Class: MysqlDumpToJson::MySQL::Reader

Inherits:
Object
  • Object
show all
Defined in:
lib/mysql_dump_to_json/mysql/reader.rb

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(database, opts = {}) ⇒ Reader

Returns a new instance of Reader.



12
13
14
15
16
 
# File 'lib/mysql_dump_to_json/mysql/reader.rb', line 12

def initialize(database, opts = {})
  @database = database
  @tables = {}
  @opts = opts
end

Instance Attribute Details

#database ⇒ Object (readonly)

Returns the value of attribute database.



10
11
12
 
# File 'lib/mysql_dump_to_json/mysql/reader.rb', line 10

def database
  @database
end

#opts ⇒ Object (readonly)

Returns the value of attribute opts.



10
11
12
 
# File 'lib/mysql_dump_to_json/mysql/reader.rb', line 10

def opts
  @opts
end

#source_dump ⇒ Object (readonly)

Returns the value of attribute source_dump.



10
11
12
 
# File 'lib/mysql_dump_to_json/mysql/reader.rb', line 10

def source_dump
  @source_dump
end

#statements ⇒ Object (readonly)

Returns the value of attribute statements.



10
11
12
 
# File 'lib/mysql_dump_to_json/mysql/reader.rb', line 10

def statements
  @statements
end

Instance Method Details

#build_database ⇒ Object

Creating the database as objects



26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
 
# File 'lib/mysql_dump_to_json/mysql/reader.rb', line 26

def build_database
  @statements.each_with_index do |sql_statement|
    case sql_statement
    when /^CREATE +DATABASE/i,
        /^USE/i,
        /^DROP +TABLE/i,
        /^LOCK TABLES/i,
        /^UNLOCK TABLES/i, ';'
      next
    when /^CREATE +TABLE/i
      create_table(sql_statement)
    when /^INSERT +INTO/i
      insert_into(sql_statement)
    else
      warn " !!! SQL statement found that is not handled by this gem: #{sql_statement.split("\n").first}"
    end
  end
  @database
end

#compress_sql_into_statements ⇒ Object

Compressing the source into distinct SQL statements



180
181
182
183
184
 
# File 'lib/mysql_dump_to_json/mysql/reader.rb', line 180

def compress_sql_into_statements
  str = remove_block_comments(@source_dump)
  uncommented = strip_comments(str)
  uncommented.split(/(?<=;)[\r\n]/)
end

#create_table(sql_statement) ⇒ Object 



46
47
48
49
 
# File 'lib/mysql_dump_to_json/mysql/reader.rb', line 46

def create_table(sql_statement)
  table = create_table_definition(sql_statement)
  @database.create_table(table[:name], table[:fields], table[:keys])
end

#create_table_definition(sql_statement) ⇒ Object 



51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
 
# File 'lib/mysql_dump_to_json/mysql/reader.rb', line 51

def create_table_definition(sql_statement)
  table = { name: nil, fields: [], keys: [] }
  sql_statement.split("\n").each do |line|
    case line.strip
    when /^CREATE +TABLE +/i
      table[:name] = table_name_from_create(line)
    when /^PRIMARY +KEY/i, /^FOREIGN +KEY/i, /^KEY/i
      table[:keys] << line.strip.delete_suffix(',')
    when ');', /ENGINE=/i, /^CONSTRAINT/i, /^ENGINE/i
    else
      table[:fields] << field_from_line(line)
    end
  end
  table
end

#field_from_line(line) ⇒ Object 



71
72
73
 
# File 'lib/mysql_dump_to_json/mysql/reader.rb', line 71

def field_from_line(line)
  line.strip.scan(/[a-z0-9_$]+/i).first
end

#fields_from_insert(sql_statement) ⇒ Object 



88
89
90
91
92
93
94
 
# File 'lib/mysql_dump_to_json/mysql/reader.rb', line 88

def fields_from_insert(sql_statement)
  before_values_section = sql_statement.split(/values/i).first
  field_section = before_values_section.gsub(/^INSERT INTO ['`]?#{table_name_from_insert(sql_statement)}['`]?/i,'').strip
  return false if field_section.empty? || field_section.nil?

  sql_statement.split(/[()]/)[1].split(',')
end

#index_of_closing_quote_value(ary, start_at_index) ⇒ Object 



168
169
170
171
172
173
 
# File 'lib/mysql_dump_to_json/mysql/reader.rb', line 168

def index_of_closing_quote_value(ary, start_at_index)
  ary.each_with_index do |value, index|
    next if index < start_at_index
    return index if value_open_start_quote?(value)
  end
end

#ingest(mysql_string) ⇒ Object 



18
19
20
21
22
 
# File 'lib/mysql_dump_to_json/mysql/reader.rb', line 18

def ingest(mysql_string)
  @source_dump = mysql_string
  @statements = compress_sql_into_statements
  build_database
end

#insert_into(sql_statement) ⇒ Object 



75
76
77
78
79
80
81
82
 
# File 'lib/mysql_dump_to_json/mysql/reader.rb', line 75

def insert_into(sql_statement)
  table_name = table_name_from_insert(sql_statement)
  table = @database.tables.fetch(table_name)
  insert_fields = fields_from_insert(sql_statement) || table.fields
  value_chunks_from_insert(sql_statement).each do |row_ary|
    table.add_row(insert_fields, row_ary)
  end
end

#parse_values_row_with_escape(values_row) ⇒ Object

Simply splitting on commas gets most rows, but fails when there are commas in quoted text. When an opening quote is found, but not a closing quote, look ahead in the array until the closing quote is found to merge those values back together with the consumed comma



107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
 
# File 'lib/mysql_dump_to_json/mysql/reader.rb', line 107

def parse_values_row_with_escape(values_row)
  simple_split = values_row.split(',')
  values = []
  merged_indexes = []
  simple_split.each_with_index do |value, index|
    next if merged_indexes.include?(index)

    if value_not_quoted?(value)
      values << value_to_numeric(value)
    elsif value_complete_quote?(value)
      values << value
    elsif value_open_end_quote?(value)
      end_of_quote_index = index_of_closing_quote_value(simple_split, index)
      values << simple_split[index..end_of_quote_index].join(',')
      merged_indexes |= (index..end_of_quote_index).to_a
    else
      binding.pry
    end
  end
  remove_quotes_from_values(values)
end

#remove_block_comments(str) ⇒ Object 



194
195
196
 
# File 'lib/mysql_dump_to_json/mysql/reader.rb', line 194

def remove_block_comments(str)
  str.gsub(/\/\*.*?\*\//m,'')
end

#remove_quotes_from_values(values) ⇒ Object 



129
130
131
132
133
134
135
136
137
138
139
 
# File 'lib/mysql_dump_to_json/mysql/reader.rb', line 129

def remove_quotes_from_values(values)
  values.map do |value|
    if value.is_a?(String)
      value.delete_suffix("'") # Remove the enacapsulating quotes
           .delete_prefix("'")
           .gsub("\\'", "'") # Remove the double escaped interior single quotes
    else
      value
    end
  end
end

#strip_comments(str) ⇒ Object 



186
187
188
189
190
191
192
 
# File 'lib/mysql_dump_to_json/mysql/reader.rb', line 186

def strip_comments(str)
  str.split(/[\n\r]+/).reject do |line|
    line.nil? ||
        line.empty? ||
        line.start_with?('--')
  end.join("\n")
end

#table_name_from_create(str) ⇒ Object 



67
68
69
 
# File 'lib/mysql_dump_to_json/mysql/reader.rb', line 67

def table_name_from_create(str)
  str.strip.gsub(/CREATE +TABLE +`?/i,'').delete_suffix("(").strip.delete_suffix('`')
end

#table_name_from_insert(sql_statement) ⇒ Object 



84
85
86
 
# File 'lib/mysql_dump_to_json/mysql/reader.rb', line 84

def table_name_from_insert(sql_statement)
  sql_statement.split(/[ ()`]+/)[2]
end

#value_chunks_from_insert(sql_statement) ⇒ Object 



96
97
98
99
100
101
102
 
# File 'lib/mysql_dump_to_json/mysql/reader.rb', line 96

def value_chunks_from_insert(sql_statement)
  values_str = sql_statement.split(/ VALUES +/i).last
  values_ary = values_str[1..-3].split(/\)\s*,\s*\(/)
  values_ary.map do |values_row|
    parse_values_row_with_escape(values_row.delete_prefix('(').delete_suffix(')'))
  end
end

#value_complete_quote?(value) ⇒ Boolean

Returns:

  • (Boolean) 


153
154
155
156
 
# File 'lib/mysql_dump_to_json/mysql/reader.rb', line 153

def value_complete_quote?(value)
  value[0] == "'" &&
      value[-1] == "'"
end

#value_not_quoted?(value) ⇒ Boolean

Returns:

  • (Boolean) 


149
150
151
 
# File 'lib/mysql_dump_to_json/mysql/reader.rb', line 149

def value_not_quoted?(value)
  value.count("'").zero?
end

#value_open_end_quote?(value) ⇒ Boolean

Returns:

  • (Boolean) 


158
159
160
161
 
# File 'lib/mysql_dump_to_json/mysql/reader.rb', line 158

def value_open_end_quote?(value)
  value[0] == "'" &&
      value[-1] != "'"
end

#value_open_start_quote?(value) ⇒ Boolean

Returns:

  • (Boolean) 


163
164
165
166
 
# File 'lib/mysql_dump_to_json/mysql/reader.rb', line 163

def value_open_start_quote?(value)
  value[0] != "'" &&
      value[-1] == "'"
end

#value_to_numeric(value) ⇒ Object 



141
142
143
144
145
146
147
 
# File 'lib/mysql_dump_to_json/mysql/reader.rb', line 141

def value_to_numeric(value)
  return nil if value == 'NULL'
  return value.to_i if value.to_i.to_s == value
  return value.to_f if value.to_f.to_s == value

  binding.pry
end