GrnMini

Groonga(Rroonga) wrapper for using easily.

Automatic generation of the column with data type
Specification of column types explicitly
Advanced Search Query
Persistence
Sort
Grouping (Drill Down)
Snippets
Pagination
Cooperation between multiple tables

Installation

$ gem install grn_mini

When you faild to install Rroonga, Please refer -> File: install — rroonga - Ranguba

Basic Usage

Create a database with the name "test.db".

require 'grn_mini'
GrnMini::create_or_open("test.db")

Add the record with the number column and text column.

Determine the column type when you first call "GrnMini::Array#add". (Add inverted index if data type is "string".)

array = GrnMini::Array.new
array.add(text: "aaa", number: 1)

It is also possible to use the '<<'

array << {text: "bbb", number: 2}
array << {text: "ccc", number: 3}
array.size  #=> 3

Open an existing database

require 'grn_mini'
GrnMini::create_or_open("test.db")
array = GrnMini::Array.new
array.size   #=> 3

Create a temporary database. (Useful for testing)

GrnMini::tmpdb do
  array = GrnMini::Array.new
  array << {text: "aaa", number: 1}
  array << {text: "bbb", number: 2}
  array << {text: "ccc", number: 3}
end
# Delete temporary database

or

require 'fileutils'

dir = GrnMini::tmpdb

array = GrnMini::Array.new
array << {text: "aaa", number: 1}
array << {text: "bbb", number: 2}
array << {text: "ccc", number: 3}

FileUtils.remove_entry_secure dir # Delete temporary database

Create Hash

require 'grn_mini'
GrnMini::create_or_open("test.db")
hash = GrnMini::Hash.new

# Add
hash["a"] = {text:"aaa", number:1}
hash["b"] = {text:"bbb", number:2}
hash["c"] = {text:"ccc", number:3}

# Read
hash["b"].text       #=> "bbb"

# Write
hash["b"].text = "BBB"

Specify table name.

Default table name is "Array"(GrnMini::Array) or "Hash"(GrnMini::Hash).

GrnMini::tmpdb do
  array = GrnMini::Array.new("Users")
  array << {text: "aaa", number: 1}
end

Specification of column types explicitly

Use GrnMini::Table#setup_columns.

GrnMini::tmpdb do
  array = GrnMini::Array.new

  # Specify dummy data
  array.setup_columns(filename: "",
                      int:      0,
                      float:    0.0,
                      time:     Time.new,
                      )
                      
  array << {filename: "a.txt", int: 1, float: 1.5, time: Time.at(1999)}
end

The following is the same meaning.

GrnMini::tmpdb do
  array = GrnMini::Array.new
  # Automatic generation of the column with data type
  array << {filename: "a.txt", int: 1, float: 1.5, time: Time.at(1999)}
end

GrnMini::Table#setup_columns is useful for below.

Specification of column types explicitly
Refer to itself
Cross-reference between tables
- See "Cooperation between multiple tables"

Data Type

GrnMini::tmpdb do
  array = GrnMini::Array.new
  array << {filename: "a.txt", int: 1, float: 1.5, time: Time.at(1999)}
  array << {filename: "b.doc", int: 2, float: 2.5, time: Time.at(2000)}

  # ShortText
  array[1].filename #=> "a.txt"
  array[2].filename #=> "b.doc"

  # Int32
  array[1].int      #=> 1
  array[2].int      #=> 2

  # Float
  array[1].float    #=> 1.5
  array[2].float    #=> 2.5

  # Time
  array[1].time    #=> 1999-01-01
  array[2].time    #=> 2000-01-01
end

See also 8.4. Data type — Groonga documentation.

Access Record

Add

require 'grn_mini'

GrnMini::create_or_open("test2.db")
array = GrnMini::Array.new
array << {name:"Tanaka",  age: 11, height: 162.5}
array << {name:"Suzuki",  age: 31, height: 170.0}

Read

record = array[1] # Read from id (> 0)
record.id         #=> 1

Access function with the same name as the column name

record.name     #=> "Tanaka
record.age      #=> 11
record.height   #=> 162.5

Groonga::Record#attributes is useful for debug

record.attributes #=> {"_id"=>1, "age"=>11, "height"=>162.5, "name"=>"Tanaka"}

Update

array[2].name = "Hayashi"
array[2].attributes #=> {"_id"=>2, "age"=>31, "height"=>170.0, "name"=>"Hayashi"}

Delete

Delete by passing id.

array.delete(1)

# It returns 'nil' value when you access a deleted record
array[1].attributes     #=> {"_id"=>1, "age"=>0, "height"=>0.0, "name"=>nil}

# Can't see deleted records if access from Enumerable
array.first.id          #=> 2
array.first.attributes  #=> {"_id"=>2, "age"=>31, "height"=>170.0, "name"=>"Hayashi"}

It is also possible to pass the block.

GrnMini::tmpdb do
  array = GrnMini::Array.new

  array << {name:"Tanaka",  age: 11, height: 162.5}
  array << {name:"Suzuki",  age: 31, height: 170.0}
  array << {name:"Hayashi", age: 20, height: 165.0}

  array.delete do |record|
    record.age <= 20
  end

  array.size             #=> 1
  array.first.attributes #=> {"_id"=>2, "age"=>31, "height"=>170.0, "name"=>"Suzuki"}
end

Search

Use GrnMini::Array#select method.

GrnMini::tmpdb do
  array = GrnMini::Array.new

  array << {text:"aaa", number:1}
  array << {text:"bbb", number:20}
  array << {text:"bbb ccc", number:2}
  array << {text:"bbb", number:15}
  array << {text:"ccc", number:3}

  results = array.select("text:aaa")
  results.map {|record| record.attributes} #=> [{"_id"=>1, "_key"=>{"_id"=>1, "number"=>1, "text"=>"aaa"}, "_score"=>1}]

  # AND
  results = array.select("text:@bbb text:@ccc")
  results.map {|record| record.attributes} #=> [{"_id"=>2, "_key"=>{"_id"=>3, "number"=>2, "text"=>"bbb ccc"}, "_score"=>2}]

  # Specify column
  results = array.select("text:@bbb number:<10")
  results.map {|record| record.attributes} #=> [{"_id"=>2, "_key"=>{"_id"=>3, "number"=>2, "text"=>"bbb ccc"}, "_score"=>2}]

  # AND, OR, Grouping
  results = array.select("text:@bbb (number:<= 10 OR number:>=20)")
  results.map {|record| record.attributes} #=> [{"_id"=>2, "_key"=>{"_id"=>3, "number"=>2, "text"=>"bbb ccc"}, "_score"=>2}, {"_id"=>4, "_key"=>{"_id"=>2, "number"=>20, "text"=>"bbb"}, "_score"=>2}]

  # NOT
  results = array.select("text:@bbb - text:@ccc")
  results.map {|record| record.attributes}  #=> [{"_id"=>1, "_key"=>{"_id"=>2, "number"=>20, "text"=>"bbb"}, "_score"=>1}, {"_id"=>3, "_key"=>{"_id"=>4, "number"=>15, "text"=>"bbb"}, "_score"=>1}]
end

Use :default_column option.

GrnMini::tmpdb do
  array = GrnMini::Array.new

  array << {text: "txt", filename:"a.txt"}
  array << {text: "txt", filename:"a.doc"}
  array << {text: "txt", filename:"a.rb"}

  # Specify column
  results = array.select("filename:@txt")
  results.first.attributes  #=> {"_id"=>1, "_key"=>{"_id"=>1, "filename"=>"a.txt", "text"=>"txt"}, "_score"=>1}

  # Change default_column
  results = array.select("txt", default_column: "filename")
  results.first.attributes  #=> {"_id"=>1, "_key"=>{"_id"=>1, "filename"=>"a.txt", "text"=>"txt"}, "_score"=>1}
end

See also 8.10.1. Query syntax, Groonga::Table#select

Sort

Specify column name to sort.

GrnMini::tmpdb do
  array = GrnMini::Array.new

  array << {name:"Tanaka",  age: 11, height: 162.5}
  array << {name:"Suzuki",  age: 31, height: 170.0}
  array << {name:"Hayashi", age: 21, height: 175.4}
  array << {name:"Suzuki",  age:  5, height: 110.0}

  sorted = array.sort(["age"])

  sorted.map {|r| {name: r.name, age: r.age}}
    #=> [{:name=>"Suzuki",  :age=> 5},
    #    {:name=>"Tanaka",  :age=>11},
    #    {:name=>"Hayashi", :age=>21},
    #    {:name=>"Suzuki",  :age=>31}]
end

Combination sort.

sorted = array.sort([{key: "name", order: :ascending},
                     {key: "age" , order: :descending}])

sorted.map {|r| {name: r.name, age: r.age}}
    #=> [{:name=>"Hayashi", :age=>21},
    #    {:name=>"Suzuki",  :age=>31},
    #    {:name=>"Suzuki",  :age=> 5},
    #    {:name=>"Tanaka",  :age=>11}]

Grouping

Drill down aka.

GrnMini::tmpdb do
  array = GrnMini::Array.new

  array << {text:"aaaa.txt", suffix:"txt", type:1}
  array << {text:"aaaa.doc", suffix:"doc", type:2}
  array << {text:"aabb.txt", suffix:"txt", type:2}

  groups = GrnMini::Util::group_with_sort(array, "suffix")

  groups.size                               #=> 2
  [groups[0].key, groups[0].n_sub_records]  #=> ["txt", 2]
  [groups[1].key, groups[1].n_sub_records]  #=> ["doc", 1]
end

Grouping from selection results.

GrnMini::tmpdb do
  array = GrnMini::Array.new

  array << {text:"aaaa", suffix:"txt"}
  array << {text:"aaaa", suffix:"doc"}
  array << {text:"aaaa", suffix:"txt"}
  array << {text:"cccc", suffix:"txt"}

  results = array.select("text:@aa")
  groups = GrnMini::Util::group_with_sort(results, "suffix")

  groups.size                               #=> 2
  [groups[0].key, groups[0].n_sub_records]  #=> ["txt", 2]
  [groups[1].key, groups[1].n_sub_records]  #=> ["doc", 1]
end

Snippet

Display of keyword surrounding text. It is often used in search engine. Use GrnMini::Util::text_snippet_from_selection_results.

GrnMini::tmpdb do
  array = GrnMini::Array.new

  array << {text: <<EOF, filename: "aaa.txt"}
[1] This is a pen pep pea pek pet.
------------------------------
------------------------------
------------------------------
------------------------------
[2] This is a pen pep pea pek pet.
------------------------------
------------------------------
------------------------------
------------------------------
EOF

  results = array.select("text:@This pen")
  snippet = GrnMini::Util::text_snippet_from_selection_results(results)

  record = results.first
  segments = snippet.execute(record.text)
  segments.size #=> 2
  segments[0]   #=> "[1] <<This>> is a <<pen>> pep pea pek pet.\n------------------------------\n------------------------------\n---"
  segments[1]   #=> "--------\n------------------------------\n[2] <<This>> is a <<pen>> pep pea pek pet.\n-------------------------"
end

GrnMini::Util::html_snippet_from_selection_results is HTML escaped.

GrnMini::tmpdb do
  array = GrnMini::Array.new

  array << {text: <<EOF, filename: "aaa.txt"}
<html>
  <div>This is a pen pep pea pek pet.</div>
</html>
EOF

  results = array.select("text:@This pen")
  snippet = GrnMini::Util::html_snippet_from_selection_results(results, '<span class="strong">', '</span>') # Default value is '<strong>', '</strong>'

  record = results.first
  segments = snippet.execute(record.text)
  segments.size   #=> 1
  segments.first  #=> "&lt;html&gt;\n  &lt;div&gt;<span class=\"strong\">This</span> is a <span class=\"strong\">pen</span> pep pea pek pet.&lt;/div&gt;\n&lt;/html&gt;\n"
end

Pagination

#paginate is more convenient than #sort if you want a pagination.

GrnMini::tmpdb do
  array = GrnMini::Array.new

  array << {text: "aaaa", filename: "1.txt"}
  array << {text: "aaaa aaaa", filename: "2a.txt"}
  array << {text: "aaaa aaaa aaaa", filename: "3.txt"}
  array << {text: "aaaa aaaa", filename: "2b.txt"}
  array << {text: "aaaa aaaa", filename: "2c.txt"}
  array << {text: "aaaa aaaa", filename: "2d.txt"}
  array << {text: "aaaa aaaa", filename: "2e.txt"}
  array << {text: "aaaa aaaa", filename: "2f.txt"}

  results = array.select("text:@aaaa")

  # -- page1 --
  page_entries = results.paginate([["_score", :desc]], :page => 1, :size => 5)

  # Total number of record
  page_entries.n_records    #=> 8

  # Page offset
  page_entries.start_offset #=> 1
  page_entries.end_offset   #=> 5

  # Page entries
  page_entries.size         #=> 5

  # -- page2 --
  page_entries = results.paginate([["_score", :desc]], :page => 2, :size => 5)

  # Sample page content display
  puts "#{page_entries.n_records} hit. (#{page_entries.start_offset} - #{page_entries.end_offset})"
  page_entries.each do |record|
    puts "#{record.filename}: #{record.text}"
  end

  #=> 8 hit. (6 - 8)
  #   2b.txt: aaaa aaaa
  #   2f.txt: aaaa aaaa
  #   1.txt: aaaa
end

Cooperation between multiple tables

Micro blog sample.

GrnMini::tmpdb do
  users = GrnMini::Hash.new("Users")
  articles = GrnMini::Hash.new("Articles")

  users.setup_columns(name: "",
                      favorites: [articles]
                      )

  articles.setup_columns(author: users,
                         text: ""
                         )

  users["aaa"] = {name: "Mr.A"}
  users["bbb"] = {name: "Mr.B"}
  users["ccc"] = {name: "Mr.C"}

  articles["aaa:1"] = {author: "aaa", text: "111"}
  articles["aaa:2"] = {author: "aaa", text: "222"}
  articles["aaa:3"] = {author: "aaa", text: "333"}
  articles["bbb:1"] = {author: "bbb", text: "111"}
  articles["bbb:2"] = {author: "bbb", text: "222"}
  articles["ccc:1"] = {author: "ccc", text: "111"}

  users["aaa"].favorites = ["aaa:1", "bbb:2"]
  users["bbb"].favorites = ["aaa:2"]
  users["ccc"].favorites = ["aaa:1", "bbb:1", "ccc:1"]

  # Search record.favorites
  users.select { |record| record.favorites == "aaa:1" }    #=> ["aaa", "ccc"]
  users.select { |record| record.favorites == "aaa:2" }  #=> ["bbb"]

  # Search record.favorites.text
  users.select { |record| record.favorites.text =~ "111" } #=> ["aaa", "ccc"]
end

Name		Name	Last commit message	Last commit date
Latest commit History 136 Commits
lib		lib
test		test
.gitignore		.gitignore
.travis.yml		.travis.yml
Gemfile		Gemfile
HISTORY.md		HISTORY.md
LICENSE.txt		LICENSE.txt
README.md		README.md
Rakefile		Rakefile
grn_mini.gemspec		grn_mini.gemspec

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GrnMini

Installation

Basic Usage

Create a database with the name "test.db".

Add the record with the number column and text column.

It is also possible to use the '<<'

Open an existing database

Create a temporary database. (Useful for testing)

Create Hash

Specify table name.

Specification of column types explicitly

Data Type

Access Record

Add

Read

Update

Delete

Search

Sort

Grouping

Snippet

Pagination

Cooperation between multiple tables

About

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ongaeshi/grn_mini

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GrnMini

Installation

Basic Usage

Create a database with the name "test.db".

Add the record with the number column and text column.

It is also possible to use the '<<'

Open an existing database

Create a temporary database. (Useful for testing)

Create Hash

Specify table name.

Specification of column types explicitly

Data Type

Access Record

Add

Read

Update

Delete

Search

Sort

Grouping

Snippet

Pagination

Cooperation between multiple tables

About

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License

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Releases

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