Updating go depencancies. Switching to go1.6 vendoring (#2949)

1 files changed, 116 insertions, 0 deletions

diff --git a/vendor/gopkg.in/throttled/throttled.v1/rate.go b/vendor/gopkg.in/throttled/throttled.v1/rate.go
new file mode 100644
index 000000000..d7a7de6d7
--- /dev/null
+++ b/vendor/gopkg.in/throttled/throttled.v1/rate.go
@@ -0,0 +1,116 @@
+package throttled
+
+import (
+	"math"
+	"net/http"
+	"strconv"
+	"time"
+)
+
+// Static check to ensure that rateLimiter implements Limiter.
+var _ Limiter = (*rateLimiter)(nil)
+
+// RateLimit creates a throttler that limits the number of requests allowed
+// in a certain time window defined by the Quota q. The q parameter specifies
+// the requests per time window, and it is silently set to at least 1 request
+// and at least a 1 second window if it is less than that. The time window
+// starts when the first request is made outside an existing window. Fractions
+// of seconds are not supported, they are truncated.
+//
+// The vary parameter indicates what criteria should be used to group requests
+// for which the limit must be applied (ex.: rate limit based on the remote address).
+// See varyby.go for the various options.
+//
+// The specified store is used to keep track of the request count and the
+// time remaining in the window. The throttled package comes with some stores
+// in the throttled/store package. Custom stores can be created too, by implementing
+// the Store interface.
+//
+// Requests that bust the rate limit are denied access and go through the denied handler,
+// which may be specified on the Throttler and that defaults to the package-global
+// variable DefaultDeniedHandler.
+//
+// The rate limit throttler sets the following headers on the response:
+//
+//    X-RateLimit-Limit : quota
+//    X-RateLimit-Remaining : number of requests remaining in the current window
+//    X-RateLimit-Reset : seconds before a new window
+//
+// Additionally, if the request was denied access, the following header is added:
+//
+//    Retry-After : seconds before the caller should retry
+//
+func RateLimit(q Quota, vary *VaryBy, store Store) *Throttler {
+	// Extract requests and window
+	reqs, win := q.Quota()
+
+	// Create and return the throttler
+	return &Throttler{
+		limiter: &rateLimiter{
+			reqs:   reqs,
+			window: win,
+			vary:   vary,
+			store:  store,
+		},
+	}
+}
+
+// The rate limiter implements limiting the request to a certain quota
+// based on the vary-by criteria. State is saved in the store.
+type rateLimiter struct {
+	reqs   int
+	window time.Duration
+	vary   *VaryBy
+	store  Store
+}
+
+// Start initializes the limiter for execution.
+func (r *rateLimiter) Start() {
+	if r.reqs < 1 {
+		r.reqs = 1
+	}
+	if r.window < time.Second {
+		r.window = time.Second
+	}
+}
+
+// Limit is called for each request to the throttled handler. It checks if
+// the request can go through and signals it via the returned channel.
+// It returns an error if the operation fails.
+func (r *rateLimiter) Limit(w http.ResponseWriter, req *http.Request) (<-chan bool, error) {
+	// Create return channel and initialize
+	ch := make(chan bool, 1)
+	ok := true
+	key := r.vary.Key(req)
+
+	// Get the current count and remaining seconds
+	cnt, secs, err := r.store.Incr(key, r.window)
+	// Handle the possible situations: error, begin new window, or increment current window.
+	switch {
+	case err != nil && err != ErrNoSuchKey:
+		// An unexpected error occurred
+		return nil, err
+	case err == ErrNoSuchKey || secs <= 0:
+		// Reset counter
+		if err := r.store.Reset(key, r.window); err != nil {
+			return nil, err
+		}
+		cnt = 1
+		secs = int(r.window.Seconds())
+	default:
+		// If the limit is reached, deny access
+		if cnt > r.reqs {
+			ok = false
+		}
+	}
+	// Set rate-limit headers
+	w.Header().Add("X-RateLimit-Limit", strconv.Itoa(r.reqs))
+	w.Header().Add("X-RateLimit-Remaining", strconv.Itoa(int(math.Max(float64(r.reqs-cnt), 0))))
+	w.Header().Add("X-RateLimit-Reset", strconv.Itoa(secs))
+	if !ok {
+		w.Header().Add("Retry-After", strconv.Itoa(secs))
+	}
+	// Send response via the return channel
+	ch <- ok
+	return ch, nil
+}