Module: SqlBeautifier::Tokenizer

Defined in:
lib/sql_beautifier/tokenizer.rb

Class Method Summary collapse

Class Method Details

.find_all_top_level_join_positions(text) ⇒ Object 



176
177
178
179
180
181
182
183
184
185
186
187
188
189
 
# File 'lib/sql_beautifier/tokenizer.rb', line 176

def find_all_top_level_join_positions(text)
  positions = []
  search_offset = 0

  while search_offset < text.length
    earliest_match = find_earliest_top_level_join_keyword(text, search_offset)
    break unless earliest_match

    positions << earliest_match
    search_offset = earliest_match[:position] + earliest_match[:keyword].length
  end

  positions
end

.find_earliest_top_level_join_keyword(text, search_offset) ⇒ Object 



191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
 
# File 'lib/sql_beautifier/tokenizer.rb', line 191

def find_earliest_top_level_join_keyword(text, search_offset)
  earliest_match = nil

  Constants::JOIN_KEYWORDS_BY_LENGTH.each do |keyword|
    remaining_text = text[search_offset..]
    keyword_position = find_top_level_keyword(remaining_text, keyword)
    next unless keyword_position

    absolute_position = search_offset + keyword_position
    next if earliest_match && absolute_position >= earliest_match[:position]

    earliest_match = {
      position: absolute_position,
      keyword: keyword,
    }
  end

  earliest_match
end

.find_top_level_keyword(sql, keyword) ⇒ Object 



7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
 
# File 'lib/sql_beautifier/tokenizer.rb', line 7

def find_top_level_keyword(sql, keyword)
  keyword_pattern = %r{#{Regexp.escape(keyword)}}i
  search_position = 0
  scanner = Scanner.new(sql)

  while search_position < sql.length
    match = sql.match(keyword_pattern, search_position)
    return nil unless match

    match_position = match.begin(0)

    if scanner.inside_sentinel?(match_position)
      search_position = scanner.sentinel_end_position(match_position) || (match_position + 1)
      next
    end

    previous_character = scanner.character_before(match_position)
    next_character = scanner.character_after(match_position, keyword.length)

    return match_position if scanner.word_boundary?(previous_character) && scanner.word_boundary?(next_character) && top_level?(sql, match_position)

    search_position = match_position + 1
  end

  nil
end

.first_clause_position(sql) ⇒ Object 



34
35
36
 
# File 'lib/sql_beautifier/tokenizer.rb', line 34

def first_clause_position(sql)
  Constants::CLAUSE_KEYWORDS.filter_map { |keyword| find_top_level_keyword(sql, keyword) }.min
end

.outer_parentheses_wrap_all?(text) ⇒ Boolean

Returns:

  • (Boolean) 


142
143
144
145
146
147
148
149
 
# File 'lib/sql_beautifier/tokenizer.rb', line 142

def outer_parentheses_wrap_all?(text)
  trimmed_text = text.strip
  return false unless trimmed_text.start_with?(Constants::OPEN_PARENTHESIS)

  closing_parenthesis_position = Scanner.new(trimmed_text).find_matching_parenthesis(0)

  closing_parenthesis_position == trimmed_text.length - 1
end

.scan_top_level_conjunctions(text) ⇒ Object 



211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
 
# File 'lib/sql_beautifier/tokenizer.rb', line 211

def scan_top_level_conjunctions(text)
  scanner = Scanner.new(text)
  conjunction_boundaries = []
  inside_between = false
  case_depth = 0

  until scanner.finished?
    next if scanner.skip_quoted_or_sentinel!

    case scanner.current_char
    when Constants::SINGLE_QUOTE
      scanner.enter_single_quote!
    when Constants::DOUBLE_QUOTE
      scanner.enter_double_quote!
    when Constants::OPEN_PARENTHESIS
      scanner.increment_depth!
      scanner.advance!
    when Constants::CLOSE_PARENTHESIS
      scanner.decrement_depth!
      scanner.advance!
    else
      if scanner.parenthesis_depth.zero?
        if scanner.keyword_at?("case")
          case_depth += 1
          scanner.advance!("case".length)
          next
        end

        if scanner.keyword_at?("end") && case_depth.positive?
          case_depth -= 1
          scanner.advance!("end".length)
          next
        end

        if case_depth.zero?
          inside_between = true if scanner.keyword_at?(Constants::BETWEEN_KEYWORD)

          matched_conjunction = scanner.detect_conjunction_at

          if matched_conjunction
            if matched_conjunction == "and" && inside_between
              inside_between = false
            else
              conjunction_boundaries << {
                conjunction: matched_conjunction,
                position: scanner.position,
              }
            end

            scanner.advance!(matched_conjunction.length)
            next
          end
        end
      end

      scanner.advance!
    end
  end

  conjunction_boundaries
end

.split_by_top_level_commas(text) ⇒ Object 



72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
 
# File 'lib/sql_beautifier/tokenizer.rb', line 72

def split_by_top_level_commas(text)
  scanner = Scanner.new(text)
  segments = []
  current_segment = +""

  until scanner.finished?
    consumed = scanner.scan_quoted_or_sentinel!
    if consumed
      current_segment << consumed
      next
    end

    character = scanner.current_char

    case character
    when Constants::OPEN_PARENTHESIS
      scanner.increment_depth!
      current_segment << character

    when Constants::CLOSE_PARENTHESIS
      scanner.decrement_depth!
      current_segment << character

    when Constants::COMMA
      if scanner.parenthesis_depth.zero?
        segments << current_segment.strip
        current_segment = +""
      else
        current_segment << character
      end

    else
      current_segment << character
    end

    scanner.advance!
  end

  segments << current_segment.strip unless current_segment.strip.empty?
  segments
end

.split_into_clauses(sql) ⇒ Object 



38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
 
# File 'lib/sql_beautifier/tokenizer.rb', line 38

def split_into_clauses(sql)
  boundaries = Constants::CLAUSE_KEYWORDS.filter_map do |keyword|
    keyword_position = find_top_level_keyword(sql, keyword)
    next unless keyword_position

    {
      keyword: keyword,
      position: keyword_position,
    }
  end

  boundaries.sort_by! { |boundary| boundary[:position] }

  clauses = {}

  boundaries.each_with_index do |boundary, boundary_index|
    content_start = boundary[:position] + boundary[:keyword].length

    content_end = begin
      if boundary_index + 1 < boundaries.length
        boundaries[boundary_index + 1][:position]
      else
        sql.length
      end
    end

    clause_symbol = boundary[:keyword].tr(" ", "_").to_sym

    clauses[clause_symbol] = sql[content_start...content_end].strip
  end

  clauses
end

.split_top_level_conditions(text) ⇒ Object 



114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
 
# File 'lib/sql_beautifier/tokenizer.rb', line 114

def split_top_level_conditions(text)
  conjunction_boundaries = scan_top_level_conjunctions(text)

  return [[nil, text.strip]] if conjunction_boundaries.empty?

  condition_pairs = []
  first_condition_text = text[0...conjunction_boundaries.first[:position]].strip
  condition_pairs << [nil, first_condition_text]

  conjunction_boundaries.each_with_index do |boundary, boundary_index|
    content_start = boundary[:position] + boundary[:conjunction].length

    content_end = begin
      if boundary_index + 1 < conjunction_boundaries.length
        conjunction_boundaries[boundary_index + 1][:position]
      else
        text.length
      end
    end

    condition_text = text[content_start...content_end].strip

    condition_pairs << [boundary[:conjunction], condition_text]
  end

  condition_pairs
end

.top_level?(sql, target_position) ⇒ Boolean

Returns:

  • (Boolean) 


151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
 
# File 'lib/sql_beautifier/tokenizer.rb', line 151

def top_level?(sql, target_position)
  scanner = Scanner.new(sql)

  while scanner.position < target_position
    next if scanner.skip_quoted_or_sentinel!

    case scanner.current_char
    when Constants::SINGLE_QUOTE
      scanner.enter_single_quote!
    when Constants::DOUBLE_QUOTE
      scanner.enter_double_quote!
    when Constants::OPEN_PARENTHESIS
      scanner.increment_depth!
      scanner.advance!
    when Constants::CLOSE_PARENTHESIS
      scanner.decrement_depth!
      scanner.advance!
    else
      scanner.advance!
    end
  end

  scanner.top_level?
end