diff options
Diffstat (limited to 'vendor/github.com/onsi/gomega/gbytes/buffer.go')
-rw-r--r-- | vendor/github.com/onsi/gomega/gbytes/buffer.go | 245 |
1 files changed, 245 insertions, 0 deletions
diff --git a/vendor/github.com/onsi/gomega/gbytes/buffer.go b/vendor/github.com/onsi/gomega/gbytes/buffer.go new file mode 100644 index 000000000..336086f4a --- /dev/null +++ b/vendor/github.com/onsi/gomega/gbytes/buffer.go @@ -0,0 +1,245 @@ +/* +Package gbytes provides a buffer that supports incrementally detecting input. + +You use gbytes.Buffer with the gbytes.Say matcher. When Say finds a match, it fastforwards the buffer's read cursor to the end of that match. + +Subsequent matches against the buffer will only operate against data that appears *after* the read cursor. + +The read cursor is an opaque implementation detail that you cannot access. You should use the Say matcher to sift through the buffer. You can always +access the entire buffer's contents with Contents(). + +*/ +package gbytes + +import ( + "errors" + "fmt" + "io" + "regexp" + "sync" + "time" +) + +/* +gbytes.Buffer implements an io.Writer and can be used with the gbytes.Say matcher. + +You should only use a gbytes.Buffer in test code. It stores all writes in an in-memory buffer - behavior that is inappropriate for production code! +*/ +type Buffer struct { + contents []byte + readCursor uint64 + lock *sync.Mutex + detectCloser chan interface{} + closed bool +} + +/* +NewBuffer returns a new gbytes.Buffer +*/ +func NewBuffer() *Buffer { + return &Buffer{ + lock: &sync.Mutex{}, + } +} + +/* +BufferWithBytes returns a new gbytes.Buffer seeded with the passed in bytes +*/ +func BufferWithBytes(bytes []byte) *Buffer { + return &Buffer{ + lock: &sync.Mutex{}, + contents: bytes, + } +} + +/* +BufferReader returns a new gbytes.Buffer that wraps a reader. The reader's contents are read into +the Buffer via io.Copy +*/ +func BufferReader(reader io.Reader) *Buffer { + b := &Buffer{ + lock: &sync.Mutex{}, + } + + go func() { + io.Copy(b, reader) + b.Close() + }() + + return b +} + +/* +Write implements the io.Writer interface +*/ +func (b *Buffer) Write(p []byte) (n int, err error) { + b.lock.Lock() + defer b.lock.Unlock() + + if b.closed { + return 0, errors.New("attempt to write to closed buffer") + } + + b.contents = append(b.contents, p...) + return len(p), nil +} + +/* +Read implements the io.Reader interface. It advances the +cursor as it reads. + +Returns an error if called after Close. +*/ +func (b *Buffer) Read(d []byte) (int, error) { + b.lock.Lock() + defer b.lock.Unlock() + + if b.closed { + return 0, errors.New("attempt to read from closed buffer") + } + + if uint64(len(b.contents)) <= b.readCursor { + return 0, io.EOF + } + + n := copy(d, b.contents[b.readCursor:]) + b.readCursor += uint64(n) + + return n, nil +} + +/* +Close signifies that the buffer will no longer be written to +*/ +func (b *Buffer) Close() error { + b.lock.Lock() + defer b.lock.Unlock() + + b.closed = true + + return nil +} + +/* +Closed returns true if the buffer has been closed +*/ +func (b *Buffer) Closed() bool { + b.lock.Lock() + defer b.lock.Unlock() + + return b.closed +} + +/* +Contents returns all data ever written to the buffer. +*/ +func (b *Buffer) Contents() []byte { + b.lock.Lock() + defer b.lock.Unlock() + + contents := make([]byte, len(b.contents)) + copy(contents, b.contents) + return contents +} + +/* +Detect takes a regular expression and returns a channel. + +The channel will receive true the first time data matching the regular expression is written to the buffer. +The channel is subsequently closed and the buffer's read-cursor is fast-forwarded to just after the matching region. + +You typically don't need to use Detect and should use the ghttp.Say matcher instead. Detect is useful, however, in cases where your code must +be branch and handle different outputs written to the buffer. + +For example, consider a buffer hooked up to the stdout of a client library. You may (or may not, depending on state outside of your control) need to authenticate the client library. + +You could do something like: + +select { +case <-buffer.Detect("You are not logged in"): + //log in +case <-buffer.Detect("Success"): + //carry on +case <-time.After(time.Second): + //welp +} +buffer.CancelDetects() + +You should always call CancelDetects after using Detect. This will close any channels that have not detected and clean up the goroutines that were spawned to support them. + +Finally, you can pass detect a format string followed by variadic arguments. This will construct the regexp using fmt.Sprintf. +*/ +func (b *Buffer) Detect(desired string, args ...interface{}) chan bool { + formattedRegexp := desired + if len(args) > 0 { + formattedRegexp = fmt.Sprintf(desired, args...) + } + re := regexp.MustCompile(formattedRegexp) + + b.lock.Lock() + defer b.lock.Unlock() + + if b.detectCloser == nil { + b.detectCloser = make(chan interface{}) + } + + closer := b.detectCloser + response := make(chan bool) + go func() { + ticker := time.NewTicker(10 * time.Millisecond) + defer ticker.Stop() + defer close(response) + for { + select { + case <-ticker.C: + b.lock.Lock() + data, cursor := b.contents[b.readCursor:], b.readCursor + loc := re.FindIndex(data) + b.lock.Unlock() + + if loc != nil { + response <- true + b.lock.Lock() + newCursorPosition := cursor + uint64(loc[1]) + if newCursorPosition >= b.readCursor { + b.readCursor = newCursorPosition + } + b.lock.Unlock() + return + } + case <-closer: + return + } + } + }() + + return response +} + +/* +CancelDetects cancels any pending detects and cleans up their goroutines. You should always call this when you're done with a set of Detect channels. +*/ +func (b *Buffer) CancelDetects() { + b.lock.Lock() + defer b.lock.Unlock() + + close(b.detectCloser) + b.detectCloser = nil +} + +func (b *Buffer) didSay(re *regexp.Regexp) (bool, []byte) { + b.lock.Lock() + defer b.lock.Unlock() + + unreadBytes := b.contents[b.readCursor:] + copyOfUnreadBytes := make([]byte, len(unreadBytes)) + copy(copyOfUnreadBytes, unreadBytes) + + loc := re.FindIndex(unreadBytes) + + if loc != nil { + b.readCursor += uint64(loc[1]) + return true, copyOfUnreadBytes + } + return false, copyOfUnreadBytes +} |