Class: TDP::DAO

Inherits:
Object
  • Object
show all
Defined in:
lib/tdp.rb

Overview

Data access object that encapsulates all operations with the database.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(db) ⇒ DAO

Creates a new DAO object.

db

must be either of:

  • instance of Sequel::Database class

  • database URL that can be passed to Sequel.connect()



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# File 'lib/tdp.rb', line 216

def initialize(db)
  case db
  when Sequel::Database
    @db = db
  when String
    @db = Sequel.connect(db)
  else
    raise ArgumentError, "Invalid argument #{db} of class #{db.class}"
  end
end

Instance Attribute Details

#db ⇒ Object (readonly)

Sequel::Database object



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# File 'lib/tdp.rb', line 207

def db
  @db
end

Instance Method Details

#applied_patches ⇒ Object

Fetches the information about applied patches and returns it as { name => signature } hash.



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# File 'lib/tdp.rb', line 245

def applied_patches
  result = {}
  @db[:tdp_patch].select(:name, :signature).each do |row|
    result[row[:name]] = row[:signature]
  end
  result
end

#applied_patches_inverse ⇒ Object

Fetches the information about applied patches and returns it as { signature => name } hash.



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# File 'lib/tdp.rb', line 257

def applied_patches_inverse
  result = {}
  applied_patches.each do |name, sig|
    raise DuplicateError, [result[sig], name] if result.key?(sig)
    result[sig] = name
  end
  result
end

#apply(patch) ⇒ Object

Applies a patch (a Patch object).



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# File 'lib/tdp.rb', line 277

def apply(patch)
  @db << patch.content
  register(patch)
rescue Sequel::Error => ex
  raise Sequel::Error,
        "Failed to apply patch #{patch.full_filename}: #{ex}"
end

#bootstrap ⇒ Object

Initializes database tables for keeping track of applied patches.



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# File 'lib/tdp.rb', line 231

def bootstrap
  return if @db.table_exists?(:tdp_patch)
  @db << %{
    CREATE TABLE tdp_patch(
    name VARCHAR PRIMARY KEY
    , signature VARCHAR NOT NULL
    )
  }
end

#erase ⇒ Object

Erases all data about applied patches.



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# File 'lib/tdp.rb', line 303

def erase
  @db[:tdp_patch].delete
end

#patch_signature(name) ⇒ Object

Looks up a signature of a patch by its name.



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# File 'lib/tdp.rb', line 269

def patch_signature(name)
  row = @db[:tdp_patch].select(:signature).where(name: name).first
  row.nil? ? nil : row[:signature]
end

#register(patch) ⇒ Object

Registers a patch (a Patch object) as applied.



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# File 'lib/tdp.rb', line 288

def register(patch)
  q = @db[:tdp_patch].where(name: patch.name)
  if q.empty?
    @db[:tdp_patch].insert(
      name: patch.name,
      signature: patch.signature
    )
  else
    q.update(signature: patch.signature)
  end
end

#rename(old_name, new_name) ⇒ Object

Renames a patch.



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# File 'lib/tdp.rb', line 310

def rename(old_name, new_name)
  @db[:tdp_patch].where(name: old_name).update(name: new_name)
end