Written by Fred Fish <fnf@cygnus.com>
Rewritten by Jim Blandy <jimb@cygnus.com>
- Copyright (C) 1999-2018 Free Software Foundation, Inc.
+ Copyright (C) 1999-2023 Free Software Foundation, Inc.
This file is part of GDB.
*/
-
-struct bcache;
-
-/* Find a copy of the LENGTH bytes at ADDR in BCACHE. If BCACHE has
- never seen those bytes before, add a copy of them to BCACHE. In
- either case, return a pointer to BCACHE's copy of that string.
- Since the cached value is ment to be read-only, return a const
- buffer. */
-extern const void *bcache (const void *addr, int length,
- struct bcache *bcache);
-
-/* Like bcache, but if ADDED is not NULL, set *ADDED to true if the
- bytes were newly added to the cache, or to false if the bytes were
- found in the cache. */
-extern const void *bcache_full (const void *addr, int length,
- struct bcache *bcache, int *added);
-
-/* Free all the storage used by BCACHE. */
-extern void bcache_xfree (struct bcache *bcache);
-
-/* Create a new bcache object. */
-extern struct bcache *bcache_xmalloc (
- unsigned long (*hash_function)(const void *, int length),
- int (*compare_function)(const void *, const void *, int length));
-
-/* Print statistics on BCACHE's memory usage and efficacity at
- eliminating duplication. TYPE should be a string describing the
- kind of data BCACHE holds. Statistics are printed using
- `printf_filtered' and its ilk. */
-extern void print_bcache_statistics (struct bcache *bcache, const char *type);
-extern int bcache_memory_used (struct bcache *bcache);
-
-/* The hash functions */
-extern unsigned long hash(const void *addr, int length);
-extern unsigned long hash_continue (const void *addr, int length,
- unsigned long h);
+namespace gdb {
+
+struct bstring;
+
+struct bcache
+{
+ virtual ~bcache ();
+
+ /* Find a copy of the LENGTH bytes at ADDR in BCACHE. If BCACHE has
+ never seen those bytes before, add a copy of them to BCACHE. In
+ either case, return a pointer to BCACHE's copy of that string.
+ Since the cached value is meant to be read-only, return a const
+ buffer. If ADDED is not NULL, set *ADDED to true if the bytes
+ were newly added to the cache, or to false if the bytes were
+ found in the cache. */
+
+ const void *insert (const void *addr, int length, bool *added = nullptr);
+
+ /* Print statistics on this bcache's memory usage and efficacity at
+ eliminating duplication. TYPE should be a string describing the
+ kind of data this bcache holds. Statistics are printed using
+ `gdb_printf' and its ilk. */
+ void print_statistics (const char *type);
+ int memory_used ();
+
+protected:
+
+ /* Hash function to be used for this bcache object. Defaults to
+ fast_hash. */
+ virtual unsigned long hash (const void *addr, int length);
+
+ /* Compare function to be used for this bcache object. Defaults to
+ memcmp. */
+ virtual int compare (const void *left, const void *right, int length);
+
+private:
+
+ /* All the bstrings are allocated here. */
+ struct obstack m_cache {};
+
+ /* How many hash buckets we're using. */
+ unsigned int m_num_buckets = 0;
+
+ /* Hash buckets. This table is allocated using malloc, so when we
+ grow the table we can return the old table to the system. */
+ struct bstring **m_bucket = nullptr;
+
+ /* Statistics. */
+ unsigned long m_unique_count = 0; /* number of unique strings */
+ long m_total_count = 0; /* total number of strings cached, including dups */
+ long m_unique_size = 0; /* size of unique strings, in bytes */
+ long m_total_size = 0; /* total number of bytes cached, including dups */
+ long m_structure_size = 0; /* total size of bcache, including infrastructure */
+ /* Number of times that the hash table is expanded and hence
+ re-built, and the corresponding number of times that a string is
+ [re]hashed as part of entering it into the expanded table. The
+ total number of hashes can be computed by adding TOTAL_COUNT to
+ expand_hash_count. */
+ unsigned long m_expand_count = 0;
+ unsigned long m_expand_hash_count = 0;
+ /* Number of times that the half-hash compare hit (compare the upper
+ 16 bits of hash values) hit, but the corresponding combined
+ length/data compare missed. */
+ unsigned long m_half_hash_miss_count = 0;
+
+ /* Expand the hash table. */
+ void expand_hash_table ();
+};
+
+} /* namespace gdb */
#endif /* BCACHE_H */
projects / platform / upstream / gdb.git / blobdiff