PKG -- [transport-http] Add BlockDigests DataProvider

packages/transport-http/src/subscribe/handlers/block-digests.ts

@@ -0,0 +1,82 @@
+import {SdkTransport} from "@onflow/typedefs"
+import {BlockArgsModel, createSubscriptionHandler} from "./types"
+
+type BlockDigestsArgs =
+  SdkTransport.SubscriptionArguments<SdkTransport.SubscriptionTopic.BLOCK_DIGESTS>
+
+type BlockDigestsData =
+  SdkTransport.SubscriptionData<SdkTransport.SubscriptionTopic.BLOCK_DIGESTS>
+
+type BlockDigestsDataDto = {
+  // TODO: We do not know the data model types yet
+  block_digest: {
+    id: string
+    height: number
+    timestamp: string
+  }
+}
+
+type BlockDigestsArgsDto = BlockArgsModel
+
+export const blockDigestsHandler = createSubscriptionHandler<{
+  Topic: SdkTransport.SubscriptionTopic.BLOCK_DIGESTS
+  Args: BlockDigestsArgs
+  Data: BlockDigestsData
+  ArgsDto: BlockDigestsArgsDto
+  DataDto: BlockDigestsDataDto
+}>({
+  topic: SdkTransport.SubscriptionTopic.BLOCK_DIGESTS,
+  createSubscriber: (initialArgs, onData, onError) => {
+    let resumeArgs: BlockDigestsArgs = {
+      ...initialArgs,
+    }
+
+    return {
+      onData(data: BlockDigestsDataDto) {
+        // Parse the raw data
+        const parsedData: BlockDigestsData = {
+          blockDigest: {
+            id: data.block_digest.id,
+            height: data.block_digest.height,
+            timestamp: data.block_digest.timestamp,
+          },
+        }
+
+        // Update the resume args
+        resumeArgs = {
+          blockStatus: resumeArgs.blockStatus,
+          startBlockId: data.block_digest.id + 1,
+        }
+
+        onData(parsedData)
+      },
+      onError(error: Error) {
+        onError(error)
+      },
+      argsToDto(args: BlockDigestsArgs) {
+        let encodedArgs: BlockDigestsArgsDto = {
+          block_status: args.blockStatus,
+        }
+
+        if ("startBlockHeight" in args) {
+          return {
+            ...encodedArgs,
+            start_block_height: args.startBlockHeight,
+          }
+        }
+
+        if ("startBlockId" in args) {
+          return {
+            ...encodedArgs,
+            start_block_id: args.startBlockId,
+          }
+        }
+
+        return encodedArgs
+      },
+      get connectionArgs() {
+        return resumeArgs
+      },
+    }
+  },
+})

packages/transport-http/src/subscribe/handlers/blocks.ts

@@ -1,5 +1,5 @@
 import {SdkTransport} from "@onflow/typedefs"
-import {createSubscriptionHandler} from "./types"
+import {createSubscriptionHandler, BlockArgsModel} from "./types"
 
 type BlocksArgs =
   SdkTransport.SubscriptionArguments<SdkTransport.SubscriptionTopic.BLOCKS>

packages/transport-http/src/subscribe/handlers/types.ts

@@ -48,3 +48,13 @@ export function createSubscriptionHandler<
 >(handler: SubscriptionHandler<T>): SubscriptionHandler<T> {
   return handler
 }
+
+export type BlockArgsModel =
+  | {
+      block_status?: number
+      start_block_id?: string
+    }
+  | {
+      block_status?: number
+      start_block_height?: number
+    }

packages/transport-http/src/subscribe/subscribe.ts

@@ -1,8 +1,9 @@
 import {SdkTransport} from "@onflow/typedefs"
 import {SubscriptionManager} from "./subscription-manager"
 import {blocksHandler} from "./handlers/blocks"
+import {blockDigestsHandler} from "./handlers/block-digests"
 
-const SUBSCRIPTION_HANDLERS = [blocksHandler]
+const SUBSCRIPTION_HANDLERS = [blocksHandler, blockDigestsHandler]
 
 // Map of SubscriptionManager instances by access node URL
 let subscriptionManagerMap: Map<

packages/typedefs/src/index.ts

@@ -120,6 +120,23 @@ export type BlockSeal = {
    */
   executionReceiptId: string
 }
+/**
+ * BlockDigest holds lightweight block information which includes only block id, block height and block timestamp.
+ */
+export type BlockDigest = {
+  /**
+   * - The id of the block
+   */
+  id: string
+  /**
+   * - The height of the block
+   */
+  height: number
+  /**
+   * - Timestamp of the block
+   */
+  timestamp: string
+}
 export type CompositeSignature = {
   /**
    * - A type identifier used internally by FCL

packages/typedefs/src/sdk-transport/subscriptions.ts

@@ -1,28 +1,38 @@
-import {Block} from ".."
+import {Block, BlockDigest} from ".."
 
-type SchemaItem<TArgs, TData> = {
-  args: TArgs
-  data: TData
+export type SubscriptionSchema = {
+  [SubscriptionTopic.BLOCKS]: SchemaItem<
+    BlockArgs,
+    {
+      block: Block
+    }
+  >
+  [SubscriptionTopic.BLOCK_DIGESTS]: SchemaItem<
+    BlockArgs,
+    {
+      blockDigest: BlockDigest
+    }
+  >
 }
 
 export enum SubscriptionTopic {
   BLOCKS = "blocks",
+  BLOCK_DIGESTS = "block_digests",
 }
 
-export type SubscriptionSchema = {
-  [SubscriptionTopic.BLOCKS]: SchemaItem<
-    | {
-        blockStatus?: number
-        startBlockId?: string
-      }
-    | {
-        blockStatus?: number
-        startBlockHeight?: number
-      },
-    {
-      block: Block
+type BlockArgs =
+  | {
+      blockStatus?: number
+      startBlockId?: string
     }
-  >
+  | {
+      blockStatus?: number
+      startBlockHeight?: number
+    }
+
+type SchemaItem<TArgs, TData> = {
+  args: TArgs
+  data: TData
 }
 
 export type SubscriptionArguments<T extends SubscriptionTopic> =