Performance

Measure performance with representative input. Document size, nesting, custom handlers, and your Ruby engine all affect conversion time.

Reuse your configuration

The default handler registries and tag library are shared and frozen. Use .default to build a fresh registry when you need to customize it.

Build a custom renderer once and reuse it across conversions:

renderer = Markbridge.discourse_renderer(escape_hard_line_breaks: true)

posts.each do |post|
  result = Markbridge.bbcode_to_markdown(post.body, renderer:)
  puts result.markdown
end

The renderer stores no per-document state. Your custom handlers and tags should follow the same rule if you share them across calls or threads.

Process one document at a time

Each conversion builds its AST and output in memory. For large collections, read and write one document at a time instead of keeping every result.

require "csv"
require "markbridge/bbcode"

CSV.foreach("posts.csv", headers: true) do |row|
  result = Markbridge.bbcode_to_markdown(row["body"])
  puts result.markdown
end

Parser limits

The BBCode parser limits nesting to 100 levels. Its built-in handlers preserve an opening tag as text when that limit is reached and record depth_exceeded_count in the diagnostics. A custom handler that calls ParserState#push without a token can raise MaxDepthExceededError at that limit.

Closing strategies search at most five levels when reconciling mismatched tags. These limits keep searches bounded on deeply nested input.

How parsing works

• BBCode: the scanner uses byte offsets and integer checks for ASCII syntax. Offsets remain on character boundaries for multibyte input.
• HTML and TextFormatter: Nokogiri parses the input before Markbridge walks the document. Pass an existing Nokogiri node if your code has already parsed it.
• MediaWiki: the parser reads block syntax by line and uses a separate parser for inline markup.

Adjacent text nodes merge during AST construction. The renderer walks the resulting tree and uses a parent context for nested content.

Measure your workload

Read input before timing if you want to measure conversion without file access:

require "benchmark"
require "markbridge/bbcode"

inputs = File.readlines("corpus.txt", chomp: true)

Benchmark.bm do |benchmark|
  benchmark.report("conversion") do
    inputs.each { |input| Markbridge.bbcode_to_markdown(input) }
  end
end

On CRuby, compare runs with YJIT enabled:

ruby --yjit your_script.rb

JRuby and TruffleRuby have their own JIT compilers. Allow time for warmup and compare both startup time and sustained conversion speed.

Repository benchmarks

Run benchmarks through bin/bench-env. It selects the fastest CPU cores and reports power and governor settings. Compare runs on AC power with the same governor.

bin/bench-env bundle exec ruby --yjit bench/bench.rb --isolated
DURATION=60 WINDOW=5 POSTS=2000 CORPUS=ascii bin/bench-env bundle exec ruby --yjit bench/sustained_bench.rb
DURATION=60 WINDOW=5 POSTS=2000 CORPUS=multi bin/bench-env bundle exec ruby --yjit bench/sustained_bench.rb

Run the ASCII and multibyte corpora in separate processes. See Benchmark results for recorded measurements and their limits.