bensadeh/tailspin 7.0.0

on GitHub

This release marks almost four years since the first version of tailspin. Since then, there have been many changes and
many refinements´, so for 7.0.0, thought it would be a good time to reflect a bit on the journey.

Starting out, I read lots of colorless logs in the terminal in very different formats. After a while, I got a very
simple idea: I know what a timestamp / IP address / UUID etc. looks like. I recognize this and this part of the log line
as distinct things, and if I can distinguish these different elements from each other, then surely a cli should be able
to as well.

The first version of tailspin (1.0) was written in Go and focused on highlighting the correct elements without
producing false positives. This version was unnecessarily inefficient because the regexes were re-compiled each line
and the engine was single threaded. However, the cli did the job for me, logs were easier to read and I didn't have to
think about what schema or format the log was in.

Since then, the cli has been re-written in Rust and become a lot faster, but the core is still the same:
"I know what a timestamp looks like--color it".

Below is a benchmark test ran over a 44 MB log file on the same machine.

Breaking Changes

• Builtin keywords (log severities, booleans, nulls and common rest verbs) are now a regular
  highlight group named keywords: use --disable keywords instead of the removed
  --disable-builtin-keywords
• --config-path has been renamed to --theme
• the hidden --generate-bash-completions, --generate-fish-completions and
  --generate-zsh-completions flags have been replaced by --completions <shell>
• the [ip_addresses] theme table has been split into [ipv4] and [ipv6], matching the
  highlight group names; each table now styles only its own highlighter
• the number key in the [numbers] theme table has been renamed to style
• Windows: the theme now resolves to %appdata%\tailspin\theme.toml instead of
  %userprofile%\tailspin\theme.toml, following the platform convention

New Features

• tailspin_theme environment variable to set the theme path without the --theme flag
• --completions <shell> prints shell completions to stdout, now also for elvish and powershell
• --highlight accepts the full 16-color palette (e.g. bright_red), using the same color names
  as theme.toml
• --generate-default-theme is no longer hidden and is documented in the man page
• highlighter implements clone
• Added duration highlighter
• Generate default-theme.toml with the default style of every highlight group

Crate

• theme config struct now derives serialize and deserialize, so theme.toml tables
  deserialize directly into the config structs
• highlighterbuilder::with_date_time_highlighters renamed to with_date_time_highlighter
• highlighterbuilder::with_keyword_highlighter renamed to with_keyword_highlighters, matching
  its vec<keywordconfig> parameter

Changed

• --exec now takes precedence over piped stdin when both are present
• --exec now exits with an error when the spawned command exits non-zero
• --pager now rejects commands missing the [FILE] placeholder
• Theme style tables now reject unknown keys
• The missing-filename message now prints to stderr

Performance

• Match all keyword groups with a single automaton instead of one per style
• Batch lines in a shared buffer instead of allocating one string per line
• Skip the JVM exception header scan on lines without Exception or Error
• Highlight batches through per-thread highlighter clones to avoid regex cache contention
• Intern styles into a build-time palette so render resolves ANSI prefixes by index

Fixed

• Highlighter::default() now applies groups in the same precedence order as the CLI
• Dates embedded in longer digit runs (e.g. 12022-09-09) no longer highlight as dates
• Ctrl+C while the pager is open exits cleanly instead of printing an error
• Keywords sharing a prefix with a shorter keyword (e.g. WARNING vs. WARN) are now highlighted
• Overlapping background-styled keywords no longer lose their badge padding
• IPv6 addresses with a netmask over 128 no longer highlight

Build

• Replace the tokio runtime with plain threads and blocking IO