Class: MysqlReplicator::Connections::Query

Inherits:
Object
  • Object
show all
Defined in:
lib/mysql_replicator/connections/query.rb

Class Method Summary collapse

Class Method Details

.execute(connection, sql) ⇒ Object 



50
51
52
53
54
55
56
57
58
59
60
61
62
63
 
# File 'lib/mysql_replicator/connections/query.rb', line 50

def self.execute(connection, sql)
  query_payload = [0x03].pack('C') + sql.encode('utf-8')
  connection.send_packet(query_payload)

  response = connection.read_packet
  case MysqlReplicator::StringUtil.read_uint8(response[:payload][0])
  when 0x00 # OK
    parse_ok(response[:payload])
  when 0xFF # Error
    parse_error(response[:payload])
  else # Result set
    parse_result_set(connection, response[:payload])
  end
end

.length_encoded_integer(payload, offset) ⇒ Object 



246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
 
# File 'lib/mysql_replicator/connections/query.rb', line 246

def self.length_encoded_integer(payload, offset)
  first_byte = MysqlReplicator::StringUtil.read_uint8(payload[offset])

  case first_byte
  when 0..250
    { value: first_byte, bytes_read: 1 }
  when 0xFC
    value = MysqlReplicator::StringUtil.read_uint16(payload[(offset + 1)..(offset + 2)])
    { value: value, bytes_read: 3 }
  when 0xFD
    value = MysqlReplicator::StringUtil.read_uint32(payload[(offset + 1)..(offset + 3)]) & 0xFFFFFF
    { value: value, bytes_read: 4 }
  when 0xFE
    value = MysqlReplicator::StringUtil.read_uint64(payload[(offset + 1)..(offset + 8)])
    { value: value, bytes_read: 9 }
  else # Included 0xFB
    { value: nil, bytes_read: 1 }
  end
end

.length_encoded_integer_size(value) ⇒ Object 



268
269
270
271
272
273
274
275
 
# File 'lib/mysql_replicator/connections/query.rb', line 268

def self.length_encoded_integer_size(value)
  return 1 if value.nil?
  return 1 if value <= 250
  return 3 if value <= 0xFFFF
  return 4 if value <= 0xFFFFFF

  9
end

.length_encoded_string(payload, offset) ⇒ Object 



280
281
282
283
284
285
286
287
288
289
290
291
292
 
# File 'lib/mysql_replicator/connections/query.rb', line 280

def self.length_encoded_string(payload, offset)
  length_info = length_encoded_integer(payload, offset)
  return { value: '', bytes_read: length_info[:bytes_read] } if length_info[:value].nil?

  string_start = offset + length_info[:bytes_read]
  string_end = string_start + length_info[:value] - 1
  value = payload[string_start..string_end] || ''

  {
    value: value,
    bytes_read: length_info[:bytes_read] + length_info[:value]
  }
end

.parse_column_definition(payload) ⇒ Object 



157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
 
# File 'lib/mysql_replicator/connections/query.rb', line 157

def self.parse_column_definition(payload)
  offset = 0

  # catalog (length-encoded string)
  catalog = length_encoded_string(payload, offset)
  offset += catalog[:bytes_read]

  # schema (length-encoded string)
  schema = length_encoded_string(payload, offset)
  offset += schema[:bytes_read]

  # table (length-encoded string)
  table = length_encoded_string(payload, offset)
  offset += table[:bytes_read]

  # org_table (length-encoded string)
  org_table = length_encoded_string(payload, offset)
  offset += org_table[:bytes_read]

  # name (length-encoded string)
  name = length_encoded_string(payload, offset)
  offset += name[:bytes_read]

  # org_name (length-encoded string)
  org_name = length_encoded_string(payload, offset)
  offset += org_name[:bytes_read]

  # length of fixed-length fields (1 byte)
  offset += 1

  # character set (2 bytes)
  charset = MysqlReplicator::StringUtil.read_uint16(payload[offset..(offset + 1)])
  offset += 2

  # column length (4 bytes)
  column_length = MysqlReplicator::StringUtil.read_uint32(payload[offset..(offset + 3)])
  offset += 4

  # type (1 byte)
  type = MysqlReplicator::StringUtil.read_uint8(payload[offset])

  {
    catalog: catalog[:value],
    schema: schema[:value],
    table: table[:value],
    org_table: org_table[:value],
    name: name[:value],
    org_name: org_name[:value],
    charset: charset,
    column_length: column_length,
    type: type_to_string(type)
  }
end

.parse_error(payload) ⇒ Object 



108
109
110
111
112
113
114
115
116
117
118
119
120
 
# File 'lib/mysql_replicator/connections/query.rb', line 108

def self.parse_error(payload)
  error_code = MysqlReplicator::StringUtil.read_uint16(payload[1..2])
  sql_state_marker = (payload[3] || '').chr
  sql_state = payload[4..8] || nil
  error_message = payload[9..] || nil

  {
    error_code: error_code,
    sql_state_marker: sql_state_marker,
    sql_state: sql_state,
    error_message: error_message
  }
end

.parse_ok(payload) ⇒ Object 



67
68
69
70
71
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
 
# File 'lib/mysql_replicator/connections/query.rb', line 67

def self.parse_ok(payload)
  offset = 1 # Skip 0x00

  # affected_rows (length-encoded integer)
  affected_rows = length_encoded_integer(payload, offset)[:value]
  offset += length_encoded_integer_size(affected_rows)

  # insert_id (length-encoded integer)
  insert_id = length_encoded_integer(payload, offset)[:value]
  offset += length_encoded_integer_size(insert_id)

  # status_flags (2 bytes)
  if payload.length > offset + 1
    status_flags = MysqlReplicator::StringUtil.read_uint16(payload[offset..(offset + 1)])
    offset += 2
  else
    status_flags = nil
  end

  # warnings (2 bytes)
  if payload.length > offset + 3
    warnings = MysqlReplicator::StringUtil.read_uint16(payload[(offset + 2)..(offset + 3)])
    offset += 2
  else
    warnings = nil
  end

  # info_message (all the rest)
  info_message = payload.length > offset + 4 ? payload[(offset + 4)..] : nil

  {
    affected_rows: affected_rows,
    insert_id: insert_id,
    status_flags: status_flags,
    warnings: warnings,
    info_message: info_message
  }
end

.parse_result_set(connection, payload) ⇒ Object 



125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
 
# File 'lib/mysql_replicator/connections/query.rb', line 125

def self.parse_result_set(connection, payload)
  # Read columns definition
  columns = []
  column_count = length_encoded_integer(payload, 0)[:value].to_i
  column_count.times do
    column_packet = connection.read_packet
    column_info = parse_column_definition(column_packet[:payload])
    columns << column_info
  end

  # EOF packet（at finish）
  connection.read_packet

  rows = [] #: Array[Hash[Symbol, String | nil]]

  loop do
    row_packet = connection.read_packet

    # Check EOF packet
    if MysqlReplicator::StringUtil.read_uint8(row_packet[:payload][0]) == 0xFE
      break
    end

    row_data = parse_row_data(row_packet[:payload], columns)
    rows << row_data
  end

  { columns: columns, rows: rows, row_count: rows.length }
end

.parse_row_data(payload, columns) ⇒ Object 



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
 
# File 'lib/mysql_replicator/connections/query.rb', line 214

def self.parse_row_data(payload, columns)
  first_byte = MysqlReplicator::StringUtil.read_uint8(payload[0])

  row = {} #: Hash[Symbol, String | nil]
  offset = 0

  columns.each do |column|
    column_name_key = column[:name].downcase.to_sym

    if offset >= payload.length
      row[column_name_key] = nil
      next
    end

    if first_byte == 0xFB
      # NULL value
      row[column_name_key] = nil
      offset += 1
    else
      # row data (length-encoded string)
      value = length_encoded_string(payload, offset)
      row[column_name_key] = value[:value]
      offset += value[:bytes_read]
    end
  end

  row
end

.type_to_string(type) ⇒ Object 



296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
 
# File 'lib/mysql_replicator/connections/query.rb', line 296

def self.type_to_string(type)
  case type
  when 0x00 then 'DECIMAL'
  when 0x01 then 'TINYINT'
  when 0x02 then 'SMALLINT'
  when 0x03 then 'INT'
  when 0x04 then 'FLOAT'
  when 0x05 then 'DOUBLE'
  when 0x06 then 'NULL'
  when 0x07 then 'TIMESTAMP'
  when 0x08 then 'BIGINT'
  when 0x09 then 'MEDIUMINT'
  when 0x0A then 'DATE'
  when 0x0B then 'TIME'
  when 0x0C then 'DATETIME'
  when 0x0D then 'YEAR'
  when 0x0F then 'VARCHAR'
  when 0xF6 then 'NEWDECIMAL'
  when 0xFC then 'BLOB'
  when 0xFD then 'VAR_STRING'
  when 0xFE then 'STRING'
  else "UNKNOWN(#{type})"
  end
end