/* Woodstox XML processor
*
* Copyright (c) 2004- Tatu Saloranta, tatu.saloranta@iki.fi
*
* Licensed under the License specified in file LICENSE, included with
* the source code.
* You may not use this file except in compliance with the License.
*
* 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.
*/
package com.ctc.wstx.sr;
import java.io.IOException;
import javax.xml.stream.Location;
import javax.xml.stream.XMLStreamException;
import javax.xml.namespace.QName;
import org.codehaus.stax2.ri.typed.CharArrayBase64Decoder;
import org.codehaus.stax2.ri.typed.ValueDecoderFactory;
import org.codehaus.stax2.typed.Base64Variant;
import org.codehaus.stax2.typed.TypedArrayDecoder;
import org.codehaus.stax2.typed.TypedValueDecoder;
import org.codehaus.stax2.typed.TypedXMLStreamException;
import com.ctc.wstx.api.ReaderConfig;
import com.ctc.wstx.sw.XmlWriter;
import com.ctc.wstx.util.StringUtil;
import com.ctc.wstx.util.StringVector;
import com.ctc.wstx.util.TextBuilder;
/**
* Shared base class that defines API stream reader uses to communicate
* with the attribute collector implementation, independent of whether it's
* operating in namespace-aware or non-namespace modes.
* Collector class is used to build up attribute lists; for the most part
* will just hold references to few specialized {@link TextBuilder}s that
* are used to create efficient semi-shared value Strings.
*/
public abstract class AttributeCollector
{
final static int INT_SPACE = 0x0020;
/**
* Threshold value that indicates minimum length for lists instances
* that need a Map structure, for fast attribute access by fully-qualified
* name.
*/
protected final static int LONG_ATTR_LIST_LEN = 4;
/**
* Expected typical maximum number of attributes for any element;
* chosen to minimize need to resize, while trying not to waste space.
* Dynamically grown; better not to set too high to avoid excessive
* overhead for small attribute-less documents.
*/
protected final static int EXP_ATTR_COUNT = 12;
/**
* This value is used to indicate that we shouldn't keep track
* of index of xml:id attribute -- generally done when Xml:id
* support is disabled
*/
protected final static int XMLID_IX_DISABLED = -2;
protected final static int XMLID_IX_NONE = -1;
/*
//////////////////////////////////////////
// Collected attribute information:
//////////////////////////////////////////
*/
/**
* Actual number of attributes collected, including attributes
* added via default values.
*/
protected int mAttrCount;
/**
* Number of attribute values actually parsed, not including
* ones created via default value expansion. Equal to or less than
* {@link #mAttrCount}.
*/
protected int mNonDefCount;
/**
* TextBuilder into which values of all attributes are appended
* to, including default valued ones (defaults are added after
* explicit ones).
* Constructed lazily, if and when needed (not needed
* for short attribute-less docs)
*/
protected TextBuilder mValueBuffer = null;
/**
* Vector in which attribute names are added; exact number of elements
* per attribute depends on whether namespace support is enabled or
* not (non-namespace mode only needs one entry; namespace mode two,
* one for prefix, one for local name).
* Constructed lazily, if and when needed (not needed
* for short attribute-less docs)
*/
protected StringVector mAttrNames = null;
/**
* Index of "xml:id" attribute, if one exists for the current
* element; {@link #XMLID_IX_NONE} if none.
*/
protected int mXmlIdAttrIndex;
/*
//////////////////////////////////////////
// Resolved (derived) attribute information:
//////////////////////////////////////////
*/
/**
* Array in which attribute value Strings are added, first time they
* are requested. Values are first added to <code>mValueBuffer</code>,
* from which a String is created, and finally substring created as
* needed and added to this array.
*/
protected String[] mAttrValues = null;
/*
//////////////////////////////////////////////////////////////
// Information that defines "Map-like" data structure used for
// quick access to attribute values by fully-qualified name
//////////////////////////////////////////////////////////////
*/
/**
* Encoding of a data structure that contains mapping from
* attribute names to attribute index in main attribute name arrays.
*<p>
* Data structure contains two separate areas; main hash area (with
* size <code>mAttrHashSize</code>), and remaining spillover area
* that follows hash area up until (but not including)
* <code>mAttrSpillEnd</code> index.
* Main hash area only contains indexes (index+1; 0 signifying empty slot)
* to actual attributes; spillover area has both hash and index for
* any spilled entry. Spilled entries are simply stored in order
* added, and need to be searched using linear search. In case of both
* primary hash hits and spills, eventual comparison with the local
* name needs to be done with actual name array.
*/
protected int[] mAttrMap = null;
/**
* Size of hash area in <code>mAttrMap</code>; generally at least 20%
* more than number of attributes (<code>mAttrCount</code>).
*/
protected int mAttrHashSize;
/**
* Pointer to int slot right after last spill entr, in
* <code>mAttrMap</code> array.
*/
protected int mAttrSpillEnd;
/*
///////////////////////////////////////////////
// Life-cycle:
///////////////////////////////////////////////
*/
protected AttributeCollector(ReaderConfig cfg)
{
mXmlIdAttrIndex = cfg.willDoXmlIdTyping() ? XMLID_IX_NONE : XMLID_IX_DISABLED;
}
/**
* Method called to allow reusing of collector, usually right before
* starting collecting attributes for a new start tag.
*/
protected abstract void reset();
/*
///////////////////////////////////////////////
// Public accesors (for stream reader)
///////////////////////////////////////////////
*/
/**
* @return Number of namespace declarations collected, including
* possible default namespace declaration
*/
protected abstract int getNsCount();
public abstract String getNsPrefix(int index);
public abstract String getNsURI(int index);
// // // Direct access to attribute/NS prefixes/localnames/URI
public final int getCount() {
return mAttrCount;
}
/**
* @return Number of attributes that were explicitly specified; may
* be less than the total count due to attributes created using
* attribute default values
*/
public int getSpecifiedCount() {
return mNonDefCount;
}
public abstract String getPrefix(int index);
public abstract String getLocalName(int index);
public abstract String getURI(int index);
public abstract QName getQName(int index);
/**
*<p>
* Note: the main reason this method is defined at this level, and
* made final, is performance. JIT may be able to fully inline this
* method, even when reference is via this base class. This is important
* since this is likely to be the most often called method of the
* collector instances.
*/
public final String getValue(int index)
{
if (index < 0 || index >= mAttrCount) {
throwIndex(index);
}
/* Note: array has been properly (re)sized by sub-classes
* resolveXxx() method, so it's either null or properly sized
* by now
*/
if (mAttrValues == null) {
mAttrValues = new String[mAttrCount];
}
String str = mAttrValues[index];
if (str == null) {
str = mValueBuffer.getEntry(index);
mAttrValues[index] = str;
}
return str;
}
public abstract String getValue(String nsURI, String localName);
public final boolean isSpecified(int index) {
return (index < mNonDefCount);
}
public final int getXmlIdAttrIndex() {
return mXmlIdAttrIndex;
}
/*
//////////////////////////////////////////////////////
// Type-safe accessors to support TypedXMLStreamReader
//////////////////////////////////////////////////////
*/
/**
* Method called to decode the whole attribute value as a single
* typed value.
* Decoding is done using the decoder provided.
*/
public final void decodeValue(int index, TypedValueDecoder tvd)
throws IllegalArgumentException
{
if (index < 0 || index >= mAttrCount) {
throwIndex(index);
}
/* Should be faster to pass the char array even if we might
* have a String
*/
// Either way, need to trim before passing:
char[] buf = mValueBuffer.getCharBuffer();
int start = mValueBuffer.getOffset(index);
int end = mValueBuffer.getOffset(index+1);
while (true) {
if (start >= end) {
tvd.handleEmptyValue();
return;
}
if (!StringUtil.isSpace(buf[start])) {
break;
}
++start;
}
// Trailing space?
while (--end > start && StringUtil.isSpace(buf[end])) { }
tvd.decode(buf, start, end+1);
}
/**
* Method called to decode the attribute value that consists of
* zero or more space-separated tokens.
* Decoding is done using the decoder provided.
* @return Number of tokens decoded
*/
public final int decodeValues(int index, TypedArrayDecoder tad,
InputProblemReporter rep)
throws XMLStreamException
{
if (index < 0 || index >= mAttrCount) {
throwIndex(index);
}
// Char[] faster than String... and no need to trim here:
return decodeValues(tad, rep,
mValueBuffer.getCharBuffer(),
mValueBuffer.getOffset(index),
mValueBuffer.getOffset(index+1));
}
public final byte[] decodeBinary(int index, Base64Variant v, CharArrayBase64Decoder dec,
InputProblemReporter rep)
throws XMLStreamException
{
if (index < 0 || index >= mAttrCount) {
throwIndex(index);
}
/* No point in trying to use String representation, even if one
* available, faster to process from char[]
*/
char[] cbuf = mValueBuffer.getCharBuffer();
int offset = mValueBuffer.getOffset(index);
int len = mValueBuffer.getOffset(index+1) - offset;
dec.init(v, true, cbuf, offset, len, null);
try {
return dec.decodeCompletely();
} catch (IllegalArgumentException iae) {
// Need to convert to a checked stream exception
String lexical = new String(cbuf, offset, len);
throw new TypedXMLStreamException(lexical, iae.getMessage(), rep.getLocation(), iae);
}
}
private final static int decodeValues(TypedArrayDecoder tad,
InputProblemReporter rep,
final char[] buf, int ptr, final int end)
throws XMLStreamException
{
int start = ptr;
int count = 0;
try {
decode_loop:
while (ptr < end) {
// First, any space to skip?
while (buf[ptr] <= INT_SPACE) {
if (++ptr >= end) {
break decode_loop;
}
}
// Then let's figure out non-space char (token)
start = ptr;
++ptr;
while (ptr < end && buf[ptr] > INT_SPACE) {
++ptr;
}
int tokenEnd = ptr;
++ptr; // to skip trailing space (or, beyond end)
// Ok, decode... any more room?
++count;
if (tad.decodeValue(buf, start, tokenEnd)) {
if (!checkExpand(tad)) {
break;
}
}
}
} catch (IllegalArgumentException iae) {
// Need to convert to a checked stream exception
Location loc = rep.getLocation();
String lexical = new String(buf, start, (ptr-start));
throw new TypedXMLStreamException(lexical, iae.getMessage(), loc, iae);
}
return count;
}
/**
* Internal method used to see if we can expand the buffer that
* the array decoder has. Bit messy, but simpler than having
* separately typed instances; and called rarely so that performance
* downside of instanceof is irrelevant.
*/
private final static boolean checkExpand(TypedArrayDecoder tad)
{
if (tad instanceof ValueDecoderFactory.BaseArrayDecoder) {
((ValueDecoderFactory.BaseArrayDecoder) tad).expand();
return true;
}
return false;
}
/*
///////////////////////////////////////////////
// Accessors for accessing helper objects
///////////////////////////////////////////////
*/
public abstract TextBuilder getDefaultNsBuilder();
public abstract TextBuilder getNsBuilder(String localName);
public abstract TextBuilder getAttrBuilder(String attrPrefix, String attrLocalName);
/**
* Method needed by event builder code; called to build a non-transient
* attribute container to use by a start element event.
*/
public abstract ElemAttrs buildAttrOb();
/*
///////////////////////////////////////////////
// Validation methods:
///////////////////////////////////////////////
*/
/**
* Low-level accessor method that attribute validation code may call
* for certain types of attributes; generally only for id and idref/idrefs
* attributes. It returns the underlying 'raw' attribute value buffer
* for direct access.
*/
public final TextBuilder getAttrBuilder()
{
return mValueBuffer;
}
/**
* Low-level mutator method that attribute validation code may call
* for certain types of attributes, when it wants to handle the whole
* validation and normalization process by itself. It is generally
* only called for id and idref/idrefs attributes, as those values
* are usually normalized.
*/
public final void setNormalizedValue(int index, String value) {
if (mAttrValues == null) {
mAttrValues = new String[mAttrCount];
}
mAttrValues[index] = value;
}
/*
///////////////////////////////////////////////
// Package/core methods:
///////////////////////////////////////////////
*/
protected void throwIndex(int index) {
throw new IllegalArgumentException("Invalid index "+index+"; current element has only "+getCount()+" attributes");
}
/**
* Method called by {@link InputElementStack} instance that "owns" this
* attribute collector;
*/
public final StringVector getNameList() {
return mAttrNames;
}
/**
* Method that basically serializes the specified (read-in) attribute
* using Writers provided. Serialization is done by
* writing out (fully-qualified) name
* of the attribute, followed by the equals sign and quoted value.
*/
public abstract void writeAttribute(int index, XmlWriter xw)
throws IOException, XMLStreamException;
/**
* Method called to initialize buffers that need not be immediately
* initialized
*/
protected final void allocBuffers()
{
if (mValueBuffer == null) {
mValueBuffer = new TextBuilder(EXP_ATTR_COUNT);
}
if (mAttrNames == null) {
mAttrNames = new StringVector(EXP_ATTR_COUNT);
}
}
/*
///////////////////////////////////////////////
// Internal methods:
///////////////////////////////////////////////
*/
/**
* Method that can be used to get the specified attribute value,
* by getting it written using Writer passed in. Can potentially
* save one String allocation, since no (temporary) Strings need
* to be created.
*/
/*
protected final void writeValue(int index, Writer w)
throws IOException
{
mValueBuffer.getEntry(index, w);
}
*/
protected static String[] resize(String[] old) {
int len = old.length;
String[] result = new String[len];
System.arraycopy(old, 0, result, 0, len);
return result;
}
protected void throwDupAttr(InputProblemReporter rep, int index)
throws XMLStreamException
{
rep.throwParseError("Duplicate attribute '"+getQName(index)+"'.");
}
}