/java/io/helidon/common/buffers/CompositeArrayBufferData.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022 Oracle and/or its affiliates.
+ * Copyright (c) 2022, 2024 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -21,7 +21,7 @@
 import java.nio.ByteBuffer;
 import java.nio.charset.Charset;
 
-class CompositeArrayBufferData extends ReadOnlyBufferData {
+class CompositeArrayBufferData extends ReadOnlyBufferData implements CompositeBufferData {
     private final BufferData[] data;
 
     CompositeArrayBufferData(BufferData[] data) {
@@ -38,6 +38,13 @@ public BufferData rewind() {
 
     @Override
     public void writeTo(OutputStream out) {
+        if (data.length == 1) {
+            BufferData datum = data[0];
+            if (!(datum instanceof CompositeBufferData)) {
+                datum.writeTo(out);
+                return;
+            }
+        }
         copy().writeTo(out);
     }
 
@@ -260,4 +267,9 @@ public int get(int index) {
     public String toString() {
         return "comp-array: a=" + available();
     }
+
+    @Override
+    public CompositeBufferData add(BufferData bufferData) {
+        throw new UnsupportedOperationException("Add not supported for " + getClass().getSimpleName() + " buffer");
+    }
 }

common/buffers/src/main/java/io/helidon/common/buffers/CompositeListBufferData.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022 Oracle and/or its affiliates.
+ * Copyright (c) 2022, 2024 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -56,6 +56,13 @@ public BufferData rewind() {
 
     @Override
     public void writeTo(OutputStream out) {
+        if (data.size() == 1) {
+            BufferData datum = data.get(0);
+            if (!(datum instanceof CompositeBufferData)) {
+                datum.writeTo(out);
+                return;
+            }
+        }
         copy().writeTo(out);
     }
 

common/buffers/src/main/java/io/helidon/common/buffers/FixedBufferData.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022 Oracle and/or its affiliates.
+ * Copyright (c) 2022, 2024 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -43,7 +43,7 @@ class FixedBufferData implements BufferData {
     FixedBufferData(byte[] bytes, int position, int length) {
         this.bytes = bytes;
         this.length = length;
-        this.writePosition = length;
+        this.writePosition = position + length;
         this.readPosition = position;
     }
 

http/http/src/main/java/io/helidon/http/HeadersImpl.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2022, 2023 Oracle and/or its affiliates.
+ * Copyright (c) 2022, 2024 Oracle and/or its affiliates.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -34,10 +34,11 @@ class HeadersImpl<T extends WritableHeaders<T>> implements WritableHeaders<T> {
      Optimization for most commonly used header names
      */
     private final Header[] knownHeaders = new Header[KNOWN_HEADER_SIZE];
-    // custom (unknown) headers are slower
-    private final Map<HeaderName, Header> customHeaders = new HashMap<>();
     private IntSet knownHeaderIndices = new IntSet(KNOWN_HEADER_SIZE);
 
+    // custom (unknown) headers are slower
+    private Map<HeaderName, Header> customHeaders = null;
+
     HeadersImpl() {
     }
 
@@ -85,7 +86,7 @@ public Header get(HeaderName name) {
 
     @Override
     public int size() {
-        return customHeaders.size() + knownHeaderIndices.size();
+        return (customHeaders == null ? 0 : customHeaders.size()) + knownHeaderIndices.size();
     }
 
     @Override
@@ -167,7 +168,7 @@ public T set(Header header) {
         }
         int index = name.index();
         if (index == -1) {
-            customHeaders.put(name, usedHeader);
+            customHeaders().put(name, usedHeader);
         } else {
             knownHeaders[index] = usedHeader;
             knownHeaderIndices.add(index);
@@ -179,7 +180,7 @@ public T set(Header header) {
     public T clear() {
         Arrays.fill(knownHeaders, null);
         knownHeaderIndices = new IntSet(KNOWN_HEADER_SIZE);
-        customHeaders.clear();
+        customHeaders().clear();
         return (T) this;
     }
 
@@ -231,20 +232,28 @@ public Header doRemove(HeaderName name) {
             knownHeaderIndices.remove(index);
             return value;
         }
-        return customHeaders.remove(name);
+        return customHeaders().remove(name);
     }
+
     private Header find(HeaderName name) {
         int index = name.index();
 
         if (index > -1) {
             return knownHeaders[index];
         }
 
-        return customHeaders.get(name);
+        return customHeaders().get(name);
+    }
+
+    private Map<HeaderName, Header> customHeaders() {
+        if (customHeaders == null) {
+            customHeaders = new HashMap<>();
+        }
+        return customHeaders;
     }
 
     private class HeaderIterator implements Iterator<Header> {
-        private final boolean noCustom = customHeaders.isEmpty();
+        private final boolean noCustom = (customHeaders == null || customHeaders.isEmpty());
 
         private boolean inKnown = true;
         private int last = -1;