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nginx-unit/src/nxt_lvlhsh.c
Alejandro Colomar 952bcc50bf Fixed #define style. 
We had a mix of styles for declaring function-like macros:

Style A:
 #define                    \
 foo()                      \
     do {                   \
         ...                \
     } while (0)

Style B:
 #define foo()              \
     do {                   \
         ...                \
     } while (0)

We had a similar number of occurences of each style:

 $ grep -rnI '^\w*(.*\\' | wc -l
 244
 $ grep -rn 'define.*(.*)' | wc -l
 239

(Those regexes aren't perfect, but a very decent approximation.)

Real examples:

 $ find src -type f | xargs sed -n '/^nxt_double_is_zero/,/^$/p'
 nxt_double_is_zero(f)                                                         \
     (fabs(f) <= FLT_EPSILON)

 $ find src -type f | xargs sed -n '/define nxt_http_field_set/,/^$/p'
 #define nxt_http_field_set(_field, _name, _value)                             \
     do {                                                                      \
         (_field)->name_length = nxt_length(_name);                            \
         (_field)->value_length = nxt_length(_value);                          \
         (_field)->name = (u_char *) _name;                                    \
         (_field)->value = (u_char *) _value;                                  \
     } while (0)

I'd like to standardize on a single style for them, and IMO,
having the identifier in the same line as #define is a better
option for the following reasons:

- Programmers are used to `#define foo() ...` (readability).
- One less line of code.
- The program for finding them is really simple (see below).

 function grep_ngx_func()
 {
     if (($# != 1)); then
         >&2 echo "Usage: ${FUNCNAME[0]} <func>";
         return 1;
     fi;

     find src -type f \
     | grep '\.[ch]$' \
     | xargs grep -l "$1" \
     | sort \
     | xargs pcregrep -Mn "(?s)^\$[\w\s*]+?^$1\(.*?^}";

     find src -type f \
     | grep '\.[ch]$' \
     | xargs grep -l "$1" \
     | sort \
     | xargs pcregrep -Mn "(?s)define $1\(.*?^$" \
     | sed -E '1s/^[^:]+:[0-9]+:/&\n\n/';
 }

 $ grep_ngx_func
 Usage: grep_ngx_func <func>

 $ grep_ngx_func nxt_http_field_set
 src/nxt_http.h:98:

 #define nxt_http_field_set(_field, _name, _value)                             \
     do {                                                                      \
         (_field)->name_length = nxt_length(_name);                            \
         (_field)->value_length = nxt_length(_value);                          \
         (_field)->name = (u_char *) _name;                                    \
         (_field)->value = (u_char *) _value;                                  \
     } while (0)

 $ grep_ngx_func nxt_sprintf
 src/nxt_sprintf.c:56:

 u_char * nxt_cdecl
 nxt_sprintf(u_char *buf, u_char *end, const char *fmt, ...)
 {
     u_char   *p;
     va_list  args;

     va_start(args, fmt);
     p = nxt_vsprintf(buf, end, fmt, args);
     va_end(args);

     return p;
 }

................
Scripted change:
................

$ find src -type f \
  | grep '\.[ch]$' \
  | xargs sed -i '/define *\\$/{N;s/ *\\\n/ /;s/        //}'
2022-05-03 12:11:14 +02:00

995 lines
25 KiB
C
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/*
* Copyright (C) Igor Sysoev
* Copyright (C) NGINX, Inc.
*/
#include <nxt_main.h>
/*
* The level hash consists of hierarchical levels of arrays of pointers.
* The pointers may point to another level, a bucket, or NULL.
* The levels and buckets must be allocated in manner alike posix_memalign()
* to bookkeep additional information in pointer low bits.
*
* A level is an array of pointers. Its size is a power of 2. Levels
* may be different sizes, but on the same level the sizes are the same.
* Level sizes are specified by number of bits per level in lvlhsh->shift
* array. A hash may have up to 7 levels. There are two predefined
* shift arrays given by the first two shift array values:
*
* 1) [0, 0]: [4, 4, 4, 4, 4, 4, 4] on a 64-bit platform or
* [5, 5, 5, 5, 5, 5, 0] on a 32-bit platform,
* so default size of levels is 128 bytes.
*
* 2) [0, 10]: [10, 4, 4, 4, 4, 4, 0] on a 64-bit platform or
* [10, 5, 5, 5, 5, 0, 0] on a 32-bit platform,
* so default size of levels is 128 bytes on all levels except
* the first level. The first level is 8K or 4K on 64-bit or 32-bit
* platforms respectively.
*
* All buckets in a hash are the same size which is a power of 2.
* A bucket contains several entries stored and tested sequentially.
* The bucket size should be one or two CPU cache line size, a minimum
* allowed size is 32 bytes. A default 128-byte bucket contains 10 64-bit
* entries or 15 32-bit entries. Each entry consists of pointer to value
* data and 32-bit key. If an entry value pointer is NULL, the entry is free.
* On a 64-bit platform entry value pointers are no aligned, therefore they
* are accessed as two 32-bit integers. The rest trailing space in a bucket
* is used as pointer to next bucket and this pointer is always aligned.
* Although the level hash allows to store a lot of values in a bucket chain,
* this is non optimal way. The large data set should be stored using
* several levels.
*/
#define nxt_lvlhsh_is_bucket(p) \
((uintptr_t) (p) & 1)
#define nxt_lvlhsh_count_inc(n) \
n = (void *) ((uintptr_t) (n) + 2)
#define nxt_lvlhsh_count_dec(n) \
n = (void *) ((uintptr_t) (n) - 2)
#define nxt_lvlhsh_level_size(proto, nlvl) \
((uintptr_t) 1 << proto->shift[nlvl])
#define nxt_lvlhsh_level(lvl, mask) \
(void **) ((uintptr_t) lvl & (~mask << 2))
#define nxt_lvlhsh_level_entries(lvl, mask) \
((uintptr_t) lvl & (mask << 1))
#define nxt_lvlhsh_store_bucket(slot, bkt) \
slot = (void **) ((uintptr_t) bkt | 2 | 1)
#define nxt_lvlhsh_bucket_size(proto) \
proto->bucket_size
#define nxt_lvlhsh_bucket(proto, bkt) \
(uint32_t *) ((uintptr_t) bkt & ~(uintptr_t) proto->bucket_mask)
#define nxt_lvlhsh_bucket_entries(proto, bkt) \
(((uintptr_t) bkt & (uintptr_t) proto->bucket_mask) >> 1)
#define nxt_lvlhsh_bucket_end(proto, bkt) \
&bkt[proto->bucket_end]
#define nxt_lvlhsh_free_entry(e) \
(!(nxt_lvlhsh_valid_entry(e)))
#define nxt_lvlhsh_next_bucket(proto, bkt) \
((void **) &bkt[proto->bucket_end])
#if (NXT_64BIT)
#define nxt_lvlhsh_valid_entry(e) \
(((e)[0] | (e)[1]) != 0)
#define nxt_lvlhsh_entry_value(e) \
(void *) (((uintptr_t) (e)[1] << 32) + (e)[0])
#define nxt_lvlhsh_set_entry_value(e, n) \
(e)[0] = (uint32_t) (uintptr_t) n; \
(e)[1] = (uint32_t) ((uintptr_t) n >> 32)
#define nxt_lvlhsh_entry_key(e) \
(e)[2]
#define nxt_lvlhsh_set_entry_key(e, n) \
(e)[2] = n
#else
#define nxt_lvlhsh_valid_entry(e) \
((e)[0] != 0)
#define nxt_lvlhsh_entry_value(e) \
(void *) (e)[0]
#define nxt_lvlhsh_set_entry_value(e, n) \
(e)[0] = (uint32_t) n
#define nxt_lvlhsh_entry_key(e) \
(e)[1]
#define nxt_lvlhsh_set_entry_key(e, n) \
(e)[1] = n
#endif
#define NXT_LVLHSH_BUCKET_DONE ((void *) -1)
typedef struct {
const nxt_lvlhsh_proto_t *proto;
void *pool;
uint32_t retrieve; /* 1 bit */
} nxt_lvlhsh_peek_t;
static nxt_int_t nxt_lvlhsh_level_find(nxt_lvlhsh_query_t *lhq, void **lvl,
uint32_t key, nxt_uint_t nlvl);
static nxt_int_t nxt_lvlhsh_bucket_find(nxt_lvlhsh_query_t *lhq, void **bkt);
static nxt_int_t nxt_lvlhsh_new_bucket(nxt_lvlhsh_query_t *lhq, void **slot);
static nxt_int_t nxt_lvlhsh_level_insert(nxt_lvlhsh_query_t *lhq,
void **slot, uint32_t key, nxt_uint_t nlvl);
static nxt_int_t nxt_lvlhsh_bucket_insert(nxt_lvlhsh_query_t *lhq,
void **slot, uint32_t key, nxt_int_t nlvl);
static nxt_int_t nxt_lvlhsh_convert_bucket_to_level(nxt_lvlhsh_query_t *lhq,
void **slot, nxt_uint_t nlvl, uint32_t *bucket);
static nxt_int_t nxt_lvlhsh_level_convertion_insert(nxt_lvlhsh_query_t *lhq,
void **parent, uint32_t key, nxt_uint_t nlvl);
static nxt_int_t nxt_lvlhsh_bucket_convertion_insert(nxt_lvlhsh_query_t *lhq,
void **slot, uint32_t key, nxt_int_t nlvl);
static nxt_int_t nxt_lvlhsh_free_level(nxt_lvlhsh_query_t *lhq, void **level,
nxt_uint_t size);
static nxt_int_t nxt_lvlhsh_level_delete(nxt_lvlhsh_query_t *lhq, void **slot,
uint32_t key, nxt_uint_t nlvl);
static nxt_int_t nxt_lvlhsh_bucket_delete(nxt_lvlhsh_query_t *lhq, void **bkt);
static void *nxt_lvlhsh_level_each(nxt_lvlhsh_each_t *lhe, void **level,
nxt_uint_t nlvl, nxt_uint_t shift);
static void *nxt_lvlhsh_bucket_each(nxt_lvlhsh_each_t *lhe);
static void *nxt_lvlhsh_level_peek(nxt_lvlhsh_peek_t *peek, void **level,
nxt_uint_t nlvl);
static void *nxt_lvlhsh_bucket_peek(nxt_lvlhsh_peek_t *peek, void **bkt);
nxt_int_t
nxt_lvlhsh_find(nxt_lvlhsh_t *lh, nxt_lvlhsh_query_t *lhq)
{
void *slot;
slot = lh->slot;
if (nxt_fast_path(slot != NULL)) {
if (nxt_lvlhsh_is_bucket(slot)) {
return nxt_lvlhsh_bucket_find(lhq, slot);
}
return nxt_lvlhsh_level_find(lhq, slot, lhq->key_hash, 0);
}
return NXT_DECLINED;
}
static nxt_int_t
nxt_lvlhsh_level_find(nxt_lvlhsh_query_t *lhq, void **lvl, uint32_t key,
nxt_uint_t nlvl)
{
void **slot;
uintptr_t mask;
nxt_uint_t shift;
shift = lhq->proto->shift[nlvl];
mask = ((uintptr_t) 1 << shift) - 1;
lvl = nxt_lvlhsh_level(lvl, mask);
slot = lvl[key & mask];
if (slot != NULL) {
if (nxt_lvlhsh_is_bucket(slot)) {
return nxt_lvlhsh_bucket_find(lhq, slot);
}
return nxt_lvlhsh_level_find(lhq, slot, key >> shift, nlvl + 1);
}
return NXT_DECLINED;
}
static nxt_int_t
nxt_lvlhsh_bucket_find(nxt_lvlhsh_query_t *lhq, void **bkt)
{
void *value;
uint32_t *bucket, *e;
nxt_uint_t n;
do {
bucket = nxt_lvlhsh_bucket(lhq->proto, bkt);
n = nxt_lvlhsh_bucket_entries(lhq->proto, bkt);
e = bucket;
do {
if (nxt_lvlhsh_valid_entry(e)) {
n--;
if (nxt_lvlhsh_entry_key(e) == lhq->key_hash) {
value = nxt_lvlhsh_entry_value(e);
if (lhq->proto->test(lhq, value) == NXT_OK) {
lhq->value = value;
return NXT_OK;
}
}
}
e += NXT_LVLHSH_ENTRY_SIZE;
} while (n != 0);
bkt = *nxt_lvlhsh_next_bucket(lhq->proto, bucket);
} while (bkt != NULL);
return NXT_DECLINED;
}
nxt_int_t
nxt_lvlhsh_insert(nxt_lvlhsh_t *lh, nxt_lvlhsh_query_t *lhq)
{
uint32_t key;
if (nxt_fast_path(lh->slot != NULL)) {
key = lhq->key_hash;
if (nxt_lvlhsh_is_bucket(lh->slot)) {
return nxt_lvlhsh_bucket_insert(lhq, &lh->slot, key, -1);
}
return nxt_lvlhsh_level_insert(lhq, &lh->slot, key, 0);
}
return nxt_lvlhsh_new_bucket(lhq, &lh->slot);
}
static nxt_int_t
nxt_lvlhsh_new_bucket(nxt_lvlhsh_query_t *lhq, void **slot)
{
uint32_t *bucket;
bucket = lhq->proto->alloc(lhq->pool, nxt_lvlhsh_bucket_size(lhq->proto));
if (nxt_fast_path(bucket != NULL)) {
nxt_lvlhsh_set_entry_value(bucket, lhq->value);
nxt_lvlhsh_set_entry_key(bucket, lhq->key_hash);
*nxt_lvlhsh_next_bucket(lhq->proto, bucket) = NULL;
nxt_lvlhsh_store_bucket(*slot, bucket);
return NXT_OK;
}
return NXT_ERROR;
}
static nxt_int_t
nxt_lvlhsh_level_insert(nxt_lvlhsh_query_t *lhq, void **parent, uint32_t key,
nxt_uint_t nlvl)
{
void **slot, **lvl;
nxt_int_t ret;
uintptr_t mask;
nxt_uint_t shift;
shift = lhq->proto->shift[nlvl];
mask = ((uintptr_t) 1 << shift) - 1;
lvl = nxt_lvlhsh_level(*parent, mask);
slot = &lvl[key & mask];
if (*slot != NULL) {
key >>= shift;
if (nxt_lvlhsh_is_bucket(*slot)) {
return nxt_lvlhsh_bucket_insert(lhq, slot, key, nlvl);
}
return nxt_lvlhsh_level_insert(lhq, slot, key, nlvl + 1);
}
ret = nxt_lvlhsh_new_bucket(lhq, slot);
if (nxt_fast_path(ret == NXT_OK)) {
nxt_lvlhsh_count_inc(*parent);
}
return ret;
}
static nxt_int_t
nxt_lvlhsh_bucket_insert(nxt_lvlhsh_query_t *lhq, void **slot, uint32_t key,
nxt_int_t nlvl)
{
void **bkt, **vacant_bucket, *value;
uint32_t *bucket, *e, *vacant_entry;
nxt_int_t ret;
uintptr_t n;
const void *new_value;
const nxt_lvlhsh_proto_t *proto;
bkt = slot;
vacant_entry = NULL;
vacant_bucket = NULL;
proto = lhq->proto;
/* Search for duplicate entry in bucket chain. */
do {
bucket = nxt_lvlhsh_bucket(proto, *bkt);
n = nxt_lvlhsh_bucket_entries(proto, *bkt);
e = bucket;
do {
if (nxt_lvlhsh_valid_entry(e)) {
if (nxt_lvlhsh_entry_key(e) == lhq->key_hash) {
value = nxt_lvlhsh_entry_value(e);
if (proto->test(lhq, value) == NXT_OK) {
new_value = lhq->value;
lhq->value = value;
if (lhq->replace) {
nxt_lvlhsh_set_entry_value(e, new_value);
return NXT_OK;
}
return NXT_DECLINED;
}
}
n--;
} else {
/*
* Save a hole vacant position in bucket
* and continue to search for duplicate entry.
*/
if (vacant_entry == NULL) {
vacant_entry = e;
vacant_bucket = bkt;
}
}
e += NXT_LVLHSH_ENTRY_SIZE;
} while (n != 0);
if (e < nxt_lvlhsh_bucket_end(proto, bucket)) {
/*
* Save a vacant position on incomplete bucket's end
* and continue to search for duplicate entry.
*/
if (vacant_entry == NULL) {
vacant_entry = e;
vacant_bucket = bkt;
}
}
bkt = nxt_lvlhsh_next_bucket(proto, bucket);
} while (*bkt != NULL);
if (vacant_entry != NULL) {
nxt_lvlhsh_set_entry_value(vacant_entry, lhq->value);
nxt_lvlhsh_set_entry_key(vacant_entry, lhq->key_hash);
nxt_lvlhsh_count_inc(*vacant_bucket);
return NXT_OK;
}
/* All buckets are full. */
nlvl++;
if (nxt_fast_path(proto->shift[nlvl] != 0)) {
ret = nxt_lvlhsh_convert_bucket_to_level(lhq, slot, nlvl, bucket);
if (nxt_fast_path(ret == NXT_OK)) {
return nxt_lvlhsh_level_insert(lhq, slot, key, nlvl);
}
return ret;
}
/* The last allowed level, only buckets may be allocated here. */
return nxt_lvlhsh_new_bucket(lhq, bkt);
}
static nxt_int_t
nxt_lvlhsh_convert_bucket_to_level(nxt_lvlhsh_query_t *lhq, void **slot,
nxt_uint_t nlvl, uint32_t *bucket)
{
void *lvl, **level;
uint32_t *e, *end, key;
nxt_int_t ret;
nxt_uint_t i, shift, size;
nxt_lvlhsh_query_t q;
const nxt_lvlhsh_proto_t *proto;
proto = lhq->proto;
size = nxt_lvlhsh_level_size(proto, nlvl);
lvl = proto->alloc(lhq->pool, size * (sizeof(void *)));
if (nxt_slow_path(lvl == NULL)) {
return NXT_ERROR;
}
nxt_memzero(lvl, size * (sizeof(void *)));
level = lvl;
shift = 0;
for (i = 0; i < nlvl; i++) {
/*
* Using SIMD operations in this trivial loop with maximum
* 8 iterations may increase code size by 170 bytes.
*/
nxt_pragma_loop_disable_vectorization;
shift += proto->shift[i];
}
end = nxt_lvlhsh_bucket_end(proto, bucket);
for (e = bucket; e < end; e += NXT_LVLHSH_ENTRY_SIZE) {
q.proto = proto;
q.pool = lhq->pool;
q.value = nxt_lvlhsh_entry_value(e);
key = nxt_lvlhsh_entry_key(e);
q.key_hash = key;
ret = nxt_lvlhsh_level_convertion_insert(&q, &lvl, key >> shift, nlvl);
if (nxt_slow_path(ret != NXT_OK)) {
return nxt_lvlhsh_free_level(lhq, level, size);
}
}
*slot = lvl;
proto->free(lhq->pool, bucket);
return NXT_OK;
}
static nxt_int_t
nxt_lvlhsh_level_convertion_insert(nxt_lvlhsh_query_t *lhq, void **parent,
uint32_t key, nxt_uint_t nlvl)
{
void **slot, **lvl;
nxt_int_t ret;
uintptr_t mask;
nxt_uint_t shift;
shift = lhq->proto->shift[nlvl];
mask = ((uintptr_t) 1 << shift) - 1;
lvl = nxt_lvlhsh_level(*parent, mask);
slot = &lvl[key & mask];
if (*slot == NULL) {
ret = nxt_lvlhsh_new_bucket(lhq, slot);
if (nxt_fast_path(ret == NXT_OK)) {
nxt_lvlhsh_count_inc(*parent);
}
return ret;
}
/* Only backets can be here. */
return nxt_lvlhsh_bucket_convertion_insert(lhq, slot, key >> shift, nlvl);
}
/*
* The special bucket insertion procedure is required because during
* convertion lhq->key contains garbage values and the test function
* cannot be called. Besides, the procedure can be simpler because
* a new entry is inserted just after occupied entries.
*/
static nxt_int_t
nxt_lvlhsh_bucket_convertion_insert(nxt_lvlhsh_query_t *lhq, void **slot,
uint32_t key, nxt_int_t nlvl)
{
void **bkt;
uint32_t *bucket, *e;
nxt_int_t ret;
uintptr_t n;
const nxt_lvlhsh_proto_t *proto;
bkt = slot;
proto = lhq->proto;
do {
bucket = nxt_lvlhsh_bucket(proto, *bkt);
n = nxt_lvlhsh_bucket_entries(proto, *bkt);
e = bucket + n * NXT_LVLHSH_ENTRY_SIZE;
if (nxt_fast_path(e < nxt_lvlhsh_bucket_end(proto, bucket))) {
nxt_lvlhsh_set_entry_value(e, lhq->value);
nxt_lvlhsh_set_entry_key(e, lhq->key_hash);
nxt_lvlhsh_count_inc(*bkt);
return NXT_OK;
}
bkt = nxt_lvlhsh_next_bucket(proto, bucket);
} while (*bkt != NULL);
/* All buckets are full. */
nlvl++;
if (nxt_fast_path(proto->shift[nlvl] != 0)) {
ret = nxt_lvlhsh_convert_bucket_to_level(lhq, slot, nlvl, bucket);
if (nxt_fast_path(ret == NXT_OK)) {
return nxt_lvlhsh_level_insert(lhq, slot, key, nlvl);
}
return ret;
}
/* The last allowed level, only buckets may be allocated here. */
return nxt_lvlhsh_new_bucket(lhq, bkt);
}
static nxt_int_t
nxt_lvlhsh_free_level(nxt_lvlhsh_query_t *lhq, void **level, nxt_uint_t size)
{
nxt_uint_t i;
const nxt_lvlhsh_proto_t *proto;
proto = lhq->proto;
for (i = 0; i < size; i++) {
if (level[i] != NULL) {
/*
* Chained buckets are not possible here, since even
* in the worst case one bucket cannot be converted
* in two chained buckets but remains the same bucket.
*/
proto->free(lhq->pool, nxt_lvlhsh_bucket(proto, level[i]));
}
}
proto->free(lhq->pool, level);
return NXT_ERROR;
}
nxt_int_t
nxt_lvlhsh_delete(nxt_lvlhsh_t *lh, nxt_lvlhsh_query_t *lhq)
{
if (nxt_fast_path(lh->slot != NULL)) {
if (nxt_lvlhsh_is_bucket(lh->slot)) {
return nxt_lvlhsh_bucket_delete(lhq, &lh->slot);
}
return nxt_lvlhsh_level_delete(lhq, &lh->slot, lhq->key_hash, 0);
}
return NXT_DECLINED;
}
static nxt_int_t
nxt_lvlhsh_level_delete(nxt_lvlhsh_query_t *lhq, void **parent, uint32_t key,
nxt_uint_t nlvl)
{
void **slot, **lvl;
uintptr_t mask;
nxt_int_t ret;
nxt_uint_t shift;
shift = lhq->proto->shift[nlvl];
mask = ((uintptr_t) 1 << shift) - 1;
lvl = nxt_lvlhsh_level(*parent, mask);
slot = &lvl[key & mask];
if (*slot != NULL) {
if (nxt_lvlhsh_is_bucket(*slot)) {
ret = nxt_lvlhsh_bucket_delete(lhq, slot);
} else {
key >>= shift;
ret = nxt_lvlhsh_level_delete(lhq, slot, key, nlvl + 1);
}
if (*slot == NULL) {
nxt_lvlhsh_count_dec(*parent);
if (nxt_lvlhsh_level_entries(*parent, mask) == 0) {
*parent = NULL;
lhq->proto->free(lhq->pool, lvl);
}
}
return ret;
}
return NXT_DECLINED;
}
static nxt_int_t
nxt_lvlhsh_bucket_delete(nxt_lvlhsh_query_t *lhq, void **bkt)
{
void *value;
uint32_t *bucket, *e;
uintptr_t n;
const nxt_lvlhsh_proto_t *proto;
proto = lhq->proto;
do {
bucket = nxt_lvlhsh_bucket(proto, *bkt);
n = nxt_lvlhsh_bucket_entries(proto, *bkt);
e = bucket;
do {
if (nxt_lvlhsh_valid_entry(e)) {
if (nxt_lvlhsh_entry_key(e) == lhq->key_hash) {
value = nxt_lvlhsh_entry_value(e);
if (proto->test(lhq, value) == NXT_OK) {
if (nxt_lvlhsh_bucket_entries(proto, *bkt) == 1) {
*bkt = *nxt_lvlhsh_next_bucket(proto, bucket);
proto->free(lhq->pool, bucket);
} else {
nxt_lvlhsh_count_dec(*bkt);
nxt_lvlhsh_set_entry_value(e, NULL);
}
lhq->value = value;
return NXT_OK;
}
}
n--;
}
e += NXT_LVLHSH_ENTRY_SIZE;
} while (n != 0);
bkt = nxt_lvlhsh_next_bucket(proto, bucket);
} while (*bkt != NULL);
return NXT_DECLINED;
}
void *
nxt_lvlhsh_each(nxt_lvlhsh_t *lh, nxt_lvlhsh_each_t *lhe)
{
void **slot;
if (lhe->bucket == NXT_LVLHSH_BUCKET_DONE) {
slot = lh->slot;
if (nxt_lvlhsh_is_bucket(slot)) {
return NULL;
}
} else {
if (nxt_slow_path(lhe->bucket == NULL)) {
/* The first iteration only. */
slot = lh->slot;
if (slot == NULL) {
return NULL;
}
if (!nxt_lvlhsh_is_bucket(slot)) {
lhe->current = 0;
goto level;
}
lhe->bucket = nxt_lvlhsh_bucket(lhe->proto, slot);
lhe->entries = nxt_lvlhsh_bucket_entries(lhe->proto, slot);
lhe->entry = 0;
}
return nxt_lvlhsh_bucket_each(lhe);
}
level:
return nxt_lvlhsh_level_each(lhe, slot, 0, 0);
}
static void *
nxt_lvlhsh_level_each(nxt_lvlhsh_each_t *lhe, void **level, nxt_uint_t nlvl,
nxt_uint_t shift)
{
void **slot, *value;
uintptr_t mask;
nxt_uint_t n, level_shift;
level_shift = lhe->proto->shift[nlvl];
mask = ((uintptr_t) 1 << level_shift) - 1;
level = nxt_lvlhsh_level(level, mask);
do {
n = (lhe->current >> shift) & mask;
slot = level[n];
if (slot != NULL) {
if (nxt_lvlhsh_is_bucket(slot)) {
if (lhe->bucket != NXT_LVLHSH_BUCKET_DONE) {
lhe->bucket = nxt_lvlhsh_bucket(lhe->proto, slot);
lhe->entries = nxt_lvlhsh_bucket_entries(lhe->proto, slot);
lhe->entry = 0;
return nxt_lvlhsh_bucket_each(lhe);
}
lhe->bucket = NULL;
} else {
value = nxt_lvlhsh_level_each(lhe, slot, nlvl + 1,
shift + level_shift);
if (value != NULL) {
return value;
}
}
}
lhe->current &= ~(mask << shift);
n = ((n + 1) & mask) << shift;
lhe->current |= n;
} while (n != 0);
return NULL;
}
static nxt_noinline void *
nxt_lvlhsh_bucket_each(nxt_lvlhsh_each_t *lhe)
{
void *value, **next;
uint32_t *bucket;
/* At least one valid entry must present here. */
do {
bucket = &lhe->bucket[lhe->entry];
lhe->entry += NXT_LVLHSH_ENTRY_SIZE;
} while (nxt_lvlhsh_free_entry(bucket));
value = nxt_lvlhsh_entry_value(bucket);
lhe->entries--;
if (lhe->entries == 0) {
next = *nxt_lvlhsh_next_bucket(lhe->proto, lhe->bucket);
lhe->bucket = (next == NULL) ? NXT_LVLHSH_BUCKET_DONE
: nxt_lvlhsh_bucket(lhe->proto, next);
lhe->entries = nxt_lvlhsh_bucket_entries(lhe->proto, next);
lhe->entry = 0;
}
return value;
}
void *
nxt_lvlhsh_peek(nxt_lvlhsh_t *lh, const nxt_lvlhsh_proto_t *proto)
{
void **slot;
nxt_lvlhsh_peek_t peek;
slot = lh->slot;
if (slot != NULL) {
peek.proto = proto;
peek.retrieve = 0;
if (nxt_lvlhsh_is_bucket(slot)) {
return nxt_lvlhsh_bucket_peek(&peek, &lh->slot);
}
return nxt_lvlhsh_level_peek(&peek, &lh->slot, 0);
}
return NULL;
}
static void *
nxt_lvlhsh_level_peek(nxt_lvlhsh_peek_t *peek, void **parent, nxt_uint_t nlvl)
{
void **slot, **level, *value;
uintptr_t mask;
nxt_uint_t n, shift;
shift = peek->proto->shift[nlvl];
mask = ((uintptr_t) 1 << shift) - 1;
level = nxt_lvlhsh_level(*parent, mask);
n = 0;
/* At least one valid level slot must present here. */
for ( ;; ) {
slot = &level[n];
if (*slot != NULL) {
if (nxt_lvlhsh_is_bucket(*slot)) {
value = nxt_lvlhsh_bucket_peek(peek, slot);
} else {
value = nxt_lvlhsh_level_peek(peek, slot, nlvl + 1);
}
/*
* Checking peek->retrieve is not required here because
* there can not be empty slots during peeking.
*/
if (*slot == NULL) {
nxt_lvlhsh_count_dec(*parent);
if (nxt_lvlhsh_level_entries(*parent, mask) == 0) {
*parent = NULL;
peek->proto->free(peek->pool, level);
}
}
return value;
}
n++;
}
}
static nxt_noinline void *
nxt_lvlhsh_bucket_peek(nxt_lvlhsh_peek_t *peek, void **bkt)
{
void *value;
uint32_t *bucket, *entry;
const nxt_lvlhsh_proto_t *proto;
bucket = nxt_lvlhsh_bucket(peek->proto, *bkt);
/* At least one valid entry must present here. */
for (entry = bucket;
nxt_lvlhsh_free_entry(entry);
entry += NXT_LVLHSH_ENTRY_SIZE)
{
/* void */
}
value = nxt_lvlhsh_entry_value(entry);
if (peek->retrieve) {
proto = peek->proto;
if (nxt_lvlhsh_bucket_entries(proto, *bkt) == 1) {
*bkt = *nxt_lvlhsh_next_bucket(proto, bucket);
proto->free(peek->pool, bucket);
} else {
nxt_lvlhsh_count_dec(*bkt);
nxt_lvlhsh_set_entry_value(entry, NULL);
}
}
return value;
}
void *
nxt_lvlhsh_retrieve(nxt_lvlhsh_t *lh, const nxt_lvlhsh_proto_t *proto,
void *pool)
{
void **slot;
nxt_lvlhsh_peek_t peek;
slot = lh->slot;
if (slot != NULL) {
peek.proto = proto;
peek.pool = pool;
peek.retrieve = 1;
if (nxt_lvlhsh_is_bucket(slot)) {
return nxt_lvlhsh_bucket_peek(&peek, &lh->slot);
}
return nxt_lvlhsh_level_peek(&peek, &lh->slot, 0);
}
return NULL;
}
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