Class: Poefy::Database

Inherits:
Object
  • Object
show all
Includes:
HandleError, StringManipulation
Defined in:
lib/poefy/database.rb

Constant Summary collapse

@@final =

Finalizer must be a class variable.

proc { |dbase, sproc| proc {
  sproc.each { |k, v| v.close }
  dbase.close if dbase
} }

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(db_file, console = false) ⇒ Database

Returns a new instance of Database.



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# File 'lib/poefy/database.rb', line 31

def initialize db_file, console = false
  @db_file = db_file
  @console = console
  @sproc = {}
  db
  ObjectSpace.define_finalizer(self, @@final.call(@db, @sproc))
end

Instance Attribute Details

#console ⇒ Object (readonly)

Returns the value of attribute console.



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# File 'lib/poefy/database.rb', line 23

def console
  @console
end

#db_file ⇒ Object (readonly)

Returns the value of attribute db_file.



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# File 'lib/poefy/database.rb', line 23

def db_file
  @db_file
end

Instance Method Details

#close ⇒ Object

Close the database file.



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# File 'lib/poefy/database.rb', line 61

def close
  @sproc.each { |k, v| v.close rescue nil }
  @db.close if @db
  @db = nil
end

#db ⇒ Object

Open global database session, if not already existing. This is called in all methods where it is needed. So no need to

execute it before any calling code.



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# File 'lib/poefy/database.rb', line 42

def db
  if not @db
    if !exists?
      @db = nil
    else
      begin
        @db = SQLite3::Database.open(@db_file)
        @db.results_as_hash = true
      rescue
        @db = nil
        return handle_error 'ERROR: Database contains invalid structure'
      end
      create_sprocs
    end
  end
  @db
end

#execute!(sql) ⇒ Object

Execute an SQL request.



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# File 'lib/poefy/database.rb', line 113

def execute! sql
  begin
    db.execute sql
  rescue
    return handle_error 'ERROR: Database has incorrect table structure', []
  end
end

#exists? ⇒ Boolean

See if the database file exists or not.

Returns:

  • (Boolean) 


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# File 'lib/poefy/database.rb', line 68

def exists?
  File.exists?(@db_file)
end

#format_sql_string(string) ⇒ Object

Format a string for SQL.



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# File 'lib/poefy/database.rb', line 122

def format_sql_string string
  string.gsub('"','""')
end

#make_new(lines) ⇒ Object

Creates a database with the correct format.

Convert input lines array to SQL import format file.
Delete database if already exists.
Create database using SQL import file.
Delete both files.



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# File 'lib/poefy/database.rb', line 77

def make_new lines
  make_new!(lines) if !exists?
end

#make_new!(lines) ⇒ Object

Force new database, overwriting existing.



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# File 'lib/poefy/database.rb', line 82

def make_new! lines

  # Convert the lines array into an import file.
  sql_import_file = save_sql_import_file lines

  # Delete any existing database.
  File.delete(@db_file) if File.exists?(@db_file)

  # Write SQL and SQLite instructions to temp file,
  #   import to database, delete temp file.
  # The SQL file is finicky. Each line requires no leading whitespace.
  sql_instruction_file = tmpfile
  sql = %Q[
    CREATE TABLE IF NOT EXISTS lines (
      line TEXT, syllables INT, final_word TEXT, rhyme TEXT
    );
    CREATE INDEX idx ON lines (rhyme, final_word, line);
    .separator "\t"
    .import #{sql_import_file} lines
  ].split("\n").map(&:strip).join("\n")
  File.open(sql_instruction_file, 'w') { |fo| fo.write sql }

  # Create the database using the SQL instructions.
  `sqlite3 #{@db_file} < #{sql_instruction_file}`

  # Delete temporary files.
  File.delete sql_instruction_file
  File.delete sql_import_file
end

#sproc_lines_all!(rhyme, syllable_min_max = nil) ⇒ Object 



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# File 'lib/poefy/database.rb', line 140

def sproc_lines_all! rhyme, syllable_min_max = nil
  db
  @la = Hash.new { |h,k| h[k] = {} } if @la.nil?
  if @la[rhyme][syllable_min_max].nil?
    @la[rhyme][syllable_min_max] = if syllable_min_max
      sproc_lines_all_syllables(rhyme, syllable_min_max)
    else
      sproc_lines_all(rhyme)
    end
  end
  @la[rhyme][syllable_min_max].dup
end

#sproc_rhymes_all!(rhyme_count, syllable_min_max = nil) ⇒ Object

Public interfaces for private stored procedure methods. Use instance variables to keep a cache of the results.



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# File 'lib/poefy/database.rb', line 128

def sproc_rhymes_all! rhyme_count, syllable_min_max = nil
  db
  @rbc = Hash.new { |h,k| h[k] = {} } if @rbc.nil?
  if @rbc[rhyme_count][syllable_min_max].nil?
    @rbc[rhyme_count][syllable_min_max] = if syllable_min_max
      sproc_rhymes_by_count_syllables(rhyme_count, syllable_min_max)
    else
      sproc_rhymes_by_count(rhyme_count)
    end
  end
  @rbc[rhyme_count][syllable_min_max].dup
end