Fix performance issue caused by using repeated > characters inside <?xml
#170
Conversation
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
…`<?xml`
A `<` is treated as a string delimiter.
In certain cases, if `<` is used in succession, read and match are repeated, which slows down the process.
Therefore, the following is used to read ahead to a specific part of the string in advance.
## Proof of Concept
```ruby
require "rexml"
require "benchmark"
def test(benchmark, payload)
benchmark.report { begin REXML::Document.new(payload) rescue Exception end }
end
Benchmark.bm do |x|
test(x, '<?xml version="1.0" ' + ">" * 20000 + ' ?>')
test(x, '<?xml version="1.0" ' + ">" * 40000 + '?>')
test(x, '<?xml version="1.0" ' + ">" * 60000 + '?>')
test(x, '<?xml version="1.0" ' + ">" * 80000 + '/>')
test(x, '<?xml version="1.0" ' + ">" * 100000 + '/>')
end
```
kou
reviewed
Jul 16, 2024
|
Thanks. |
# for free
to join this conversation on GitHub.
Already have an account?
# to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
A
<is treated as a string delimiter.In certain cases, if
<is used in succession, read and match are repeated, which slows down the process. Therefore, the following is used to read ahead to a specific part of the string in advance.