src/java/org/apache/cassandra/cql3/ColumnIdentifier.java - cassandra - Git at Google

 /*
  * Licensed to the Apache Software Foundation (ASF) under one
  * or more contributor license agreements.  See the NOTICE file
  * distributed with this work for additional information
  * regarding copyright ownership.  The ASF licenses this file
  * to you 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.
  */
 package org.apache.cassandra.cql3;

 import java.nio.ByteBuffer;
 import java.util.List;
 import java.util.Locale;
 import java.util.concurrent.ConcurrentMap;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;

 import com.google.common.collect.MapMaker;

 import org.apache.cassandra.cache.IMeasurableMemory;
 import org.apache.cassandra.config.CFMetaData;
 import org.apache.cassandra.config.ColumnDefinition;
 import org.apache.cassandra.cql3.selection.Selectable;
 import org.apache.cassandra.cql3.selection.Selector;
 import org.apache.cassandra.cql3.selection.SimpleSelector;
 import org.apache.cassandra.db.marshal.AbstractType;
 import org.apache.cassandra.exceptions.InvalidRequestException;
 import org.apache.cassandra.db.marshal.UTF8Type;
 import org.apache.cassandra.utils.ByteBufferUtil;
 import org.apache.cassandra.utils.ObjectSizes;
 import org.apache.cassandra.utils.memory.AbstractAllocator;

 /**
  * Represents an identifer for a CQL column definition.
  * TODO : should support light-weight mode without text representation for when not interned
  */
 public class ColumnIdentifier extends Selectable implements IMeasurableMemory, Comparable<ColumnIdentifier>
 {
     private static final Pattern PATTERN_DOUBLE_QUOTE = Pattern.compile("\"", Pattern.LITERAL);

     public final ByteBuffer bytes;
     private final String text;
     /**
      * since these objects are compared frequently, we stash an efficiently compared prefix of the bytes, in the expectation
      * that the majority of comparisons can be answered by this value only
      */
     public final long prefixComparison;
     private final boolean interned;

     private static final Pattern UNQUOTED_IDENTIFIER = Pattern.compile("[a-z][a-z0-9_]*");

     private static final long EMPTY_SIZE = ObjectSizes.measure(new ColumnIdentifier(ByteBufferUtil.EMPTY_BYTE_BUFFER, "", false));

     private static final ConcurrentMap<InternedKey, ColumnIdentifier> internedInstances = new MapMaker().weakValues().makeMap();

     private static final class InternedKey
     {
         private final AbstractType<?> type;
         private final ByteBuffer bytes;

         InternedKey(AbstractType<?> type, ByteBuffer bytes)
         {
             this.type = type;
             this.bytes = bytes;
         }

         @Override
         public boolean equals(Object o)
         {
             if (this == o)
                 return true;

             if (o == null || getClass() != o.getClass())
                 return false;

             InternedKey that = (InternedKey) o;
             return bytes.equals(that.bytes) && type.equals(that.type);
         }

         @Override
         public int hashCode()
         {
             return bytes.hashCode() + 31 * type.hashCode();
         }
     }

     private static long prefixComparison(ByteBuffer bytes)
     {
         long prefix = 0;
         ByteBuffer read = bytes.duplicate();
         int i = 0;
         while (read.hasRemaining() && i < 8)
         {
             prefix <<= 8;
             prefix |= read.get() & 0xFF;
             i++;
         }
         prefix <<= (8 - i) * 8;
         // by flipping the top bit (==Integer.MIN_VALUE), we ensure that signed comparison gives the same result
         // as an unsigned without the bit flipped
         prefix ^= Long.MIN_VALUE;
         return prefix;
     }

     public ColumnIdentifier(String rawText, boolean keepCase)
     {
         this.text = keepCase ? rawText : rawText.toLowerCase(Locale.US);
         this.bytes = ByteBufferUtil.bytes(this.text);
         this.prefixComparison = prefixComparison(bytes);
         this.interned = false;
     }

     public ColumnIdentifier(ByteBuffer bytes, AbstractType<?> type)
     {
         this(bytes, type.getString(bytes), false);
     }

     public ColumnIdentifier(ByteBuffer bytes, String text)
     {
         this(bytes, text, false);
     }

     private ColumnIdentifier(ByteBuffer bytes, String text, boolean interned)
     {
         this.bytes = bytes;
         this.text = text;
         this.interned = interned;
         this.prefixComparison = prefixComparison(bytes);
     }

     public static ColumnIdentifier getInterned(ByteBuffer bytes, AbstractType<?> type)
     {
         return getInterned(type, bytes, type.getString(bytes));
     }

     public static ColumnIdentifier getInterned(String rawText, boolean keepCase)
     {
         String text = keepCase ? rawText : rawText.toLowerCase(Locale.US);
         ByteBuffer bytes = ByteBufferUtil.bytes(text);
         return getInterned(UTF8Type.instance, bytes, text);
     }

     public static ColumnIdentifier getInterned(AbstractType<?> type, ByteBuffer bytes, String text)
     {
         bytes = ByteBufferUtil.minimalBufferFor(bytes);

         InternedKey key = new InternedKey(type, bytes);
         ColumnIdentifier id = internedInstances.get(key);
         if (id != null)
             return id;

         ColumnIdentifier created = new ColumnIdentifier(bytes, text, true);
         ColumnIdentifier previous = internedInstances.putIfAbsent(key, created);
         return previous == null ? created : previous;
     }

     public boolean isInterned()
     {
         return interned;
     }

     @Override
     public final int hashCode()
     {
         return bytes.hashCode();
     }

     @Override
     public final boolean equals(Object o)
     {
         if (this == o)
             return true;

         if(!(o instanceof ColumnIdentifier))
             return false;
         ColumnIdentifier that = (ColumnIdentifier)o;
         return bytes.equals(that.bytes);
     }

     @Override
     public String toString()
     {
         return text;
     }

     /**
      * Returns a string representation of the identifier that is safe to use directly in CQL queries.
      * In necessary, the string will be double-quoted, and any quotes inside the string will be escaped.
      */
     public String toCQLString()
     {
         return maybeQuote(text);
     }

     public long unsharedHeapSize()
     {
         return EMPTY_SIZE
              + ObjectSizes.sizeOnHeapOf(bytes)
              + ObjectSizes.sizeOf(text);
     }

     public long unsharedHeapSizeExcludingData()
     {
         return EMPTY_SIZE
              + ObjectSizes.sizeOnHeapExcludingData(bytes)
              + ObjectSizes.sizeOf(text);
     }

     public ColumnIdentifier clone(AbstractAllocator allocator)
     {
         return interned ? this : new ColumnIdentifier(allocator.clone(bytes), text, false);
     }

     public Selector.Factory newSelectorFactory(CFMetaData cfm, List<ColumnDefinition> defs) throws InvalidRequestException
     {
         ColumnDefinition def = cfm.getColumnDefinitionForCQL(this);
         if (def == null)
             throw new InvalidRequestException(String.format("Undefined name %s in selection clause", this));

         return SimpleSelector.newFactory(def, addAndGetIndex(def, defs));
     }

     public int compareTo(ColumnIdentifier that)
     {
         int c = Long.compare(this.prefixComparison, that.prefixComparison);
         if (c != 0)
             return c;
         if (this == that)
             return 0;
         return ByteBufferUtil.compareUnsigned(this.bytes, that.bytes);
     }

     /**
      * Because Thrift-created tables may have a non-text comparator, we cannot determine the proper 'key' until
      * we know the comparator. ColumnIdentifier.Raw is a placeholder that can be converted to a real ColumnIdentifier
      * once the comparator is known with prepare(). This should only be used with identifiers that are actual
      * column names. See CASSANDRA-8178 for more background.
      */
     public static interface Raw extends Selectable.Raw
     {

         public ColumnIdentifier prepare(CFMetaData cfm);

         /**
          * Returns a string representation of the identifier that is safe to use directly in CQL queries.
          * In necessary, the string will be double-quoted, and any quotes inside the string will be escaped.
          */
         public String toCQLString();
     }

     public static class Literal implements Raw
     {
         private final String rawText;
         private final String text;

         public Literal(String rawText, boolean keepCase)
         {
             this.rawText = rawText;
             this.text =  keepCase ? rawText : rawText.toLowerCase(Locale.US);
         }

         public ColumnIdentifier prepare(CFMetaData cfm)
         {
             if (!cfm.isStaticCompactTable())
                 return getInterned(text, true);

             AbstractType<?> thriftColumnNameType = cfm.thriftColumnNameType();
             if (thriftColumnNameType instanceof UTF8Type)
                 return getInterned(text, true);

             // We have a Thrift-created table with a non-text comparator. Check if we have a match column, otherwise assume we should use
             // thriftColumnNameType
             ByteBuffer bufferName = ByteBufferUtil.bytes(text);
             for (ColumnDefinition def : cfm.allColumns())
             {
                 if (def.name.bytes.equals(bufferName))
                     return def.name;
             }
             return getInterned(thriftColumnNameType, thriftColumnNameType.fromString(rawText), text);
         }

         public boolean processesSelection()
         {
             return false;
         }

         @Override
         public final int hashCode()
         {
             return text.hashCode();
         }

         @Override
         public final boolean equals(Object o)
         {
             if(!(o instanceof Literal))
                 return false;

             Literal that = (Literal) o;
             return text.equals(that.text);
         }

         @Override
         public String toString()
         {
             return text;
         }

         public String toCQLString()
         {
             return maybeQuote(text);
         }
     }

     public static class ColumnIdentifierValue implements Raw
     {
         private final ColumnIdentifier identifier;

         public ColumnIdentifierValue(ColumnIdentifier identifier)
         {
             this.identifier = identifier;
         }

         public ColumnIdentifier prepare(CFMetaData cfm)
         {
             return identifier;
         }

         public boolean processesSelection()
         {
             return false;
         }

         @Override
         public final int hashCode()
         {
             return identifier.hashCode();
         }

         @Override
         public final boolean equals(Object o)
         {
             if(!(o instanceof ColumnIdentifierValue))
                 return false;
             ColumnIdentifierValue that = (ColumnIdentifierValue) o;
             return identifier.equals(that.identifier);
         }

         @Override
         public String toString()
         {
             return identifier.toString();
         }

         public String toCQLString()
         {
             return maybeQuote(identifier.text);
         }
     }

     public static String maybeQuote(String text)
     {
         if (UNQUOTED_IDENTIFIER.matcher(text).matches() && !ReservedKeywords.isReserved(text))
             return text;

         return '"' + PATTERN_DOUBLE_QUOTE.matcher(text).replaceAll(Matcher.quoteReplacement("\"\"")) + '"';
     }
 }
	/*
	* Licensed to the Apache Software Foundation (ASF) under one
	* or more contributor license agreements. See the NOTICE file
	* distributed with this work for additional information
	* regarding copyright ownership. The ASF licenses this file
	* to you 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.
	*/
	package org.apache.cassandra.cql3;

	import java.nio.ByteBuffer;
	import java.util.List;
	import java.util.Locale;
	import java.util.concurrent.ConcurrentMap;
	import java.util.regex.Matcher;
	import java.util.regex.Pattern;

	import com.google.common.collect.MapMaker;

	import org.apache.cassandra.cache.IMeasurableMemory;
	import org.apache.cassandra.config.CFMetaData;
	import org.apache.cassandra.config.ColumnDefinition;
	import org.apache.cassandra.cql3.selection.Selectable;
	import org.apache.cassandra.cql3.selection.Selector;
	import org.apache.cassandra.cql3.selection.SimpleSelector;
	import org.apache.cassandra.db.marshal.AbstractType;
	import org.apache.cassandra.exceptions.InvalidRequestException;
	import org.apache.cassandra.db.marshal.UTF8Type;
	import org.apache.cassandra.utils.ByteBufferUtil;
	import org.apache.cassandra.utils.ObjectSizes;
	import org.apache.cassandra.utils.memory.AbstractAllocator;

	/**
	* Represents an identifer for a CQL column definition.
	* TODO : should support light-weight mode without text representation for when not interned
	*/
	public class ColumnIdentifier extends Selectable implements IMeasurableMemory, Comparable<ColumnIdentifier>
	{
	private static final Pattern PATTERN_DOUBLE_QUOTE = Pattern.compile("\"", Pattern.LITERAL);

	public final ByteBuffer bytes;
	private final String text;
	/**
	* since these objects are compared frequently, we stash an efficiently compared prefix of the bytes, in the expectation
	* that the majority of comparisons can be answered by this value only
	*/
	public final long prefixComparison;
	private final boolean interned;

	private static final Pattern UNQUOTED_IDENTIFIER = Pattern.compile("[a-z][a-z0-9_]*");

	private static final long EMPTY_SIZE = ObjectSizes.measure(new ColumnIdentifier(ByteBufferUtil.EMPTY_BYTE_BUFFER, "", false));

	private static final ConcurrentMap<InternedKey, ColumnIdentifier> internedInstances = new MapMaker().weakValues().makeMap();

	private static final class InternedKey
	{
	private final AbstractType<?> type;
	private final ByteBuffer bytes;

	InternedKey(AbstractType<?> type, ByteBuffer bytes)
	{
	this.type = type;
	this.bytes = bytes;
	}

	@Override
	public boolean equals(Object o)
	{
	if (this == o)
	return true;

	if (o == null \|\| getClass() != o.getClass())
	return false;

	InternedKey that = (InternedKey) o;
	return bytes.equals(that.bytes) && type.equals(that.type);
	}

	@Override
	public int hashCode()
	{
	return bytes.hashCode() + 31 * type.hashCode();
	}
	}

	private static long prefixComparison(ByteBuffer bytes)
	{
	long prefix = 0;
	ByteBuffer read = bytes.duplicate();
	int i = 0;
	while (read.hasRemaining() && i < 8)
	{
	prefix <<= 8;
	prefix \|= read.get() & 0xFF;
	i++;
	}
	prefix <<= (8 - i) * 8;
	// by flipping the top bit (==Integer.MIN_VALUE), we ensure that signed comparison gives the same result
	// as an unsigned without the bit flipped
	prefix ^= Long.MIN_VALUE;
	return prefix;
	}

	public ColumnIdentifier(String rawText, boolean keepCase)
	{
	this.text = keepCase ? rawText : rawText.toLowerCase(Locale.US);
	this.bytes = ByteBufferUtil.bytes(this.text);
	this.prefixComparison = prefixComparison(bytes);
	this.interned = false;
	}

	public ColumnIdentifier(ByteBuffer bytes, AbstractType<?> type)
	{
	this(bytes, type.getString(bytes), false);
	}

	public ColumnIdentifier(ByteBuffer bytes, String text)
	{
	this(bytes, text, false);
	}

	private ColumnIdentifier(ByteBuffer bytes, String text, boolean interned)
	{
	this.bytes = bytes;
	this.text = text;
	this.interned = interned;
	this.prefixComparison = prefixComparison(bytes);
	}

	public static ColumnIdentifier getInterned(ByteBuffer bytes, AbstractType<?> type)
	{
	return getInterned(type, bytes, type.getString(bytes));
	}

	public static ColumnIdentifier getInterned(String rawText, boolean keepCase)
	{
	String text = keepCase ? rawText : rawText.toLowerCase(Locale.US);
	ByteBuffer bytes = ByteBufferUtil.bytes(text);
	return getInterned(UTF8Type.instance, bytes, text);
	}

	public static ColumnIdentifier getInterned(AbstractType<?> type, ByteBuffer bytes, String text)
	{
	bytes = ByteBufferUtil.minimalBufferFor(bytes);

	InternedKey key = new InternedKey(type, bytes);
	ColumnIdentifier id = internedInstances.get(key);
	if (id != null)
	return id;

	ColumnIdentifier created = new ColumnIdentifier(bytes, text, true);
	ColumnIdentifier previous = internedInstances.putIfAbsent(key, created);
	return previous == null ? created : previous;
	}

	public boolean isInterned()
	{
	return interned;
	}

	@Override
	public final int hashCode()
	{
	return bytes.hashCode();
	}

	@Override
	public final boolean equals(Object o)
	{
	if (this == o)
	return true;

	if(!(o instanceof ColumnIdentifier))
	return false;
	ColumnIdentifier that = (ColumnIdentifier)o;
	return bytes.equals(that.bytes);
	}

	@Override
	public String toString()
	{
	return text;
	}

	/**
	* Returns a string representation of the identifier that is safe to use directly in CQL queries.
	* In necessary, the string will be double-quoted, and any quotes inside the string will be escaped.
	*/
	public String toCQLString()
	{
	return maybeQuote(text);
	}

	public long unsharedHeapSize()
	{
	return EMPTY_SIZE
	+ ObjectSizes.sizeOnHeapOf(bytes)
	+ ObjectSizes.sizeOf(text);
	}

	public long unsharedHeapSizeExcludingData()
	{
	return EMPTY_SIZE
	+ ObjectSizes.sizeOnHeapExcludingData(bytes)
	+ ObjectSizes.sizeOf(text);
	}

	public ColumnIdentifier clone(AbstractAllocator allocator)
	{
	return interned ? this : new ColumnIdentifier(allocator.clone(bytes), text, false);
	}

	public Selector.Factory newSelectorFactory(CFMetaData cfm, List<ColumnDefinition> defs) throws InvalidRequestException
	{
	ColumnDefinition def = cfm.getColumnDefinitionForCQL(this);
	if (def == null)
	throw new InvalidRequestException(String.format("Undefined name %s in selection clause", this));

	return SimpleSelector.newFactory(def, addAndGetIndex(def, defs));
	}

	public int compareTo(ColumnIdentifier that)
	{
	int c = Long.compare(this.prefixComparison, that.prefixComparison);
	if (c != 0)
	return c;
	if (this == that)
	return 0;
	return ByteBufferUtil.compareUnsigned(this.bytes, that.bytes);
	}

	/**
	* Because Thrift-created tables may have a non-text comparator, we cannot determine the proper 'key' until
	* we know the comparator. ColumnIdentifier.Raw is a placeholder that can be converted to a real ColumnIdentifier
	* once the comparator is known with prepare(). This should only be used with identifiers that are actual
	* column names. See CASSANDRA-8178 for more background.
	*/
	public static interface Raw extends Selectable.Raw
	{

	public ColumnIdentifier prepare(CFMetaData cfm);

	/**
	* Returns a string representation of the identifier that is safe to use directly in CQL queries.
	* In necessary, the string will be double-quoted, and any quotes inside the string will be escaped.
	*/
	public String toCQLString();
	}

	public static class Literal implements Raw
	{
	private final String rawText;
	private final String text;

	public Literal(String rawText, boolean keepCase)
	{
	this.rawText = rawText;
	this.text = keepCase ? rawText : rawText.toLowerCase(Locale.US);
	}

	public ColumnIdentifier prepare(CFMetaData cfm)
	{
	if (!cfm.isStaticCompactTable())
	return getInterned(text, true);

	AbstractType<?> thriftColumnNameType = cfm.thriftColumnNameType();
	if (thriftColumnNameType instanceof UTF8Type)
	return getInterned(text, true);

	// We have a Thrift-created table with a non-text comparator. Check if we have a match column, otherwise assume we should use
	// thriftColumnNameType
	ByteBuffer bufferName = ByteBufferUtil.bytes(text);
	for (ColumnDefinition def : cfm.allColumns())
	{
	if (def.name.bytes.equals(bufferName))
	return def.name;
	}
	return getInterned(thriftColumnNameType, thriftColumnNameType.fromString(rawText), text);
	}

	public boolean processesSelection()
	{
	return false;
	}

	@Override
	public final int hashCode()
	{
	return text.hashCode();
	}

	@Override
	public final boolean equals(Object o)
	{
	if(!(o instanceof Literal))
	return false;

	Literal that = (Literal) o;
	return text.equals(that.text);
	}

	@Override
	public String toString()
	{
	return text;
	}

	public String toCQLString()
	{
	return maybeQuote(text);
	}
	}

	public static class ColumnIdentifierValue implements Raw
	{
	private final ColumnIdentifier identifier;

	public ColumnIdentifierValue(ColumnIdentifier identifier)
	{
	this.identifier = identifier;
	}

	public ColumnIdentifier prepare(CFMetaData cfm)
	{
	return identifier;
	}

	public boolean processesSelection()
	{
	return false;
	}

	@Override
	public final int hashCode()
	{
	return identifier.hashCode();
	}

	@Override
	public final boolean equals(Object o)
	{
	if(!(o instanceof ColumnIdentifierValue))
	return false;
	ColumnIdentifierValue that = (ColumnIdentifierValue) o;
	return identifier.equals(that.identifier);
	}

	@Override
	public String toString()
	{
	return identifier.toString();
	}

	public String toCQLString()
	{
	return maybeQuote(identifier.text);
	}
	}

	public static String maybeQuote(String text)
	{
	if (UNQUOTED_IDENTIFIER.matcher(text).matches() && !ReservedKeywords.isReserved(text))
	return text;

	return '"' + PATTERN_DOUBLE_QUOTE.matcher(text).replaceAll(Matcher.quoteReplacement("\"\"")) + '"';
	}
	}