Performance in debug mode degraded by slow std::string::const_iterator constructor
Nobody has claimed this yet.
Assessment
- Difficulty
- 4/5
- Estimated time
- 3-5 days
- Newbie friendliness
- 35/100
- Issue type
- Bug
- Clarity
- Mostly clear
- Activity status
- Stale
- Tech stack
- cpp
- Domain
- performance
Research direction
No file or test is named in the issue. Start by locating Boost.Parser's iterator-taking interfaces and reproducing the reported MSVC debug profile; done means changing the justified pass-by-value arguments without altering parser behavior and confirming the debug performance improvement.
Written by the indexing model from the issue text.
Description
Unfortunately, boost.parser is very slow in debug mode.
Fortunately, this would be rather easy to change.
I have colleagues complaining because the Boost.Parser based parser takes forever in debug mode. I fired up VTune and quickly found that more than 60% of the total runtime is spent in the constructor and destructor of std::string::const_iterator. Boost.Parser is written under the assumption (it seems) that copying an iterator is basically free, which is probably true in release mode. But in MSVC/Debug it is a very expensive operation.
Looking at the code, I got the impression that in most places, nothing would be lost passing the iterators as const-ref instead of by-value. And the debug runtime would dramatically improve. Would you be open to change to const-ref for most iterator arguments? If so, I'd consider creating a Pull request doing this. Or am I missing a use case where the pass-by-value is beneficial?
- Dominant language
- C++
- Stars
- 182
- Forks
- 28
- PR merge metrics
- No merged PRs in 30d
Contributor guide
No contributing guide indexed for this repository
First steps
- Read the whole issue, then the project's contributing guide.
- Comment on the issue to say you are picking it up — it saves two people doing the same work.
- Fork the repository and make your change on a branch.
- Open a pull request that references the issue number.
More from boostorg/parser
-
Difficulty 2/5 1-3 hours Newbie friendliness 68/100
-
Difficulty 1/5 Under an hour Newbie friendliness 82/100
-
Difficulty 1/5 Under an hour Newbie friendliness 20/100
-
Difficulty 3/5 1-2 days Newbie friendliness 55/100
-
Difficulty 3/5 1-2 days Newbie friendliness 48/100
Similar issues
-
Difficulty 2/5 1-3 hours Newbie friendliness 70/100
google/libultrahdr#485 ·
-
Difficulty 2/5 1-3 hours Newbie friendliness 75/100
godotengine/godot#123776 ·
-
bug
Difficulty 1/5 Under an hour Newbie friendliness 60/100
-
good first issue
Difficulty 1/5 Under an hour Newbie friendliness 90/100
-
good first issue
Difficulty 2/5 1-3 hours Newbie friendliness 75/100
ros2/common_interfaces#344 ·