text: /*
  ***************************************************************************
  * Copyright (C) 2008-2013, International Business Machines Corporation
  * and others. All Rights Reserved.
  ***************************************************************************
  *
  *  uspoof_impl.h
  *
  *    Implemenation header for spoof detection
  *
  */
  
  #ifndef USPOOFIM_H
  #define USPOOFIM_H
  
  #include "unicode/utypes.h"
  #include "unicode/uspoof.h"
  #include "unicode/uscript.h"
  #include "unicode/udata.h"
  
  #include "utrie2.h"
  
  #if !UCONFIG_NO_NORMALIZATION
  
  #ifdef __cplusplus
  
  U_NAMESPACE_BEGIN
  
  // The maximium length (in UTF-16 UChars) of the skeleton replacement string resulting from
  //   a single input code point.  This is function of the unicode.org data.
  #define USPOOF_MAX_SKELETON_EXPANSION 20
  
  // The default stack buffer size for copies or conversions or normalizations
  // of input strings being checked.  (Used in multiple places.)
  #define USPOOF_STACK_BUFFER_SIZE 100
  
  // Magic number for sanity checking spoof data.
  #define USPOOF_MAGIC 0x3845fdef
  
  class IdentifierInfo;
  class ScriptSet;
  class SpoofData;
  struct SpoofDataHeader;
  struct SpoofStringLengthsElement;
  
  /**
    *  Class SpoofImpl corresponds directly to the plain C API opaque type
    *  USpoofChecker.  One can be cast to the other.
    */
  class SpoofImpl : public UObject  {
  public:
  	SpoofImpl(SpoofData *data, UErrorCode &status);
  	SpoofImpl();
  	virtual ~SpoofImpl();
  
      /** Copy constructor, used by the user level uspoof_clone() function.
       */
      SpoofImpl(const SpoofImpl &src, UErrorCode &status);
  
      static SpoofImpl *validateThis(USpoofChecker *sc, UErrorCode &status);
      static const SpoofImpl *validateThis(const USpoofChecker *sc, UErrorCode &status);
  
      /** Get the confusable skeleton transform for a single code point.
       *  The result is a string with a length between 1 and 18.
       *  @param    tableMask  bit flag specifying which confusable table to use.
       *                       One of USPOOF_SL_TABLE_FLAG, USPOOF_MA_TABLE_FLAG, etc.
       *  @return   The length in UTF-16 code units of the substition string.
       */
      int32_t confusableLookup(UChar32 inChar, int32_t tableMask, UnicodeString &destBuf) const;
  
      /** Set and Get AllowedLocales, implementations of the corresponding API */
      void setAllowedLocales(const char *localesList, UErrorCode &status);
      const char * getAllowedLocales(UErrorCode &status);
  
      // Add (union) to the UnicodeSet all of the characters for the scripts used for
      // the specified locale.  Part of the implementation of setAllowedLocales.
      void addScriptChars(const char *locale, UnicodeSet *allowedChars, UErrorCode &status);
  
  
      /** parse a hex number.  Untility used by the builders.   */
      static UChar32 ScanHex(const UChar *s, int32_t start, int32_t limit, UErrorCode &status);
  
      // Implementation for Whole Script tests.
      // Return the test bit flag to be ORed into the eventual user return value
      //    if a Spoof opportunity is detected.
      void wholeScriptCheck(
          const UnicodeString &text, ScriptSet *result, UErrorCode &status) const;
  
      static UClassID U_EXPORT2 getStaticClassID(void);
      virtual UClassID getDynamicClassID(void) const;
  
      // IdentifierInfo Cache. IdentifierInfo objects are somewhat expensive to create.
      //                       Maintain a one-element cache, which is sufficient to avoid repeatedly
      //                       creating new ones unless we get multi-thread concurrency in spoof
      //                       check operations, which should be statistically uncommon.
      IdentifierInfo *getIdentifierInfo(UErrorCode &status) const;
      void releaseIdentifierInfo(IdentifierInfo *idInfo) const;
  
      //
      // Data Members
      //
  
      int32_t           fMagic;             // Internal sanity check.
      int32_t           fChecks;            // Bit vector of checks to perform.
  
      SpoofData        *fSpoofData;
  
      const UnicodeSet *fAllowedCharsSet;   // The UnicodeSet of allowed characters.
                                            //   for this Spoof Checker.  Defaults to all chars.
  
      const char       *fAllowedLocales;    // The list of allowed locales.
      URestrictionLevel fRestrictionLevel;  // The maximum restriction level for an acceptable identifier.
  
      IdentifierInfo    *fCachedIdentifierInfo;    // Do not use directly. See getIdentifierInfo().:w
  };
  
  
  
  //
  //  Confusable Mappings Data Structures
  //
  //    For the confusable data, we are essentially implementing a map,
  //       key:    a code point
  //       value:  a string.  Most commonly one char in length, but can be more.
  //
  //    The keys are stored as a sorted array of 32 bit ints.
  //             bits 0-23    a code point value
  //             bits 24-31   flags
  //                24:  1 if entry applies to SL table
  //                25:  1 if entry applies to SA table
  //                26:  1 if entry applies to ML table
  //                27:  1 if entry applies to MA table
  //                28:  1 if there are multiple entries for this code point.
  //                29-30:  length of value string, in UChars.
  //                         values are (1, 2, 3, other)
  //        The key table is sorted in ascending code point order.  (not on the
  //        32 bit int value, the flag bits do not participate in the sorting.)
  //
  //        Lookup is done by means of a binary search in the key table.
  //
  //    The corresponding values are kept in a parallel array of 16 bit ints.
  //        If the value string is of length 1, it is literally in the value array.
  //        For longer strings, the value array contains an index into the strings table.
  //
  //    String Table:
  //       The strings table contains all of the value strings (those of length two or greater)
  //       concatentated together into one long UChar (UTF-16) array.
  //
  //       The array is arranged by length of the strings - all strings of the same length
  //       are stored together.  The sections are ordered by length of the strings -
  //       all two char strings first, followed by all of the three Char strings, etc.
  //
  //       There is no nul character or other mark between adjacent strings.
  //
  //    String Lengths table
  //       The length of strings from 1 to 3 is flagged in the key table.
  //       For strings of length 4 or longer, the string length table provides a
  //       mapping between an index into the string table and the corresponding length.
  //       Strings of these lengths are rare, so lookup time is not an issue.
  //       Each entry consists of
  //            uint16_t      index of the _last_ string with this length
  //            uint16_t      the length
  //
  
  // Flag bits in the Key entries
  #define USPOOF_SL_TABLE_FLAG (1<<24)
  #define USPOOF_SA_TABLE_FLAG (1<<25)
  #define USPOOF_ML_TABLE_FLAG (1<<26)
  #define USPOOF_MA_TABLE_FLAG (1<<27)
  #define USPOOF_KEY_MULTIPLE_VALUES (1<<28)
  #define USPOOF_KEY_LENGTH_SHIFT 29
  #define USPOOF_KEY_LENGTH_FIELD(x) (((x)>>29) & 3)
  
  
  struct SpoofStringLengthsElement {
      uint16_t      fLastString;         // index in string table of last string with this length
      uint16_t      fStrLength;           // Length of strings
  };
  
  
  
  //-------------------------------------------------------------------------------------
  //
  //  SpoofData
  //
  //    A small class that wraps the raw (usually memory mapped) spoof data.
  //    Serves two primary functions:
  //      1.  Convenience.  Contains real pointers to the data, to avoid dealing with
  //          the offsets in the raw data.
  //      2.  Reference counting.  When a spoof checker is cloned, the raw data is shared
  //          and must be retained until all checkers using the data are closed.
  //    Nothing in this struct includes state that is specific to any particular
  //    USpoofDetector object.
  //
  //---------------------------------------------------------------------------------------
  class SpoofData: public UMemory {
    public:
      static SpoofData *getDefault(UErrorCode &status);   // Load standard ICU spoof data.
      SpoofData(UErrorCode &status);   // Create new spoof data wrapper.
                                       // Only used when building new data from rules.
  
      // Constructor for use when creating from prebuilt default data.
      //   A UDataMemory is what the ICU internal data loading functions provide.
      //   The udm is adopted by the SpoofData.
      SpoofData(UDataMemory *udm, UErrorCode &status);
  
      // Constructor for use when creating from serialized data.
      //
      SpoofData(const void *serializedData, int32_t length, UErrorCode &status);
  
      //  Check raw Spoof Data Version compatibility.
      //  Return TRUE it looks good.
      static UBool validateDataVersion(const SpoofDataHeader *rawData, UErrorCode &status);
      ~SpoofData();                    // Destructor not normally used.
                                       // Use removeReference() instead.
      // Reference Counting functions.
      //    Clone of a user-level spoof detector increments the ref count on the data.
      //    Close of a user-level spoof detector decrements the ref count.
      //    If the data is owned by us, it will be deleted when count goes to zero.
      SpoofData *addReference();
      void removeReference();
  
      // Reserve space in the raw data.  For use by builder when putting together a
      //   new set of data.  Init the new storage to zero, to prevent inconsistent
      //   results if it is not all otherwise set by the requester.
      //  Return:
      //    pointer to the new space that was added by this function.
      void *reserveSpace(int32_t numBytes, UErrorCode &status);
  
      // initialize the pointers from this object to the raw data.
      void initPtrs(UErrorCode &status);
  
      // Reset all fields to an initial state.
      // Called from the top of all constructors.
      void reset();
  
      SpoofDataHeader             *fRawData;          // Ptr to the raw memory-mapped data
      UBool                       fDataOwned;         // True if the raw data is owned, and needs
                                                      //  to be deleted when refcount goes to zero.
      UDataMemory                 *fUDM;              // If not NULL, our data came from a
                                                      //   UDataMemory, which we must close when
                                                      //   we are done.
  
      uint32_t                    fMemLimit;          // Limit of available raw data space
      u_atomic_int32_t            fRefCount;
  
      // Confusable data
      int32_t                     *fCFUKeys;
      uint16_t                    *fCFUValues;
      SpoofStringLengthsElement   *fCFUStringLengths;
      UChar                       *fCFUStrings;
  
      // Whole Script Confusable Data
      UTrie2                      *fAnyCaseTrie;
      UTrie2                      *fLowerCaseTrie;
      ScriptSet                   *fScriptSets;
      };
  
  
  //---------------------------------------------------------------------------------------
  //
  //  Raw Binary Data Formats, as loaded from the ICU data file,
  //    or as built by the builder.
  //
  //---------------------------------------------------------------------------------------
  struct SpoofDataHeader {
      int32_t       fMagic;                // (0x3845fdef)
      uint8_t       fFormatVersion[4];     // Data Format. Same as the value in struct UDataInfo
                                           //   if there is one associated with this data.
      int32_t       fLength;               // Total lenght in bytes of this spoof data,
                                           //   including all sections, not just the header.
  
      // The following four sections refer to data representing the confusable data
      //   from the Unicode.org data from "confusables.txt"
  
      int32_t       fCFUKeys;               // byte offset to Keys table (from SpoofDataHeader *)
      int32_t       fCFUKeysSize;           // number of entries in keys table  (32 bits each)
  
      // TODO: change name to fCFUValues, for consistency.
      int32_t       fCFUStringIndex;        // byte offset to String Indexes table
      int32_t       fCFUStringIndexSize;    // number of entries in String Indexes table (16 bits each)
                                            //     (number of entries must be same as in Keys table
  
      int32_t       fCFUStringTable;        // byte offset of String table
      int32_t       fCFUStringTableLen;     // length of string table (in 16 bit UChars)
  
      int32_t       fCFUStringLengths;      // byte offset to String Lengths table
      int32_t       fCFUStringLengthsSize;  // number of entries in lengths table. (2 x 16 bits each)
  
  
      // The following sections are for data from confusablesWholeScript.txt
  
      int32_t       fAnyCaseTrie;           // byte offset to the serialized Any Case Trie
      int32_t       fAnyCaseTrieLength;     // Length (bytes) of the serialized Any Case Trie
  
      int32_t       fLowerCaseTrie;         // byte offset to the serialized Lower Case Trie
      int32_t       fLowerCaseTrieLength;   // Length (bytes) of the serialized Lower Case Trie
  
      int32_t       fScriptSets;            // byte offset to array of ScriptSets
      int32_t       fScriptSetsLength;      // Number of ScriptSets (24 bytes each)
  
  
      // The following sections are for data from xidmodifications.txt
  
  
      int32_t       unused[15];              // Padding, Room for Expansion
  
   };
  
  
  
  
  //
  //  Structure for the Whole Script Confusable Data
  //    See Unicode UAX-39, Unicode Security Mechanisms, for a description of the
  //    Whole Script confusable data
  //
  //  The data provides mappings from code points to a set of scripts
  //    that contain characters that might be confused with the code point.
  //  There are two mappings, one for lower case only, and one for characters
  //    of any case.
  //
  //  The actual data consists of a utrie2 to map from a code point to an offset,
  //  and an array of UScriptSets (essentially bit maps) that is indexed
  //  by the offsets obtained from the Trie.
  //
  //
  
  
  U_NAMESPACE_END
  #endif /* __cplusplus */
  
  /**
    * Endianness swap function for binary spoof data.
    * @internal
    */
  U_CAPI int32_t U_EXPORT2
  uspoof_swap(const UDataSwapper *ds, const void *inData, int32_t length, void *outData,
              UErrorCode *status);
  
  
  #endif
  
  #endif  /* USPOOFIM_H */
  