Class ElementIdMap

java.lang.Object
com.ctc.wstx.util.ElementIdMap

public final class ElementIdMap extends Object
This class is a specialized type-safe linked hash map used for storing ElementId instances. ElementId instances represent both id definitions (values of element attributes that have type ID in DTD), and references (values of element attributes of type IDREF and IDREFS). These definitions and references are stored for the purpose of verifying that all referenced id values are defined, and that none are defined more than once.

Note: there are 2 somewhat distinct usage modes, by DTDValidator and by MSV-based validators. DTDs pass raw character arrays, whereas MSV-based validators operate on Strings. This is the main reason for 2 distinct sets of methods.

  • Field Details

    • DEFAULT_SIZE

      protected static final int DEFAULT_SIZE
      Default initial table size; set so that usually it need not be expanded.
      See Also:
    • MIN_SIZE

      protected static final int MIN_SIZE
      See Also:
    • FILL_PCT

      protected static final int FILL_PCT
      Let's use 80% fill factor...
      See Also:
    • mTable

      protected ElementId[] mTable
      Actual hash table area
    • mSize

      protected int mSize
      Current size (number of entries); needed to know if and when rehash.
    • mSizeThreshold

      protected int mSizeThreshold
      Limit that indicates maximum size this instance can hold before it needs to be expanded and rehashed. Calculated using fill factor passed in to constructor.
    • mIndexMask

      protected int mIndexMask
      Mask used to get index from hash values; equal to mBuckets.length - 1, when mBuckets.length is a power of two.
    • mHead

      protected ElementId mHead
    • mTail

      protected ElementId mTail
  • Constructor Details

    • ElementIdMap

      public ElementIdMap()
    • ElementIdMap

      public ElementIdMap(int initialSize)
      This constructor is mainly used for testing, as it can be sized appropriately to test rehashing etc.
  • Method Details

    • getFirstUndefined

      public ElementId getFirstUndefined()
    • addReferenced

      public ElementId addReferenced(char[] buffer, int start, int len, int hash, Location loc, PrefixedName elemName, PrefixedName attrName)
      Method called when a reference to id is encountered. If so, need to check if specified id entry (ref or definiton) exists; and if not, to add a reference marker.
    • addReferenced

      public ElementId addReferenced(String idStr, Location loc, PrefixedName elemName, PrefixedName attrName)
    • addDefined

      public ElementId addDefined(char[] buffer, int start, int len, int hash, Location loc, PrefixedName elemName, PrefixedName attrName)
      Method called when an id definition is encountered. If so, need to check if specified id entry (ref or definiton) exists. If not, need to add the definition marker. If it does exist, need to 'upgrade it', if it was a reference marker; otherwise need to just return the old entry, and expect caller to check for dups and report the error.
    • addDefined

      public ElementId addDefined(String idStr, Location loc, PrefixedName elemName, PrefixedName attrName)
    • calcHash

      public static int calcHash(char[] buffer, int start, int len)
      Implementation of a hashing method for variable length Strings. Most of the time intention is that this calculation is done by caller during parsing, not here; however, sometimes it needs to be done for parsed "String" too.

      Note: identical to SymbolTable.calcHash(char[], int, int), although not required to be.

      Parameters:
      len - Length of String; has to be at least 1 (caller guarantees this pre-condition)
    • calcHash

      public static int calcHash(String key)
    • rehash

      private void rehash()
      Method called when size (number of entries) of symbol table grows so big that load factor is exceeded. Since size has to remain power of two, arrays will then always be doubled. Main work is really redistributing old entries into new String/Bucket entries.