Class: FtsLite::Index

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

Defined Under Namespace

Classes: RuntimeError

Constant Summary collapse

DEFAULT_TOKENIZER = 
:bigram
DEFAULT_JURNAL_MODE = 
"MEMORY"
DEFAULT_TEMP_STORE = 
"MEMORY"
DEFAULT_CACHE_SIZE = 
32000
SQLITE_HAVE_FT4_REPLACE = 
SQLite3.libversion >= 3007007

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(path, options = {}) ⇒ Index

Returns a new instance of Index.



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# File 'lib/fts_lite/index.rb', line 20

def initialize(path, options = {})
  @db = SQLite3::Database.new(path)
  @table_name = options[:table_name] || "fts_lite"
  create_table!(options)
  set_db_param(options)
  @tokenizer = Tokenizer.create(options[:tokenizer] || DEFAULT_TOKENIZER)
end

Class Method Details

.have_ft4_replace ⇒ Object 



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# File 'lib/fts_lite/index.rb', line 11

def self.have_ft4_replace
  SQLITE_HAVE_FT4_REPLACE
end

.open(path, options = {}) ⇒ Object 



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# File 'lib/fts_lite/index.rb', line 27

def self.open(path, options = {})
  if (block_given?)
    index = Index.new(path, options)
    begin
      yield(index)
    ensure
      index.close
    end
  else
    Index.new(path, options)
  end
end

.sqlite3_version ⇒ Object 



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# File 'lib/fts_lite/index.rb', line 14

def self.sqlite3_version
  SQLite3.libversion
end

Instance Method Details

#close ⇒ Object 



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# File 'lib/fts_lite/index.rb', line 40

def close
  @db.close
end

#count ⇒ Object 



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# File 'lib/fts_lite/index.rb', line 95

def count
  @db.execute("SELECT COUNT(*) FROM #{@table_name} ;").first.first
end

#delete(docid) ⇒ Object 



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# File 'lib/fts_lite/index.rb', line 69

def delete(docid)
  @db.execute("DELETE FROM #{@table_name} WHERE docid = ?;", [docid])
end

#delete_all ⇒ Object 



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# File 'lib/fts_lite/index.rb', line 98

def delete_all
  @db.execute("DELETE FROM #{@table_name} ;")
end

#drop_table! ⇒ Object 



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# File 'lib/fts_lite/index.rb', line 101

def drop_table!
  if (table_exist?)
    @db.execute("DROP TABLE #{@table_name};")
  end
end

#search(text, options = {}) ⇒ Object 



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# File 'lib/fts_lite/index.rb', line 72

def search(text, options = {})
  limit = options[:limit]
  order = nil
  if (options[:order])
    case options[:order].to_sym
    when :desc
      order = :desc
    when :asc
      order = :asc
    end
  end
  sql = "SELECT docid FROM #{@table_name} WHERE text MATCH ?"
  if (order)
    sql += sprintf(" ORDER BY sort_value %s", order == :desc ? "DESC" : "ASC")
  else
    sql += sprintf(" ORDER BY docid ASC")
  end
  if (limit)
    sql += sprintf(" LIMIT %d", limit)
  end
  sql += ";"
  @db.execute(sql, [@tokenizer.vector(text)]).flatten
end

#set(docid, text, sort_value = nil) ⇒ Object 



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# File 'lib/fts_lite/index.rb', line 51

def set(docid, text, sort_value = nil)
  if (SQLITE_HAVE_FT4_REPLACE)
    @db.execute("INSERT OR REPLACE INTO #{@table_name} (docid, text, sort_value) VALUES(?, ?, ?);",
                [docid, @tokenizer.vector(text), sort_value])
  else
    begin
      @db.execute("INSERT INTO #{@table_name} (docid, text, sort_value) VALUES(?, ?, ?);",
                  [docid, @tokenizer.vector(text), sort_value])
    rescue SQLite3::ConstraintException
      @db.execute("UPDATE #{@table_name} SET text = ?, sort_value = ? WHERE docid = ?;",
                  [@tokenizer.vector(text), sort_value, docid])
    end
  end
end

#tokenize(text) ⇒ Object 



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# File 'lib/fts_lite/index.rb', line 43

def tokenize(text)
  @tokenizer.vector(text).split(" ")
end

#transaction(&block) ⇒ Object 



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# File 'lib/fts_lite/index.rb', line 46

def transaction(&block)
  @db.transaction do
    block.call
  end
end

#update_sort_value(docid, sort_value) ⇒ Object 



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# File 'lib/fts_lite/index.rb', line 65

def update_sort_value(docid, sort_value)
  @db.execute("UPDATE #{@table_name} SET sort_value = ? WHERE docid = ?;",
              [sort_value, docid])
end