| 1 | 38 | julius | /* Hash tables.
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         | 2 |  |  |    Copyright (C) 2000, 2001, 2003, 2004 Free Software Foundation, Inc.
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         | 3 |  |  |  
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         | 4 |  |  | This program is free software; you can redistribute it and/or modify it
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         | 5 |  |  | under the terms of the GNU General Public License as published by the
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         | 6 |  |  | Free Software Foundation; either version 2, or (at your option) any
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         | 7 |  |  | later version.
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         | 8 |  |  |  
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         | 9 |  |  | This program is distributed in the hope that it will be useful,
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         | 10 |  |  | but WITHOUT ANY WARRANTY; without even the implied warranty of
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         | 11 |  |  | MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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         | 12 |  |  | GNU General Public License for more details.
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         | 13 |  |  |  
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         | 14 |  |  | You should have received a copy of the GNU General Public License
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         | 15 |  |  | along with this program; if not, write to the Free Software
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         | 16 |  |  | Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.  */
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         | 17 |  |  |  
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         | 18 |  |  | #ifndef LIBCPP_SYMTAB_H
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         | 19 |  |  | #define LIBCPP_SYMTAB_H
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         | 20 |  |  |  
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         | 21 |  |  | #include "obstack.h"
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         | 22 |  |  | #define GTY(x) /* nothing */
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         | 23 |  |  |  
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         | 24 |  |  | /* This is what each hash table entry points to.  It may be embedded
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         | 25 |  |  |    deeply within another object.  */
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         | 26 |  |  | typedef struct ht_identifier ht_identifier;
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         | 27 |  |  | struct ht_identifier GTY(())
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         | 28 |  |  | {
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         | 29 |  |  |   const unsigned char *str;
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         | 30 |  |  |   unsigned int len;
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         | 31 |  |  |   unsigned int hash_value;
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         | 32 |  |  | };
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         | 33 |  |  |  
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         | 34 |  |  | #define HT_LEN(NODE) ((NODE)->len)
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         | 35 |  |  | #define HT_STR(NODE) ((NODE)->str)
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         | 36 |  |  |  
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         | 37 |  |  | typedef struct ht hash_table;
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         | 38 |  |  | typedef struct ht_identifier *hashnode;
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         | 39 |  |  |  
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         | 40 |  |  | enum ht_lookup_option {HT_NO_INSERT = 0, HT_ALLOC, HT_ALLOCED};
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         | 41 |  |  |  
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         | 42 |  |  | /* An identifier hash table for cpplib and the front ends.  */
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         | 43 |  |  | struct ht
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         | 44 |  |  | {
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         | 45 |  |  |   /* Identifiers are allocated from here.  */
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         | 46 |  |  |   struct obstack stack;
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         | 47 |  |  |  
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         | 48 |  |  |   hashnode *entries;
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         | 49 |  |  |   /* Call back, allocate a node.  */
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         | 50 |  |  |   hashnode (*alloc_node) (hash_table *);
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         | 51 |  |  |   /* Call back, allocate something that hangs off a node like a cpp_macro.
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         | 52 |  |  |      NULL means use the usual allocator.  */
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         | 53 |  |  |   void * (*alloc_subobject) (size_t);
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         | 54 |  |  |  
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         | 55 |  |  |   unsigned int nslots;          /* Total slots in the entries array.  */
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         | 56 |  |  |   unsigned int nelements;       /* Number of live elements.  */
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         | 57 |  |  |  
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         | 58 |  |  |   /* Link to reader, if any.  For the benefit of cpplib.  */
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         | 59 |  |  |   struct cpp_reader *pfile;
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         | 60 |  |  |  
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         | 61 |  |  |   /* Table usage statistics.  */
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         | 62 |  |  |   unsigned int searches;
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         | 63 |  |  |   unsigned int collisions;
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         | 64 |  |  |  
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         | 65 |  |  |   /* Should 'entries' be freed when it is no longer needed?  */
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         | 66 |  |  |   bool entries_owned;
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         | 67 |  |  | };
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         | 68 |  |  |  
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         | 69 |  |  | /* Initialize the hashtable with 2 ^ order entries.  */
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         | 70 |  |  | extern hash_table *ht_create (unsigned int order);
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         | 71 |  |  |  
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         | 72 |  |  | /* Frees all memory associated with a hash table.  */
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         | 73 |  |  | extern void ht_destroy (hash_table *);
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         | 74 |  |  |  
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         | 75 |  |  | extern hashnode ht_lookup (hash_table *, const unsigned char *,
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         | 76 |  |  |                            size_t, enum ht_lookup_option);
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         | 77 |  |  | extern hashnode ht_lookup_with_hash (hash_table *, const unsigned char *,
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         | 78 |  |  |                                      size_t, unsigned int,
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         | 79 |  |  |                                      enum ht_lookup_option);
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         | 80 |  |  | #define HT_HASHSTEP(r, c) ((r) * 67 + ((c) - 113));
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         | 81 |  |  | #define HT_HASHFINISH(r, len) ((r) + (len))
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         | 82 |  |  |  
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         | 83 |  |  | /* For all nodes in TABLE, make a callback.  The callback takes
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         | 84 |  |  |    TABLE->PFILE, the node, and a PTR, and the callback sequence stops
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         | 85 |  |  |    if the callback returns zero.  */
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         | 86 |  |  | typedef int (*ht_cb) (struct cpp_reader *, hashnode, const void *);
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         | 87 |  |  | extern void ht_forall (hash_table *, ht_cb, const void *);
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         | 88 |  |  |  
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         | 89 |  |  | /* Restore the hash table.  */
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         | 90 |  |  | extern void ht_load (hash_table *ht, hashnode *entries,
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         | 91 |  |  |                      unsigned int nslots, unsigned int nelements, bool own);
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         | 92 |  |  |  
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         | 93 |  |  | /* Dump allocation statistics to stderr.  */
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         | 94 |  |  | extern void ht_dump_statistics (hash_table *);
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         | 95 |  |  |  
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         | 96 |  |  | #endif /* LIBCPP_SYMTAB_H */
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