Move a specific regex to static variable

internal/cachedregexp/regex.go

@@ -0,0 +1,17 @@
+package cachedregexp
+
+import (
+	"regexp"
+	"sync"
+)
+
+var cache sync.Map
+
+func MustCompile(exp string) *regexp.Regexp {
+	compiled, ok := cache.Load(exp)
+	if !ok {
+		compiled, _ = cache.LoadOrStore(exp, regexp.MustCompile(exp))
+	}
+
+	return compiled.(*regexp.Regexp)
+}

internal/semantic/version-maven.go

@@ -2,9 +2,10 @@ package semantic
 
 import (
 	"fmt"
-	"regexp"
 	"sort"
 	"strings"
+
+	"github.com/google/osv-scanner/internal/cachedregexp"
 )
 
 type mavenVersionToken struct {
@@ -175,11 +176,11 @@ func (mv MavenVersion) lessThan(mw MavenVersion) bool {
 // According to Maven's implementation, any non-digit is a "character":
 // https://github.com/apache/maven/blob/965aaa53da5c2d814e94a41d37142d0d6830375d/maven-artifact/src/main/java/org/apache/maven/artifact/versioning/ComparableVersion.java#L627
 func mavenFindTransitions(token string) (ints []int) {
-	for _, span := range regexp.MustCompile(`\D\d`).FindAllStringIndex(token, -1) {
+	for _, span := range cachedregexp.MustCompile(`\D\d`).FindAllStringIndex(token, -1) {
 		ints = append(ints, span[0]+1)
 	}
 
-	for _, span := range regexp.MustCompile(`\d\D`).FindAllStringIndex(token, -1) {
+	for _, span := range cachedregexp.MustCompile(`\d\D`).FindAllStringIndex(token, -1) {
 		ints = append(ints, span[0]+1)
 	}
 

internal/semantic/version-packagist.go

@@ -1,9 +1,10 @@
 package semantic
 
 import (
-	"regexp"
 	"strconv"
 	"strings"
+
+	"github.com/google/osv-scanner/internal/cachedregexp"
 )
 
 func canonicalizePackagistVersion(v string) string {
@@ -15,9 +16,9 @@ func canonicalizePackagistVersion(v string) string {
 	//   the trimming...)
 	v = strings.TrimPrefix(strings.TrimPrefix(v, "v"), "V")
 
-	v = regexp.MustCompile(`[-_+]`).ReplaceAllString(v, ".")
-	v = regexp.MustCompile(`([^\d.])(\d)`).ReplaceAllString(v, "$1.$2")
-	v = regexp.MustCompile(`(\d)([^\d.])`).ReplaceAllString(v, "$1.$2")
+	v = cachedregexp.MustCompile(`[-_+]`).ReplaceAllString(v, ".")
+	v = cachedregexp.MustCompile(`([^\d.])(\d)`).ReplaceAllString(v, "$1.$2")
+	v = cachedregexp.MustCompile(`(\d)([^\d.])`).ReplaceAllString(v, "$1.$2")
 
 	return v
 }

internal/semantic/version-pypi.go

@@ -3,8 +3,9 @@ package semantic
 import (
 	"fmt"
 	"math/big"
-	"regexp"
 	"strings"
+
+	"github.com/google/osv-scanner/internal/cachedregexp"
 )
 
 type PyPIVersion struct {
@@ -67,7 +68,7 @@ func parseLetterVersion(letter, number string) letterAndNumber {
 }
 
 func parseLocalVersion(local string) (parts []string) {
-	for _, part := range regexp.MustCompile(`[._-]`).Split(local, -1) {
+	for _, part := range cachedregexp.MustCompile(`[._-]`).Split(local, -1) {
 		parts = append(parts, strings.ToLower(part))
 	}
 
@@ -88,7 +89,7 @@ func normalizePyPILegacyPart(part string) string {
 		part = "@"
 	}
 
-	if regexp.MustCompile(`\d`).MatchString(part[:1]) {
+	if cachedregexp.MustCompile(`\d`).MatchString(part[:1]) {
 		// pad for numeric comparison
 		return fmt.Sprintf("%08s", part)
 	}
@@ -97,7 +98,7 @@ func normalizePyPILegacyPart(part string) string {
 }
 
 func parsePyPIVersionParts(str string) (parts []string) {
-	re := regexp.MustCompile(`(\d+|[a-z]+|\.|-)`)
+	re := cachedregexp.MustCompile(`(\d+|[a-z]+|\.|-)`)
 
 	splits := re.FindAllString(str, -1)
 	splits = append(splits, "final")
@@ -137,7 +138,7 @@ func parsePyPIVersion(str string) PyPIVersion {
 	str = strings.ToLower(str)
 
 	// from https://peps.python.org/pep-0440/#appendix-b-parsing-version-strings-with-regular-expressions
-	re := regexp.MustCompile(`^\s*v?(?:(?:(?P<epoch>[0-9]+)!)?(?P<release>[0-9]+(?:\.[0-9]+)*)(?P<pre>[-_\.]?(?P<pre_l>(a|b|c|rc|alpha|beta|pre|preview))[-_\.]?(?P<pre_n>[0-9]+)?)?(?P<post>(?:-(?P<post_n1>[0-9]+))|(?:[-_\.]?(?P<post_l>post|rev|r)[-_\.]?(?P<post_n2>[0-9]+)?))?(?P<dev>[-_\.]?(?P<dev_l>dev)[-_\.]?(?P<dev_n>[0-9]+)?)?)(?:\+(?P<local>[a-z0-9]+(?:[-_\.][a-z0-9]+)*))?\s*$`)
+	re := cachedregexp.MustCompile(`^\s*v?(?:(?:(?P<epoch>[0-9]+)!)?(?P<release>[0-9]+(?:\.[0-9]+)*)(?P<pre>[-_\.]?(?P<pre_l>(a|b|c|rc|alpha|beta|pre|preview))[-_\.]?(?P<pre_n>[0-9]+)?)?(?P<post>(?:-(?P<post_n1>[0-9]+))|(?:[-_\.]?(?P<post_l>post|rev|r)[-_\.]?(?P<post_n2>[0-9]+)?))?(?P<dev>[-_\.]?(?P<dev_l>dev)[-_\.]?(?P<dev_n>[0-9]+)?)?)(?:\+(?P<local>[a-z0-9]+(?:[-_\.][a-z0-9]+)*))?\s*$`)
 	match := re.FindStringSubmatch(str)
 
 	if len(match) == 0 {

internal/semantic/version-semver-like.go

@@ -3,8 +3,9 @@ package semantic
 import (
 	"fmt"
 	"math/big"
-	"regexp"
 	"strings"
+
+	"github.com/google/osv-scanner/internal/cachedregexp"
 )
 
 // SemverLikeVersion is a version that is _like_ a version as defined by the
@@ -55,7 +56,7 @@ func parseSemverLike(line string) SemverLikeVersion {
 	var components []*big.Int
 	originStr := line
 
-	numberReg := regexp.MustCompile(`\d`)
+	numberReg := cachedregexp.MustCompile(`\d`)
 
 	currentCom := ""
 	foundBuild := false

pkg/lockfile/dpkg-status.go

@@ -4,9 +4,10 @@ import (
 	"bufio"
 	"fmt"
 	"os"
-	"regexp"
 	"sort"
 	"strings"
+
+	"github.com/google/osv-scanner/internal/cachedregexp"
 )
 
 const DebianEcosystem Ecosystem = "Debian"
@@ -38,7 +39,7 @@ func groupDpkgPackageLines(scanner *bufio.Scanner) [][]string {
 // Return name and version if "Source" field contains them
 func parseSourceField(source string) (string, string) {
 	// Pattern: name (version)
-	re := regexp.MustCompile(`^(.*)\((.*)\)`)
+	re := cachedregexp.MustCompile(`^(.*)\((.*)\)`)
 	matches := re.FindStringSubmatch(source)
 	if len(matches) == 3 {
 		return strings.TrimSpace(matches[1]), strings.TrimSpace(matches[2])

pkg/lockfile/parse-gemfile-lock.go

@@ -4,8 +4,9 @@ import (
 	"fmt"
 	"log"
 	"os"
-	"regexp"
 	"strings"
+
+	"github.com/google/osv-scanner/internal/cachedregexp"
 )
 
 const BundlerEcosystem Ecosystem = "RubyGems"
@@ -55,8 +56,8 @@ func (parser *gemfileLockfileParser) addDependency(name string, version string)
 }
 
 func (parser *gemfileLockfileParser) parseSpec(line string) {
-	// nameVersionReg := regexp.MustCompile(`^( {2}| {4}| {6})(?! )(.*?)(?: \(([^-]*)(?:-(.*))?\))?(!)?$`)
-	nameVersionReg := regexp.MustCompile(`^( +)(.*?)(?: \(([^-]*)(?:-(.*))?\))?(!)?$`)
+	// nameVersionReg := cachedregexp.MustCompile(`^( {2}| {4}| {6})(?! )(.*?)(?: \(([^-]*)(?:-(.*))?\))?(!)?$`)
+	nameVersionReg := cachedregexp.MustCompile(`^( +)(.*?)(?: \(([^-]*)(?:-(.*))?\))?(!)?$`)
 
 	results := nameVersionReg.FindStringSubmatch(line)
 
@@ -82,7 +83,7 @@ func (parser *gemfileLockfileParser) parseSource(line string) {
 	}
 
 	// OPTIONS      = /^  ([a-z]+): (.*)$/i.freeze
-	optionsRegexp := regexp.MustCompile(`(?i)^ {2}([a-z]+): (.*)$`)
+	optionsRegexp := cachedregexp.MustCompile(`(?i)^ {2}([a-z]+): (.*)$`)
 
 	// todo: support
 	options := optionsRegexp.FindStringSubmatch(line)
@@ -105,7 +106,7 @@ func (parser *gemfileLockfileParser) parseSource(line string) {
 }
 
 func isNotIndented(line string) bool {
-	re := regexp.MustCompile(`^\S`)
+	re := cachedregexp.MustCompile(`^\S`)
 
 	return re.MatchString(line)
 }
@@ -127,7 +128,7 @@ func (parser *gemfileLockfileParser) parseLineBasedOnState(line string) {
 }
 
 func (parser *gemfileLockfileParser) parse(contents string) {
-	lineMatcher := regexp.MustCompile(`(?:\r?\n)+`)
+	lineMatcher := cachedregexp.MustCompile(`(?:\r?\n)+`)
 
 	lines := lineMatcher.Split(contents, -1)
 

pkg/lockfile/parse-maven-lock.go

@@ -4,7 +4,8 @@ import (
 	"encoding/xml"
 	"fmt"
 	"os"
-	"regexp"
+
+	"github.com/google/osv-scanner/internal/cachedregexp"
 )
 
 type MavenLockDependency struct {
@@ -15,7 +16,7 @@ type MavenLockDependency struct {
 }
 
 func (mld MavenLockDependency) parseResolvedVersion(version string) string {
-	versionRequirementReg := regexp.MustCompile(`[[(]?(.*?)(?:,|[)\]]|$)`)
+	versionRequirementReg := cachedregexp.MustCompile(`[[(]?(.*?)(?:,|[)\]]|$)`)
 
 	results := versionRequirementReg.FindStringSubmatch(version)
 
@@ -27,7 +28,7 @@ func (mld MavenLockDependency) parseResolvedVersion(version string) string {
 }
 
 func (mld MavenLockDependency) resolveVersionValue(lockfile MavenLockFile) string {
-	interpolationReg := regexp.MustCompile(`\${(.+)}`)
+	interpolationReg := cachedregexp.MustCompile(`\${(.+)}`)
 
 	results := interpolationReg.FindStringSubmatch(mld.Version)
 

pkg/lockfile/parse-mix-lock.go

@@ -4,8 +4,9 @@ import (
 	"bufio"
 	"fmt"
 	"os"
-	"regexp"
 	"strings"
+
+	"github.com/google/osv-scanner/internal/cachedregexp"
 )
 
 const MixEcosystem Ecosystem = "Hex"
@@ -17,7 +18,7 @@ func ParseMixLock(pathToLockfile string) ([]PackageDetails, error) {
 	}
 	defer file.Close()
 
-	re := regexp.MustCompile(`^ +"(\w+)": \{.+,$`)
+	re := cachedregexp.MustCompile(`^ +"(\w+)": \{.+,$`)
 
 	scanner := bufio.NewScanner(file)
 

pkg/lockfile/parse-pnpm-lock.go

@@ -3,10 +3,10 @@ package lockfile
 import (
 	"fmt"
 	"os"
-	"regexp"
 	"strconv"
 	"strings"
 
+	"github.com/google/osv-scanner/internal/cachedregexp"
 	"gopkg.in/yaml.v3"
 )
 
@@ -55,7 +55,7 @@ func (l *PnpmLockfile) UnmarshalYAML(unmarshal func(interface{}) error) error {
 const PnpmEcosystem = NpmEcosystem
 
 func startsWithNumber(str string) bool {
-	matcher := regexp.MustCompile(`^\d`)
+	matcher := cachedregexp.MustCompile(`^\d`)
 
 	return matcher.MatchString(str)
 }
@@ -108,7 +108,7 @@ func extractPnpmPackageNameAndVersion(dependencyPath string) (string, string) {
 
 func parseNameAtVersion(value string) (name string, version string) {
 	// look for pattern "name@version", where name is allowed to contain zero or more "@"
-	matches := regexp.MustCompile(`^(.+)@([\d.]+)$`).FindStringSubmatch(value)
+	matches := cachedregexp.MustCompile(`^(.+)@([\d.]+)$`).FindStringSubmatch(value)
 
 	if len(matches) != 3 {
 		return name, ""
@@ -142,7 +142,7 @@ func parsePnpmLock(lockfile PnpmLockfile) []PackageDetails {
 		commit := pkg.Resolution.Commit
 
 		if strings.HasPrefix(pkg.Resolution.Tarball, "https://codeload.github.com") {
-			re := regexp.MustCompile(`https://codeload\.github\.com(?:/[\w-.]+){2}/tar\.gz/(\w+)$`)
+			re := cachedregexp.MustCompile(`https://codeload\.github\.com(?:/[\w-.]+){2}/tar\.gz/(\w+)$`)
 			matched := re.FindStringSubmatch(pkg.Resolution.Tarball)
 
 			if matched != nil {

pkg/lockfile/parse-requirements-txt.go

@@ -5,8 +5,9 @@ import (
 	"fmt"
 	"os"
 	"path/filepath"
-	"regexp"
 	"strings"
+
+	"github.com/google/osv-scanner/internal/cachedregexp"
 )
 
 const PipEcosystem Ecosystem = "PyPI"
@@ -67,15 +68,15 @@ func parseLine(line string) PackageDetails {
 // than false negatives, and can be dealt with when/if it actually happens.
 func normalizedRequirementName(name string) string {
 	// per https://www.python.org/dev/peps/pep-0503/#normalized-names
-	name = regexp.MustCompile(`[-_.]+`).ReplaceAllString(name, "-")
+	name = cachedregexp.MustCompile(`[-_.]+`).ReplaceAllString(name, "-")
 	name = strings.ToLower(name)
 	name = strings.Split(name, "[")[0]
 
 	return name
 }
 
 func removeComments(line string) string {
-	var re = regexp.MustCompile(`(^|\s+)#.*$`)
+	var re = cachedregexp.MustCompile(`(^|\s+)#.*$`)
 
 	return strings.TrimSpace(re.ReplaceAllString(line, ""))
 }

pkg/lockfile/parse-yarn-lock.go

@@ -5,8 +5,9 @@ import (
 	"fmt"
 	"net/url"
 	"os"
-	"regexp"
 	"strings"
+
+	"github.com/google/osv-scanner/internal/cachedregexp"
 )
 
 const YarnEcosystem = NpmEcosystem
@@ -63,7 +64,7 @@ func extractYarnPackageName(str string) string {
 }
 
 func determineYarnPackageVersion(group []string) string {
-	re := regexp.MustCompile(`^ {2}"?version"?:? "?([\w-.]+)"?$`)
+	re := cachedregexp.MustCompile(`^ {2}"?version"?:? "?([\w-.]+)"?$`)
 
 	for _, s := range group {
 		matched := re.FindStringSubmatch(s)
@@ -78,7 +79,7 @@ func determineYarnPackageVersion(group []string) string {
 }
 
 func determineYarnPackageResolution(group []string) string {
-	re := regexp.MustCompile(`^ {2}"?(?:resolution:|resolved)"? "([^ '"]+)"$`)
+	re := cachedregexp.MustCompile(`^ {2}"?(?:resolution:|resolved)"? "([^ '"]+)"$`)
 
 	for _, s := range group {
 		matched := re.FindStringSubmatch(s)
@@ -111,7 +112,7 @@ func tryExtractCommit(resolution string) string {
 	}
 
 	for _, matcher := range matchers {
-		re := regexp.MustCompile(matcher)
+		re := cachedregexp.MustCompile(matcher)
 		matched := re.FindStringSubmatch(resolution)
 
 		if matched != nil {