Global dedupe work in progress.

This commit is contained in:
Moinak Ghosh 2013-02-14 23:10:53 +05:30
parent 1eae57c8a2
commit 24d62bfde9
5 changed files with 104 additions and 12 deletions

View file

@ -176,7 +176,7 @@ read_config(char *configfile, archive_config_t *cfg)
cfg->verify_chunks = 0;
cfg->algo = COMPRESS_LZ4;
cfg->chunk_cksum_type = DEFAULT_CKSUM;
cfg->similarity_interval = DEFAULT_SIMILARITY_INTERVAL;
cfg->pct_interval = DEFAULT_SIMILARITY_INTERVAL;
fh = fopen(configfile, "r");
if (fh == NULL) {
@ -286,6 +286,7 @@ read_config(char *configfile, archive_config_t *cfg)
cfg->directory_levels = 3;
}
cfg->segment_sz_bytes = segment_sz_bytes;
cfg->segment_sz = segment_sz_bytes / cfg->chunk_sz_bytes;
total_dirs = 1;
@ -329,8 +330,8 @@ write_config(char *configfile, archive_config_t *cfg)
}
int
set_simple_config(archive_config_t *cfg, compress_algo_t algo, cksum_t ck, uint32_t chunksize,
size_t file_sz, uint32_t chunks_per_seg)
set_config_s(archive_config_t *cfg, compress_algo_t algo, cksum_t ck, uint32_t chunksize,
size_t file_sz, int pct_interval)
{
cfg->algo = algo;
cfg->chunk_cksum_type = ck;
@ -338,6 +339,7 @@ set_simple_config(archive_config_t *cfg, compress_algo_t algo, cksum_t ck, uint3
cfg->chunk_cksum_sz = get_cksum_sz(cfg->chunk_cksum_type);
cfg->chunk_sz = chunksize;
cfg->chunk_sz_bytes = RAB_BLK_AVG_SZ(cfg->chunk_sz);
cfg->pct_interval = pct_interval;
cfg->archive_sz = file_sz;
if (cfg->archive_sz < ONE_TB) {
@ -346,5 +348,10 @@ set_simple_config(archive_config_t *cfg, compress_algo_t algo, cksum_t ck, uint3
} else {
segment_sz_bytes = EIGHT_MB;
}
cfg->segment_sz_bytes = segment_sz_bytes;
cfg->segment_sz = segment_sz_bytes / cfg->chunk_sz_bytes;
return (0);
}

View file

@ -46,22 +46,24 @@ typedef struct {
compress_algo_t compress_level; // Default preset compression level per algo.
cksum_t chunk_cksum_type; // Which digest to use for hash based chunk lookup.
int chunk_cksum_sz; // Size of cksum in bytes.
int similarity_interval; // Similarity based match intervals in %age.
int pct_interval; // Similarity based match intervals in %age.
// The items below are computed given the above
// components.
uint32_t chunk_sz_bytes; // Average chunk size
uint32_t segment_sz; // Number of chunks
uint32_t segment_sz_bytes; // Segment size in bytes
uint32_t segment_sz; // Number of chunks in one segment
uint32_t container_sz; // Number of segments
int directory_fanout; // Number of subdirectories in a directory
int directory_levels; // Levels of nested directories
int num_containers; // Number of containers in a directory
void *dbdata;
} archive_config_t;
int read_config(char *configfile, archive_config_t *cfg);
int write_config(char *configfile, archive_config_t *cfg);
int set_simple_config(archive_config_t *cfg, compress_algo_t algo, cksum_t ck,
uint32_t chunksize, size_t file_sz, uint32_t chunks_per_seg);
int set_config_s(archive_config_t *cfg, compress_algo_t algo, cksum_t ck,
uint32_t chunksize, size_t file_sz, int pct_interval);
#ifdef __cplusplus
}

View file

@ -28,7 +28,8 @@
#include <stdio.h>
#include <errno.h>
#include <utils.h>
#include <config.h>
#include <allocator.h>
#include <pthread.h>
#include "initdb.h"
#include "config.h"
@ -38,6 +39,28 @@
#define FOUR_MB (4194304ULL)
#define EIGHT_MB (8388608ULL)
/*
* Hashtable structures for in-memory index.
*/
typedef struct _hash_entry {
uchar_t *cksum;
struct _hash_entry *next;
struct _hash_entry *lru_prev;
struct _hash_entry *lru_next;
} hash_entry_t;
typedef struct {
hash_entry_t **htab;
} htab_t;
typedef struct {
htab_t *htablst;
pthread_mutex_t *mlist;
hash_entry_t *lru_head;
hash_entry_t *lru_tail;
uint64_t memlimit;
uint64_t memused;
} htablst_t;
archive_config_t *
init_global_db(char *configfile)
@ -59,12 +82,67 @@ init_global_db(char *configfile)
}
archive_config_t *
init_global_db_simple(char *path, uint32_t chunksize, uint32_t chunks_per_seg,
init_global_db_s(char *path, uint32_t chunksize, int pct_interval,
compress_algo_t algo, cksum_t ck, size_t file_sz, size_t memlimit)
{
archive_config_t *cfg;
int rv;
float diff;
cfg = calloc(1, sizeof (archive_config_t));
rv = set_simple_config(cfg, algo, ck, chunksize, file_sz, chunks_per_seg);
rv = set_config_s(cfg, algo, ck, chunksize, file_sz, chunks_per_seg, pct_interval);
if (path != NULL) {
printf("Disk based index not yet implemented.\n");
free(cfg);
return (NULL);
} else {
uint32_t hash_slots, intervals, i;
uint64_t memreqd;
htablst_t *htablst;
// Compute total hashtable entries first
intervals = 100 / pct_interval - 1;
hash_slots = file_sz / cfg->segment_sz_bytes + 1;
hash_slots *= intervals;
// Compute memory required to hold all hash entries assuming worst case 50%
// occupancy.
memreqd = hash_slots * (sizeof (hash_entry_t) + cfg->chunk_cksum_sz +
sizeof (hash_entry_t *) + (sizeof (hash_entry_t *)) / 2);
memreqd += hash_slots * sizeof (hash_entry_t **);
diff = (float)pct_interval / 100.0;
// Reduce hash_slots to remain within memlimit
while (memreqd > memlimit) {
hash_slots -= (hash_slots * diff);
memreqd = hash_slots * (sizeof (hash_entry_t) +
cfg->chunk_cksum_sz + sizeof (hash_entry_t *) +
(sizeof (hash_entry_t *)) / 2);
memreqd += hash_slots * sizeof (hash_entry_t **);
}
// Now create as many hash tables as there are similarity match intervals
// each having hash_slots / intervals slots.
htablst = calloc(1, sizeof (htablst_t));
htablst->memlimit = memlimit;
htablst->htablst = (htab_t *)calloc(intervals, sizeof (htab_t));
htablst->mlist = (pthread_mutex_t *)malloc(intervals * sizeof (pthread_mutex_t));
for (i = 0; i < intervals; i++) {
htablst->htablst[i].htab = (hash_entry_t **)calloc(hash_slots / intervals,
sizeof (hash_entry_t *));
htablst->memused += ((hash_slots / intervals) * (sizeof (hash_entry_t *)));
pthread_mutex_init(&(htablst->mlist[i]), NULL);
}
cfg->dbdata = htablst;
slab_cache_add(sizeof (hash_entry_t));
slab_cache_add(cfg->chunk_cksum_sz);
}
return (cfg);
}
int
db_insert_s(archive_config_t *cfg, uchar_t *cksum, int interval_num)
{
}

View file

@ -26,8 +26,8 @@ extern "C" {
#endif
archive_config_t *init_global_db(char *configfile);
archive_config_t *init_global_db_simple(char *path, uint32_t chunksize, uint32_t chunks_per_seg,
compress_algo_t algo, cksum_t ck, size_t file_sz, size_t memlimit)
archive_config_t *init_global_db_s(char *path, uint32_t chunksize, int pct_interval,
compress_algo_t algo, cksum_t ck, size_t file_sz, size_t memlimit);
#ifdef __cplusplus
}

View file

@ -149,6 +149,11 @@ typedef struct rab_blockentry {
struct rab_blockentry *next;
} rabin_blockentry_t;
typedef struct global_blockentry {
uint64_t offset;
uint32_t length;
} global_blockentry_t;
typedef struct {
unsigned char *current_window_data;
rabin_blockentry_t **blocks;