From 6a721b5b3f253b86eac3f34c66e6b2d47bb08c9e Mon Sep 17 00:00:00 2001 From: "Mark D. Roth" Date: Fri, 14 Oct 2016 12:43:34 -0700 Subject: Rename grpc_hash_table to grpc_mdstr_hash_table. --- src/core/lib/transport/mdstr_hash_table.c | 142 ++++++++++++++++++++++++++++++ 1 file changed, 142 insertions(+) create mode 100644 src/core/lib/transport/mdstr_hash_table.c (limited to 'src/core/lib/transport/mdstr_hash_table.c') diff --git a/src/core/lib/transport/mdstr_hash_table.c b/src/core/lib/transport/mdstr_hash_table.c new file mode 100644 index 0000000000..4be0536dd7 --- /dev/null +++ b/src/core/lib/transport/mdstr_hash_table.c @@ -0,0 +1,142 @@ +// +// 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. +// + +#include "src/core/lib/transport/mdstr_hash_table.h" + +#include +#include + +#include +#include + +#include "src/core/lib/transport/metadata.h" + +struct grpc_mdstr_hash_table { + gpr_refcount refs; + size_t num_entries; + grpc_mdstr_hash_table_entry* entries; +}; + +// Helper function for insert and get operations that performs quadratic +// probing (https://en.wikipedia.org/wiki/Quadratic_probing). +static size_t grpc_mdstr_hash_table_find_index( + const grpc_mdstr_hash_table* table, const grpc_mdstr* key, + bool find_empty) { + for (size_t i = 0; i < table->num_entries; ++i) { + const size_t idx = (key->hash + i * i) % table->num_entries; + if (table->entries[idx].key == NULL) + return find_empty ? idx : table->num_entries; + if (table->entries[idx].key == key) return idx; + } + return table->num_entries; // Not found. +} + +static void grpc_mdstr_hash_table_add( + grpc_mdstr_hash_table* table, grpc_mdstr* key, void* value, + const grpc_mdstr_hash_table_vtable* vtable) { + GPR_ASSERT(value != NULL); + const size_t idx = + grpc_mdstr_hash_table_find_index(table, key, true /* find_empty */); + GPR_ASSERT(idx != table->num_entries); // Table should never be full. + grpc_mdstr_hash_table_entry* entry = &table->entries[idx]; + entry->key = GRPC_MDSTR_REF(key); + entry->value = vtable->copy_value(value); + entry->vtable = vtable; +} + +grpc_mdstr_hash_table* grpc_mdstr_hash_table_create( + size_t num_entries, grpc_mdstr_hash_table_entry* entries) { + grpc_mdstr_hash_table* table = gpr_malloc(sizeof(*table)); + memset(table, 0, sizeof(*table)); + gpr_ref_init(&table->refs, 1); + // Quadratic probing gets best performance when the table is no more + // than half full. + table->num_entries = num_entries * 2; + const size_t entry_size = + sizeof(grpc_mdstr_hash_table_entry) * table->num_entries; + table->entries = gpr_malloc(entry_size); + memset(table->entries, 0, entry_size); + for (size_t i = 0; i < num_entries; ++i) { + grpc_mdstr_hash_table_entry* entry = &entries[i]; + grpc_mdstr_hash_table_add(table, entry->key, entry->value, entry->vtable); + } + return table; +} + +grpc_mdstr_hash_table* grpc_mdstr_hash_table_ref(grpc_mdstr_hash_table* table) { + if (table != NULL) gpr_ref(&table->refs); + return table; +} + +int grpc_mdstr_hash_table_unref(grpc_mdstr_hash_table* table) { + if (table != NULL && gpr_unref(&table->refs)) { + for (size_t i = 0; i < table->num_entries; ++i) { + grpc_mdstr_hash_table_entry* entry = &table->entries[i]; + if (entry->key != NULL) { + GRPC_MDSTR_UNREF(entry->key); + entry->vtable->destroy_value(entry->value); + } + } + gpr_free(table->entries); + gpr_free(table); + return 1; + } + return 0; +} + +void* grpc_mdstr_hash_table_get(const grpc_mdstr_hash_table* table, + const grpc_mdstr* key) { + const size_t idx = + grpc_mdstr_hash_table_find_index(table, key, false /* find_empty */); + if (idx == table->num_entries) return NULL; // Not found. + return table->entries[idx].value; +} + +int grpc_mdstr_hash_table_cmp(const grpc_mdstr_hash_table* table1, + const grpc_mdstr_hash_table* table2) { + // Compare by num_entries. + if (table1->num_entries < table2->num_entries) return -1; + if (table1->num_entries > table2->num_entries) return 1; + for (size_t i = 0; i < table1->num_entries; ++i) { + grpc_mdstr_hash_table_entry* e1 = &table1->entries[i]; + grpc_mdstr_hash_table_entry* e2 = &table2->entries[i]; + // Compare keys by hash value. + if (e1->key->hash < e2->key->hash) return -1; + if (e1->key->hash > e2->key->hash) return 1; + // Compare by vtable (pointer equality). + if (e1->vtable < e2->vtable) return -1; + if (e1->vtable > e2->vtable) return 1; + // Compare values via vtable. + const int value_result = e1->vtable->compare_value(e1->value, e2->value); + if (value_result != 0) return value_result; + } + return 0; +} -- cgit v1.2.3