copiousfreetime / amalgalite
watch download tarball
public
Forks1Right
Watchers20Right
Description: SQLite database engine embedded in a ruby extension.
Homepage: http://copiousfreetime.rubyforge.org/amalgalite/
Clone URL: git://github.com/copiousfreetime/amalgalite.git
amalgalite / examples / blob.rb
raw normal view history
7751e6eb » copiousfreetime 2008-07-04 Added access to sqlite3_err... 1 #!/usr/bin/env ruby
2
3 #
4 # An Amalgalite example showing how Blob's can be utilized
5 #
6 # We'll make a database with one table, that we store files in. We'll use the
7 # Blob incremental IO to store the files and retrieve them from the database
8 #
9 # This little program will store 1 or more files in the sqlite3 database when
10 # the 'store' action is given, and cat a file to stdout on 'retrieve'
11 #
12 # e.g.
13 #
14 # ruby blob.rb store a.rb b.rb c.rb # => stores a.rb b.rb and c.rb in the db
15 #
16 # ruby blob.rb retrieve a.rb # => dumps a.rb to stdout
17 #
18
19 require 'rubygems'
1e931bd1 » copiousfreetime 2008-11-02 fixed storing compressed blobs 20 $: << "../lib"
21 $: << "../ext"
7751e6eb » copiousfreetime 2008-07-04 Added access to sqlite3_err... 22 require 'amalgalite'
9103eceb » copiousfreetime 2008-11-16 Refactor gzip, gunzip and a... 23 require 'amalgalite/packer'
af4db9b7 » copiousfreetime 2008-07-04 added 'list' command to blo... 24 VALID_ACTIONS = %w[ list retrieve store ]
7751e6eb » copiousfreetime 2008-07-04 Added access to sqlite3_err... 25 def usage
af4db9b7 » copiousfreetime 2008-07-04 added 'list' command to blo... 26 STDERR.puts "Usage: #{File.basename($0)} ( #{VALID_ACTIONS.join(' | ')} ) file(s)"
7751e6eb » copiousfreetime 2008-07-04 Added access to sqlite3_err... 27 exit 1
28 end
29
30 #
31 # This does the basic command line parsing
32 #
af4db9b7 » copiousfreetime 2008-07-04 added 'list' command to blo... 33 usage if ARGV.size < 1
7751e6eb » copiousfreetime 2008-07-04 Added access to sqlite3_err... 34 action = ARGV.shift
af4db9b7 » copiousfreetime 2008-07-04 added 'list' command to blo... 35 usage unless VALID_ACTIONS.include? action
7751e6eb » copiousfreetime 2008-07-04 Added access to sqlite3_err... 36 file_list = ARGV
37
38 #
39 # create the database if it doesn't exist
40 #
41 db = Amalgalite::Database.new( "filestore.db" )
42
43 case action
44 #
af4db9b7 » copiousfreetime 2008-07-04 added 'list' command to blo... 45 # list all the files that are stored in the database
46 #
47 when 'list'
ae1a6632 » copiousfreetime 2008-10-22 added store_dir in db and r... 48 db.execute("SELECT filename FROM rubylibs") do |row|
49 puts row['filename']
af4db9b7 » copiousfreetime 2008-07-04 added 'list' command to blo... 50 end
51
52 #
7751e6eb » copiousfreetime 2008-07-04 Added access to sqlite3_err... 53 # if we are doing the store action, then loop over the files and store them in
54 # the database. This will use incremental IO to store the files directly from
55 # the file names.
56 #
57 # It is slightly strange in that you have to tell the Blob object what column
58 # it is going to, but that is necessary at this point to be able to hook
59 # automatically into the lower level incremental blob IO api.
60 #
61 # This also shows using the $var syntax for binding name sql values in a
62 # prepared statement.
63 #
64 when 'store'
af4db9b7 » copiousfreetime 2008-07-04 added 'list' command to blo... 65 usage if file_list.empty?
1e931bd1 » copiousfreetime 2008-11-02 fixed storing compressed blobs 66 require 'amalgalite/packer'
ae1a6632 » copiousfreetime 2008-10-22 added store_dir in db and r... 67
1e931bd1 » copiousfreetime 2008-11-02 fixed storing compressed blobs 68 packer = Amalgalite::Packer.new( :dbfile => 'filestore.db',
9103eceb » copiousfreetime 2008-11-16 Refactor gzip, gunzip and a... 69 :compressed => false )
1e931bd1 » copiousfreetime 2008-11-02 fixed storing compressed blobs 70 packer.pack( file_list )
7751e6eb » copiousfreetime 2008-07-04 Added access to sqlite3_err... 71
72 #
73 # dump the file that matches the right path to stdout. This also shows
74 # positional sql varible binding using the '?' syntax.
75 #
76 when 'retrieve'
af4db9b7 » copiousfreetime 2008-07-04 added 'list' command to blo... 77 usage if file_list.empty?
1e931bd1 » copiousfreetime 2008-11-02 fixed storing compressed blobs 78 db.execute("SELECT id, compressed, filename, contents FROM rubylibs WHERE filename = ?", file_list.first) do |row|
79 STDERR.puts "Dumping #{row['filename']} to stdout"
80 if row['compressed'] then
81 s = row['contents'].to_s
9103eceb » copiousfreetime 2008-11-16 Refactor gzip, gunzip and a... 82 STDOUT.puts Amalgalite::Packer.gunzip( s )
1e931bd1 » copiousfreetime 2008-11-02 fixed storing compressed blobs 83 else
84 row['contents'].write_to_io( STDOUT )
85 end
7751e6eb » copiousfreetime 2008-07-04 Added access to sqlite3_err... 86 end
87 end
88 db.close