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nghttp2_map backed by nghttp2_ksl

This commit is contained in:
Tatsuhiro Tsujikawa 2020-07-26 14:00:45 +09:00
parent 6089353d52
commit 1ce628529b
5 changed files with 1245 additions and 63 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

6
lib/Makefile.am
View File

@ -49,7 +49,8 @@ OBJECTS = nghttp2_pq.c nghttp2_map.c nghttp2_queue.c \
nghttp2_mem.c \
nghttp2_http.c \
nghttp2_rcbuf.c \
nghttp2_debug.c
nghttp2_debug.c \
nghttp2_ksl.c
HFILES = nghttp2_pq.h nghttp2_int.h nghttp2_map.h nghttp2_queue.h \
nghttp2_frame.h \
@ -65,7 +66,8 @@ HFILES = nghttp2_pq.h nghttp2_int.h nghttp2_map.h nghttp2_queue.h \
nghttp2_mem.h \
nghttp2_http.h \
nghttp2_rcbuf.h \
nghttp2_debug.h
nghttp2_debug.h \
nghttp2_ksl.h
libnghttp2_la_SOURCES = $(HFILES) $(OBJECTS)
libnghttp2_la_LDFLAGS = -no-undefined \

707
lib/nghttp2_ksl.c Normal file
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@ -0,0 +1,707 @@
/*
* nghttp2 - HTTP/2 C Library
*
* Copyright (c) 2020 nghttp2 contributors
* Copyright (c) 2018 ngtcp2 contributors
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#include "nghttp2_ksl.h"
#include <stdlib.h>
#include <string.h>
#include <assert.h>
#include <stdio.h>
#include "nghttp2_mem.h"
static size_t ksl_nodelen(size_t keylen) {
return (sizeof(nghttp2_ksl_node) + keylen - sizeof(uint64_t) + 0xf) &
(size_t)~0xf;
}
static size_t ksl_blklen(size_t nodelen) {
return sizeof(nghttp2_ksl_blk) + nodelen * NGHTTP2_KSL_MAX_NBLK -
sizeof(uint64_t);
}
/*
* ksl_node_set_key sets |key| to |node|.
*/
static void ksl_node_set_key(nghttp2_ksl *ksl, nghttp2_ksl_node *node,
const void *key) {
memcpy(node->key, key, ksl->keylen);
}
int nghttp2_ksl_init(nghttp2_ksl *ksl, nghttp2_ksl_compar compar, size_t keylen,
nghttp2_mem *mem) {
size_t nodelen = ksl_nodelen(keylen);
size_t blklen = ksl_blklen(nodelen);
nghttp2_ksl_blk *head;
ksl->head = nghttp2_mem_malloc(mem, blklen);
if (!ksl->head) {
return NGHTTP2_ERR_NOMEM;
}
ksl->front = ksl->back = ksl->head;
ksl->compar = compar;
ksl->keylen = keylen;
ksl->nodelen = nodelen;
ksl->n = 0;
ksl->mem = mem;
head = ksl->head;
head->next = head->prev = NULL;
head->n = 0;
head->leaf = 1;
return 0;
}
/*
* ksl_free_blk frees |blk| recursively.
*/
static void ksl_free_blk(nghttp2_ksl *ksl, nghttp2_ksl_blk *blk) {
size_t i;
if (!blk->leaf) {
for (i = 0; i < blk->n; ++i) {
ksl_free_blk(ksl, nghttp2_ksl_nth_node(ksl, blk, i)->blk);
}
}
nghttp2_mem_free(ksl->mem, blk);
}
void nghttp2_ksl_free(nghttp2_ksl *ksl) {
if (!ksl) {
return;
}
ksl_free_blk(ksl, ksl->head);
}
/*
* ksl_split_blk splits |blk| into 2 nghttp2_ksl_blk objects. The new
* nghttp2_ksl_blk is always the "right" block.
*
* It returns the pointer to the nghttp2_ksl_blk created which is the
* located at the right of |blk|, or NULL which indicates out of
* memory error.
*/
static nghttp2_ksl_blk *ksl_split_blk(nghttp2_ksl *ksl, nghttp2_ksl_blk *blk) {
nghttp2_ksl_blk *rblk;
rblk = nghttp2_mem_malloc(ksl->mem, ksl_blklen(ksl->nodelen));
if (rblk == NULL) {
return NULL;
}
rblk->next = blk->next;
blk->next = rblk;
if (rblk->next) {
rblk->next->prev = rblk;
} else if (ksl->back == blk) {
ksl->back = rblk;
}
rblk->prev = blk;
rblk->leaf = blk->leaf;
rblk->n = blk->n / 2;
memcpy(rblk->nodes, blk->nodes + ksl->nodelen * (blk->n - rblk->n),
ksl->nodelen * rblk->n);
blk->n -= rblk->n;
assert(blk->n >= NGHTTP2_KSL_MIN_NBLK);
assert(rblk->n >= NGHTTP2_KSL_MIN_NBLK);
return rblk;
}
/*
* ksl_split_node splits a node included in |blk| at the position |i|
* into 2 adjacent nodes. The new node is always inserted at the
* position |i+1|.
*
* It returns 0 if it succeeds, or one of the following negative error
* codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory.
*/
static int ksl_split_node(nghttp2_ksl *ksl, nghttp2_ksl_blk *blk, size_t i) {
nghttp2_ksl_node *node;
nghttp2_ksl_blk *lblk = nghttp2_ksl_nth_node(ksl, blk, i)->blk, *rblk;
rblk = ksl_split_blk(ksl, lblk);
if (rblk == NULL) {
return NGHTTP2_ERR_NOMEM;
}
memmove(blk->nodes + (i + 2) * ksl->nodelen,
blk->nodes + (i + 1) * ksl->nodelen,
ksl->nodelen * (blk->n - (i + 1)));
node = nghttp2_ksl_nth_node(ksl, blk, i + 1);
node->blk = rblk;
++blk->n;
ksl_node_set_key(ksl, node,
nghttp2_ksl_nth_node(ksl, rblk, rblk->n - 1)->key);
node = nghttp2_ksl_nth_node(ksl, blk, i);
ksl_node_set_key(ksl, node,
nghttp2_ksl_nth_node(ksl, lblk, lblk->n - 1)->key);
return 0;
}
/*
* ksl_split_head splits a head (root) block. It increases the height
* of skip list by 1.
*
* It returns 0 if it succeeds, or one of the following negative error
* codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory.
*/
static int ksl_split_head(nghttp2_ksl *ksl) {
nghttp2_ksl_blk *rblk = NULL, *lblk, *nhead = NULL;
nghttp2_ksl_node *node;
rblk = ksl_split_blk(ksl, ksl->head);
if (rblk == NULL) {
return NGHTTP2_ERR_NOMEM;
}
lblk = ksl->head;
nhead = nghttp2_mem_malloc(ksl->mem, ksl_blklen(ksl->nodelen));
if (nhead == NULL) {
nghttp2_mem_free(ksl->mem, rblk);
return NGHTTP2_ERR_NOMEM;
}
nhead->next = nhead->prev = NULL;
nhead->n = 2;
nhead->leaf = 0;
node = nghttp2_ksl_nth_node(ksl, nhead, 0);
ksl_node_set_key(ksl, node,
nghttp2_ksl_nth_node(ksl, lblk, lblk->n - 1)->key);
node->blk = lblk;
node = nghttp2_ksl_nth_node(ksl, nhead, 1);
ksl_node_set_key(ksl, node,
nghttp2_ksl_nth_node(ksl, rblk, rblk->n - 1)->key);
node->blk = rblk;
ksl->head = nhead;
return 0;
}
/*
* insert_node inserts a node whose key is |key| with the associated
* |data| at the index of |i|. This function assumes that the number
* of nodes contained by |blk| is strictly less than
* NGHTTP2_KSL_MAX_NBLK.
*/
static void ksl_insert_node(nghttp2_ksl *ksl, nghttp2_ksl_blk *blk, size_t i,
const nghttp2_ksl_key *key, void *data) {
nghttp2_ksl_node *node;
assert(blk->n < NGHTTP2_KSL_MAX_NBLK);
memmove(blk->nodes + (i + 1) * ksl->nodelen, blk->nodes + i * ksl->nodelen,
ksl->nodelen * (blk->n - i));
node = nghttp2_ksl_nth_node(ksl, blk, i);
ksl_node_set_key(ksl, node, key);
node->data = data;
++blk->n;
}
static size_t ksl_bsearch(nghttp2_ksl *ksl, nghttp2_ksl_blk *blk,
const nghttp2_ksl_key *key,
nghttp2_ksl_compar compar) {
ssize_t left = -1, right = (ssize_t)blk->n, mid;
nghttp2_ksl_node *node;
while (right - left > 1) {
mid = (left + right) / 2;
node = nghttp2_ksl_nth_node(ksl, blk, (size_t)mid);
if (compar((nghttp2_ksl_key *)node->key, key)) {
left = mid;
} else {
right = mid;
}
}
return (size_t)right;
}
int nghttp2_ksl_insert(nghttp2_ksl *ksl, nghttp2_ksl_it *it,
const nghttp2_ksl_key *key, void *data) {
nghttp2_ksl_blk *blk = ksl->head;
nghttp2_ksl_node *node;
size_t i;
int rv;
if (blk->n == NGHTTP2_KSL_MAX_NBLK) {
rv = ksl_split_head(ksl);
if (rv != 0) {
return rv;
}
blk = ksl->head;
}
for (;;) {
i = ksl_bsearch(ksl, blk, key, ksl->compar);
if (blk->leaf) {
if (i < blk->n &&
!ksl->compar(key, nghttp2_ksl_nth_node(ksl, blk, i)->key)) {
if (it) {
*it = nghttp2_ksl_end(ksl);
}
return NGHTTP2_ERR_INVALID_ARGUMENT;
}
ksl_insert_node(ksl, blk, i, key, data);
++ksl->n;
if (it) {
nghttp2_ksl_it_init(it, ksl, blk, i);
}
return 0;
}
if (i == blk->n) {
/* This insertion extends the largest key in this subtree. */
for (; !blk->leaf;) {
node = nghttp2_ksl_nth_node(ksl, blk, blk->n - 1);
if (node->blk->n == NGHTTP2_KSL_MAX_NBLK) {
rv = ksl_split_node(ksl, blk, blk->n - 1);
if (rv != 0) {
return rv;
}
node = nghttp2_ksl_nth_node(ksl, blk, blk->n - 1);
}
ksl_node_set_key(ksl, node, key);
blk = node->blk;
}
ksl_insert_node(ksl, blk, blk->n, key, data);
++ksl->n;
if (it) {
nghttp2_ksl_it_init(it, ksl, blk, blk->n - 1);
}
return 0;
}
node = nghttp2_ksl_nth_node(ksl, blk, i);
if (node->blk->n == NGHTTP2_KSL_MAX_NBLK) {
rv = ksl_split_node(ksl, blk, i);
if (rv != 0) {
return rv;
}
if (ksl->compar((nghttp2_ksl_key *)node->key, key)) {
node = nghttp2_ksl_nth_node(ksl, blk, i + 1);
if (ksl->compar((nghttp2_ksl_key *)node->key, key)) {
ksl_node_set_key(ksl, node, key);
}
}
}
blk = node->blk;
}
}
/*
* ksl_remove_node removes the node included in |blk| at the index of
* |i|.
*/
static void ksl_remove_node(nghttp2_ksl *ksl, nghttp2_ksl_blk *blk, size_t i) {
memmove(blk->nodes + i * ksl->nodelen, blk->nodes + (i + 1) * ksl->nodelen,
ksl->nodelen * (blk->n - (i + 1)));
--blk->n;
}
/*
* ksl_merge_node merges 2 nodes which are the nodes at the index of
* |i| and |i + 1|.
*
* If |blk| is the direct descendant of head (root) block and the head
* block contains just 2 nodes, the merged block becomes head block,
* which decreases the height of |ksl| by 1.
*
* This function returns the pointer to the merged block.
*/
static nghttp2_ksl_blk *ksl_merge_node(nghttp2_ksl *ksl, nghttp2_ksl_blk *blk,
size_t i) {
nghttp2_ksl_blk *lblk, *rblk;
assert(i + 1 < blk->n);
lblk = nghttp2_ksl_nth_node(ksl, blk, i)->blk;
rblk = nghttp2_ksl_nth_node(ksl, blk, i + 1)->blk;
assert(lblk->n + rblk->n < NGHTTP2_KSL_MAX_NBLK);
memcpy(lblk->nodes + ksl->nodelen * lblk->n, rblk->nodes,
ksl->nodelen * rblk->n);
lblk->n += rblk->n;
lblk->next = rblk->next;
if (lblk->next) {
lblk->next->prev = lblk;
} else if (ksl->back == rblk) {
ksl->back = lblk;
}
nghttp2_mem_free(ksl->mem, rblk);
if (ksl->head == blk && blk->n == 2) {
nghttp2_mem_free(ksl->mem, ksl->head);
ksl->head = lblk;
} else {
ksl_remove_node(ksl, blk, i + 1);
ksl_node_set_key(ksl, nghttp2_ksl_nth_node(ksl, blk, i),
nghttp2_ksl_nth_node(ksl, lblk, lblk->n - 1)->key);
}
return lblk;
}
/*
* ksl_shift_left moves the first node in blk->nodes[i]->blk->nodes to
* blk->nodes[i - 1]->blk->nodes.
*/
static void ksl_shift_left(nghttp2_ksl *ksl, nghttp2_ksl_blk *blk, size_t i) {
nghttp2_ksl_node *lnode, *rnode, *dest, *src;
assert(i > 0);
lnode = nghttp2_ksl_nth_node(ksl, blk, i - 1);
rnode = nghttp2_ksl_nth_node(ksl, blk, i);
assert(lnode->blk->n < NGHTTP2_KSL_MAX_NBLK);
assert(rnode->blk->n > NGHTTP2_KSL_MIN_NBLK);
dest = nghttp2_ksl_nth_node(ksl, lnode->blk, lnode->blk->n);
src = nghttp2_ksl_nth_node(ksl, rnode->blk, 0);
memcpy(dest, src, ksl->nodelen);
ksl_node_set_key(ksl, lnode, dest->key);
++lnode->blk->n;
--rnode->blk->n;
memmove(rnode->blk->nodes, rnode->blk->nodes + ksl->nodelen,
ksl->nodelen * rnode->blk->n);
}
/*
* ksl_shift_right moves the last node in blk->nodes[i]->blk->nodes to
* blk->nodes[i + 1]->blk->nodes.
*/
static void ksl_shift_right(nghttp2_ksl *ksl, nghttp2_ksl_blk *blk, size_t i) {
nghttp2_ksl_node *lnode, *rnode, *dest, *src;
assert(i < blk->n - 1);
lnode = nghttp2_ksl_nth_node(ksl, blk, i);
rnode = nghttp2_ksl_nth_node(ksl, blk, i + 1);
assert(lnode->blk->n > NGHTTP2_KSL_MIN_NBLK);
assert(rnode->blk->n < NGHTTP2_KSL_MAX_NBLK);
memmove(rnode->blk->nodes + ksl->nodelen, rnode->blk->nodes,
ksl->nodelen * rnode->blk->n);
++rnode->blk->n;
dest = nghttp2_ksl_nth_node(ksl, rnode->blk, 0);
src = nghttp2_ksl_nth_node(ksl, lnode->blk, lnode->blk->n - 1);
memcpy(dest, src, ksl->nodelen);
--lnode->blk->n;
ksl_node_set_key(
ksl, lnode,
nghttp2_ksl_nth_node(ksl, lnode->blk, lnode->blk->n - 1)->key);
}
/*
* key_equal returns nonzero if |lhs| and |rhs| are equal using the
* function |compar|.
*/
static int key_equal(nghttp2_ksl_compar compar, const nghttp2_ksl_key *lhs,
const nghttp2_ksl_key *rhs) {
return !compar(lhs, rhs) && !compar(rhs, lhs);
}
int nghttp2_ksl_remove(nghttp2_ksl *ksl, nghttp2_ksl_it *it,
const nghttp2_ksl_key *key) {
nghttp2_ksl_blk *blk = ksl->head;
nghttp2_ksl_node *node;
size_t i;
if (!blk->leaf && blk->n == 2 &&
nghttp2_ksl_nth_node(ksl, blk, 0)->blk->n == NGHTTP2_KSL_MIN_NBLK &&
nghttp2_ksl_nth_node(ksl, blk, 1)->blk->n == NGHTTP2_KSL_MIN_NBLK) {
blk = ksl_merge_node(ksl, ksl->head, 0);
}
for (;;) {
i = ksl_bsearch(ksl, blk, key, ksl->compar);
if (i == blk->n) {
if (it) {
*it = nghttp2_ksl_end(ksl);
}
return NGHTTP2_ERR_INVALID_ARGUMENT;
}
if (blk->leaf) {
if (ksl->compar(key, nghttp2_ksl_nth_node(ksl, blk, i)->key)) {
if (it) {
*it = nghttp2_ksl_end(ksl);
}
return NGHTTP2_ERR_INVALID_ARGUMENT;
}
ksl_remove_node(ksl, blk, i);
--ksl->n;
if (it) {
if (blk->n == i && blk->next) {
nghttp2_ksl_it_init(it, ksl, blk->next, 0);
} else {
nghttp2_ksl_it_init(it, ksl, blk, i);
}
}
return 0;
}
node = nghttp2_ksl_nth_node(ksl, blk, i);
if (node->blk->n == NGHTTP2_KSL_MIN_NBLK) {
if (i > 0 && nghttp2_ksl_nth_node(ksl, blk, i - 1)->blk->n >
NGHTTP2_KSL_MIN_NBLK) {
ksl_shift_right(ksl, blk, i - 1);
blk = node->blk;
} else if (i + 1 < blk->n &&
nghttp2_ksl_nth_node(ksl, blk, i + 1)->blk->n >
NGHTTP2_KSL_MIN_NBLK) {
ksl_shift_left(ksl, blk, i + 1);
blk = node->blk;
} else if (i > 0) {
blk = ksl_merge_node(ksl, blk, i - 1);
} else {
assert(i + 1 < blk->n);
blk = ksl_merge_node(ksl, blk, i);
}
} else {
blk = node->blk;
}
}
}
nghttp2_ksl_it nghttp2_ksl_lower_bound(nghttp2_ksl *ksl,
const nghttp2_ksl_key *key) {
nghttp2_ksl_blk *blk = ksl->head;
nghttp2_ksl_it it;
size_t i;
for (;;) {
i = ksl_bsearch(ksl, blk, key, ksl->compar);
if (blk->leaf) {
if (i == blk->n && blk->next) {
blk = blk->next;
i = 0;
}
nghttp2_ksl_it_init(&it, ksl, blk, i);
return it;
}
if (i == blk->n) {
/* This happens if descendant has smaller key. Fast forward to
find last node in this subtree. */
for (; !blk->leaf; blk = nghttp2_ksl_nth_node(ksl, blk, blk->n - 1)->blk)
;
if (blk->next) {
blk = blk->next;
i = 0;
} else {
i = blk->n;
}
nghttp2_ksl_it_init(&it, ksl, blk, i);
return it;
}
blk = nghttp2_ksl_nth_node(ksl, blk, i)->blk;
}
}
nghttp2_ksl_it nghttp2_ksl_lower_bound_compar(nghttp2_ksl *ksl,
const nghttp2_ksl_key *key,
nghttp2_ksl_compar compar) {
nghttp2_ksl_blk *blk = ksl->head;
nghttp2_ksl_it it;
size_t i;
for (;;) {
i = ksl_bsearch(ksl, blk, key, compar);
if (blk->leaf) {
if (i == blk->n && blk->next) {
blk = blk->next;
i = 0;
}
nghttp2_ksl_it_init(&it, ksl, blk, i);
return it;
}
if (i == blk->n) {
/* This happens if descendant has smaller key. Fast forward to
find last node in this subtree. */
for (; !blk->leaf; blk = nghttp2_ksl_nth_node(ksl, blk, blk->n - 1)->blk)
;
if (blk->next) {
blk = blk->next;
i = 0;
} else {
i = blk->n;
}
nghttp2_ksl_it_init(&it, ksl, blk, i);
return it;
}
blk = nghttp2_ksl_nth_node(ksl, blk, i)->blk;
}
}
void nghttp2_ksl_update_key(nghttp2_ksl *ksl, const nghttp2_ksl_key *old_key,
const nghttp2_ksl_key *new_key) {
nghttp2_ksl_blk *blk = ksl->head;
nghttp2_ksl_node *node;
size_t i;
for (;;) {
i = ksl_bsearch(ksl, blk, old_key, ksl->compar);
assert(i < blk->n);
node = nghttp2_ksl_nth_node(ksl, blk, i);
if (blk->leaf) {
assert(key_equal(ksl->compar, (nghttp2_ksl_key *)node->key, old_key));
ksl_node_set_key(ksl, node, new_key);
return;
}
if (key_equal(ksl->compar, (nghttp2_ksl_key *)node->key, old_key) ||
ksl->compar((nghttp2_ksl_key *)node->key, new_key)) {
ksl_node_set_key(ksl, node, new_key);
}
blk = node->blk;
}
}
static void ksl_print(nghttp2_ksl *ksl, nghttp2_ksl_blk *blk, size_t level) {
size_t i;
nghttp2_ksl_node *node;
fprintf(stderr, "LV=%zu n=%zu\n", level, blk->n);
if (blk->leaf) {
for (i = 0; i < blk->n; ++i) {
node = nghttp2_ksl_nth_node(ksl, blk, i);
fprintf(stderr, " %" PRId64, *(int64_t *)(void *)node->key);
}
fprintf(stderr, "\n");
return;
}
for (i = 0; i < blk->n; ++i) {
ksl_print(ksl, nghttp2_ksl_nth_node(ksl, blk, i)->blk, level + 1);
}
}
size_t nghttp2_ksl_len(nghttp2_ksl *ksl) { return ksl->n; }
void nghttp2_ksl_clear(nghttp2_ksl *ksl) {
size_t i;
nghttp2_ksl_blk *head;
if (!ksl->head->leaf) {
for (i = 0; i < ksl->head->n; ++i) {
ksl_free_blk(ksl, nghttp2_ksl_nth_node(ksl, ksl->head, i)->blk);
}
}
ksl->front = ksl->back = ksl->head;
ksl->n = 0;
head = ksl->head;
head->next = head->prev = NULL;
head->n = 0;
head->leaf = 1;
}
void nghttp2_ksl_print(nghttp2_ksl *ksl) { ksl_print(ksl, ksl->head, 0); }
nghttp2_ksl_it nghttp2_ksl_begin(const nghttp2_ksl *ksl) {
nghttp2_ksl_it it;
nghttp2_ksl_it_init(&it, ksl, ksl->front, 0);
return it;
}
nghttp2_ksl_it nghttp2_ksl_end(const nghttp2_ksl *ksl) {
nghttp2_ksl_it it;
nghttp2_ksl_it_init(&it, ksl, ksl->back, ksl->back->n);
return it;
}
void nghttp2_ksl_it_init(nghttp2_ksl_it *it, const nghttp2_ksl *ksl,
nghttp2_ksl_blk *blk, size_t i) {
it->ksl = ksl;
it->blk = blk;
it->i = i;
}
void *nghttp2_ksl_it_get(const nghttp2_ksl_it *it) {
assert(it->i < it->blk->n);
return nghttp2_ksl_nth_node(it->ksl, it->blk, it->i)->data;
}
void nghttp2_ksl_it_prev(nghttp2_ksl_it *it) {
assert(!nghttp2_ksl_it_begin(it));
if (it->i == 0) {
it->blk = it->blk->prev;
it->i = it->blk->n - 1;
} else {
--it->i;
}
}
int nghttp2_ksl_it_begin(const nghttp2_ksl_it *it) {
return it->i == 0 && it->blk->prev == NULL;
}

315
lib/nghttp2_ksl.h Normal file
View File

@ -0,0 +1,315 @@
/*
* nghttp2 - HTTP/2 C Library
*
* Copyright (c) 2020 nghttp2 contributors
* Copyright (c) 2018 ngtcp2 contributors
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#ifndef NGHTTP2_KSL_H
#define NGHTTP2_KSL_H
#ifdef HAVE_CONFIG_H
# include <config.h>
#endif /* HAVE_CONFIG_H */
#include <stdlib.h>
#include <nghttp2/nghttp2.h>
/*
* Skip List using single key instead of range.
*/
#define NGHTTP2_KSL_DEGR 16
/* NGHTTP2_KSL_MAX_NBLK is the maximum number of nodes which a single
block can contain. */
#define NGHTTP2_KSL_MAX_NBLK (2 * NGHTTP2_KSL_DEGR - 1)
/* NGHTTP2_KSL_MIN_NBLK is the minimum number of nodes which a single
block other than root must contains. */
#define NGHTTP2_KSL_MIN_NBLK (NGHTTP2_KSL_DEGR - 1)
/*
* nghttp2_ksl_key represents key in nghttp2_ksl.
*/
typedef void nghttp2_ksl_key;
struct nghttp2_ksl_node;
typedef struct nghttp2_ksl_node nghttp2_ksl_node;
struct nghttp2_ksl_blk;
typedef struct nghttp2_ksl_blk nghttp2_ksl_blk;
/*
* nghttp2_ksl_node is a node which contains either nghttp2_ksl_blk or
* opaque data. If a node is an internal node, it contains
* nghttp2_ksl_blk. Otherwise, it has data. The key is stored at the
* location starting at key.
*/
struct nghttp2_ksl_node {
union {
nghttp2_ksl_blk *blk;
void *data;
};
union {
uint64_t align;
/* key is a buffer to include key associated to this node.
Because the length of key is unknown until nghttp2_ksl_init is
called, the actual buffer will be allocated after this
field. */
uint8_t key[1];
};
};
/*
* nghttp2_ksl_blk contains nghttp2_ksl_node objects.
*/
struct nghttp2_ksl_blk {
/* next points to the next block if leaf field is nonzero. */
nghttp2_ksl_blk *next;
/* prev points to the previous block if leaf field is nonzero. */
nghttp2_ksl_blk *prev;
/* n is the number of nodes this object contains in nodes. */
size_t n;
/* leaf is nonzero if this block contains leaf nodes. */
int leaf;
union {
uint64_t align;
/* nodes is a buffer to contain NGHTTP2_KSL_MAX_NBLK
nghttp2_ksl_node objects. Because nghttp2_ksl_node object is
allocated along with the additional variable length key
storage, the size of buffer is unknown until nghttp2_ksl_init is
called. */
uint8_t nodes[1];
};
};
/*
* nghttp2_ksl_compar is a function type which returns nonzero if key
* |lhs| should be placed before |rhs|. It returns 0 otherwise.
*/
typedef int (*nghttp2_ksl_compar)(const nghttp2_ksl_key *lhs,
const nghttp2_ksl_key *rhs);
struct nghttp2_ksl;
typedef struct nghttp2_ksl nghttp2_ksl;
struct nghttp2_ksl_it;
typedef struct nghttp2_ksl_it nghttp2_ksl_it;
/*
* nghttp2_ksl_it is a forward iterator to iterate nodes.
*/
struct nghttp2_ksl_it {
const nghttp2_ksl *ksl;
nghttp2_ksl_blk *blk;
size_t i;
};
/*
* nghttp2_ksl is a deterministic paged skip list.
*/
struct nghttp2_ksl {
/* head points to the root block. */
nghttp2_ksl_blk *head;
/* front points to the first leaf block. */
nghttp2_ksl_blk *front;
/* back points to the last leaf block. */
nghttp2_ksl_blk *back;
nghttp2_ksl_compar compar;
size_t n;
/* keylen is the size of key */
size_t keylen;
/* nodelen is the actual size of nghttp2_ksl_node including key
storage. */
size_t nodelen;
nghttp2_mem *mem;
};
/*
* nghttp2_ksl_init initializes |ksl|. |compar| specifies compare
* function. |keylen| is the length of key.
*
* It returns 0 if it succeeds, or one of the following negative error
* codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory.
*/
int nghttp2_ksl_init(nghttp2_ksl *ksl, nghttp2_ksl_compar compar, size_t keylen,
nghttp2_mem *mem);
/*
* nghttp2_ksl_free frees resources allocated for |ksl|. If |ksl| is
* NULL, this function does nothing. It does not free the memory
* region pointed by |ksl| itself.
*/
void nghttp2_ksl_free(nghttp2_ksl *ksl);
/*
* nghttp2_ksl_insert inserts |key| with its associated |data|. On
* successful insertion, the iterator points to the inserted node is
* stored in |*it|.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_NOMEM
* Out of memory.
* NGHTTP2_ERR_INVALID_ARGUMENT
* |key| already exists.
*/
int nghttp2_ksl_insert(nghttp2_ksl *ksl, nghttp2_ksl_it *it,
const nghttp2_ksl_key *key, void *data);
/*
* nghttp2_ksl_remove removes the |key| from |ksl|.
*
* This function assigns the iterator to |*it|, which points to the
* node which is located at the right next of the removed node if |it|
* is not NULL. If |key| is not found, no deletion takes place and
* the return value of nghttp2_ksl_end(ksl) is assigned to |*it|.
*
* This function returns 0 if it succeeds, or one of the following
* negative error codes:
*
* NGHTTP2_ERR_INVALID_ARGUMENT
* |key| does not exist.
*/
int nghttp2_ksl_remove(nghttp2_ksl *ksl, nghttp2_ksl_it *it,
const nghttp2_ksl_key *key);
/*
* nghttp2_ksl_lower_bound returns the iterator which points to the
* first node which has the key which is equal to |key| or the last
* node which satisfies !compar(&node->key, key). If there is no such
* node, it returns the iterator which satisfies nghttp2_ksl_it_end(it)
* != 0.
*/
nghttp2_ksl_it nghttp2_ksl_lower_bound(nghttp2_ksl *ksl,
const nghttp2_ksl_key *key);
/*
* nghttp2_ksl_lower_bound_compar works like nghttp2_ksl_lower_bound,
* but it takes custom function |compar| to do lower bound search.
*/
nghttp2_ksl_it nghttp2_ksl_lower_bound_compar(nghttp2_ksl *ksl,
const nghttp2_ksl_key *key,
nghttp2_ksl_compar compar);
/*
* nghttp2_ksl_update_key replaces the key of nodes which has |old_key|
* with |new_key|. |new_key| must be strictly greater than the
* previous node and strictly smaller than the next node.
*/
void nghttp2_ksl_update_key(nghttp2_ksl *ksl, const nghttp2_ksl_key *old_key,
const nghttp2_ksl_key *new_key);
/*
* nghttp2_ksl_begin returns the iterator which points to the first
* node. If there is no node in |ksl|, it returns the iterator which
* satisfies nghttp2_ksl_it_end(it) != 0.
*/
nghttp2_ksl_it nghttp2_ksl_begin(const nghttp2_ksl *ksl);
/*
* nghttp2_ksl_end returns the iterator which points to the node
* following the last node. The returned object satisfies
* nghttp2_ksl_it_end(). If there is no node in |ksl|, it returns the
* iterator which satisfies nghttp2_ksl_it_begin(it) != 0.
*/
nghttp2_ksl_it nghttp2_ksl_end(const nghttp2_ksl *ksl);
/*
* nghttp2_ksl_len returns the number of elements stored in |ksl|.
*/
size_t nghttp2_ksl_len(nghttp2_ksl *ksl);
/*
* nghttp2_ksl_clear removes all elements stored in |ksl|.
*/
void nghttp2_ksl_clear(nghttp2_ksl *ksl);
/*
* nghttp2_ksl_nth_node returns the |n|th node under |blk|.
*/
#define nghttp2_ksl_nth_node(KSL, BLK, N) \
((nghttp2_ksl_node *)(void *)((BLK)->nodes + (KSL)->nodelen * (N)))
/*
* nghttp2_ksl_print prints its internal state in stderr. It assumes
* that the key is of type int64_t. This function should be used for
* the debugging purpose only.
*/
void nghttp2_ksl_print(nghttp2_ksl *ksl);
/*
* nghttp2_ksl_it_init initializes |it|.
*/
void nghttp2_ksl_it_init(nghttp2_ksl_it *it, const nghttp2_ksl *ksl,
nghttp2_ksl_blk *blk, size_t i);
/*
* nghttp2_ksl_it_get returns the data associated to the node which
* |it| points to. It is undefined to call this function when
* nghttp2_ksl_it_end(it) returns nonzero.
*/
void *nghttp2_ksl_it_get(const nghttp2_ksl_it *it);
/*
* nghttp2_ksl_it_next advances the iterator by one. It is undefined
* if this function is called when nghttp2_ksl_it_end(it) returns
* nonzero.
*/
#define nghttp2_ksl_it_next(IT) \
(++(IT)->i == (IT)->blk->n && (IT)->blk->next \
? ((IT)->blk = (IT)->blk->next, (IT)->i = 0) \
: 0)
/*
* nghttp2_ksl_it_prev moves backward the iterator by one. It is
* undefined if this function is called when nghttp2_ksl_it_begin(it)
* returns nonzero.
*/
void nghttp2_ksl_it_prev(nghttp2_ksl_it *it);
/*
* nghttp2_ksl_it_end returns nonzero if |it| points to the beyond the
* last node.
*/
#define nghttp2_ksl_it_end(IT) \
((IT)->blk->n == (IT)->i && (IT)->blk->next == NULL)
/*
* nghttp2_ksl_it_begin returns nonzero if |it| points to the first
* node. |it| might satisfy both nghttp2_ksl_it_begin(&it) and
* nghttp2_ksl_it_end(&it) if the skip list has no node.
*/
int nghttp2_ksl_it_begin(const nghttp2_ksl_it *it);
/*
* nghttp2_ksl_key returns the key of the node which |it| points to.
* It is undefined to call this function when nghttp2_ksl_it_end(it)
* returns nonzero.
*/
#define nghttp2_ksl_it_key(IT) \
((nghttp2_ksl_key *)nghttp2_ksl_nth_node((IT)->ksl, (IT)->blk, (IT)->i)->key)
#endif /* NGHTTP2_KSL_H */

268
lib/nghttp2_map.c
View File

@ -1,7 +1,8 @@
/*
* nghttp2 - HTTP/2 C Library
*
* Copyright (c) 2012 Tatsuhiro Tsujikawa
* Copyright (c) 2017 ngtcp2 contributors
* Copyright (c) 2012 nghttp2 contributors
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
@ -25,6 +26,9 @@
#include "nghttp2_map.h"
#include <string.h>
#include <assert.h>
#include "nghttp2_helper.h"
#define INITIAL_TABLE_LENGTH 256
@ -32,7 +36,7 @@ int nghttp2_map_init(nghttp2_map *map, nghttp2_mem *mem) {
map->mem = mem;
map->tablelen = INITIAL_TABLE_LENGTH;
map->table =
nghttp2_mem_calloc(mem, map->tablelen, sizeof(nghttp2_map_entry *));
nghttp2_mem_calloc(mem, map->tablelen, sizeof(nghttp2_map_bucket));
if (map->table == NULL) {
return NGHTTP2_ERR_NOMEM;
}
@ -43,6 +47,21 @@ int nghttp2_map_init(nghttp2_map *map, nghttp2_mem *mem) {
}
void nghttp2_map_free(nghttp2_map *map) {
size_t i;
nghttp2_map_bucket *bkt;
if (!map) {
return;
}
for (i = 0; i < map->tablelen; ++i) {
bkt = &map->table[i];
if (bkt->ksl) {
nghttp2_ksl_free(bkt->ksl);
nghttp2_mem_free(map->mem, bkt->ksl);
}
}
nghttp2_mem_free(map->mem, map->table);
}
@ -50,14 +69,29 @@ void nghttp2_map_each_free(nghttp2_map *map,
int (*func)(nghttp2_map_entry *entry, void *ptr),
void *ptr) {
uint32_t i;
nghttp2_map_bucket *bkt;
nghttp2_ksl_it it;
for (i = 0; i < map->tablelen; ++i) {
nghttp2_map_entry *entry;
for (entry = map->table[i]; entry;) {
nghttp2_map_entry *next = entry->next;
func(entry, ptr);
entry = next;
bkt = &map->table[i];
if (bkt->ptr) {
func(bkt->ptr, ptr);
bkt->ptr = NULL;
assert(bkt->ksl == NULL || nghttp2_ksl_len(bkt->ksl) == 0);
continue;
}
if (bkt->ksl) {
for (it = nghttp2_ksl_begin(bkt->ksl); !nghttp2_ksl_it_end(&it);
nghttp2_ksl_it_next(&it)) {
func(nghttp2_ksl_it_get(&it), ptr);
}
nghttp2_ksl_free(bkt->ksl);
nghttp2_mem_free(map->mem, bkt->ksl);
bkt->ksl = NULL;
}
map->table[i] = NULL;
}
}
@ -66,13 +100,29 @@ int nghttp2_map_each(nghttp2_map *map,
void *ptr) {
int rv;
uint32_t i;
nghttp2_map_bucket *bkt;
nghttp2_ksl_it it;
for (i = 0; i < map->tablelen; ++i) {
nghttp2_map_entry *entry;
for (entry = map->table[i]; entry; entry = entry->next) {
rv = func(entry, ptr);
bkt = &map->table[i];
if (bkt->ptr) {
rv = func(bkt->ptr, ptr);
if (rv != 0) {
return rv;
}
assert(bkt->ksl == NULL || nghttp2_ksl_len(bkt->ksl) == 0);
continue;
}
if (bkt->ksl) {
for (it = nghttp2_ksl_begin(bkt->ksl); !nghttp2_ksl_it_end(&it);
nghttp2_ksl_it_next(&it)) {
rv = func(nghttp2_ksl_it_get(&it), ptr);
if (rv != 0) {
return rv;
}
}
}
}
return 0;
@ -83,72 +133,133 @@ void nghttp2_map_entry_init(nghttp2_map_entry *entry, key_type key) {
entry->next = NULL;
}
/* Same hash function in android HashMap source code. */
/* The |mod| must be power of 2 */
static uint32_t hash(int32_t key, uint32_t mod) {
uint32_t h = (uint32_t)key;
h ^= (h >> 20) ^ (h >> 12);
h ^= (h >> 7) ^ (h >> 4);
/* FNV1a hash */
static uint32_t hash(key_type key, uint32_t mod) {
uint8_t *p, *end;
uint32_t h = 0x811C9DC5u;
p = (uint8_t *)&key;
end = p + sizeof(key_type);
for (; p != end;) {
h ^= *p++;
h += (h << 1) + (h << 4) + (h << 7) + (h << 8) + (h << 24);
}
return h & (mod - 1);
}
static int insert(nghttp2_map_entry **table, uint32_t tablelen,
nghttp2_map_entry *entry) {
static int less(const nghttp2_ksl_key *lhs, const nghttp2_ksl_key *rhs) {
return *(key_type *)lhs < *(key_type *)rhs;
}
static int map_insert(nghttp2_map *map, nghttp2_map_bucket *table,
uint32_t tablelen, nghttp2_map_entry *entry) {
uint32_t h = hash(entry->key, tablelen);
if (table[h] == NULL) {
table[h] = entry;
} else {
nghttp2_map_entry *p;
/* We won't allow duplicated key, so check it out. */
for (p = table[h]; p; p = p->next) {
if (p->key == entry->key) {
return NGHTTP2_ERR_INVALID_ARGUMENT;
}
}
entry->next = table[h];
table[h] = entry;
}
nghttp2_map_bucket *bkt = &table[h];
nghttp2_mem *mem = map->mem;
int rv;
if (bkt->ptr == NULL &&
(bkt->ksl == NULL || nghttp2_ksl_len(bkt->ksl) == 0)) {
bkt->ptr = entry;
return 0;
}
if (!bkt->ksl) {
bkt->ksl = nghttp2_mem_malloc(mem, sizeof(*bkt->ksl));
if (bkt->ksl == NULL) {
return NGHTTP2_ERR_NOMEM;
}
nghttp2_ksl_init(bkt->ksl, less, sizeof(key_type), mem);
}
if (bkt->ptr) {
rv = nghttp2_ksl_insert(bkt->ksl, NULL, &bkt->ptr->key, bkt->ptr);
if (rv != 0) {
return rv;
}
bkt->ptr = NULL;
}
return nghttp2_ksl_insert(bkt->ksl, NULL, &entry->key, entry);
}
/* new_tablelen must be power of 2 */
static int resize(nghttp2_map *map, uint32_t new_tablelen) {
static int map_resize(nghttp2_map *map, uint32_t new_tablelen) {
uint32_t i;
nghttp2_map_entry **new_table;
nghttp2_map_bucket *new_table;
nghttp2_map_bucket *bkt;
nghttp2_ksl_it it;
int rv;
new_table =
nghttp2_mem_calloc(map->mem, new_tablelen, sizeof(nghttp2_map_entry *));
nghttp2_mem_calloc(map->mem, new_tablelen, sizeof(nghttp2_map_bucket));
if (new_table == NULL) {
return NGHTTP2_ERR_NOMEM;
}
for (i = 0; i < map->tablelen; ++i) {
nghttp2_map_entry *entry;
for (entry = map->table[i]; entry;) {
nghttp2_map_entry *next = entry->next;
entry->next = NULL;
/* This function must succeed */
insert(new_table, new_tablelen, entry);
entry = next;
bkt = &map->table[i];
if (bkt->ptr) {
rv = map_insert(map, new_table, new_tablelen, bkt->ptr);
if (rv != 0) {
goto fail;
}
assert(bkt->ksl == NULL || nghttp2_ksl_len(bkt->ksl) == 0);
continue;
}
if (bkt->ksl) {
for (it = nghttp2_ksl_begin(bkt->ksl); !nghttp2_ksl_it_end(&it);
nghttp2_ksl_it_next(&it)) {
rv = map_insert(map, new_table, new_tablelen, nghttp2_ksl_it_get(&it));
if (rv != 0) {
goto fail;
}
}
}
}
for (i = 0; i < map->tablelen; ++i) {
bkt = &map->table[i];
if (bkt->ksl) {
nghttp2_ksl_free(bkt->ksl);
nghttp2_mem_free(map->mem, bkt->ksl);
}
}
nghttp2_mem_free(map->mem, map->table);
map->tablelen = new_tablelen;
map->table = new_table;
return 0;
fail:
for (i = 0; i < new_tablelen; ++i) {
bkt = &new_table[i];
if (bkt->ksl) {
nghttp2_ksl_free(bkt->ksl);
nghttp2_mem_free(map->mem, bkt->ksl);
}
}
return rv;
}
int nghttp2_map_insert(nghttp2_map *map, nghttp2_map_entry *new_entry) {
int rv;
/* Load factor is 0.75 */
if ((map->size + 1) * 4 > map->tablelen * 3) {
rv = resize(map, map->tablelen * 2);
rv = map_resize(map, map->tablelen * 2);
if (rv != 0) {
return rv;
}
}
rv = insert(map->table, map->tablelen, new_entry);
rv = map_insert(map, map->table, map->tablelen, new_entry);
if (rv != 0) {
return rv;
}
@ -157,33 +268,68 @@ int nghttp2_map_insert(nghttp2_map *map, nghttp2_map_entry *new_entry) {
}
nghttp2_map_entry *nghttp2_map_find(nghttp2_map *map, key_type key) {
uint32_t h;
nghttp2_map_entry *entry;
h = hash(key, map->tablelen);
for (entry = map->table[h]; entry; entry = entry->next) {
if (entry->key == key) {
return entry;
}
nghttp2_map_bucket *bkt = &map->table[hash(key, map->tablelen)];
nghttp2_ksl_it it;
if (bkt->ptr) {
if (bkt->ptr->key == key) {
return bkt->ptr;
}
return NULL;
}
int nghttp2_map_remove(nghttp2_map *map, key_type key) {
uint32_t h;
nghttp2_map_entry **dst;
h = hash(key, map->tablelen);
for (dst = &map->table[h]; *dst; dst = &(*dst)->next) {
if ((*dst)->key != key) {
continue;
if (bkt->ksl) {
it = nghttp2_ksl_lower_bound(bkt->ksl, &key);
if (nghttp2_ksl_it_end(&it) ||
*(key_type *)nghttp2_ksl_it_key(&it) != key) {
return NULL;
}
return nghttp2_ksl_it_get(&it);
}
*dst = (*dst)->next;
return NULL;
}
int nghttp2_map_remove(nghttp2_map *map, key_type key) {
nghttp2_map_bucket *bkt = &map->table[hash(key, map->tablelen)];
int rv;
if (bkt->ptr) {
if (bkt->ptr->key == key) {
bkt->ptr = NULL;
--map->size;
return 0;
}
return NGHTTP2_ERR_INVALID_ARGUMENT;
}
if (bkt->ksl) {
rv = nghttp2_ksl_remove(bkt->ksl, NULL, &key);
if (rv != 0) {
return rv;
}
--map->size;
return 0;
}
return NGHTTP2_ERR_INVALID_ARGUMENT;
}
void nghttp2_map_clear(nghttp2_map *map) {
uint32_t i;
nghttp2_map_bucket *bkt;
for (i = 0; i < map->tablelen; ++i) {
bkt = &map->table[i];
bkt->ptr = NULL;
if (bkt->ksl) {
nghttp2_ksl_free(bkt->ksl);
nghttp2_mem_free(map->mem, bkt->ksl);
bkt->ksl = NULL;
}
}
map->size = 0;
}
size_t nghttp2_map_size(nghttp2_map *map) { return map->size; }

18
lib/nghttp2_map.h
View File

@ -1,7 +1,8 @@
/*
* nghttp2 - HTTP/2 C Library
*
* Copyright (c) 2012 Tatsuhiro Tsujikawa
* Copyright (c) 2017 ngtcp2 contributors
* Copyright (c) 2012 nghttp2 contributors
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
@ -30,8 +31,9 @@
#endif /* HAVE_CONFIG_H */
#include <nghttp2/nghttp2.h>
#include "nghttp2_int.h"
#include "nghttp2_mem.h"
#include "nghttp2_ksl.h"
/* Implementation of unordered map */
@ -46,8 +48,13 @@ typedef struct nghttp2_map_entry {
#endif
} nghttp2_map_entry;
typedef struct nghttp2_map_bucket {
nghttp2_map_entry *ptr;
nghttp2_ksl *ksl;
} nghttp2_map_bucket;
typedef struct {
nghttp2_map_entry **table;
nghttp2_map_bucket *table;
nghttp2_mem *mem;
size_t size;
uint32_t tablelen;
@ -118,6 +125,11 @@ nghttp2_map_entry *nghttp2_map_find(nghttp2_map *map, key_type key);
*/
int nghttp2_map_remove(nghttp2_map *map, key_type key);
/*
* Removes all entries from |map|.
*/
void nghttp2_map_clear(nghttp2_map *map);
/*
* Returns the number of items stored in the map |map|.
*/