diff --git a/event_bus.go b/event_bus.go index d4cf80f..66a0db1 100644 --- a/event_bus.go +++ b/event_bus.go @@ -4,6 +4,8 @@ import ( "fmt" "reflect" "sync" + + "github.com/bcw104/EventBus/wildcard" ) //BusSubscriber defines subscription-related bus behavior @@ -45,7 +47,7 @@ type eventHandler struct { flagOnce bool async bool transactional bool - sync.Mutex // lock for an event handler - useful for running async callbacks serially + sync.Mutex // lock for an event handler - useful for running async callbacks serially } // New returns new EventBus with empty handlers. @@ -131,23 +133,25 @@ func (bus *EventBus) Unsubscribe(topic string, handler interface{}) error { func (bus *EventBus) Publish(topic string, args ...interface{}) { bus.lock.Lock() // will unlock if handler is not found or always after setUpPublish defer bus.lock.Unlock() - if handlers, ok := bus.handlers[topic]; ok && 0 < len(handlers) { - // Handlers slice may be changed by removeHandler and Unsubscribe during iteration, - // so make a copy and iterate the copied slice. - copyHandlers := make([]*eventHandler, 0, len(handlers)) - copyHandlers = append(copyHandlers, handlers...) - for i, handler := range copyHandlers { - if handler.flagOnce { - bus.removeHandler(topic, i) - } - if !handler.async { - bus.doPublish(handler, topic, args...) - } else { - bus.wg.Add(1) - if handler.transactional { - handler.Lock() + for topicPattern, handlers := range bus.handlers { + if 0 < len(handlers) && wildcard.MatchSimple(topicPattern, topic) { + // Handlers slice may be changed by removeHandler and Unsubscribe during iteration, + // so make a copy and iterate the copied slice. + copyHandlers := make([]*eventHandler, 0, len(handlers)) + copyHandlers = append(copyHandlers, handlers...) + for i, handler := range copyHandlers { + if handler.flagOnce { + bus.removeHandler(topic, i) + } + if !handler.async { + bus.doPublish(handler, topic, args...) + } else { + bus.wg.Add(1) + if handler.transactional { + handler.Lock() + } + go bus.doPublishAsync(handler, topic, args...) } - go bus.doPublishAsync(handler, topic, args...) } } } diff --git a/wildcard/match.go b/wildcard/match.go new file mode 100644 index 0000000..aab13d4 --- /dev/null +++ b/wildcard/match.go @@ -0,0 +1,67 @@ +package wildcard + +// MatchSimple - finds whether the text matches/satisfies the pattern string. +// supports only '*' wildcard in the pattern. +// considers a file system path as a flat name space. +func MatchSimple(pattern, name string) bool { + if pattern == "" { + return name == pattern + } + if pattern == "*" { + return true + } + rname := make([]rune, 0, len(name)) + rpattern := make([]rune, 0, len(pattern)) + for _, r := range name { + rname = append(rname, r) + } + for _, r := range pattern { + rpattern = append(rpattern, r) + } + simple := true // Does only wildcard '*' match. + return deepMatchRune(rname, rpattern, simple) +} + +// Match - finds whether the text matches/satisfies the pattern string. +// supports '*' and '?' wildcards in the pattern string. +// unlike path.Match(), considers a path as a flat name space while matching the pattern. +// The difference is illustrated in the example here https://play.golang.org/p/Ega9qgD4Qz . +func Match(pattern, name string) (matched bool) { + if pattern == "" { + return name == pattern + } + if pattern == "*" { + return true + } + rname := make([]rune, 0, len(name)) + rpattern := make([]rune, 0, len(pattern)) + for _, r := range name { + rname = append(rname, r) + } + for _, r := range pattern { + rpattern = append(rpattern, r) + } + simple := false // Does extended wildcard '*' and '?' match. + return deepMatchRune(rname, rpattern, simple) +} + +func deepMatchRune(str, pattern []rune, simple bool) bool { + for len(pattern) > 0 { + switch pattern[0] { + default: + if len(str) == 0 || str[0] != pattern[0] { + return false + } + case '?': + if len(str) == 0 && !simple { + return false + } + case '*': + return deepMatchRune(str, pattern[1:], simple) || + (len(str) > 0 && deepMatchRune(str[1:], pattern, simple)) + } + str = str[1:] + pattern = pattern[1:] + } + return len(str) == 0 && len(pattern) == 0 +} diff --git a/wildcard/match_test.go b/wildcard/match_test.go new file mode 100644 index 0000000..883f054 --- /dev/null +++ b/wildcard/match_test.go @@ -0,0 +1,526 @@ +package wildcard_test + +import ( + "testing" + + "github.com/bcw104/EventBus/wildcard" +) + +// TestMatch - Tests validate the logic of wild card matching. +// `Match` supports '*' and '?' wildcards. +// Sample usage: In resource matching for bucket policy validation. +func TestMatch(t *testing.T) { + testCases := []struct { + pattern string + text string + matched bool + }{ + // Test case - 1. + // Test case with pattern "*". Expected to match any text. + { + pattern: "*", + text: "s3:GetObject", + matched: true, + }, + // Test case - 2. + // Test case with empty pattern. This only matches empty string. + { + pattern: "", + text: "s3:GetObject", + matched: false, + }, + // Test case - 3. + // Test case with empty pattern. This only matches empty string. + { + pattern: "", + text: "", + matched: true, + }, + // Test case - 4. + // Test case with single "*" at the end. + { + pattern: "s3:*", + text: "s3:ListMultipartUploadParts", + matched: true, + }, + // Test case - 5. + // Test case with a no "*". In this case the pattern and text should be the same. + { + pattern: "s3:ListBucketMultipartUploads", + text: "s3:ListBucket", + matched: false, + }, + // Test case - 6. + // Test case with a no "*". In this case the pattern and text should be the same. + { + pattern: "s3:ListBucket", + text: "s3:ListBucket", + matched: true, + }, + // Test case - 7. + // Test case with a no "*". In this case the pattern and text should be the same. + { + pattern: "s3:ListBucketMultipartUploads", + text: "s3:ListBucketMultipartUploads", + matched: true, + }, + // Test case - 8. + // Test case with pattern containing key name with a prefix. Should accept the same text without a "*". + { + pattern: "my-bucket/oo*", + text: "my-bucket/oo", + matched: true, + }, + // Test case - 9. + // Test case with "*" at the end of the pattern. + { + pattern: "my-bucket/In*", + text: "my-bucket/India/Karnataka/", + matched: true, + }, + // Test case - 10. + // Test case with prefixes shuffled. + // This should fail. + { + pattern: "my-bucket/In*", + text: "my-bucket/Karnataka/India/", + matched: false, + }, + // Test case - 11. + // Test case with text expanded to the wildcards in the pattern. + { + pattern: "my-bucket/In*/Ka*/Ban", + text: "my-bucket/India/Karnataka/Ban", + matched: true, + }, + // Test case - 12. + // Test case with the keyname part is repeated as prefix several times. + // This is valid. + { + pattern: "my-bucket/In*/Ka*/Ban", + text: "my-bucket/India/Karnataka/Ban/Ban/Ban/Ban/Ban", + matched: true, + }, + // Test case - 13. + // Test case to validate that `*` can be expanded into multiple prefixes. + { + pattern: "my-bucket/In*/Ka*/Ban", + text: "my-bucket/India/Karnataka/Area1/Area2/Area3/Ban", + matched: true, + }, + // Test case - 14. + // Test case to validate that `*` can be expanded into multiple prefixes. + { + pattern: "my-bucket/In*/Ka*/Ban", + text: "my-bucket/India/State1/State2/Karnataka/Area1/Area2/Area3/Ban", + matched: true, + }, + // Test case - 15. + // Test case where the keyname part of the pattern is expanded in the text. + { + pattern: "my-bucket/In*/Ka*/Ban", + text: "my-bucket/India/Karnataka/Bangalore", + matched: false, + }, + // Test case - 16. + // Test case with prefixes and wildcard expanded for all "*". + { + pattern: "my-bucket/In*/Ka*/Ban*", + text: "my-bucket/India/Karnataka/Bangalore", + matched: true, + }, + // Test case - 17. + // Test case with keyname part being a wildcard in the pattern. + { + pattern: "my-bucket/*", + text: "my-bucket/India", + matched: true, + }, + // Test case - 18. + { + pattern: "my-bucket/oo*", + text: "my-bucket/odo", + matched: false, + }, + + // Test case with pattern containing wildcard '?'. + // Test case - 19. + // "my-bucket?/" matches "my-bucket1/", "my-bucket2/", "my-bucket3" etc... + // doesn't match "mybucket/". + { + pattern: "my-bucket?/abc*", + text: "mybucket/abc", + matched: false, + }, + // Test case - 20. + { + pattern: "my-bucket?/abc*", + text: "my-bucket1/abc", + matched: true, + }, + // Test case - 21. + { + pattern: "my-?-bucket/abc*", + text: "my--bucket/abc", + matched: false, + }, + // Test case - 22. + { + pattern: "my-?-bucket/abc*", + text: "my-1-bucket/abc", + matched: true, + }, + // Test case - 23. + { + pattern: "my-?-bucket/abc*", + text: "my-k-bucket/abc", + matched: true, + }, + // Test case - 24. + { + pattern: "my??bucket/abc*", + text: "mybucket/abc", + matched: false, + }, + // Test case - 25. + { + pattern: "my??bucket/abc*", + text: "my4abucket/abc", + matched: true, + }, + // Test case - 26. + { + pattern: "my-bucket?abc*", + text: "my-bucket/abc", + matched: true, + }, + // Test case 27-28. + // '?' matches '/' too. (works with s3). + // This is because the namespace is considered flat. + // "abc?efg" matches both "abcdefg" and "abc/efg". + { + pattern: "my-bucket/abc?efg", + text: "my-bucket/abcdefg", + matched: true, + }, + { + pattern: "my-bucket/abc?efg", + text: "my-bucket/abc/efg", + matched: true, + }, + // Test case - 29. + { + pattern: "my-bucket/abc????", + text: "my-bucket/abc", + matched: false, + }, + // Test case - 30. + { + pattern: "my-bucket/abc????", + text: "my-bucket/abcde", + matched: false, + }, + // Test case - 31. + { + pattern: "my-bucket/abc????", + text: "my-bucket/abcdefg", + matched: true, + }, + // Test case 32-34. + // test case with no '*'. + { + pattern: "my-bucket/abc?", + text: "my-bucket/abc", + matched: false, + }, + { + pattern: "my-bucket/abc?", + text: "my-bucket/abcd", + matched: true, + }, + { + pattern: "my-bucket/abc?", + text: "my-bucket/abcde", + matched: false, + }, + // Test case 35. + { + pattern: "my-bucket/mnop*?", + text: "my-bucket/mnop", + matched: false, + }, + // Test case 36. + { + pattern: "my-bucket/mnop*?", + text: "my-bucket/mnopqrst/mnopqr", + matched: true, + }, + // Test case 37. + { + pattern: "my-bucket/mnop*?", + text: "my-bucket/mnopqrst/mnopqrs", + matched: true, + }, + // Test case 38. + { + pattern: "my-bucket/mnop*?", + text: "my-bucket/mnop", + matched: false, + }, + // Test case 39. + { + pattern: "my-bucket/mnop*?", + text: "my-bucket/mnopq", + matched: true, + }, + // Test case 40. + { + pattern: "my-bucket/mnop*?", + text: "my-bucket/mnopqr", + matched: true, + }, + // Test case 41. + { + pattern: "my-bucket/mnop*?and", + text: "my-bucket/mnopqand", + matched: true, + }, + // Test case 42. + { + pattern: "my-bucket/mnop*?and", + text: "my-bucket/mnopand", + matched: false, + }, + // Test case 43. + { + pattern: "my-bucket/mnop*?and", + text: "my-bucket/mnopqand", + matched: true, + }, + // Test case 44. + { + pattern: "my-bucket/mnop*?", + text: "my-bucket/mn", + matched: false, + }, + // Test case 45. + { + pattern: "my-bucket/mnop*?", + text: "my-bucket/mnopqrst/mnopqrs", + matched: true, + }, + // Test case 46. + { + pattern: "my-bucket/mnop*??", + text: "my-bucket/mnopqrst", + matched: true, + }, + // Test case 47. + { + pattern: "my-bucket/mnop*qrst", + text: "my-bucket/mnopabcdegqrst", + matched: true, + }, + // Test case 48. + { + pattern: "my-bucket/mnop*?and", + text: "my-bucket/mnopqand", + matched: true, + }, + // Test case 49. + { + pattern: "my-bucket/mnop*?and", + text: "my-bucket/mnopand", + matched: false, + }, + // Test case 50. + { + pattern: "my-bucket/mnop*?and?", + text: "my-bucket/mnopqanda", + matched: true, + }, + // Test case 51. + { + pattern: "my-bucket/mnop*?and", + text: "my-bucket/mnopqanda", + matched: false, + }, + // Test case 52. + + { + pattern: "my-?-bucket/abc*", + text: "my-bucket/mnopqanda", + matched: false, + }, + } + // Iterating over the test cases, call the function under test and asert the output. + for i, testCase := range testCases { + actualResult := wildcard.Match(testCase.pattern, testCase.text) + if testCase.matched != actualResult { + t.Errorf("Test %d: Expected the result to be `%v`, but instead found it to be `%v`", i+1, testCase.matched, actualResult) + } + } +} + +// TestMatchSimple - Tests validate the logic of wild card matching. +// `MatchSimple` supports matching for only '*' in the pattern string. +func TestMatchSimple(t *testing.T) { + testCases := []struct { + pattern string + text string + matched bool + }{ + // Test case - 1. + // Test case with pattern "*". Expected to match any text. + { + pattern: "*", + text: "s3:GetObject", + matched: true, + }, + // Test case - 2. + // Test case with empty pattern. This only matches empty string. + { + pattern: "", + text: "s3:GetObject", + matched: false, + }, + // Test case - 3. + // Test case with empty pattern. This only matches empty string. + { + pattern: "", + text: "", + matched: true, + }, + // Test case - 4. + // Test case with single "*" at the end. + { + pattern: "s3:*", + text: "s3:ListMultipartUploadParts", + matched: true, + }, + // Test case - 5. + // Test case with a no "*". In this case the pattern and text should be the same. + { + pattern: "s3:ListBucketMultipartUploads", + text: "s3:ListBucket", + matched: false, + }, + // Test case - 6. + // Test case with a no "*". In this case the pattern and text should be the same. + { + pattern: "s3:ListBucket", + text: "s3:ListBucket", + matched: true, + }, + // Test case - 7. + // Test case with a no "*". In this case the pattern and text should be the same. + { + pattern: "s3:ListBucketMultipartUploads", + text: "s3:ListBucketMultipartUploads", + matched: true, + }, + // Test case - 8. + // Test case with pattern containing key name with a prefix. Should accept the same text without a "*". + { + pattern: "my-bucket/oo*", + text: "my-bucket/oo", + matched: true, + }, + // Test case - 9. + // Test case with "*" at the end of the pattern. + { + pattern: "my-bucket/In*", + text: "my-bucket/India/Karnataka/", + matched: true, + }, + // Test case - 10. + // Test case with prefixes shuffled. + // This should fail. + { + pattern: "my-bucket/In*", + text: "my-bucket/Karnataka/India/", + matched: false, + }, + // Test case - 11. + // Test case with text expanded to the wildcards in the pattern. + { + pattern: "my-bucket/In*/Ka*/Ban", + text: "my-bucket/India/Karnataka/Ban", + matched: true, + }, + // Test case - 12. + // Test case with the keyname part is repeated as prefix several times. + // This is valid. + { + pattern: "my-bucket/In*/Ka*/Ban", + text: "my-bucket/India/Karnataka/Ban/Ban/Ban/Ban/Ban", + matched: true, + }, + // Test case - 13. + // Test case to validate that `*` can be expanded into multiple prefixes. + { + pattern: "my-bucket/In*/Ka*/Ban", + text: "my-bucket/India/Karnataka/Area1/Area2/Area3/Ban", + matched: true, + }, + // Test case - 14. + // Test case to validate that `*` can be expanded into multiple prefixes. + { + pattern: "my-bucket/In*/Ka*/Ban", + text: "my-bucket/India/State1/State2/Karnataka/Area1/Area2/Area3/Ban", + matched: true, + }, + // Test case - 15. + // Test case where the keyname part of the pattern is expanded in the text. + { + pattern: "my-bucket/In*/Ka*/Ban", + text: "my-bucket/India/Karnataka/Bangalore", + matched: false, + }, + // Test case - 16. + // Test case with prefixes and wildcard expanded for all "*". + { + pattern: "my-bucket/In*/Ka*/Ban*", + text: "my-bucket/India/Karnataka/Bangalore", + matched: true, + }, + // Test case - 17. + // Test case with keyname part being a wildcard in the pattern. + { + pattern: "my-bucket/*", + text: "my-bucket/India", + matched: true, + }, + // Test case - 18. + { + pattern: "my-bucket/oo*", + text: "my-bucket/odo", + matched: false, + }, + // Test case - 11. + { + pattern: "my-bucket/oo?*", + text: "my-bucket/oo???", + matched: true, + }, + // Test case - 12: + { + pattern: "my-bucket/oo??*", + text: "my-bucket/odo", + matched: false, + }, + // Test case - 13: + { + pattern: "?h?*", + text: "?h?hello", + matched: true, + }, + } + // Iterating over the test cases, call the function under test and asert the output. + for i, testCase := range testCases { + actualResult := wildcard.MatchSimple(testCase.pattern, testCase.text) + if testCase.matched != actualResult { + t.Errorf("Test %d: Expected the result to be `%v`, but instead found it to be `%v`", i+1, testCase.matched, actualResult) + } + } +}