1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
|
/*
*
* Copyright 2018 gRPC authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
*/
#include <grpc/support/port_platform.h>
#include "src/core/lib/gprpp/mutex_lock.h"
#include "src/core/tsi/ssl/session_cache/ssl_session.h"
#include "src/core/tsi/ssl/session_cache/ssl_session_cache.h"
#include <grpc/support/log.h>
#include <grpc/support/string_util.h>
namespace tsi {
static void cache_key_avl_destroy(void* key, void* unused) {}
static void* cache_key_avl_copy(void* key, void* unused) { return key; }
static long cache_key_avl_compare(void* key1, void* key2, void* unused) {
return grpc_slice_cmp(*static_cast<grpc_slice*>(key1),
*static_cast<grpc_slice*>(key2));
}
static void cache_value_avl_destroy(void* value, void* unused) {}
static void* cache_value_avl_copy(void* value, void* unused) { return value; }
// AVL only stores pointers, ownership belonges to the linked list.
static const grpc_avl_vtable cache_avl_vtable = {
cache_key_avl_destroy, cache_key_avl_copy, cache_key_avl_compare,
cache_value_avl_destroy, cache_value_avl_copy,
};
/// Node for single cached session.
class SslSessionLRUCache::Node {
public:
Node(const grpc_slice& key, SslSessionPtr session) : key_(key) {
SetSession(std::move(session));
}
~Node() { grpc_slice_unref(key_); }
// Not copyable nor movable.
Node(const Node&) = delete;
Node& operator=(const Node&) = delete;
void* AvlKey() { return &key_; }
/// Returns a copy of the node's cache session.
SslSessionPtr CopySession() const { return session_->CopySession(); }
/// Set the \a session (which is moved) for the node.
void SetSession(SslSessionPtr session) {
session_ = SslCachedSession::Create(std::move(session));
}
private:
friend class SslSessionLRUCache;
grpc_slice key_;
grpc_core::UniquePtr<SslCachedSession> session_;
Node* next_ = nullptr;
Node* prev_ = nullptr;
};
SslSessionLRUCache::SslSessionLRUCache(size_t capacity) : capacity_(capacity) {
GPR_ASSERT(capacity > 0);
gpr_mu_init(&lock_);
entry_by_key_ = grpc_avl_create(&cache_avl_vtable);
}
SslSessionLRUCache::~SslSessionLRUCache() {
Node* node = use_order_list_head_;
while (node) {
Node* next = node->next_;
grpc_core::Delete(node);
node = next;
}
grpc_avl_unref(entry_by_key_, nullptr);
gpr_mu_destroy(&lock_);
}
size_t SslSessionLRUCache::Size() {
grpc_core::MutexLock lock(&lock_);
return use_order_list_size_;
}
SslSessionLRUCache::Node* SslSessionLRUCache::FindLocked(
const grpc_slice& key) {
void* value =
grpc_avl_get(entry_by_key_, const_cast<grpc_slice*>(&key), nullptr);
if (value == nullptr) {
return nullptr;
}
Node* node = static_cast<Node*>(value);
// Move to the beginning.
Remove(node);
PushFront(node);
AssertInvariants();
return node;
}
void SslSessionLRUCache::Put(const char* key, SslSessionPtr session) {
grpc_core::MutexLock lock(&lock_);
Node* node = FindLocked(grpc_slice_from_static_string(key));
if (node != nullptr) {
node->SetSession(std::move(session));
return;
}
grpc_slice key_slice = grpc_slice_from_copied_string(key);
node = grpc_core::New<Node>(key_slice, std::move(session));
PushFront(node);
entry_by_key_ = grpc_avl_add(entry_by_key_, node->AvlKey(), node, nullptr);
AssertInvariants();
if (use_order_list_size_ > capacity_) {
GPR_ASSERT(use_order_list_tail_);
node = use_order_list_tail_;
Remove(node);
// Order matters, key is destroyed after deleting node.
entry_by_key_ = grpc_avl_remove(entry_by_key_, node->AvlKey(), nullptr);
grpc_core::Delete(node);
AssertInvariants();
}
}
SslSessionPtr SslSessionLRUCache::Get(const char* key) {
grpc_core::MutexLock lock(&lock_);
// Key is only used for lookups.
grpc_slice key_slice = grpc_slice_from_static_string(key);
Node* node = FindLocked(key_slice);
if (node == nullptr) {
return nullptr;
}
return node->CopySession();
}
void SslSessionLRUCache::Remove(SslSessionLRUCache::Node* node) {
if (node->prev_ == nullptr) {
use_order_list_head_ = node->next_;
} else {
node->prev_->next_ = node->next_;
}
if (node->next_ == nullptr) {
use_order_list_tail_ = node->prev_;
} else {
node->next_->prev_ = node->prev_;
}
GPR_ASSERT(use_order_list_size_ >= 1);
use_order_list_size_--;
}
void SslSessionLRUCache::PushFront(SslSessionLRUCache::Node* node) {
if (use_order_list_head_ == nullptr) {
use_order_list_head_ = node;
use_order_list_tail_ = node;
node->next_ = nullptr;
node->prev_ = nullptr;
} else {
node->next_ = use_order_list_head_;
node->next_->prev_ = node;
use_order_list_head_ = node;
node->prev_ = nullptr;
}
use_order_list_size_++;
}
#ifndef NDEBUG
static size_t calculate_tree_size(grpc_avl_node* node) {
if (node == nullptr) {
return 0;
}
return 1 + calculate_tree_size(node->left) + calculate_tree_size(node->right);
}
void SslSessionLRUCache::AssertInvariants() {
size_t size = 0;
Node* prev = nullptr;
Node* current = use_order_list_head_;
while (current != nullptr) {
size++;
GPR_ASSERT(current->prev_ == prev);
void* node = grpc_avl_get(entry_by_key_, current->AvlKey(), nullptr);
GPR_ASSERT(node == current);
prev = current;
current = current->next_;
}
GPR_ASSERT(prev == use_order_list_tail_);
GPR_ASSERT(size == use_order_list_size_);
GPR_ASSERT(calculate_tree_size(entry_by_key_.root) == use_order_list_size_);
}
#else
void SslSessionLRUCache::AssertInvariants() {}
#endif
} // namespace tsi
|
