| // Copyright (C) 2019 Google LLC |
| // |
| // 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 "icing/performance-configuration.h" |
| |
| #include "icing/result/result-state.h" |
| #include "icing/scoring/scored-document-hit.h" |
| |
| namespace icing { |
| namespace lib { |
| |
| namespace { |
| // Search-related thresholds: |
| // Search performance mainly involves the following components: |
| // 1. QueryProcessor |
| // Running time is O(query_length) according to results of |
| // //icing/query:query-processor_benchmark. |
| // 2. ScoringProcessor and Ranker |
| // Running time is O(num_to_score) according to results of |
| // //icing/scoring:score-and-rank_benchmark. Note that the |
| // process includes scoring, building a heap, and popping results from the |
| // heap. |
| // 3. ResultRetriever |
| // Running time is O(page_size). Assuming page_size is always a small number, |
| // it's actually O(1). |
| // |
| // Overall Search performance goal: 33 ms. On a 60FPS screen it's the time of |
| // rendering 2 frames. |
| // |
| // With the information above, we then try to choose default values for |
| // query_length and num_to_score so that the overall time can comfortably fit |
| // in with our goal. |
| // 1. Set query_length to 23000 so that any query can be executed by |
| // QueryProcessor within 15 ms on a Pixel 3 XL according to results of |
| // //icing/query:query-processor_benchmark. |
| // 2. Set num_to_score to 30000 so that results can be scored and ranked within |
| // 3 ms on a Pixel 3 XL according to results of |
| // //icing/scoring:score-and-rank_benchmark. |
| // |
| // In the worse-case scenario, we still have [33 ms - 15 ms - 3 ms] = 15 ms left |
| // for all the other things like proto parsing, document fetching, and even |
| // Android Binder calls if Icing search engine runs in a separate process. |
| constexpr int kMaxQueryLength = 23000; |
| constexpr int kDefaultNumToScore = 30000; |
| |
| // New Android devices nowadays all allow more than 16 MB memory per app. Using |
| // that as a guideline and being more conservative, we set 4 MB as the safe |
| // memory threshold. |
| // TODO(b/150029642): Android apps / framework have better understanding of how |
| // much memory is allowed, so it would be better to let clients pass in this |
| // value. |
| constexpr int kSafeMemoryUsage = 4 * 1024 * 1024; // 4MB |
| |
| // The maximum number of hits that can fit below the kSafeMemoryUsage threshold. |
| constexpr int kMaxNumTotalHits = kSafeMemoryUsage / sizeof(ScoredDocumentHit); |
| |
| } // namespace |
| |
| PerformanceConfiguration::PerformanceConfiguration() |
| : PerformanceConfiguration(kMaxQueryLength, kDefaultNumToScore, |
| kMaxNumTotalHits) {} |
| |
| } // namespace lib |
| } // namespace icing |