qlog

A TUI (Terminal User Interface) application for viewing and filtering como-data-center log files with Helix-style keybindings.

Features

• Unified Log View: Merge all log files chronologically with auto-detected timestamps
• Filters: Include/exclude filters with case-insensitive substring matching
• Search: Incremental search with n/N navigation and match highlighting
• Selection & Yank: Select lines with x and copy to clipboard with y
• Helix Keybindings: Modal editing with hjkl navigation and : command mode
• Generic Log Support: Works with any text log format (not just JSON)
• Async Loading: Efficient loading for large datasets
• Virtual Scrolling: Handle millions of lines with only visible lines rendered
• Horizontal Scroll: View wide log content with wrap mode toggle
• Configurable Log Coloring: Customize line colors via TOML config files
• Export: Save filtered results to file with :write command

Installation

cd qlog
cargo build --release

The binary will be at target/release/qlog.

Usage

# Automatically find *.log files in current directory
./qlog

# Or specify specific log files
./qlog /path/to/*.log

Keybindings

Navigation (Normal Mode)

• j/k or Arrow Up/Down - Scroll through logs
• h/l or Arrow Left/Right - Horizontal scroll
• g - Go to top
• G - Go to bottom
• w - Toggle wrap mode
• : - Enter command mode
• / - Enter search mode
• n - Next search match
• N - Previous search match
• x - Start/extend line selection
• y - Yank (copy) selected lines to clipboard
• Esc - Clear selection
• q - Quit application (or :q / :quit in command mode)

Command Mode (:)

• filter <text> - Add include filter
• filter-out <text> - Add exclude filter
• filter-clear - Clear all filters
• list-filters - Show filter list view
• write [filename] or w [filename] - Save filtered logs to file
• quit or q - Quit application
• Enter - Execute command
• Esc - Cancel and return to normal mode
• Backspace - Delete character

Filter List Mode

• j/k or Arrow Up/Down - Select filter
• d - Delete selected filter
• Enter / Esc / q - Return to normal mode

Search Input Mode (/)

• Enter - Execute search
• Esc - Cancel and return to normal mode
• Backspace - Delete character

Filters

qlog supports include and exclude filters:

• Include filters: Lines must contain at least one include filter text (OR logic between multiple includes)
• Exclude filters: Lines containing any exclude filter text are hidden
• Filters are combined as: `(include1 OR include2) AND NOT (exclude1 OR exclude2)

Filter matching is case-insensitive substring search against the raw log line.

Add filters via command mode (:):

• :filter <text> - Add include filter
• :filter-out <text> - Add exclude filter
• :filter-clear - Remove all filters
• :list-filters - View and manage active filters

Log Coloring

Log lines can be colored based on pattern matching. Create a configuration file at:

1. ./.qlog/qlog.toml (current directory) - takes precedence
2. ~/.qlog/qlog.toml (home directory) - fallback

Example Configuration

[colors]
error = "red"
warn = "yellow"
success = "green"
"*TODO*" = "magenta"

Pattern Matching

• error - matches lines containing "error" (case-insensitive)
• *error - matches lines ending with "error"
• error* - matches lines starting with "error"
• *error* - matches lines containing "error"

First match wins based on config file order. Timestamps remain cyan regardless of line color.

Supported Colors

Basic: red, green, blue, yellow, magenta, cyan, white, black, gray

Extended: dark_gray, light_red, light_green, light_blue, light_yellow, light_magenta, light_cyan

Architecture

src/
├── main.rs              # Entry point and CLI args
├── lib.rs               # Library exports
├── app.rs               # Application state and key handling
├── clipboard.rs         # Clipboard integration for copy operations
├── config.rs            # Log coloring configuration
├── model/
│   ├── log_entry.rs     # Log entry (raw text + optional timestamp)
│   ├── filter.rs        # FilterList with include/exclude logic
│   ├── timestamp.rs     # Timestamp detection from log lines
│   ├── mmap_str.rs      # Memory-mapped string wrapper
│   ├── line_info.rs     # Line position tracking for log files
│   ├── log_storage.rs   # Memory-mapped log storage with indexing
│   ├── visual_line_cache.rs  # Visual line calculation caching
│   ├── selection.rs     # Line selection state management
│   └── mod.rs           # Model module exports
├── storage/
│   ├── loader.rs        # Log file loading
│   └── mod.rs           # Storage module exports
└── ui/
    └── mod.rs           # TUI rendering (filter bar, log list, status)

Testing

cargo test

Tests cover:

• Filter matching logic (include/exclude filters)
• Case-insensitive text matching
• Timestamp detection from various formats
• Log loading from files
• Memory-mapped string operations
• Visual line calculation caching
• Selection state management
• Configuration parsing
• Search matching with Boyer-Moore-Horspool algorithm

Performance

• Memory-mapped files for efficient reading
• Virtual scrolling renders only visible lines
• Async file loading keeps UI responsive
• Optimized filtering with Boyer-Moore-Horspool algorithm - 10-100x faster substring matching
• Zero-allocation, byte-level case-insensitive matching (ASCII-only)
• Early termination for AND-combined filter groups
• Optimized for 2.5GB+ datasets

License

MIT