X-Git-Url: https://pd.if.org/git/?p=nbds;a=blobdiff_plain;f=struct%2Fhashtable.c;h=0e9c57e4fdfb4ce71a477c271bb72a0b85cd72b7;hp=523a29a5fd7664c591809e72fdec314f4ecb9e82;hb=53d171373819e921da8f8648eea236a08ff6a702;hpb=a1fae129c758d7ea83dfdbb5f14ec1df12f0aa34 diff --git a/struct/hashtable.c b/struct/hashtable.c index 523a29a..0e9c57e 100644 --- a/struct/hashtable.c +++ b/struct/hashtable.c @@ -16,19 +16,15 @@ #include "murmur.h" #include "mem.h" #include "struct.h" +#include "nstring.h" -#define GET_PTR(x) ((string_t *)((x) & MASK(48))) // low-order 48 bits is a pointer to a string_t +#define GET_PTR(x) ((nstring_t *)((x) & MASK(48))) // low-order 48 bits is a pointer to a nstring_t typedef struct ht_entry { - uint64_t key; + uint64_t key; // ptr to nstring_t uint64_t value; } entry_t; -typedef struct string { - uint32_t len; - char val[]; -} string_t; - typedef struct hti { volatile entry_t *table; hashtable_t *ht; // parent ht; @@ -49,8 +45,7 @@ static const unsigned ENTRIES_PER_COPY_CHUNK = CACHE_LINE_SIZE/sizeof(entry_t)*2 static const unsigned MIN_SCALE = 4; // min 16 entries (4 buckets) static const unsigned MAX_BUCKETS_TO_PROBE = 250; -static int hti_copy_entry - (hashtable_i_t *ht1, volatile entry_t *e, uint32_t e_key_hash, hashtable_i_t *ht2); +static int hti_copy_entry (hashtable_i_t *ht1, volatile entry_t *e, uint32_t e_key_hash, hashtable_i_t *ht2); // Choose the next bucket to probe using the high-order bits of . static inline int get_next_ndx(int old_ndx, uint32_t key_hash, int ht_scale) { @@ -67,9 +62,7 @@ static inline int get_next_ndx(int old_ndx, uint32_t key_hash, int ht_scale) { static inline int ht_key_equals (uint64_t a, uint32_t b_hash, const char *b_value, uint32_t b_len) { if ((b_hash >> 16) != (a >> 48)) // high-order 16 bits are from the hash value return FALSE; - const string_t *a_key = GET_PTR(a); - assert(a_key); - return a_key->len == b_len && memcmp(a_key->val, b_value, b_len) == 0; + return ns_cmp_raw(GET_PTR(a), b_value, b_len) == 0; } // Lookup in . @@ -80,8 +73,8 @@ static inline int ht_key_equals (uint64_t a, uint32_t b_hash, const char *b_valu // // Record if the entry being returned is empty. Otherwise the caller will have to waste time with // ht_key_equals() to confirm that it did not lose a race to fill an empty entry. -static volatile entry_t *hti_lookup (hashtable_i_t *hti, uint32_t key_hash, const char *key_val, uint32_t key_len, int *is_empty) { - TRACE("h2", "hti_lookup(key %p in hti %p)", key_val, hti); +static volatile entry_t *hti_lookup (hashtable_i_t *hti, uint32_t key_hash, const char *key_data, uint32_t key_len, int *is_empty) { + TRACE("h2", "hti_lookup(key %p in hti %p)", key_data, hti); *is_empty = 0; // Probe one cache line at a time @@ -97,14 +90,14 @@ static volatile entry_t *hti_lookup (hashtable_i_t *hti, uint32_t key_hash, cons uint64_t e_key = e->key; if (e_key == DOES_NOT_EXIST) { - TRACE("h1", "hti_lookup: entry %p for key \"%s\" is empty", e, GET_PTR(e_key)->val); + TRACE("h1", "hti_lookup: entry %p for key \"%s\" is empty", e, ns_data(GET_PTR(e_key))); *is_empty = 1; // indicate an empty so the caller avoids an expensive ht_key_equals return e; } - if (ht_key_equals(e_key, key_hash, key_val, key_len)) { - TRACE("h1", "hti_lookup: entry %p key \"%s\"", e, GET_PTR(e_key)->val); - TRACE("h2", "hti_lookup: entry key len %llu, value %p", GET_PTR(e_key)->len, e->value); + if (ht_key_equals(e_key, key_hash, key_data, key_len)) { + TRACE("h1", "hti_lookup: entry %p key \"%s\"", e, ns_data(GET_PTR(e_key))); + TRACE("h2", "hti_lookup: entry key len %llu, value %p", ns_len(GET_PTR(e_key)), e->value); return e; } } @@ -216,25 +209,24 @@ static int hti_copy_entry (hashtable_i_t *ht1, volatile entry_t *ht1_e, uint32_t // to be freed. assert(COPIED_VALUE == TAG_VALUE(TOMBSTONE)); if (ht1_e_value == TOMBSTONE) { - TRACE("h1", "hti_copy_entry: entry %p old value was deleted, now freeing key %p", ht1_e, - GET_PTR(ht1_e->key)); + TRACE("h1", "hti_copy_entry: entry %p old value was deleted, now freeing key %p", ht1_e, GET_PTR(ht1_e->key)); nbd_defer_free(GET_PTR(ht1_e->key)); return TRUE; } // Install the key in the new table. uint64_t key = ht1_e->key; - string_t *key_string = GET_PTR(key); + nstring_t *key_string = GET_PTR(key); uint64_t value = STRIP_TAG(ht1_e_value); // We use 0 to indicate that isn't initiallized. Occasionally the will // really be 0 and we will waste time recomputing it. That is rare enough that it is OK. if (key_hash == 0) { - key_hash = murmur32(key_string->val, key_string->len); + key_hash = murmur32(ns_data(key_string), ns_len(key_string)); } int is_empty; - volatile entry_t *ht2_e = hti_lookup(ht2, key_hash, key_string->val, key_string->len, &is_empty); + volatile entry_t *ht2_e = hti_lookup(ht2, key_hash, ns_data(key_string), ns_len(key_string), &is_empty); TRACE("h0", "hti_copy_entry: copy entry %p to entry %p", ht1_e, ht2_e); // it is possible that there is not any room in the new table either @@ -270,7 +262,7 @@ static int hti_copy_entry (hashtable_i_t *ht1, volatile entry_t *ht1_e, uint32_t // Update the count if we were the one that completed the copy. if (old_ht2_e_value == DOES_NOT_EXIST) { - TRACE("h0", "hti_copy_entry: key \"%s\" value %p copied to new entry", key_string->val, value); + TRACE("h0", "hti_copy_entry: key \"%s\" value %p copied to new entry", ns_data(key_string), value); SYNC_ADD(&ht1->count, -1); SYNC_ADD(&ht2->count, 1); return TRUE; @@ -295,16 +287,16 @@ static int hti_copy_entry (hashtable_i_t *ht1, volatile entry_t *ht1_e, uint32_t // real value matches (i.e. not a TOMBSTONE or DOES_NOT_EXIST) as long as is in the table. If // is EXPECT_WHATEVER then skip the test entirely. // -static uint64_t hti_compare_and_set (hashtable_i_t *hti, uint32_t key_hash, const char *key_val, +static uint64_t hti_compare_and_set (hashtable_i_t *hti, uint32_t key_hash, const char *key_data, uint32_t key_len, uint64_t expected, uint64_t new) { - TRACE("h1", "hti_compare_and_set: hti %p key %p", hti, key_val); + TRACE("h1", "hti_compare_and_set: hti %p key %p", hti, key_data); TRACE("h1", "hti_compare_and_set: value %p expect %p", new, expected); assert(hti); assert(new != DOES_NOT_EXIST && !IS_TAGGED(new)); - assert(key_val); + assert(key_data); int is_empty; - volatile entry_t *e = hti_lookup(hti, key_hash, key_val, key_len, &is_empty); + volatile entry_t *e = hti_lookup(hti, key_hash, key_data, key_len, &is_empty); // There is no room for , grow the table and try again. if (e == NULL) { @@ -325,9 +317,7 @@ static uint64_t hti_compare_and_set (hashtable_i_t *hti, uint32_t key_hash, cons return DOES_NOT_EXIST; // Allocate . - string_t *key = nbd_malloc(sizeof(uint32_t) + key_len); - key->len = key_len; - memcpy(key->val, key_val, key_len); + nstring_t *key = ns_alloc(key_data, key_len); // Combine pointer with bits from its hash, CAS it into the table. uint64_t temp = ((uint64_t)(key_hash >> 16) << 48) | (uint64_t)key; @@ -338,12 +328,12 @@ static uint64_t hti_compare_and_set (hashtable_i_t *hti, uint32_t key_hash, cons TRACE("h0", "hti_compare_and_set: lost race to install key %p in entry %p", key, e); TRACE("h0", "hti_compare_and_set: found %p instead of NULL", GET_PTR(e_key), 0); nbd_free(key); - return hti_compare_and_set(hti, key_hash, key_val, key_len, expected, new); // tail-call + return hti_compare_and_set(hti, key_hash, key_data, key_len, expected, new); // tail-call } TRACE("h2", "hti_compare_and_set: installed key %p in entry %p", key, e); } - TRACE("h0", "hti_compare_and_set: entry for key \"%s\" is %p", GET_PTR(e->key)->val, e); + TRACE("h0", "hti_compare_and_set: entry for key \"%s\" is %p", ns_data(GET_PTR(e->key)), e); // If the entry is in the middle of a copy, the copy must be completed first. uint64_t e_value = e->value; @@ -380,7 +370,7 @@ static uint64_t hti_compare_and_set (hashtable_i_t *hti, uint32_t key_hash, cons uint64_t v = SYNC_CAS(&e->value, e_value, new); if (EXPECT_FALSE(v != e_value)) { TRACE("h0", "hti_compare_and_set: value CAS failed; expected %p found %p", e_value, v); - return hti_compare_and_set(hti, key_hash, key_val, key_len, expected, new); // recursive tail-call + return hti_compare_and_set(hti, key_hash, key_data, key_len, expected, new); // recursive tail-call } // The set succeeded. Adjust the value count. @@ -396,18 +386,18 @@ static uint64_t hti_compare_and_set (hashtable_i_t *hti, uint32_t key_hash, cons } // -static uint64_t hti_get (hashtable_i_t *hti, uint32_t key_hash, const char *key_val, uint32_t key_len) { - assert(key_val); +static uint64_t hti_get (hashtable_i_t *hti, uint32_t key_hash, const char *key_data, uint32_t key_len) { + assert(key_data); int is_empty; - volatile entry_t *e = hti_lookup(hti, key_hash, key_val, key_len, &is_empty); + volatile entry_t *e = hti_lookup(hti, key_hash, key_data, key_len, &is_empty); // When hti_lookup() returns NULL it means we hit the reprobe limit while // searching the table. In that case, if a copy is in progress the key // might exist in the copy. if (EXPECT_FALSE(e == NULL)) { if (((volatile hashtable_i_t *)hti)->next != NULL) - return hti_get(hti->next, key_hash, key_val, key_len); // recursive tail-call + return hti_get(hti->next, key_hash, key_data, key_len); // recursive tail-call return DOES_NOT_EXIST; } @@ -423,24 +413,24 @@ static uint64_t hti_get (hashtable_i_t *hti, uint32_t key_hash, const char *key_ SYNC_ADD(&hti->num_entries_copied, 1); } } - return hti_get(((volatile hashtable_i_t *)hti)->next, key_hash, key_val, key_len); // tail-call + return hti_get(((volatile hashtable_i_t *)hti)->next, key_hash, key_data, key_len); // tail-call } return (e_value == TOMBSTONE) ? DOES_NOT_EXIST : e_value; } // -uint64_t ht_get (hashtable_t *ht, const char *key_val, uint32_t key_len) { - return hti_get(*ht, murmur32(key_val, key_len), key_val, key_len); +uint64_t ht_get (hashtable_t *ht, const char *key_data, uint32_t key_len) { + return hti_get(*ht, murmur32(key_data, key_len), key_data, key_len); } // -uint64_t ht_compare_and_set (hashtable_t *ht, const char *key_val, uint32_t key_len, +uint64_t ht_compare_and_set (hashtable_t *ht, const char *key_data, uint32_t key_len, uint64_t expected_val, uint64_t new_val) { - TRACE("h2", "ht_compare_and_set: key %p len %u", key_val, key_len); + TRACE("h2", "ht_compare_and_set: key %p len %u", key_data, key_len); TRACE("h2", "ht_compare_and_set: expected val %p new val %p", expected_val, new_val); - assert(key_val); + assert(key_data); assert(!IS_TAGGED(new_val) && new_val != DOES_NOT_EXIST); hashtable_i_t *hti = *ht; @@ -492,8 +482,8 @@ uint64_t ht_compare_and_set (hashtable_t *ht, const char *key_val, uint32_t key_ } uint64_t old_val; - uint32_t key_hash = murmur32(key_val, key_len); - while ((old_val = hti_compare_and_set(hti, key_hash, key_val, key_len, expected_val, new_val)) + uint32_t key_hash = murmur32(key_data, key_len); + while ((old_val = hti_compare_and_set(hti, key_hash, key_data, key_len, expected_val, new_val)) == COPIED_VALUE) { assert(hti->next); hti = hti->next; @@ -502,14 +492,14 @@ uint64_t ht_compare_and_set (hashtable_t *ht, const char *key_val, uint32_t key_ return old_val == TOMBSTONE ? DOES_NOT_EXIST : old_val; } -// Remove the value in associated with . Returns the value removed, or +// Remove the value in associated with . Returns the value removed, or // DOES_NOT_EXIST if there was no value for that key. -uint64_t ht_remove (hashtable_t *ht, const char *key_val, uint32_t key_len) { +uint64_t ht_remove (hashtable_t *ht, const char *key_data, uint32_t key_len) { hashtable_i_t *hti = *ht; uint64_t val; - uint32_t key_hash = murmur32(key_val, key_len); + uint32_t key_hash = murmur32(key_data, key_len); do { - val = hti_compare_and_set(hti, key_hash, key_val, key_len, EXPECT_WHATEVER, TOMBSTONE); + val = hti_compare_and_set(hti, key_hash, key_data, key_len, EXPECT_WHATEVER, TOMBSTONE); if (val != COPIED_VALUE) return val == TOMBSTONE ? DOES_NOT_EXIST : val; assert(hti->next);