com.fasterxml.jackson.core.json.JsonReadContext Maven / Gradle / Ivy
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package com.fasterxml.jackson.core.json;
import com.fasterxml.jackson.core.*;
import com.fasterxml.jackson.core.io.ContentReference;
/**
* Extension of {@link JsonStreamContext}, which implements
* core methods needed, and also exposes
* more complete API to parser implementation classes.
*/
public final class JsonReadContext extends JsonStreamContext
{
// // // Configuration
/**
* Parent context for this context; null for root context.
*/
protected final JsonReadContext _parent;
// // // Optional duplicate detection
protected DupDetector _dups;
/*
/**********************************************************
/* Simple instance reuse slots; speeds up things a bit (10-15%)
/* for docs with lots of small arrays/objects (for which
/* allocation was visible in profile stack frames)
/**********************************************************
*/
protected JsonReadContext _child;
/*
/**********************************************************
/* Location/state information (minus source reference)
/**********************************************************
*/
protected String _currentName;
/**
* @since 2.5
*/
protected Object _currentValue;
protected int _lineNr;
protected int _columnNr;
/*
/**********************************************************
/* Instance construction, config, reuse
/**********************************************************
*/
public JsonReadContext(JsonReadContext parent, DupDetector dups, int type, int lineNr, int colNr) {
super();
_parent = parent;
_dups = dups;
_type = type;
_lineNr = lineNr;
_columnNr = colNr;
_index = -1;
}
/**
* Internal method to allow instance reuse: DO NOT USE unless you absolutely
* know what you are doing.
* Clears up state (including "current value"), changes type to one specified;
* resets current duplicate-detection state (if any).
* Parent link left as-is since it is {@code final}.
*
* NOTE: Public since 2.12.
*
* @param type Type to assign to this context node
* @param lineNr Line of the starting position of this context
* @param colNr Column of the starting position of this context
*/
public void reset(int type, int lineNr, int colNr) {
_type = type;
_index = -1;
_lineNr = lineNr;
_columnNr = colNr;
_currentName = null;
_currentValue = null;
if (_dups != null) {
_dups.reset();
}
}
/*
public void trackDups(JsonParser p) {
_dups = DupDetector.rootDetector(p);
}
*/
public JsonReadContext withDupDetector(DupDetector dups) {
_dups = dups;
return this;
}
@Override
public Object getCurrentValue() {
return _currentValue;
}
@Override
public void setCurrentValue(Object v) {
_currentValue = v;
}
/*
/**********************************************************
/* Factory methods
/**********************************************************
*/
public static JsonReadContext createRootContext(int lineNr, int colNr, DupDetector dups) {
return new JsonReadContext(null, dups, TYPE_ROOT, lineNr, colNr);
}
public static JsonReadContext createRootContext(DupDetector dups) {
return new JsonReadContext(null, dups, TYPE_ROOT, 1, 0);
}
public JsonReadContext createChildArrayContext(int lineNr, int colNr) {
JsonReadContext ctxt = _child;
if (ctxt == null) {
_child = ctxt = new JsonReadContext(this,
(_dups == null) ? null : _dups.child(), TYPE_ARRAY, lineNr, colNr);
} else {
ctxt.reset(TYPE_ARRAY, lineNr, colNr);
}
return ctxt;
}
public JsonReadContext createChildObjectContext(int lineNr, int colNr) {
JsonReadContext ctxt = _child;
if (ctxt == null) {
_child = ctxt = new JsonReadContext(this,
(_dups == null) ? null : _dups.child(), TYPE_OBJECT, lineNr, colNr);
return ctxt;
}
ctxt.reset(TYPE_OBJECT, lineNr, colNr);
return ctxt;
}
/*
/**********************************************************
/* Abstract method implementations, overrides
/**********************************************************
*/
@Override public String getCurrentName() { return _currentName; }
// @since 2.9
@Override public boolean hasCurrentName() { return _currentName != null; }
@Override public JsonReadContext getParent() { return _parent; }
@Override
public JsonLocation startLocation(ContentReference srcRef) {
// We don't keep track of offsets at this level (only reader does)
long totalChars = -1L;
return new JsonLocation(srcRef, totalChars, _lineNr, _columnNr);
}
@Override
@Deprecated // since 2.13
public JsonLocation getStartLocation(Object rawSrc) {
return startLocation(ContentReference.rawReference(rawSrc));
}
/*
/**********************************************************
/* Extended API
/**********************************************************
*/
/**
* Method that can be used to both clear the accumulated references
* (specifically value set with {@link #setCurrentValue(Object)})
* that should not be retained, and returns parent (as would
* {@link #getParent()} do). Typically called when closing the active
* context when encountering {@link JsonToken#END_ARRAY} or
* {@link JsonToken#END_OBJECT}.
*
* @return Parent context of this context node, if any; {@code null} for root context
*
* @since 2.7
*/
public JsonReadContext clearAndGetParent() {
_currentValue = null;
// could also clear the current name, but seems cheap enough to leave?
return _parent;
}
public DupDetector getDupDetector() {
return _dups;
}
/*
/**********************************************************
/* State changes
/**********************************************************
*/
public boolean expectComma() {
/* Assumption here is that we will be getting a value (at least
* before calling this method again), and
* so will auto-increment index to avoid having to do another call
*/
int ix = ++_index; // starts from -1
return (_type != TYPE_ROOT && ix > 0);
}
public void setCurrentName(String name) throws JsonProcessingException {
_currentName = name;
if (_dups != null) { _checkDup(_dups, name); }
}
private void _checkDup(DupDetector dd, String name) throws JsonProcessingException {
if (dd.isDup(name)) {
Object src = dd.getSource();
throw new JsonParseException(((src instanceof JsonParser) ? ((JsonParser) src) : null),
"Duplicate field '"+name+"'");
}
}
}