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addresses #993

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use heaviside function for index_read

git-svn-id: file:///svn/mysql/tokudb-engine/src@5164 c7de825b-a66e-492c-adef-691d508d4ae1
This commit is contained in:
Zardosht Kasheff 2013-04-17 00:01:44 -04:00 committed by Yoni Fogel
parent a099911b21
commit 6589ed4d1d
1 changed files with 171 additions and 35 deletions
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206
storage/tokudb/ha_tokudb.cc
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@ -2540,6 +2540,147 @@ TODO: QQQ maybe need to pass true/1 as last parameter of read_row (this would ma
return END_OF_FILE instead of just NOT_FOUND
*/
//
// This struct is used to copy results from the DB search into local memory.
//
typedef struct dbt_copy_info {
DBT *key;
DBT *val;
int error;
} *DBT_COPY_INFO;
//
// Verify which are supposed to be prefix and not prefix.
//
// Copies the contents of key and val, the returned values from the search in
// the DB, into a DBT_COPY_INFO.
// Parameters:
// [in] key - returned key object from the search in the DB
// [in] val - returned value object from the search in the DB
// [out] extra_f - context information that was passed into the search
// in the appropriate cursor call
// r_h - value returned by heaviside function
//
//
//
//
static void dbt_copy_heavi(DBT const *key, DBT const *val, void *extra_f, int r_h) {
DBT_COPY_INFO info = (DBT_COPY_INFO)extra_f;
int r;
info->key->size = key->size;
info->key->data = malloc(key->size);
if (!info->key->data) { r = errno; goto cleanup; }
info->key->flags = DB_DBT_REALLOC;
if (key->size) memcpy(info->key->data, key->data, key->size);
info->val->size = val->size;
info->val->data = malloc(val->size);
if (!info->val->data) { r = errno; goto cleanup; }
info->val->flags = DB_DBT_REALLOC;
if (val->size) memcpy(info->val->data, val->data, val->size);
r = 0;
cleanup:
info->error = r;
}
//
// context information for the heaviside functions.
// Context information includes data necessary
// to perform comparisons
//
typedef struct heavi_info {
DB *db;
const DBT *key;
} *HEAVI_INFO;
//
// effect:
// heaviside function used for HA_READ_AFTER_KEY.
// to use this heaviside function in ha_read_after_key, use direction>0
// the stored key (in heavi_info) contains a prefix of the columns in the candidate
// keys. only the columns in the stored key will be used for comparison.
//
// parameters:
// [in] key - candidate key in db that is being compared
// [in] value - candidate value, unused
// [in] extra_h - a heavi_info that contains information necessary for
// the comparison
// returns:
// >0 : candidate key > stored key
// <0 : otherwise
// examples:
// columns: (a,b,c,d)
// stored key = (3,4) (only a,b)
// candidate keys have (a,b,c,d)
// (3,2,1,1) < (3,4)
// (3,4,1,1) == (3,4)
// (3,5,1,1) > (3,4)
//
static int after_key_heavi(const DBT *key, const DBT *value, void *extra_h) {
HEAVI_INFO info = (HEAVI_INFO)extra_h;
int cmp = tokudb_prefix_cmp_packed_key(info->db, key, info->key);
return cmp>0 ? 1 : -1;
}
//
// effect:
// heaviside function used for HA_READ_PREFIX_LAST_OR_PREV.
// to use this heaviside function in HA_READ_PREFIX_LAST_OR_PREV, use direction<0
// the stored key (in heavi_info) contains a prefix of the columns in the candidate
// keys. only the columns in the stored key will be used for comparison.
//
// parameters:
// [in] key - candidate key in db that is being compared
// [in] value - candidate value, unused
// [in] extra_h - a heavi_info that contains information necessary for
// the comparison
// returns:
// >0 : candidate key > stored key
// 0 : candidate key == stored key
// <0 : candidate key < stored key
// examples:
// columns: (a,b,c,d)
// stored key = (3,4) (only a,b)
// candidate keys have (a,b,c,d)
// (3,2,1,1) < (3,4)
// (3,4,1,1) == (3,4)
// (3,5,1,1) > (3,4)
//
static int prefix_last_or_prev_heavi(const DBT *key, const DBT *value, void *extra_h) {
HEAVI_INFO info = (HEAVI_INFO)extra_h;
int cmp = tokudb_prefix_cmp_packed_key(info->db, key, info->key);
return cmp;
}
//
// effect:
// heaviside function used for HA_READ_BEFORE_KEY.
// to use this heaviside function in HA_READ_BEFORE_KEY, use direction<0
// the stored key (in heavi_info) contains a prefix of the columns in the candidate
// keys. only the columns in the stored key will be used for comparison.
//
// parameters:
// [in] key - candidate key in db that is being compared
// [in] value - candidate value, unused
// [in] extra_h - a heavi_info that contains information necessary for
// the comparison
// returns:
// <0 : candidate key < stored key
// >0 : otherwise
// examples:
// columns: (a,b,c,d)
// stored key = (3,4) (only a,b)
// candidate keys have (a,b,c,d)
// (3,2,1,1) < (3,4)
// (3,4,1,1) == (3,4)
// (3,5,1,1) > (3,4)
//
static int before_key_heavi(const DBT *key, const DBT *value, void *extra_h) {
HEAVI_INFO info = (HEAVI_INFO)extra_h;
int cmp = tokudb_prefix_cmp_packed_key(info->db, key, info->key);
return (cmp<0) ? -1 : 1;
}
//
// According to InnoDB handlerton: Positions an index cursor to the index
// specified in keynr. Fetches the row if any
@ -2569,6 +2710,12 @@ int ha_tokudb::index_read(uchar * buf, const uchar * key, uint key_len, enum ha_
bzero((void *) &row, sizeof(row));
pack_key(&last_key, active_index, key_buff, key, key_len);
struct dbt_copy_info copy_info; //Needed as part of the smart dbt.
struct heavi_info heavi_info; //Needed for the heaviside function.
copy_info.key = &last_key;
copy_info.val = &row;
heavi_info.db = share->key_file[active_index];
heavi_info.key = &last_key;
switch (find_flag) {
case HA_READ_KEY_EXACT: /* Find first record else error */
error = cursor->c_get(cursor, &last_key, &row, DB_SET_RANGE);
@ -2580,25 +2727,14 @@ int ha_tokudb::index_read(uchar * buf, const uchar * key, uint key_len, enum ha_
}
break;
case HA_READ_AFTER_KEY: /* Find next rec. after key-record */
error = cursor->c_get(cursor, &last_key, &row, DB_SET_RANGE);
if (error == 0) {
DBT orig_key;
pack_key(&orig_key, active_index, key_buff2, key, key_len);
for (;;) {
if (tokudb_prefix_cmp_packed_key(share->key_file[active_index], &orig_key, &last_key) != 0)
break;
error = cursor->c_get(cursor, &last_key, &row, DB_NEXT_NODUP);
if (error != 0)
break;
}
}
error = cursor->c_getf_heavi(cursor, 0, dbt_copy_heavi, &copy_info,
after_key_heavi, &heavi_info, 1);
if (error==0 && copy_info.error!=0) error = copy_info.error;
break;
case HA_READ_BEFORE_KEY: /* Find next rec. before key-record */
error = cursor->c_get(cursor, &last_key, &row, DB_SET_RANGE);
if (error == 0)
error = cursor->c_get(cursor, &last_key, &row, DB_PREV);
else if (error == DB_NOTFOUND)
error = cursor->c_get(cursor, &last_key, &row, DB_LAST);
error = cursor->c_getf_heavi(cursor, 0, dbt_copy_heavi, &copy_info,
before_key_heavi, &heavi_info, -1);
if (error==0 && copy_info.error!=0) error = copy_info.error;
break;
case HA_READ_KEY_OR_NEXT: /* Record or next record */
error = cursor->c_get(cursor, &last_key, &row, DB_SET_RANGE);
@ -2615,24 +2751,9 @@ int ha_tokudb::index_read(uchar * buf, const uchar * key, uint key_len, enum ha_
error = cursor->c_get(cursor, &last_key, &row, DB_LAST);
break;
case HA_READ_PREFIX_LAST_OR_PREV: /* Last or prev key with the same prefix */
error = cursor->c_get(cursor, &last_key, &row, DB_SET_RANGE);
if (error == 0) {
DBT orig_key;
pack_key(&orig_key, active_index, key_buff2, key, key_len);
for (;;) {
if (tokudb_prefix_cmp_packed_key(share->key_file[active_index], &orig_key, &last_key) != 0)
break;
error = cursor->c_get(cursor, &last_key, &row, DB_NEXT_NODUP);
if (error != 0)
break;
}
if (error == 0)
error = cursor->c_get(cursor, &last_key, &row, DB_PREV);
else if (error == DB_NOTFOUND)
error = cursor->c_get(cursor, &last_key, &row, DB_LAST);
}
else if (error == DB_NOTFOUND)
error = cursor->c_get(cursor, &last_key, &row, DB_LAST);
error = cursor->c_getf_heavi(cursor, 0, dbt_copy_heavi, &copy_info,
prefix_last_or_prev_heavi, &heavi_info, -1);
if (error==0 && copy_info.error!=0) error = copy_info.error;
break;
default:
TOKUDB_TRACE("unsupported:%d\n", find_flag);
@ -2643,6 +2764,21 @@ int ha_tokudb::index_read(uchar * buf, const uchar * key, uint key_len, enum ha_
if (error && (tokudb_debug & TOKUDB_DEBUG_ERROR))
TOKUDB_TRACE("error:%d:%d\n", error, find_flag);
cleanup:
//
// Using dbt_copy_heavi (used with c_getf_heavi) will set
// flags==DB_DBT_REALLOC.
// Otherwise, flags will be 0 (which means the DB does memory cleanup).
// We need to clean up our own memory with heaviside functions, since they
// use smart dbts.
//
if (last_key.flags==DB_DBT_REALLOC && last_key.data) {
free(last_key.data);
bzero((void *) &last_key, sizeof(last_key));
}
if (row.flags==DB_DBT_REALLOC && row.data) {
free(row.data);
bzero((void *) &row, sizeof(row));
}
TOKUDB_DBUG_RETURN(error);
}