Class: Annotato::IndexFormatter

Inherits:
Object
  • Object
show all
Defined in:
lib/annotato/index_formatter.rb

Constant Summary collapse

MAX_LINE = 
100

Class Method Summary collapse

Class Method Details

.format(conn, table_name) ⇒ Object 



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# File 'lib/annotato/index_formatter.rb', line 7

def self.format(conn, table_name)
  conn.indexes(table_name).map do |idx|
    cols_list = Array(idx.columns).join(',')
    unique_clause = idx.unique ? " unique" : ""

    where_clause = ""
    if idx.where
      where_clause = "\n" + wrap_where(idx.where, max_len: MAX_LINE)
    end

    "#  #{idx.name} (#{cols_list})#{unique_clause}#{where_clause}"
  end
end

.wrap_where(where_sql, max_len:) ⇒ Object

Produces one or more lines, each already prefixed with “# ” First line: “# where (…” Next lines: “# …” (aligned under the “(”)



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# File 'lib/annotato/index_formatter.rb', line 24

def self.wrap_where(where_sql, max_len:)
  first_prefix = "#    where ("
  cont_prefix  = "#          " # aligns under the "(" after "where "

  text = where_sql.to_s
  lines = []

  # If it already fits, keep it one-liner
  if (first_prefix.length + text.length + 1) <= max_len
    return "#{first_prefix}#{text})"
  end

  remaining = text.dup
  current_prefix = first_prefix

  while remaining.length > 0
    available = max_len - current_prefix.length - 1 # -1 for closing ")" on last line (or just safety)
    available = 20 if available < 20

    if remaining.length <= available
      lines << "#{current_prefix}#{remaining}"
      remaining = ""
      break
    end

    # Prefer breaking on logical operators within the window
    window = remaining[0, available]
    cut =
      window.rindex(" AND ") ||
      window.rindex(" OR ")  ||
      window.rindex(", ")    ||
      window.rindex(") ")    ||
      window.rindex(" ")     # last resort: whitespace

    # If we found a breakpoint, include it in the line (so operators stay visible)
    if cut
      # If we’re cutting on AND/OR/comma, keep that token at the end of the line when possible
      if window[cut, 5] == " AND " || window[cut, 4] == " OR "
        cut += (window[cut, 5] == " AND " ? 5 : 4)
      elsif window[cut, 2] == ", "
        cut += 2
      elsif window[cut, 2] == ") "
        cut += 2
      else
        cut += 1
      end
    else
      cut = available
    end

    lines << "#{current_prefix}#{remaining[0, cut].rstrip}"
    remaining = remaining[cut..].to_s.lstrip
    current_prefix = cont_prefix
  end

  # Close the paren on the last line
  lines[-1] = "#{lines[-1]})"

  lines.join("\n")
end