Deletes+unboosts (#52)

* Status deletes properly streamed now.
* Unboosts now work locally and federated.
* Documentation updates.

internal/processing/synchronous/streaming/streamdelete.go

@@ -0,0 +1,51 @@
+package streaming
+
+import (
+	"fmt"
+	"strings"
+
+	"github.com/superseriousbusiness/gotosocial/internal/gtsmodel"
+)
+
+func (p *processor) StreamDelete(statusID string) error {
+	errs := []string{}
+
+	// we want to range through ALL streams for ALL accounts here to make sure it's very clear to everyone that the status has been deleted
+	p.streamMap.Range(func(k interface{}, v interface{}) bool {
+		// the key of this map should be an accountID (string)
+		accountID, ok := k.(string)
+		if !ok {
+			errs = append(errs, "key in streamMap was not a string!")
+			return false
+		}
+
+		// the value of the map should be a buncha streams
+		streamsForAccount, ok := v.(*gtsmodel.StreamsForAccount)
+		if !ok {
+			errs = append(errs, fmt.Sprintf("stream map error for account stream %s", accountID))
+		}
+
+		// lock the streams while we work on them
+		streamsForAccount.Lock()
+		defer streamsForAccount.Unlock()
+		for _, stream := range streamsForAccount.Streams {
+			// lock each individual stream as we work on it
+			stream.Lock()
+			defer stream.Unlock()
+			if stream.Connected {
+				stream.Messages <- &gtsmodel.Message{
+					Stream:  []string{stream.Type},
+					Event:   "delete",
+					Payload: statusID,
+				}
+			}
+		}
+		return true
+	})
+
+	if len(errs) != 0 {
+		return fmt.Errorf("one or more errors streaming status delete: %s", strings.Join(errs, ";"))
+	}
+
+	return nil
+}