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#ifndef NEOVIM_MEMFILE_DEFS_H
#define NEOVIM_MEMFILE_DEFS_H
typedef struct block_hdr bhdr_T;
typedef long blocknr_T;
/*
* mf_hashtab_T is a chained hashtable with blocknr_T key and arbitrary
* structures as items. This is an intrusive data structure: we require
* that items begin with mf_hashitem_T which contains the key and linked
* list pointers. List of items in each bucket is doubly-linked.
*/
typedef struct mf_hashitem_S mf_hashitem_T;
struct mf_hashitem_S {
mf_hashitem_T *mhi_next;
mf_hashitem_T *mhi_prev;
blocknr_T mhi_key;
};
#define MHT_INIT_SIZE 64
typedef struct mf_hashtab_S {
long_u mht_mask; /* mask used for hash value (nr of items
* in array is "mht_mask" + 1) */
long_u mht_count; /* nr of items inserted into hashtable */
mf_hashitem_T **mht_buckets; /* points to mht_small_buckets or
*dynamically allocated array */
mf_hashitem_T *mht_small_buckets[MHT_INIT_SIZE]; /* initial buckets */
char mht_fixed; /* non-zero value forbids growth */
} mf_hashtab_T;
/*
* for each (previously) used block in the memfile there is one block header.
*
* The block may be linked in the used list OR in the free list.
* The used blocks are also kept in hash lists.
*
* The used list is a doubly linked list, most recently used block first.
* The blocks in the used list have a block of memory allocated.
* mf_used_count is the number of pages in the used list.
* The hash lists are used to quickly find a block in the used list.
* The free list is a single linked list, not sorted.
* The blocks in the free list have no block of memory allocated and
* the contents of the block in the file (if any) is irrelevant.
*/
struct block_hdr {
mf_hashitem_T bh_hashitem; /* header for hash table and key */
#define bh_bnum bh_hashitem.mhi_key /* block number, part of bh_hashitem */
bhdr_T *bh_next; /* next block_hdr in free or used list */
bhdr_T *bh_prev; /* previous block_hdr in used list */
char_u *bh_data; /* pointer to memory (for used block) */
int bh_page_count; /* number of pages in this block */
#define BH_DIRTY 1
#define BH_LOCKED 2
char bh_flags; /* BH_DIRTY or BH_LOCKED */
};
/*
* when a block with a negative number is flushed to the file, it gets
* a positive number. Because the reference to the block is still the negative
* number, we remember the translation to the new positive number in the
* double linked trans lists. The structure is the same as the hash lists.
*/
typedef struct nr_trans NR_TRANS;
struct nr_trans {
mf_hashitem_T nt_hashitem; /* header for hash table and key */
#define nt_old_bnum nt_hashitem.mhi_key /* old, negative, number */
blocknr_T nt_new_bnum; /* new, positive, number */
};
#define MF_SEED_LEN 8
struct memfile {
char_u *mf_fname; /* name of the file */
char_u *mf_ffname; /* idem, full path */
int mf_fd; /* file descriptor */
bhdr_T *mf_free_first; /* first block_hdr in free list */
bhdr_T *mf_used_first; /* mru block_hdr in used list */
bhdr_T *mf_used_last; /* lru block_hdr in used list */
unsigned mf_used_count; /* number of pages in used list */
unsigned mf_used_count_max; /* maximum number of pages in memory */
mf_hashtab_T mf_hash; /* hash lists */
mf_hashtab_T mf_trans; /* trans lists */
blocknr_T mf_blocknr_max; /* highest positive block number + 1*/
blocknr_T mf_blocknr_min; /* lowest negative block number - 1 */
blocknr_T mf_neg_count; /* number of negative blocks numbers */
blocknr_T mf_infile_count; /* number of pages in the file */
unsigned mf_page_size; /* number of bytes in a page */
int mf_dirty; /* TRUE if there are dirty blocks */
buf_T *mf_buffer; /* bufer this memfile is for */
char_u mf_seed[MF_SEED_LEN]; /* seed for encryption */
/* Values for key, method and seed used for reading data blocks when
* updating for a newly set key or method. Only when mf_old_key != NULL. */
char_u *mf_old_key;
int mf_old_cm;
char_u mf_old_seed[MF_SEED_LEN];
};
#endif // NEOVIM_MEMFILE_DEFS_H
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