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Three Ruby usages
Kouhei Sutou
ClearCode Inc.
RubyKaigi 2014
2014/09/20
Three Ruby usages
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Silver sponsor
Three Ruby usages
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Goal
✓ You know three Ruby usages
✓ High-level interface
✓ Glue
✓ Embed
✓ You can remember them later
Three Ruby usages
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Targets
✓ High-level interface
✓ Pure Rubyists
✓ Glue
✓ Rubyists who can write C/C++
✓ Embed
✓ Rubyists who also write C/C++
Three Ruby usages
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Case study
Implement distributed
full-text search engine in
Ruby
Abbreviation: DFTSE = Distributed Full-Text Search Engine
Three Ruby usages
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DFTSE?
1: Full-text search
2: Distribute
sub requests
3: Merge
responses
Distrubuted
Full-
Text
Search
Engine
Full-
Text
Search
Engine
Three Ruby usages
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Why do we use DFTSE?
I'm developing
Droonga
(A DFTSE implementation in Ruby)
😃
Three Ruby usages
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High-level interface
Three Ruby usages
✓ High-level interface
✓ Target: Pure Rubyists
✓ Glue
✓ Embed
Three Ruby usages
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High-level interface
✓ Provides
lower layer feature to
higher layer
✓ With simpler/convenience API
Three Ruby usages
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High-level interface
Higher layer users
High-level
interface
by Yukihiro Matsumoto
Feature
Application/Library
Three Ruby usages
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Example
Vagrant Active Record
Developers Developers
Vagrantfile Object based API
by Yukihiro Matsumoto
Build
development
environment
Vagrant
Three Ruby usages
by Yukihiro Matsumoto
Access data in RDBMS
Active Record
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Droonga: High-level IF
DFTSE components
✓ Full-text search engine
✓ Messaging system
✓ Cluster management
✓ Process management
Three Ruby usages
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Messaging system
1: Full-text search
2: Distribute
sub requests
3: Merge
responses
DTFSE
FTSE
Worker
process
Messaging
system
Three Ruby usages
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Messaging system
✓ Provides
distributed search feature
✓ Plan how to search
✓ Distribute requests
✓ Merge responses
✓ Users don't know details
Three Ruby usages
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Characteristic
✓ Plan how to search
✓ May speed up/down over 100 times
✓ Distribute requests
✓ Network bound operation
✓ Merge responses
✓ CPU and network bound operation
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Point
✓ Algorithm is important
✓ Need to find new/existing better
algorithm
✓ "Rapid prototype and measure"
feedback loop is helpful
✓ Ruby is good at rapid dev.
Three Ruby usages
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Glue
Three Ruby usages
✓ High-level interface
✓ Glue
✓ Target:
Rubyists who can write C/C++
✓ Embed
Three Ruby usages
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Glue
Export
a feature
Ruby
Combine
features
Other
Language
Feature
Three Ruby usages
Glue
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Example
Active Record
Vagrant
mysql2 gem
Access to MySQL
libmysqlclient.so
VM Provision
(VirtualBox) (Chef)
Feature
Three Ruby usages
Glue
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Why do we glue?
✓ Reuse existing features
Three Ruby usages
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How to glue
✓ Use external library
✓ Implement bindings
(mysql2 gem)
✓ Use external command
✓ Spawn command
(Vagrant)
✓ Use external service
✓ Implement client
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Glue in Droonga
✓ Rroonga: Groonga bindings
✓ Groonga: FTSE C library
(and server)
✓ Cool.io: libev bindings
✓ libev: Event loop C library
(Based on I/O multiplexing and non-blocking I/O)
✓ Serf: Clustering tool
Three Ruby usages
(in Droonga)
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Rroonga in Droonga
1: Full-text search
2: Distribute
sub requests
3: Merge
responses
DTFSE
FTSE
Worker
process
Messaging
system
Three Ruby usages
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FTSE in Droonga
✓ Must be fast!
✓ CPU bound processing
Three Ruby usages
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For fast Rroonga
✓ Do heavy processing in C
✓ Nice to have Ruby-ish API
✓ Less memory allocation
✓ Cache internal buffer
✓ Multiprocessing
✓ Groonga supports multiprocessing
Three Ruby usages
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Search
Groonga::Database.open(ARGV[0])
entries = Groonga["Entries"]
entries.select do |record|
record.description =~ "Ruby"
end
Three Ruby usages
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Search - Pure Ruby (ref)
Groonga::Database.open(ARGV[0])
entries = Groonga["Entries"]
entries.find_all do |record|
# This block is evaluated for each record
/Ruby/ =~ record.description
end
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Search impl.
# (2) Evaluate expression in C
entries.select do |record|
# (1) Build expression in Ruby
# This block is evaluated only once
record.description =~ "Ruby"
end
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Search impl. - Fig.
Ruby
entries.select do |record|
record.description =~ "Ruby"
end
Build
by Groonga project
C
Three Ruby usages
Search
request
Expression
Result set
by Groonga project
Evaluate expression
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Search - Benchmark
✓ Ruby
(It's already showed)
✓ C
Three Ruby usages
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Search - C
grn_obj *expr;
grn_obj *variable;
const gchar *filter = "description @ \"Ruby\"";
grn_obj *result;
GRN_EXPR_CREATE_FOR_QUERY(&ctx, table, expr, variable);
grn_expr_parse(&ctx, expr,
filter, strlen(filter), NULL,
GRN_OP_MATCH, GRN_OP_AND,
GRN_EXPR_SYNTAX_SCRIPT);
result = grn_table_select(&ctx, table, expr, NULL, GRN_OP_OR);
grn_obj_unlink(&ctx, expr);
grn_obj_unlink(&ctx, result);
Three Ruby usages
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Search - Benchmark
Ruby impl. is fast enough 😃
Impl.
C
Ruby
Elapsed time
0.6ms
0.8ms
(Full-text search with "Ruby" against 72632 records)
Three Ruby usages
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Embed
Three Ruby usages
✓ High-level interface
✓ Glue
✓ Embed
✓ Target:
Rubyists who also write C/C++
Three Ruby usages
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Embed
Internal engine
C/C++ application
C/C++ library
Implement
some features
in Ruby
by Yukihiro Matsumoto
Three Ruby usages
Interface
Plugin API
Conifugration
by Yukihiro Matsumoto
C/C++ application
C/C++ library
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Examples
Internal engine
Interface
vim-ruby
Implement
query optimizer
in Ruby
by Yukihiro Matsumoto
Three Ruby usages
by Yukihiro Matsumoto
VIM
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Embed in Droonga
by Yukihiro Matsumoto
by The Groonga Project
by Yukihiro Matsumoto
...
by The Groonga Project
by The Groonga Project
mruby
Three Ruby usages
by Yukihiro Matsumoto
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CRuby vs. mruby
✓ CRuby
✓ Full featured!
✓ Signal handler isn't needed 😞
✓ mruby
✓ Multi-interpreters in a process!
✓ You may miss some features 😞
Three Ruby usages
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mruby in Groonga
✓ Query optimizer
✓ Command interface (plan)
✓ Interface
and also high-level interface!
✓ Plugin API (plan)
✓ Interface!
Three Ruby usages
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Query optimizer
Query
Optimize
Optimized
Full-text search
query
Query
Optimizer
by Yukihiro Matsumoto
Evaluator
Result set
Three Ruby usages
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Query optimizer
✓ Plan how to search
✓ It's a bother 😞
✓ Light operation than FTS
✓ Depends on data
(Choose effective index, use table scan and so on)
Three Ruby usages
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Example
rank < 200 && rank > 100
Three Ruby usages
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Simple impl.
rank
1 2 ... 100 101 ... 199 200 ... ... 10000
rank < 200
rank > 100
&&
101 ... 199
rank < 200 && rank > 100
Three Ruby usages
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Simple impl.
✓ Slow against
many out of range data
Three Ruby usages
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Optimized impl.
rank
1 2 ... 100 101 ... 199 200 ... ... 10000
100 < rank < 200
101 ... 199
rank < 200 && rank > 100
Three Ruby usages
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Is embedding reasonable?
Measure
Three Ruby usages
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Measure
✓ mruby overhead
✓ Speed-up by optimization
Three Ruby usages
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Overhead
Small overhead: Reasonable😃
# conds
mruby
1
1
4
4
Three Ruby usages
○
×
○
×
Elapsed
0.24ms
0.16ms
0.45ms
0.19ms
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Speed-up
Fast for many data:Reasonable😃
# records
1000
10000
100000
1000000
Three Ruby usages
mruby
no mruby
0.29ms
0.31ms
0.31ms
2.3ms
0.26ms
21.1ms
0.26ms
210.2ms
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Note
✓ Embedding needs many works
✓ Write bindings, import mruby your
build system and ...
✓ How to test your mruby part?
✓ And how to debug?
Three Ruby usages
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Conclusion 1
✓ Describe three Ruby usages
✓ High-level interface
✓ Glue
✓ Embed
Three Ruby usages
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Conclusion 2
✓ High-level interface
✓ Target: Pure Rubyists
✓ Provides lower layer feature to
higher layer w/ usable interface
✓ Ruby's flexibility is useful
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Conclusion 3
✓ Glue
✓ Target:
Rubyists who can write C/C++
✓ Why: Reuse existing feature
✓ To be fast, do the process in C
Three Ruby usages
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Conclusion 4
✓ Embed
✓ Target:
Rubyists who also write C/C++
✓ Why:
Avoid bother programming by Ruby
Three Ruby usages
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Conclusion 5
✓ Embed
✓ Is it reasonable for your case?
✓ You need many works
✓ Very powerful
if your case is reasonable😃
Three Ruby usages
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Announcement
✓ ClearCode Inc.
✓ A silver sponsor
✓ Is recruiting
✓ Will do readable code workshop
✓ The next Groonga conference
✓ It's held at 11/29
Three Ruby usages
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![](30.png "Search - C
grn_obj *expr;
grn_obj *variable;
const gchar *filter = \"description @ \\"Ruby\\"\";
grn_obj *result;
GRN_EXPR_CREATE_FOR_QUERY(&ctx, table, expr, variable);
grn_expr_parse(&ctx, expr,
filter, strlen(filter), NULL,
GRN_OP_MATCH, GRN_OP_AND,
GRN_EXPR_SYNTAX_SCRIPT);
result = grn_table_select(&ctx, table, expr, NULL, GRN_OP_OR);
grn_obj_unlink(&ctx, expr);
grn_obj_unlink(&ctx, result);
Three Ruby usages
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![](mini-30.png "Search - C
grn_obj *expr;
grn_obj *variable;
const gchar *filter = \"description @ \\"Ruby\\"\";
grn_obj *result;
GRN_EXPR_CREATE_FOR_QUERY(&ctx, table, expr, variable);
grn_expr_parse(&ctx, expr,
filter, strlen(filter), NULL,
GRN_OP_MATCH, GRN_OP_AND,
GRN_EXPR_SYNTAX_SCRIPT);
result = grn_table_select(&ctx, table, expr, NULL, GRN_OP_OR);
grn_obj_unlink(&ctx, expr);
grn_obj_unlink(&ctx, result);
Three Ruby usages
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