1
0
forked from aniani/vim

updated for version 7.3.143

Problem:    Memfile is not tested sufficiently.  Looking up blocks in a
            memfile is slow when there are many blocks.
Solution:   Add high level test and unittest.  Adjust the number of hash
            buckets to the number of blocks.  (Ivan Krasilnikov)
This commit is contained in:
Bram Moolenaar
2011-03-22 18:10:45 +01:00
parent cab49dff91
commit b05b10a3c0
11 changed files with 382 additions and 128 deletions

View File

@@ -377,6 +377,35 @@ typedef struct block_hdr bhdr_T;
typedef struct memfile memfile_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.
*
@@ -394,11 +423,11 @@ typedef long blocknr_T;
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 */
bhdr_T *bh_hash_next; /* next block_hdr in hash list */
bhdr_T *bh_hash_prev; /* previous block_hdr in hash list */
blocknr_T bh_bnum; /* block number */
char_u *bh_data; /* pointer to memory (for used block) */
int bh_page_count; /* number of pages in this block */
@@ -417,9 +446,9 @@ typedef struct nr_trans NR_TRANS;
struct nr_trans
{
NR_TRANS *nt_next; /* next nr_trans in hash list */
NR_TRANS *nt_prev; /* previous nr_trans in hash list */
blocknr_T nt_old_bnum; /* old, negative, number */
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 */
};
@@ -499,12 +528,6 @@ typedef struct
typedef struct file_buffer buf_T; /* forward declaration */
/*
* Simplistic hashing scheme to quickly locate the blocks in the used list.
* 64 blocks are found directly (64 * 4K = 256K, most files are smaller).
*/
#define MEMHASHSIZE 64
#define MEMHASH(nr) ((nr) & (MEMHASHSIZE - 1))
#define MF_SEED_LEN 8
struct memfile
@@ -517,8 +540,8 @@ struct memfile
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 */
bhdr_T *mf_hash[MEMHASHSIZE]; /* array of hash lists */
NR_TRANS *mf_trans[MEMHASHSIZE]; /* array of trans lists */
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 */