Remove WebSocket to REST fallback for attachments.

libsignal-service/src/main/java/org/whispersystems/signalservice/api/NetworkResult.kt

@@ -248,34 +248,6 @@ sealed class NetworkResult<T>(
     }
   }
 
-  /**
-   * Provides the ability to fallback to [fromFetch] if the current [NetworkResult] is non-successful.
-   *
-   * The [fallback] will only be triggered on non-[Success] results. You can provide a [unless] to limit what kinds of errors you fallback on
-   * (the default is to fallback on every error).
-   *
-   * This primary usecase of this is to make a websocket request (see [fromWebSocketRequest]) and fallback to rest upon failure.
-   *
-   * ```kotlin
-   * val user: NetworkResult<LocalUserModel> = NetworkResult
-   *   .fromWebSocketRequest(websocket, request, LocalUserMode.class.java)
-   *   .fallbackTo { result -> NetworkResult.fromFetch { http.getUser() } }
-   * ```
-   *
-   * @param unless If this lamba returns true, the fallback will not be triggered.
-   */
-  fun fallbackToFetch(unless: (NetworkResult<T>) -> Boolean = { false }, fallback: Fetcher<T>): NetworkResult<T> {
-    if (this is Success) {
-      return this
-    }
-
-    return if (unless(this)) {
-      fromFetch(fallback)
-    } else {
-      this
-    }
-  }
-
   /**
    * Takes the output of one [NetworkResult] and passes it as the input to another if the operation is successful.
    * If it's non-successful, the [result] lambda is not run, and instead the original failure will be propagated.

libsignal-service/src/main/java/org/whispersystems/signalservice/api/attachment/AttachmentApi.kt

@@ -11,6 +11,7 @@ import org.whispersystems.signalservice.api.messages.SignalServiceAttachmentRemo
 import org.whispersystems.signalservice.api.messages.SignalServiceAttachmentStream
 import org.whispersystems.signalservice.api.websocket.SignalWebSocket
 import org.whispersystems.signalservice.internal.crypto.PaddingInputStream
+import org.whispersystems.signalservice.internal.get
 import org.whispersystems.signalservice.internal.push.AttachmentUploadForm
 import org.whispersystems.signalservice.internal.push.PushAttachmentData
 import org.whispersystems.signalservice.internal.push.PushServiceSocket
@@ -18,7 +19,6 @@ import org.whispersystems.signalservice.internal.push.http.AttachmentCipherOutpu
 import org.whispersystems.signalservice.internal.push.http.ResumableUploadSpec
 import org.whispersystems.signalservice.internal.websocket.WebSocketRequestMessage
 import java.io.InputStream
-import java.security.SecureRandom
 import kotlin.jvm.optionals.getOrNull
 
 /**
@@ -28,29 +28,17 @@ class AttachmentApi(
   private val authWebSocket: SignalWebSocket.AuthenticatedWebSocket,
   private val pushServiceSocket: PushServiceSocket
 ) {
-  companion object {
-    @JvmStatic
-    fun create(authWebSocket: SignalWebSocket.AuthenticatedWebSocket, pushServiceSocket: PushServiceSocket): AttachmentApi {
-      return AttachmentApi(authWebSocket, pushServiceSocket)
-    }
-  }
-
   /**
    * Gets a v4 attachment upload form, which provides the necessary information to upload an attachment.
+   *
+   * GET /v4/attachments/form/upload
+   * - 200: Success
+   * - 413: Too many attempts
+   * - 429: Too many attempts
    */
   fun getAttachmentV4UploadForm(): NetworkResult<AttachmentUploadForm> {
-    val request = WebSocketRequestMessage(
-      id = SecureRandom().nextLong(),
-      verb = "GET",
-      path = "/v4/attachments/form/upload"
-    )
-
-    return NetworkResult
-      .fromWebSocketRequest(authWebSocket, request, AttachmentUploadForm::class)
-      .fallbackToFetch(
-        unless = { it is NetworkResult.StatusCodeError && it.code == 209 },
-        fallback = { pushServiceSocket.attachmentV4UploadAttributes }
-      )
+    val request = WebSocketRequestMessage.get("/v4/attachments/form/upload")
+    return NetworkResult.fromWebSocketRequest(authWebSocket, request, AttachmentUploadForm::class)
   }
 
   /**