rabbitmq-server/deps/rabbitmq_cli/lib/table_print.ex

133 lines
4.0 KiB
Elixir

## The contents of this file are subject to the Mozilla Public License
## Version 1.1 (the "License"); you may not use this file except in
## compliance with the License. You may obtain a copy of the License
## at http://www.mozilla.org/MPL/
##
## Software distributed under the License is distributed on an "AS IS"
## basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
## the License for the specific language governing rights and
## limitations under the License.
##
## The Original Code is RabbitMQ.
##
## The Initial Developer of the Original Code is GoPivotal, Inc.
## Copyright (c) 2007-2016 Pivotal Software, Inc. All rights reserved.
defmodule TablePrint do
@n_app_divider_space 3
def print_table(result, _, _) when not is_list(result), do: nil
def print_table(result, field, table_name) do
case result[field] do
nil -> nil
[] -> IO.puts "#{table_name}: None"
_ -> tuple_to_table(result[field], table_name)
end
end
def tuple_to_table(nil, _), do: nil
def tuple_to_table([], _), do: nil
def tuple_to_table(table, table_name) do
ncols = table |> List.first |> tuple_size
widths = column_widths(table, ncols)
io_format_str = generate_io_format(List.first(table), widths)
print_table_name(table_name)
print_dashed_line(widths)
Enum.map(
table,
fn (field_tuple) ->
:io.format(io_format_str, Tuple.to_list(field_tuple))
end
)
end
def generate_io_format({}, _), do: ""
def generate_io_format(_, {}), do: ""
def generate_io_format(field_tuple, field_widths) do
io_str = List.zip([field_widths |> Tuple.to_list, field_tuple |> Tuple.to_list])
|> Enum.map(fn({width, name}) -> "~-#{width}#{io_wildcard(name)}" end)
|> Enum.join(" | ")
io_str <> "\n"
end
# Calculates the widths needed to print the given columns
def column_widths(tuple_list, ncols) do
case tuple_list do
nil -> List.duplicate(0, ncols) |> List.to_tuple
[] -> List.duplicate(0, ncols) |> List.to_tuple
_ -> tuple_list |> get_field_widths |> max_accumulator(ncols)
end
end
def print_dashed_line(nil), do: nil
def print_dashed_line({}), do: nil
def print_dashed_line(field_widths) do
line_length = dividing_line_length(field_widths)
IO.puts String.duplicate("-", line_length)
end
defp get_field_widths(tuple_list) do
tuple_list |> Enum.map(
fn(tup) ->
tup
|> Tuple.to_list
|> Enum.map(&elt_length/1)
end
)
end
# input: a list of n-element lists generated by get_field_widths
# an integer of value > 0 representing the number of fields
# output: an n-tuple containing the largest element in each column.
defp max_accumulator(app_widths_list, ncols) do
Enum.reduce(
app_widths_list,
List.duplicate(0, ncols),
fn (app_widths, acc) ->
List.zip([app_widths, acc])
|> Enum.map(fn({a,b}) -> max(a,b) end)
|> List.to_tuple
end
)
end
defp dividing_line_length(field_widths) do
field_widths
|> Tuple.to_list
|> Enum.sum
|> + (@n_app_divider_space * num_dividers(field_widths))
end
defp num_dividers(field_widths) do
tuple_size(field_widths) - 1
end
defp elt_length(target) when is_list(target) do
target |> length
end
defp elt_length(target) when is_atom(target) do
target |> Atom.to_char_list |> length
end
defp elt_length(target) when is_integer(target) do
target |> Integer.to_char_list |> length
end
defp print_table_name(nil), do: nil
defp print_table_name(""), do: nil
defp print_table_name(name) when is_binary(name), do: IO.puts "#{name}:"
defp print_table_name(name) when is_list(name), do: IO.puts "#{name}:"
defp io_wildcard(field) when is_integer(field), do: "w"
defp io_wildcard(field) when is_atom(field), do: "w"
defp io_wildcard(field) when is_float(field), do: "w"
defp io_wildcard(field) when is_binary(field), do: "s"
defp io_wildcard(field) when is_list(field), do: "s"
end