Simplify by using a list

3 files changed, 39 insertions, 41 deletions

diff --git a/document/src/main/java/com/yahoo/document/json/TokenBuffer.java b/document/src/main/java/com/yahoo/document/json/TokenBuffer.java
index e1214920296..f4573adc41e 100644
--- a/document/src/main/java/com/yahoo/document/json/TokenBuffer.java
+++ b/document/src/main/java/com/yahoo/document/json/TokenBuffer.java
@@ -2,9 +2,9 @@
 package com.yahoo.document.json;
 
 import java.io.IOException;
-import java.util.ArrayDeque;
-import java.util.Deque;
+import java.util.ArrayList;
 import java.util.Iterator;
+import java.util.List;
 
 import com.fasterxml.jackson.core.JsonParser;
 import com.fasterxml.jackson.core.JsonToken;
@@ -17,72 +17,68 @@ import com.google.common.base.Preconditions;
  */
 public class TokenBuffer {
 
-    private final Deque<Token> buffer;
+    private final List<Token> tokens;
 
+    private int position = 0;
     private int nesting = 0;
-    private Token previousToken;
 
     public TokenBuffer() {
-        this(new ArrayDeque<>());
+        this(new ArrayList<>());
     }
 
-    public TokenBuffer(Deque<Token> buffer) {
-        this.buffer = buffer;
-        if (buffer.size() > 0) {
-            updateNesting(buffer.peekFirst().token);
-        }
+    public TokenBuffer(List<Token> tokens) {
+        this.tokens = tokens;
+        if (tokens.size() > 0)
+            updateNesting(tokens.get(position).token);
     }
 
     /** Returns whether any tokens are available in this */
-    public boolean isEmpty() { return size() == 0; }
+    public boolean isEmpty() { return tokens.isEmpty(); }
 
     public JsonToken next() {
-        previousToken = buffer.removeFirst();
-        Token t = buffer.peekFirst();
-        if (t == null) {
-            return null;
-        }
-        updateNesting(t.token);
-        return t.token;
+        position++;
+        JsonToken token = currentToken();
+        updateNesting(token);
+        return token;
     }
 
     /** Goes one token back. Repeated calls to this method will *not* go back further. */
     public JsonToken previous() {
-        if (previousToken == null) return null;
         updateNestingGoingBackwards(currentToken());
-        Token newCurrent = previousToken;
-        previousToken = null;
-        buffer.push(newCurrent);
-        return newCurrent.token;
+        position--;
+        return currentToken();
     }
 
     /** Returns the current token without changing position, or null if none */
     public JsonToken currentToken() {
-        Token token = buffer.peekFirst();
+        if (position >= tokens.size()) return null;
+        Token token = tokens.get(position);
         if (token == null) return null;
         return token.token;
     }
 
     /** Returns the current token name without changing position, or null if none */
     public String currentName() {
-        Token token = buffer.peekFirst();
+        if (position >= tokens.size()) return null;
+        Token token = tokens.get(position);
         if (token == null) return null;
         return token.name;
     }
 
     /** Returns the current token text without changing position, or null if none */
     public String currentText() {
-        Token token = buffer.peekFirst();
+        if (position >= tokens.size()) return null;
+        Token token = tokens.get(position);
         if (token == null) return null;
         return token.text;
     }
 
     public int size() {
-        return buffer.size();
+        return tokens.size() - position;
     }
 
     private void add(JsonToken token, String name, String text) {
-        buffer.addLast(new Token(token, name, text));
+        tokens.add(tokens.size(), new Token(token, name, text));
     }
 
     public void bufferObject(JsonToken first, JsonParser tokens) {
@@ -110,10 +106,11 @@ public class TokenBuffer {
         return nesting + nestingOffset(t);
     }
 
-    private int nestingOffset(JsonToken t) {
-        if (t.isStructStart()) {
+    private int nestingOffset(JsonToken token) {
+        if (token == null) return 0;
+        if (token.isStructStart()) {
             return 1;
-        } else if (t.isStructEnd()) {
+        } else if (token.isStructEnd()) {
             return -1;
         } else {
             return 0;
@@ -138,12 +135,12 @@ public class TokenBuffer {
         }
     }
 
-    private void updateNesting(JsonToken t) {
-        nesting += nestingOffset(t);
+    private void updateNesting(JsonToken token) {
+        nesting += nestingOffset(token);
     }
 
-    private void updateNestingGoingBackwards(JsonToken t) {
-        nesting -= nestingOffset(t);
+    private void updateNestingGoingBackwards(JsonToken token) {
+        nesting -= nestingOffset(token);
     }
 
     public int nesting() {
@@ -157,9 +154,9 @@ public class TokenBuffer {
         Iterator<Token> i;
 
         if (name.equals(currentName()) && currentToken().isScalarValue()) {
-            toReturn = buffer.peekFirst();
+            toReturn = tokens.get(position);
         } else {
-            i = buffer.iterator();
+            i = tokens.iterator();
             i.next(); // just ignore the first value, as we know it's not what
                       // we're looking for, and it's nesting effect is already
                       // included
@@ -185,8 +182,8 @@ public class TokenBuffer {
         } while ( nesting() > initialNesting + relativeNesting);
     }
 
-    public Deque<Token> rest() {
-        return buffer;
+    public List<Token> rest() {
+        return tokens.subList(position, tokens.size());
     }
 
     public static final class Token {
diff --git a/document/src/main/java/com/yahoo/document/json/readers/TensorReader.java b/document/src/main/java/com/yahoo/document/json/readers/TensorReader.java
index 4b2da912c37..fc9f5d0995d 100644
--- a/document/src/main/java/com/yahoo/document/json/readers/TensorReader.java
+++ b/document/src/main/java/com/yahoo/document/json/readers/TensorReader.java
@@ -14,6 +14,7 @@ import com.yahoo.tensor.TensorAddress;
 import com.yahoo.tensor.TensorType;
 
 import java.util.ArrayDeque;
+import java.util.ArrayList;
 import java.util.Deque;
 
 import static com.yahoo.document.json.readers.JsonParserHelpers.*;
@@ -40,7 +41,7 @@ public class TensorReader {
         expectOneOf(buffer.currentToken(), JsonToken.START_OBJECT, JsonToken.START_ARRAY);
         int initNesting = buffer.nesting();
         for (buffer.next(); buffer.nesting() >= initNesting; buffer.next()) {
-            if (TENSOR_CELLS.equals(buffer.currentName()) && ! primitiveContent(new TokenBuffer(new ArrayDeque<>(buffer.rest())))) {
+            if (TENSOR_CELLS.equals(buffer.currentName()) && ! primitiveContent(new TokenBuffer(new ArrayList<>(buffer.rest())))) {
                 readTensorCells(buffer, builder);
             }
             else if (TENSOR_VALUES.equals(buffer.currentName()) && builder.type().dimensions().stream().allMatch(d -> d.isIndexed())) {
diff --git a/document/src/main/java/com/yahoo/document/json/readers/VespaJsonDocumentReader.java b/document/src/main/java/com/yahoo/document/json/readers/VespaJsonDocumentReader.java
index 22a9e7a1119..33f47beb01e 100644
--- a/document/src/main/java/com/yahoo/document/json/readers/VespaJsonDocumentReader.java
+++ b/document/src/main/java/com/yahoo/document/json/readers/VespaJsonDocumentReader.java
@@ -219,7 +219,7 @@ public class VespaJsonDocumentReader {
                                                                 TokenBuffer buffer, String fieldPathOperation) {
         AssignFieldPathUpdate fieldPathUpdate = new AssignFieldPathUpdate(documentType, fieldPath);
         String arithmeticSign = SingleValueReader.UPDATE_OPERATION_TO_ARITHMETIC_SIGN.get(fieldPathOperation);
-        double value = Double.valueOf(buffer.currentText());
+        double value = Double.parseDouble(buffer.currentText());
         String expression = String.format("$value %s %s", arithmeticSign, value);
         fieldPathUpdate.setExpression(expression);
         return fieldPathUpdate;