Initial import of the CDE 2.1.30 sources from the Open Group.

cde/programs/dtinfo/DtMmdb/compression/trie.h

@@ -0,0 +1,138 @@
+/*
+ * $XConsortium: trie.h /main/3 1996/06/11 17:15:31 cde-hal $
+ *
+ * Copyright (c) 1993 HAL Computer Systems International, Ltd.
+ * All rights reserved.  Unpublished -- rights reserved under
+ * the Copyright Laws of the United States.  USE OF A COPYRIGHT
+ * NOTICE IS PRECAUTIONARY ONLY AND DOES NOT IMPLY PUBLICATION
+ * OR DISCLOSURE.
+ * 
+ * THIS SOFTWARE CONTAINS CONFIDENTIAL INFORMATION AND TRADE
+ * SECRETS OF HAL COMPUTER SYSTEMS INTERNATIONAL, LTD.  USE,
+ * DISCLOSURE, OR REPRODUCTION IS PROHIBITED WITHOUT THE
+ * PRIOR EXPRESS WRITTEN PERMISSION OF HAL COMPUTER SYSTEMS
+ * INTERNATIONAL, LTD.
+ * 
+ *                         RESTRICTED RIGHTS LEGEND
+ * Use, duplication, or disclosure by the Government is subject
+ * to the restrictions as set forth in subparagraph (c)(l)(ii)
+ * of the Rights in Technical Data and Computer Software clause
+ * at DFARS 252.227-7013.
+ *
+ *          HAL COMPUTER SYSTEMS INTERNATIONAL, LTD.
+ *                  1315 Dell Avenue
+ *                  Campbell, CA  95008
+ * 
+ */
+
+
+#ifndef _trie_h
+#define _trie_h 1
+
+#include "compression/code.h"
+#include "dstr/heap.h"
+
+#define MAX_LEVELS 50
+#define LANG_ALPHABET_SZ 256
+
+class trie_node;
+
+struct info_t {
+   unsigned freq:	23;
+   unsigned letter:	8;
+   unsigned mark:	1;
+};
+
+class trie_node_info 
+{
+   trie_node* child;
+   union {
+      struct info_t info_view;
+      int int_view;
+   } info;
+   union {
+      encoding_unit* eu;
+      int heap;
+      int pos;
+   } image;
+
+public:
+   //trie_node_info (char letter = 0, int freq = 0, trie_node* child = 0);
+   trie_node_info ();
+   ~trie_node_info ();
+
+   friend class trie_node;
+   friend class trie;
+   friend Boolean trie_node_ls(voidPtr n1, voidPtr n2);
+   friend Boolean trie_node_eq(voidPtr n1, voidPtr n2);
+   friend void update_index(int ind, void* x);
+};
+
+typedef trie_node_info* trie_node_info_ptr_t;
+
+class trie_node 
+{
+
+protected:
+#ifdef C_API
+   trie_node_info_ptr_t* children; 
+#else
+   trie_node_info children[LANG_ALPHABET_SZ+1]; 
+         // children[LANG_ALPHABET_SZ+1].child encodes the parent
+#endif
+
+
+public:
+   trie_node(trie_node_info* parent);
+   ~trie_node();
+
+   void _print(ostream& out, char* prefix, int prefix_sz);
+
+   friend class trie;
+};
+
+class trie 
+{
+
+protected:
+   int max_trie_level;
+   int total_nodes;
+   int level_sz[MAX_LEVELS];
+
+   trie_node* root;
+   heap* sorted_freqs;
+
+   int  estimated_sz;
+   encoding_unit** alphabet;
+   unsigned int alphabet_sz;
+
+protected:
+   void collect_freqs(trie_node* rt, int level);
+   ostring* get_word(trie_node_info* x);
+
+   void _find_leaf(trie_node* z, int& j);
+   void extend_alphabet();
+
+public:
+   trie(int estimated_alphabet_sz = 400) ;
+   virtual ~trie() ;
+
+   virtual void add(unsigned char* word, int len, int freq = 1) ;
+   virtual void add_letters(unsigned char* letters, int len) ;
+   virtual encoding_unit* add_to_alphabet(unsigned char* word, int sz, int fq);
+
+   virtual encoding_unit** get_alphabet(unsigned int& alphabet_sz);
+
+   virtual Boolean travers_to(char* str, int sz, 
+                              trie_node*& node, trie_node_info*& node_info
+                             );
+
+// take the longest substring from str and returns its
+// encoding_unit.
+   virtual encoding_unit* parse(unsigned char* str, int len);
+
+   friend ostream& operator <<(ostream& out, trie& tr);
+};
+
+
+#endif