1 //
2 //
3 // Copyright 2015 gRPC authors.
4 //
5 // Licensed under the Apache License, Version 2.0 (the "License");
6 // you may not use this file except in compliance with the License.
7 // You may obtain a copy of the License at
8 //
9 //     http://www.apache.org/licenses/LICENSE-2.0
10 //
11 // Unless required by applicable law or agreed to in writing, software
12 // distributed under the License is distributed on an "AS IS" BASIS,
13 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 // See the License for the specific language governing permissions and
15 // limitations under the License.
16 //
17 //
18 
19 #ifndef GRPC_SRC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_STREAM_MAP_H
20 #define GRPC_SRC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_STREAM_MAP_H
21 
22 #include <grpc/support/port_platform.h>
23 
24 #include <stddef.h>
25 #include <stdint.h>
26 
27 // Data structure to map a uint32_t to a data object (represented by a void*)
28 
29 // Represented as a sorted array of keys, and a corresponding array of values.
30 // Lookups are performed with binary search.
31 // Adds are restricted to strictly higher keys than previously seen (this is
32 // guaranteed by http2).
33 struct grpc_chttp2_stream_map {
34   uint32_t* keys;
35   void** values;
36   size_t count;
37   size_t free;
38   size_t capacity;
39 };
40 void grpc_chttp2_stream_map_init(grpc_chttp2_stream_map* map,
41                                  size_t initial_capacity);
42 void grpc_chttp2_stream_map_destroy(grpc_chttp2_stream_map* map);
43 
44 // Add a new key: given http2 semantics, new keys must always be greater than
45 // existing keys - this is asserted
46 void grpc_chttp2_stream_map_add(grpc_chttp2_stream_map* map, uint32_t key,
47                                 void* value);
48 
49 // Delete an existing key - returns the previous value of the key if it existed,
50 // or NULL otherwise
51 void* grpc_chttp2_stream_map_delete(grpc_chttp2_stream_map* map, uint32_t key);
52 
53 // Return an existing key, or NULL if it does not exist
54 void* grpc_chttp2_stream_map_find(grpc_chttp2_stream_map* map, uint32_t key);
55 
56 // Return a random entry
57 void* grpc_chttp2_stream_map_rand(grpc_chttp2_stream_map* map);
58 
59 // How many (populated) entries are in the stream map?
60 size_t grpc_chttp2_stream_map_size(grpc_chttp2_stream_map* map);
61 
62 // Callback on each stream
63 void grpc_chttp2_stream_map_for_each(grpc_chttp2_stream_map* map,
64                                      void (*f)(void* user_data, uint32_t key,
65                                                void* value),
66                                      void* user_data);
67 
68 #endif  // GRPC_SRC_CORE_EXT_TRANSPORT_CHTTP2_TRANSPORT_STREAM_MAP_H
69