class Chamomile::LogView

A scrollable log view with auto-scroll and SQL/error highlighting. Designed for streaming log panels.

Usage:

@log_view = Chamomile::LogView.new(max_lines: 1000)
@log_view.push("GET /users 200 10ms")
@log_view.push("SELECT * FROM users")
rendered = @log_view.render(width: 80, height: 20)

Constants

DIM_COLOR
ERROR_COLOR
ERROR_PATTERN
REQUEST_COLOR
REQUEST_PATTERN
RESET
SQL_COLOR
SQL_PATTERN

Attributes

line_count [R]

paused [R]

Public Class Methods

new (max_lines: 1000)

Source

# File lib/chamomile/components/log_view.rb, line 25
def initialize(max_lines: 1000)
  @lines         = []
  @max_lines     = max_lines
  @scroll_offset = 0
  @paused        = false
  @line_count    = 0
  @mutex         = Mutex.new
end

Public Instance Methods

at_bottom? (= @scroll_offset.zero?)

Source

# File lib/chamomile/components/log_view.rb, line 65
  def at_bottom? = @scroll_offset.zero?

  def render(width:, height:)
    @mutex.synchronize do
      return "" if height <= 0

      # Clamp scroll so we can't scroll past showing the first lines
      max_scroll = [@lines.size - height, 0].max
      effective_offset = [@scroll_offset, max_scroll].min

      visible = if effective_offset.zero?
                  @lines.last(height)
                else
                  bottom_idx = @lines.size - effective_offset
                  start_idx  = [bottom_idx - height, 0].max
                  @lines[start_idx...bottom_idx] || []
                end

      padded = visible.map { |l| truncate_ansi(l, width) }
      padded.fill("", padded.size...height)

      if effective_offset.positive? && height > 1
        status = " #{DIM_COLOR}↑ #{effective_offset} newer lines below (G to jump to bottom)#{RESET} "
        padded[-1] = status
      end

      padded.join("\n")
    end
  end

  def clear
    @mutex.synchronize do
      @lines.clear
      @scroll_offset = 0
      @line_count = 0
    end
  end

  private

  def highlight(line)
    case line
    when ERROR_PATTERN   then "#{ERROR_COLOR}#{line}#{RESET}"
    when SQL_PATTERN     then "#{SQL_COLOR}#{line}#{RESET}"
    when REQUEST_PATTERN then "#{REQUEST_COLOR}#{line}#{RESET}"
    else line
    end
  end

  def truncate_ansi(str, width)
    visible = 0
    result  = +""
    i       = 0
    in_escape = false
    has_escape = false
    while i < str.length
      char = str[i]
      if in_escape
        result << char
        in_escape = false if char == "m"
      elsif char == "\e"
        in_escape = true
        has_escape = true
        result << char
      else
        break if visible >= width

        result << char
        visible += 1
      end
      i += 1
    end
    result << RESET if has_escape
    result
  end
end

clear ()

Source

# File lib/chamomile/components/log_view.rb, line 95
def clear
  @mutex.synchronize do
    @lines.clear
    @scroll_offset = 0
    @line_count = 0
  end
end

highlight (line)

Source

# File lib/chamomile/components/log_view.rb, line 105
def highlight(line)
  case line
  when ERROR_PATTERN   then "#{ERROR_COLOR}#{line}#{RESET}"
  when SQL_PATTERN     then "#{SQL_COLOR}#{line}#{RESET}"
  when REQUEST_PATTERN then "#{REQUEST_COLOR}#{line}#{RESET}"
  else line
  end
end

pause! (= (@paused = true))

Source

# File lib/chamomile/components/log_view.rb, line 46
  def pause!  = (@paused = true)
  def resume! = (@paused = false)

  def scroll_up(n = 1)
    @mutex.synchronize do
      @scroll_offset = (@scroll_offset + n).clamp(0, [@lines.size - 1, 0].max)
    end
  end

  def scroll_down(n = 1)
    @mutex.synchronize do
      @scroll_offset = [@scroll_offset - n, 0].max
    end
  end

  def scroll_to_bottom
    @mutex.synchronize { @scroll_offset = 0 }
  end

  def at_bottom? = @scroll_offset.zero?

  def render(width:, height:)
    @mutex.synchronize do
      return "" if height <= 0

      # Clamp scroll so we can't scroll past showing the first lines
      max_scroll = [@lines.size - height, 0].max
      effective_offset = [@scroll_offset, max_scroll].min

      visible = if effective_offset.zero?
                  @lines.last(height)
                else
                  bottom_idx = @lines.size - effective_offset
                  start_idx  = [bottom_idx - height, 0].max
                  @lines[start_idx...bottom_idx] || []
                end

      padded = visible.map { |l| truncate_ansi(l, width) }
      padded.fill("", padded.size...height)

      if effective_offset.positive? && height > 1
        status = " #{DIM_COLOR}↑ #{effective_offset} newer lines below (G to jump to bottom)#{RESET} "
        padded[-1] = status
      end

      padded.join("\n")
    end
  end

  def clear
    @mutex.synchronize do
      @lines.clear
      @scroll_offset = 0
      @line_count = 0
    end
  end

  private

  def highlight(line)
    case line
    when ERROR_PATTERN   then "#{ERROR_COLOR}#{line}#{RESET}"
    when SQL_PATTERN     then "#{SQL_COLOR}#{line}#{RESET}"
    when REQUEST_PATTERN then "#{REQUEST_COLOR}#{line}#{RESET}"
    else line
    end
  end

  def truncate_ansi(str, width)
    visible = 0
    result  = +""
    i       = 0
    in_escape = false
    has_escape = false
    while i < str.length
      char = str[i]
      if in_escape
        result << char
        in_escape = false if char == "m"
      elsif char == "\e"
        in_escape = true
        has_escape = true
        result << char
      else
        break if visible >= width

        result << char
        visible += 1
      end
      i += 1
    end
    result << RESET if has_escape
    result
  end
end

push (line)

Source

# File lib/chamomile/components/log_view.rb, line 35
def push(line)
  @mutex.synchronize do
    return if @paused

    @lines << highlight(line.chomp)
    @lines.shift if @lines.size > @max_lines
    @line_count += 1
    @scroll_offset += 1 if @scroll_offset.positive?
  end
end

Thread-safe line push. Called from stream command threads.

render (width:, height:)

Source

# File lib/chamomile/components/log_view.rb, line 67
def render(width:, height:)
  @mutex.synchronize do
    return "" if height <= 0

    # Clamp scroll so we can't scroll past showing the first lines
    max_scroll = [@lines.size - height, 0].max
    effective_offset = [@scroll_offset, max_scroll].min

    visible = if effective_offset.zero?
                @lines.last(height)
              else
                bottom_idx = @lines.size - effective_offset
                start_idx  = [bottom_idx - height, 0].max
                @lines[start_idx...bottom_idx] || []
              end

    padded = visible.map { |l| truncate_ansi(l, width) }
    padded.fill("", padded.size...height)

    if effective_offset.positive? && height > 1
      status = " #{DIM_COLOR}↑ #{effective_offset} newer lines below (G to jump to bottom)#{RESET} "
      padded[-1] = status
    end

    padded.join("\n")
  end
end

resume! (= (@paused = false))

Source

# File lib/chamomile/components/log_view.rb, line 47
    def resume! = (@paused = false)

    def scroll_up(n = 1)
      @mutex.synchronize do
        @scroll_offset = (@scroll_offset + n).clamp(0, [@lines.size - 1, 0].max)
      end
    end

    def scroll_down(n = 1)
      @mutex.synchronize do
        @scroll_offset = [@scroll_offset - n, 0].max
      end
    end

    def scroll_to_bottom
      @mutex.synchronize { @scroll_offset = 0 }
    end

    def at_bottom? = @scroll_offset.zero?

    def render(width:, height:)
      @mutex.synchronize do
        return "" if height <= 0

        # Clamp scroll so we can't scroll past showing the first lines
        max_scroll = [@lines.size - height, 0].max
        effective_offset = [@scroll_offset, max_scroll].min

        visible = if effective_offset.zero?
                    @lines.last(height)
                  else
                    bottom_idx = @lines.size - effective_offset
                    start_idx  = [bottom_idx - height, 0].max
                    @lines[start_idx...bottom_idx] || []
                  end

        padded = visible.map { |l| truncate_ansi(l, width) }
        padded.fill("", padded.size...height)

        if effective_offset.positive? && height > 1
          status = " #{DIM_COLOR}↑ #{effective_offset} newer lines below (G to jump to bottom)#{RESET} "
          padded[-1] = status
        end

        padded.join("\n")
      end
    end

    def clear
      @mutex.synchronize do
        @lines.clear
        @scroll_offset = 0
        @line_count = 0
      end
    end

    private

    def highlight(line)
      case line
      when ERROR_PATTERN   then "#{ERROR_COLOR}#{line}#{RESET}"
      when SQL_PATTERN     then "#{SQL_COLOR}#{line}#{RESET}"
      when REQUEST_PATTERN then "#{REQUEST_COLOR}#{line}#{RESET}"
      else line
      end
    end

    def truncate_ansi(str, width)
      visible = 0
      result  = +""
      i       = 0
      in_escape = false
      has_escape = false
      while i < str.length
        char = str[i]
        if in_escape
          result << char
          in_escape = false if char == "m"
        elsif char == "\e"
          in_escape = true
          has_escape = true
          result << char
        else
          break if visible >= width

          result << char
          visible += 1
        end
        i += 1
      end
      result << RESET if has_escape
      result
    end
  end
end

scroll_down (n = 1)

Source

# File lib/chamomile/components/log_view.rb, line 55
def scroll_down(n = 1)
  @mutex.synchronize do
    @scroll_offset = [@scroll_offset - n, 0].max
  end
end

scroll_to_bottom ()

Source

# File lib/chamomile/components/log_view.rb, line 61
def scroll_to_bottom
  @mutex.synchronize { @scroll_offset = 0 }
end

scroll_up (n = 1)

Source

# File lib/chamomile/components/log_view.rb, line 49
def scroll_up(n = 1)
  @mutex.synchronize do
    @scroll_offset = (@scroll_offset + n).clamp(0, [@lines.size - 1, 0].max)
  end
end

truncate_ansi (str, width)

Source

# File lib/chamomile/components/log_view.rb, line 114
def truncate_ansi(str, width)
  visible = 0
  result  = +""
  i       = 0
  in_escape = false
  has_escape = false
  while i < str.length
    char = str[i]
    if in_escape
      result << char
      in_escape = false if char == "m"
    elsif char == "\e"
      in_escape = true
      has_escape = true
      result << char
    else
      break if visible >= width

      result << char
      visible += 1
    end
    i += 1
  end
  result << RESET if has_escape
  result
end