From 238b72fdb42cfdfe78a75a366b599b58a245705c Mon Sep 17 00:00:00 2001 From: suoyuan666 <107405806+suoyuan666@users.noreply.github.com> Date: Thu, 25 Jul 2024 11:00:20 +0800 Subject: [PATCH] update site --- src/content/blog/CS144_lab1.md | 71 ++++++++++++++++------------------ 1 file changed, 34 insertions(+), 37 deletions(-) diff --git a/src/content/blog/CS144_lab1.md b/src/content/blog/CS144_lab1.md index 80e4284..2b9d22d 100644 --- a/src/content/blog/CS144_lab1.md +++ b/src/content/blog/CS144_lab1.md @@ -18,11 +18,12 @@ description: "CS144 课程 Lab Assignment 中的 Checkpoint 1: stitching substr 在 `Reassembler` 类中添加下面这些字段: ```cpp - std::unordered_map buffer_ {}; - uint64_t used_index {0}; + std::deque buffer_ {}; + std::deque buf_enable_ {false}; + uint64_t used_index_ {0}; uint64_t wcount_ {0}; - bool fetch_last {false}; - uint64_t max_length {0}; + bool fetch_last_ {false}; + uint64_t max_length_ {0}; ``` 对于 `insert()` 和 `bytes_pending()` 的实现: @@ -30,38 +31,34 @@ description: "CS144 课程 Lab Assignment 中的 Checkpoint 1: stitching substr ```cpp void Reassembler::insert( uint64_t first_index, string data, bool is_last_substring ) { - auto& write = output_.writer(); - const auto& available_capacity = write.available_capacity(); - if (available_capacity == 0) { - return; + const auto limit = std::min( data.size(), used_index_ + output_.writer().available_capacity() - first_index ); + + if (buffer_.size() < first_index + limit) { + buffer_.resize(first_index + limit); + buf_enable_.resize(first_index + limit); } - const auto &dlen = static_cast(data.length()); - for (auto i = 0; i < dlen; ++i){ - const auto index = first_index + i; - if (buffer_.contains(index)) { + for ( uint64_t i = 0; i < limit; ++i ) { + if (buf_enable_.at(first_index + i)) { continue; } - if (index < used_index + available_capacity) { - buffer_.insert({index, data.at(i)}); - wcount_ += 1; - } + buffer_[first_index + i] = data.at(i); + buf_enable_[first_index + i] = true; + wcount_ += 1; } - if (is_last_substring) { - fetch_last = true; - max_length = first_index + dlen; + if ( is_last_substring ) { + fetch_last_ = true; + max_length_ = first_index + data.size(); } - - std::string str {}; - for (; buffer_.contains(used_index); ++used_index ) { - str.push_back(std::move(buffer_.at(used_index))); + for (; used_index_ < buf_enable_.size() && buf_enable_.at(used_index_); ++used_index_) { + output_.writer().push( std::string { buffer_.at( used_index_ ) } ); --wcount_; } - write.push(std::move(str)); - if (fetch_last && used_index == max_length) { + if ( fetch_last_ && used_index_ == max_length_ ) { buffer_.clear(); - write.close(); + buf_enable_.clear(); + output_.writer().close(); } } @@ -71,26 +68,26 @@ uint64_t Reassembler::bytes_pending() const } ``` -不过这样得不到太高的速度，我等下次尝试优化一下吧（逃 +~~不过这样得不到太高的速度，我等下次尝试优化一下吧（逃~~ 我就是 C++ 菜狗，优化也优化不了什么，换了个数据结构，一开始用 `std::unordered_map`，查找很方便，但是插入擦除貌似就不是很行了，我选择用了 `std::deque` 和 `std::deque` 来代替，需要一个 bool 类型的 `std::deque<>` 是因为我为了让插入字符的位置就是该字符实际的索引位置，直接 `resize` 放大 buffer 的大小，我想通过 `std::deque buf_enable_` 标示一下哪个位是真实有效的，哪个是还没有值的。 ```bash $ cmake --build build -j`nproc` --target check1 Test project /home/zuos/codPjt/Cpp/minnow/build Connected to MAKE jobserver Start 1: compile with bug-checkers - 1/17 Test #1: compile with bug-checkers ........ Passed 2.79 sec + 1/17 Test #1: compile with bug-checkers ........ Passed 0.17 sec Start 3: byte_stream_basics 2/17 Test #3: byte_stream_basics ............... Passed 0.01 sec Start 4: byte_stream_capacity 3/17 Test #4: byte_stream_capacity ............. Passed 0.01 sec Start 5: byte_stream_one_write - 4/17 Test #5: byte_stream_one_write ............ Passed 0.02 sec + 4/17 Test #5: byte_stream_one_write ............ Passed 0.01 sec Start 6: byte_stream_two_writes 5/17 Test #6: byte_stream_two_writes ........... Passed 0.01 sec Start 7: byte_stream_many_writes 6/17 Test #7: byte_stream_many_writes .......... Passed 0.04 sec Start 8: byte_stream_stress_test - 7/17 Test #8: byte_stream_stress_test .......... Passed 0.26 sec + 7/17 Test #8: byte_stream_stress_test .......... Passed 0.25 sec Start 9: reassembler_single 8/17 Test #9: reassembler_single ............... Passed 0.01 sec Start 10: reassembler_cap @@ -104,18 +101,18 @@ Connected to MAKE jobserver Start 14: reassembler_overlapping 13/17 Test #14: reassembler_overlapping .......... Passed 0.01 sec Start 15: reassembler_win -14/17 Test #15: reassembler_win .................. Passed 6.99 sec +14/17 Test #15: reassembler_win .................. Passed 5.40 sec Start 37: compile with optimization -15/17 Test #37: compile with optimization ........ Passed 1.80 sec +15/17 Test #37: compile with optimization ........ Passed 0.11 sec Start 38: byte_stream_speed_test - ByteStream throughput: 0.66 Gbit/s -16/17 Test #38: byte_stream_speed_test ........... Passed 0.18 sec + ByteStream throughput: 0.59 Gbit/s +16/17 Test #38: byte_stream_speed_test ........... Passed 0.19 sec Start 39: reassembler_speed_test - Reassembler throughput: 0.12 Gbit/s -17/17 Test #39: reassembler_speed_test ........... Passed 1.19 sec + Reassembler throughput: 0.30 Gbit/s +17/17 Test #39: reassembler_speed_test ........... Passed 0.50 sec 100% tests passed, 0 tests failed out of 17 -Total Test time (real) = 13.40 sec +Total Test time (real) = 6.78 sec Built target check1 ```