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Diffstat (limited to 'src/core/lib/transport/mdstr_hash_table.h')
-rw-r--r-- | src/core/lib/transport/mdstr_hash_table.h | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/src/core/lib/transport/mdstr_hash_table.h b/src/core/lib/transport/mdstr_hash_table.h new file mode 100644 index 0000000000..57f497ee27 --- /dev/null +++ b/src/core/lib/transport/mdstr_hash_table.h @@ -0,0 +1,77 @@ +/* + * Copyright 2016, Google Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions are + * met: + * + * * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * * Redistributions in binary form must reproduce the above + * copyright notice, this list of conditions and the following disclaimer + * in the documentation and/or other materials provided with the + * distribution. + * * Neither the name of Google Inc. nor the names of its + * contributors may be used to endorse or promote products derived from + * this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR + * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT + * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, + * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT + * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, + * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY + * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT + * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE + * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + */ + +#ifndef GRPC_CORE_LIB_TRANSPORT_MDSTR_HASH_TABLE_H +#define GRPC_CORE_LIB_TRANSPORT_MDSTR_HASH_TABLE_H + +#include "src/core/lib/transport/metadata.h" + +/** Hash table implementation. + * + * This implementation uses open addressing + * (https://en.wikipedia.org/wiki/Open_addressing) with quadratic + * probing (https://en.wikipedia.org/wiki/Quadratic_probing). + * + * The keys are \a grpc_mdstr objects. The values are arbitrary pointers + * with a common vtable. + * + * Hash tables are intentionally immutable, to avoid the need for locking. + */ + +typedef struct grpc_mdstr_hash_table grpc_mdstr_hash_table; + +typedef struct grpc_mdstr_hash_table_vtable { + void (*destroy_value)(grpc_exec_ctx* exec_ctx, void* value); + void* (*copy_value)(void* value); +} grpc_mdstr_hash_table_vtable; + +typedef struct grpc_mdstr_hash_table_entry { + grpc_mdstr* key; + void* value; /* Must not be NULL. */ + const grpc_mdstr_hash_table_vtable* vtable; +} grpc_mdstr_hash_table_entry; + +/** Creates a new hash table of containing \a entries, which is an array + of length \a num_entries. + Creates its own copy of all keys and values from \a entries. */ +grpc_mdstr_hash_table* grpc_mdstr_hash_table_create( + size_t num_entries, grpc_mdstr_hash_table_entry* entries); + +grpc_mdstr_hash_table* grpc_mdstr_hash_table_ref(grpc_mdstr_hash_table* table); +void grpc_mdstr_hash_table_unref(grpc_exec_ctx* exec_ctx, + grpc_mdstr_hash_table* table); + +/** Returns the value from \a table associated with \a key. + Returns NULL if \a key is not found. */ +void* grpc_mdstr_hash_table_get(const grpc_mdstr_hash_table* table, + const grpc_mdstr* key); + +#endif /* GRPC_CORE_LIB_TRANSPORT_MDSTR_HASH_TABLE_H */ |