Class: ReadTool

Inherits:
LlmGateway::Tool show all
Defined in:
lib/llm_gateway/agents/tools/read_tool.rb

Constant Summary collapse

IMAGE_TYPE_SNIFF_BYTES = 
4100
PNG_SIGNATURE = 
[ 0x89, 0x50, 0x4e, 0x47, 0x0d, 0x0a, 0x1a, 0x0a ].freeze

Instance Method Summary collapse

Methods inherited from LlmGateway::Tool

cache, definition, description, #initialize, input_schema, name, tool_name, #tool_result

Constructor Details

This class inherits a constructor from LlmGateway::Tool

Instance Method Details

#execute(input, tool_use_id:) ⇒ Object 



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# File 'lib/llm_gateway/agents/tools/read_tool.rb', line 25

def execute(input, tool_use_id:)
  path = input[:path] || input["path"]
  offset = input[:offset] || input["offset"]
  limit = input[:limit] || input["limit"]

  absolute_path = ToolUtils.resolve_read_path(path)

  return tool_result("File not found: #{path}", tool_use_id: tool_use_id) unless File.exist?(absolute_path)
  return tool_result("Cannot read directory: #{path}", tool_use_id: tool_use_id) if File.directory?(absolute_path)
  return tool_result("File is not readable: #{path}", tool_use_id: tool_use_id) unless File.readable?(absolute_path)

  mime_type = detect_supported_image_mime_type_from_file(absolute_path)
  if mime_type
    data = Base64.strict_encode64(File.binread(absolute_path))
    return tool_result([
      { type: "text", text: "Read image file [#{mime_type}]" },
      { type: "image", data: data, media_type: mime_type }
    ], tool_use_id: tool_use_id)
  end

  content = File.read(absolute_path, mode: "r:bom|utf-8")
  all_lines = content.split("\n", -1)
  total_file_lines = all_lines.length

  start_line = [ 0, (offset || 1).to_i - 1 ].max
  return tool_result("Offset #{offset} is beyond end of file (#{all_lines.length} lines total)", tool_use_id: tool_use_id) if start_line >= all_lines.length

  selected_content = if limit
    end_line = [ start_line + limit.to_i, all_lines.length ].min
    all_lines[start_line...end_line].join("\n")
  else
    all_lines[start_line..].join("\n")
  end

  truncation = ToolUtils.truncate_head(selected_content)
  start_display = start_line + 1

  if truncation[:first_line_exceeds_limit]
    first_line_size = ToolUtils.format_size(all_lines[start_line].to_s.bytesize)
    return tool_result("[Line #{start_display} is #{first_line_size}, exceeds #{ToolUtils.format_size(ToolUtils::DEFAULT_MAX_BYTES)} limit. Use bash: sed -n '#{start_display}p' #{path} | head -c #{ToolUtils::DEFAULT_MAX_BYTES}]", tool_use_id: tool_use_id)
  end

  output = truncation[:content]

  if truncation[:truncated]
    end_display = start_display + truncation[:output_lines] - 1
    next_offset = end_display + 1
    suffix = if truncation[:truncated_by] == "lines"
      "[Showing lines #{start_display}-#{end_display} of #{total_file_lines}. Use offset=#{next_offset} to continue.]"
    else
      "[Showing lines #{start_display}-#{end_display} of #{total_file_lines} (#{ToolUtils.format_size(ToolUtils::DEFAULT_MAX_BYTES)} limit). Use offset=#{next_offset} to continue.]"
    end
    output = "#{output}\n\n#{suffix}"
  elsif limit && (start_line + limit.to_i) < all_lines.length
    next_offset = start_line + limit.to_i + 1
    remaining = all_lines.length - (start_line + limit.to_i)
    output = "#{output}\n\n[#{remaining} more lines in file. Use offset=#{next_offset} to continue.]"
  end

  tool_result(output, tool_use_id: tool_use_id)
rescue StandardError => e
  tool_result("Error reading file: #{e.message}", tool_use_id: tool_use_id)
end