Merge pull request #113 from vmarkovtsev/master

Use rubex for faster regular expressions

.travis.yml

@@ -4,16 +4,26 @@ go:
   - 1.8
   - tip
 
+addons:
+  apt:
+    packages:
+      - libonig-dev
+
 matrix:
   allow_failures:
     - go: tip
   fast_finish: true
 
+env:
+  - ONIGUMURA=0
+  - ONIGUMURA=1
+
 install:
   - rm -rf $GOPATH/src/gopkg.in/src-d
   - mkdir -p $GOPATH/src/gopkg.in/src-d
   - ln -s $PWD $GOPATH/src/gopkg.in/src-d/enry.v1
   - cd $GOPATH/src/gopkg.in/src-d/enry.v1
+  - if [ "$ONIGUMURA" == "1" ]; then make onigumura; fi
   - go get -v -t ./...
 
 script:
@@ -36,6 +46,8 @@ deploy:
     tags: true
 
 jobs:
+  env:
+    - ONIGUMURA=0    
   include:
     - stage: test
       language: scala

Makefile

@@ -38,6 +38,12 @@ DARWIN_SHARED_LIB=$(DARWIN_DIR)/libenry.dylib
 HEADER_FILE=libenry.h
 NATIVE_LIB=./shared/enry.go
 
+# source files to be patched for using "rubex" instead of "regexp"
+RUBEX_PATCHED := internal/code-generator/generator/heuristics.go internal/tokenizer/tokenize.go common.go
+RUBEX_ORIG := $(RUBEX_PATCHED:=.orig)
+
+.PHONY: revert-onigumura
+
 $(LINGUIST_PATH):
 	git clone https://github.com/github/linguist.git $@
 
@@ -63,6 +69,15 @@ benchmarks-slow: $(LINGUST_PATH)
 	mkdir -p benchmarks/output && go test -run=NONE -bench=. -slow -benchtime=100ms -timeout=100h >benchmarks/output/enry_samples.bench && \
 	benchmarks/linguist-samples.rb 5 >benchmarks/output/linguist_samples.bench
 
+$(RUBEX_ORIG): %.orig : %
+	sed -i.orig -e 's/"regexp"/regexp "github.com\/moovweb\/rubex"/g' $<
+	@touch $@
+
+onigumura: $(RUBEX_ORIG)
+
+revert-onigumura:
+	@for file in $(RUBEX_PATCHED); do if [ -e "$$file.orig" ]; then mv "$$file.orig" "$$file" && echo mv "$$file.orig" "$$file"; fi; done
+
 build-cli:
 	go build -o enry -ldflags "$(LOCAL_LDFLAGS)" cli/enry/main.go
 

README.md

@@ -19,6 +19,32 @@ To build enry's CLI you must run
 this will generate a binary in the project's root directory called `enry`. You can then move this binary to anywhere in your `PATH`.
 
 
+### Faster regexp engine (optional)
+
+[Onigumura](https://github.com/kkos/oniguruma) is CRuby's regular expression engine.
+It is very fast and performs better than the one built into Go runtime. *enry* supports swapping
+between those two engines thanks to [rubex](https://github.com/moovweb/rubex) project.
+The typical overall speedup from using Onigumura is 1.5-2x. However, it requires CGo and the external shared library.
+On macOS with brew, it is
+
+```
+brew install onigumura
+```
+
+On Ubuntu, it is
+
+```
+sudo apt install libonig-dev
+```
+
+To build enry with Onigumura regexps, patch the imports with
+
+```
+make onigumura
+```
+
+and then rebuild the project.
+
 Examples
 ------------
 

internal/tokenizer/tokenize.go

@@ -43,17 +43,46 @@ var (
 		extractRemainders,
 	}
 
-	reLiteralStringQuotes = regexp.MustCompile(`(?sU)(".*"|'.*')`)
-	reSingleLineComment   = regexp.MustCompile(`(?m)(//|--|#|%|")\s(.*$)`)
-	reMultilineComment    = regexp.MustCompile(`(?sU)(/\*.*\*/|<!--.*-->|\{-.*-\}|\(\*.*\*\)|""".*"""|'''.*''')`)
+	// Differences between golang regexp and onigumura:
+	// 1. no (?s) in onigumura - makes dot match \n
+	// 2. no (?U) in onigumura - ungreedy *
+	// 3. (?m) implies dot matches \n in onigumura
+	// 4. onigumura handles \w differently - impossible, but true
+	//
+	// Workarounds:
+	// 1. (.|\n)
+	// 2. replace * with *?
+	// 3. replace . with [^\n]
+	// 4. replace \w with [0-9A-Za-z_]
+	//
+	// Original golang regexps:
+	//
+	// reLiteralStringQuotes = regexp.MustCompile(`(?sU)(".*"|'.*')`)
+	// reSingleLineComment   = regexp.MustCompile(`(?m)(//|--|#|%|")\s(.*$)`)
+	// reMultilineComment    = regexp.MustCompile(`(?sU)(/\*.*\*/|<!--.*-->|\{-.*-\}|\(\*.*\*\)|""".*"""|'''.*''')`)
+	// reLiteralNumber       = regexp.MustCompile(`(0x[0-9A-Fa-f]([0-9A-Fa-f]|\.)*|\d(\d|\.)*)([uU][lL]{0,2}|([eE][-+]\d*)?[fFlL]*)`)
+	// reShebang             = regexp.MustCompile(`(?m)^#!(?:/\w+)*/(?:(\w+)|\w+(?:\s*\w+=\w+\s*)*\s*(\w+))(?:\s*-\w+\s*)*$`)
+	// rePunctuation         = regexp.MustCompile(`;|\{|\}|\(|\)|\[|\]`)
+	// reSGML                = regexp.MustCompile(`(?sU)(<\/?[^\s<>=\d"']+)(?:\s.*\/?>|>)`)
+	// reSGMLComment         = regexp.MustCompile(`(?sU)(<!--.*-->)`)
+	// reSGMLAttributes      = regexp.MustCompile(`\s+(\w+=)|\s+([^\s>]+)`)
+	// reSGMLLoneAttribute   = regexp.MustCompile(`(\w+)`)
+	// reRegularToken        = regexp.MustCompile(`[\w\.@#\/\*]+`)
+	// reOperators           = regexp.MustCompile(`<<?|\+|\-|\*|\/|%|&&?|\|\|?`)
+	//
+	// These regexps were converted to work in the same way for both engines:
+	//
+	reLiteralStringQuotes = regexp.MustCompile(`("(.|\n)*?"|'(.|\n)*?')`)
+	reSingleLineComment   = regexp.MustCompile(`(?m)(//|--|#|%|")\s([^\n]*$)`)
+	reMultilineComment    = regexp.MustCompile(`(/\*(.|\n)*?\*/|<!--(.|\n)*?-->|\{-(.|\n)*?-\}|\(\*(.|\n)*?\*\)|"""(.|\n)*?"""|'''(.|\n)*?''')`)
 	reLiteralNumber       = regexp.MustCompile(`(0x[0-9A-Fa-f]([0-9A-Fa-f]|\.)*|\d(\d|\.)*)([uU][lL]{0,2}|([eE][-+]\d*)?[fFlL]*)`)
-	reShebang             = regexp.MustCompile(`(?m)^#!(?:/\w+)*/(?:(\w+)|\w+(?:\s*\w+=\w+\s*)*\s*(\w+))(?:\s*-\w+\s*)*$`)
+	reShebang             = regexp.MustCompile(`(?m)^#!(?:/[0-9A-Za-z_]+)*/(?:([0-9A-Za-z_]+)|[0-9A-Za-z_]+(?:\s*[0-9A-Za-z_]+=[0-9A-Za-z_]+\s*)*\s*([0-9A-Za-z_]+))(?:\s*-[0-9A-Za-z_]+\s*)*$`)
 	rePunctuation         = regexp.MustCompile(`;|\{|\}|\(|\)|\[|\]`)
-	reSGML                = regexp.MustCompile(`(?sU)(<\/?[^\s<>=\d"']+)(?:\s.*\/?>|>)`)
-	reSGMLComment         = regexp.MustCompile(`(?sU)(<!--.*-->)`)
-	reSGMLAttributes      = regexp.MustCompile(`\s+(\w+=)|\s+([^\s>]+)`)
-	reSGMLLoneAttribute   = regexp.MustCompile(`(\w+)`)
-	reRegularToken        = regexp.MustCompile(`[\w\.@#\/\*]+`)
+	reSGML                = regexp.MustCompile(`(<\/?[^\s<>=\d"']+)(?:\s(.|\n)*?\/?>|>)`)
+	reSGMLComment         = regexp.MustCompile(`(<!--(.|\n)*?-->)`)
+	reSGMLAttributes      = regexp.MustCompile(`\s+([0-9A-Za-z_]+=)|\s+([^\s>]+)`)
+	reSGMLLoneAttribute   = regexp.MustCompile(`([0-9A-Za-z_]+)`)
+	reRegularToken        = regexp.MustCompile(`[0-9A-Za-z_\.@#\/\*]+`)
 	reOperators           = regexp.MustCompile(`<<?|\+|\-|\*|\/|%|&&?|\|\|?`)
 
 	regexToSkip = []*regexp.Regexp{