diff options
Diffstat (limited to 'src/gdbmdefs.h')
| -rw-r--r-- | src/gdbmdefs.h | 59 |
1 files changed, 45 insertions, 14 deletions
diff --git a/src/gdbmdefs.h b/src/gdbmdefs.h index 1ab4abb..c6df13d 100644 --- a/src/gdbmdefs.h +++ b/src/gdbmdefs.h @@ -142,13 +142,35 @@ typedef struct int elem_loc; } data_cache_elem; -typedef struct +typedef struct cache_elem cache_elem; +typedef struct cache_node cache_node; + +struct cache_node +{ + cache_node *left, *right, *parent; + int color; + off_t adr; + cache_elem *elem; +}; + +struct cache_elem { - hash_bucket * ca_bucket; off_t ca_adr; - char ca_changed; /* Data in the bucket changed. */ - data_cache_elem ca_data; -} cache_elem; + char ca_changed; /* Data in the bucket changed. */ + data_cache_elem ca_data; /* Cached datum */ + cache_elem *ca_prev, /* Previous element in LRU list. */ + *ca_next; /* Next elements in LRU list. + If the item is in cache_avail list, only + ca_next is used. It points to the next + available element. */ + size_t ca_hits; /* Number of times this element was requested */ + cache_node *ca_node; /* Points back to the RBT node for this + element. */ + hash_bucket ca_bucket[1];/* Associated bucket (dbf->header->bucket_size + bytes). */ +}; + +typedef struct cache_tree cache_tree; /* This final structure contains all main memory based information for a gdbm file. This allows multiple gdbm files to be opened at the same @@ -184,7 +206,7 @@ struct gdbm_file_info /* Last error was fatal, the database needs recovery */ unsigned need_recovery :1; - + /* Last GDBM error number */ gdbm_error last_error; /* Last system error number */ @@ -210,19 +232,28 @@ struct gdbm_file_info off_t *dir; /* The bucket cache. */ - cache_elem *bucket_cache; - size_t cache_size; - size_t last_read; - + size_t cache_size; /* Cache capacity */ + size_t cache_num; /* Actual number of elements in cache */ + /* Cache elements form a binary search tree. */ + cache_tree *cache_tree; + /* Cache elements are linked in a list sorted by relative access time */ + cache_elem *cache_mru; /* Most recently used element - head of the list */ + cache_elem *cache_lru; /* Last recently used element - tail of the list */ + cache_elem *cache_avail; /* Pool of available elements (linked by prev, next) + */ + /* Pointer to the current bucket's cache entry. */ + cache_elem *cache_entry; + /* Points to the current hash bucket in the cache. */ hash_bucket *bucket; - + /* The directory entry used to get the current hash bucket. */ int bucket_dir; - /* Pointer to the current bucket's cache entry. */ - cache_elem *cache_entry; - + /* Cache statistics */ + size_t cache_access_count; /* Number of cache accesses */ + size_t cache_hits; /* Number of cache hits */ + /* Bookkeeping of things that need to be written back at the end of an update. */ unsigned header_changed :1; |