Workshop o mikrokontrolérech na SKSP 2024.
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
 
 
 
 
 
 

252 lines
7.3 KiB

/*
* UCW Library -- Universal Sorter: Internal Sorting Module
*
* (c) 2007 Martin Mares <mj@ucw.cz>
*
* This software may be freely distributed and used according to the terms
* of the GNU Lesser General Public License.
*/
#include <ucw/stkstring.h>
#ifdef SORT_INTERNAL_RADIX
/* Keep copies of the items' hashes to save cache misses */
#define SORT_COPY_HASH
#endif
typedef struct {
P(key) *key;
#ifdef SORT_COPY_HASH
P(hash_t) hash;
#endif
} P(internal_item_t);
#define ASORT_PREFIX(x) SORT_PREFIX(array_##x)
#define ASORT_KEY_TYPE P(internal_item_t)
#ifdef SORT_COPY_HASH
# ifdef SORT_INT
# define ASORT_LT(x,y) ((x).hash < (y).hash) // In this mode, the hash is the value
# else
# define ASORT_LT(x,y) ((x).hash < (y).hash || (x).hash == (y).hash && P(compare)((x).key, (y).key) < 0)
# endif
#else
# define ASORT_LT(x,y) (P(compare)((x).key, (y).key) < 0)
#endif
#ifdef SORT_INTERNAL_RADIX
# ifdef SORT_COPY_HASH
# define ASORT_HASH(x) (x).hash
# else
# define ASORT_HASH(x) P(hash)((x).key)
# endif
# ifdef SORT_LONG_HASH
# define ASORT_LONG_HASH
# endif
#endif
#include <ucw/sorter/array.h>
/*
* The big_buf has the following layout:
*
* +-------------------------------------------------------------------------------+
* | array of internal_item's |
* +-------------------------------------------------------------------------------+
* | padding to make the following part page-aligned |
* +--------------------------------+----------------------------------------------+
* | shadow copy of item array | array of pointers to data for write_merged() |
* | used if radix-sorting +----------------------------------------------+
* | | workspace for write_merged() |
* +--------------------------------+----------------------------------------------+
* | +---------+ |
* | | key | |
* | +---------+ |
* | sequence of | padding | |
* | items +---------+ |
* | | data | |
* | +---------+ |
* | | padding | |
* | +---------+ |
* +-------------------------------------------------------------------------------+
*
* (the data which are in different columns are never accessed simultaneously,
* so we use a single buffer for both)
*/
static inline void *P(internal_get_data)(P(key) *key)
{
uint ksize = SORT_KEY_SIZE(*key);
#ifdef SORT_UNIFY
ksize = ALIGN_TO(ksize, CPU_STRUCT_ALIGN);
#endif
return (byte *) key + ksize;
}
static inline size_t P(internal_workspace)(P(key) *key UNUSED)
{
size_t ws = 0;
#ifdef SORT_UNIFY
ws += sizeof(void *);
#endif
#ifdef SORT_UNIFY_WORKSPACE
ws += SORT_UNIFY_WORKSPACE(*key);
#endif
#ifdef SORT_INTERNAL_RADIX
ws = MAX(ws, sizeof(P(internal_item_t)));
#endif
return ws;
}
static int P(internal)(struct sort_context *ctx, struct sort_bucket *bin, struct sort_bucket *bout, struct sort_bucket *bout_only)
{
sorter_alloc_buf(ctx);
struct fastbuf *in = sbuck_read(bin);
P(key) key, *keybuf = ctx->key_buf;
if (!keybuf)
keybuf = ctx->key_buf = sorter_alloc(ctx, sizeof(key));
if (ctx->more_keys)
{
key = *keybuf;
ctx->more_keys = 0;
}
else if (!P(read_key)(in, &key))
return 0;
size_t bufsize = ctx->big_buf_size;
#ifdef SORT_VAR_DATA
if (sizeof(key) + 2*CPU_PAGE_SIZE + SORT_DATA_SIZE(key) + P(internal_workspace)(&key) > bufsize)
{
SORT_XTRACE(4, "s-internal: Generating a giant run");
struct fastbuf *out = sbuck_write(bout);
P(copy_data)(&key, in, out);
bout->runs++;
return 1; // We don't know, but 1 is always safe
}
#endif
SORT_XTRACE(5, "s-internal: Reading");
P(internal_item_t) *item_array = ctx->big_buf, *item = item_array, *last_item;
byte *end = (byte *) ctx->big_buf + bufsize;
size_t remains = bufsize - CPU_PAGE_SIZE;
do
{
uint ksize = SORT_KEY_SIZE(key);
#ifdef SORT_UNIFY
uint ksize_aligned = ALIGN_TO(ksize, CPU_STRUCT_ALIGN);
#else
uint ksize_aligned = ksize;
#endif
uint dsize = SORT_DATA_SIZE(key);
uint recsize = ALIGN_TO(ksize_aligned + dsize, CPU_STRUCT_ALIGN);
size_t totalsize = recsize + sizeof(P(internal_item_t)) + P(internal_workspace)(&key);
if (unlikely(totalsize > remains
#ifdef CPU_64BIT_POINTERS
|| item >= item_array + ~0U // The number of items must fit in an uint
#endif
))
{
ctx->more_keys = 1;
*keybuf = key;
break;
}
remains -= totalsize;
end -= recsize;
memcpy(end, &key, ksize);
#ifdef SORT_VAR_DATA
breadb(in, end + ksize_aligned, dsize);
#endif
item->key = (P(key)*) end;
#ifdef SORT_COPY_HASH
item->hash = P(hash)(item->key);
#endif
item++;
}
while (P(read_key)(in, &key));
last_item = item;
uint count = last_item - item_array;
void *workspace UNUSED = ALIGN_PTR(last_item, CPU_PAGE_SIZE);
SORT_XTRACE(4, "s-internal: Read %u items (%s items, %s workspace, %s data)",
count,
stk_fsize((byte*)last_item - (byte*)item_array),
stk_fsize(end - (byte*)last_item - remains),
stk_fsize((byte*)ctx->big_buf + bufsize - end));
timestamp_t timer;
init_timer(&timer);
item_array = P(array_sort)(item_array, count
#ifdef SORT_INTERNAL_RADIX
, workspace, bin->hash_bits
#endif
);
if ((void *)item_array != ctx->big_buf)
workspace = ctx->big_buf;
last_item = item_array + count;
ctx->total_int_time += get_timer(&timer);
SORT_XTRACE(5, "s-internal: Writing");
if (!ctx->more_keys)
bout = bout_only;
struct fastbuf *out = sbuck_write(bout);
bout->runs++;
uint merged UNUSED = 0;
for (item = item_array; item < last_item; item++)
{
#ifdef SORT_UNIFY
if (item < last_item - 1 && !P(compare)(item->key, item[1].key))
{
// Rewrite the item structures with just pointers to keys and place
// pointers to data in the workspace.
P(key) **key_array = (void *) item;
void **data_array = workspace;
key_array[0] = item[0].key;
data_array[0] = P(internal_get_data)(key_array[0]);
uint cnt;
for (cnt=1; item+cnt < last_item && !P(compare)(key_array[0], item[cnt].key); cnt++)
{
key_array[cnt] = item[cnt].key;
data_array[cnt] = P(internal_get_data)(key_array[cnt]);
}
P(write_merged)(out, key_array, data_array, cnt, data_array+cnt);
item += cnt - 1;
merged += cnt - 1;
continue;
}
#endif
#ifdef SORT_ASSERT_UNIQUE
ASSERT(item == last_item-1 || P(compare)(item->key, item[1].key) < 0);
#endif
P(write_key)(out, item->key);
#ifdef SORT_VAR_DATA
bwrite(out, P(internal_get_data)(item->key), SORT_DATA_SIZE(*item->key));
#endif
}
#ifdef SORT_UNIFY
SORT_XTRACE(4, "Merging reduced %u records", merged);
#endif
return ctx->more_keys;
}
static u64
P(internal_estimate)(struct sort_context *ctx, struct sort_bucket *b UNUSED)
{
// Most of this is just wild guesses
#ifdef SORT_VAR_KEY
uint avg = ALIGN_TO(sizeof(P(key))/4, CPU_STRUCT_ALIGN);
#else
uint avg = ALIGN_TO(sizeof(P(key)), CPU_STRUCT_ALIGN);
#endif
uint ws = 0;
#ifdef SORT_UNIFY
ws += sizeof(void *);
#endif
#ifdef SORT_UNIFY_WORKSPACE
ws += avg;
#endif
#ifdef SORT_INTERNAL_RADIX
ws = MAX(ws, sizeof(P(internal_item_t)));
#endif
// We ignore the data part of records, it probably won't make the estimate much worse
return (ctx->big_buf_size / (avg + ws + sizeof(P(internal_item_t))) * avg);
}
#undef SORT_COPY_HASH