added directory snapshot

README.md

@@ -102,6 +102,19 @@ await api.directory.list('/', async (remote_path, page_count, get_page) => {
   }
 });
 
+// Asynchronous directory list
+const snap = await api.directory.snapshot('/');
+try {
+  for (let i = 0; i < snap.page_count; i++) {
+    const items = await snap.get_page(i); // Always 'await'
+    console.log(items);
+  }
+} catch (err) {
+  console.log(err);
+} finally {
+  await snap.release();
+}
+
 // Create new directory
 await api.directory.create('/test');
 

src/__tests__/repertory.test.js

@@ -91,12 +91,12 @@ test('can create and remove a directory using api', async () => {
   await conn.disconnect();
 });
 
-test('can get directory list using api', async () => {
+test('can get directory list and snapshot using api', async () => {
   const conn =
     await repertory.create_pool(2, TEST_HOST, TEST_PORT, TEST_PASSWORD);
   const api = repertory.create_api(conn);
-  await api.directory.list('/', async (remote_path, page_count, get_page) => {
+
-    console.log(remote_path, page_count, get_page);
+  const test_results = async (remote_path, page_count, get_page) => {
     expect(remote_path).toEqual('/');
     expect(page_count).toBeGreaterThanOrEqual(1);
     expect(get_page).toBeInstanceOf(Function);
@@ -110,8 +110,23 @@ test('can get directory list using api', async () => {
       expect(items[1].directory).toBeTruthy();
       expect(items[1].path).toEqual('..');
     }
+  };
+
+  await api.directory.list('/', async (remote_path, page_count, get_page) => {
+    console.log(remote_path, page_count, get_page);
+    await test_results(remote_path, page_count, get_page);
   });
 
+  const snap = await api.directory.snapshot('/');
+  try {
+    console.log(snap.remote_path, snap.page_count, snap.get_page);
+    await test_results(snap.remote_path, snap.page_count, snap.get_page);
+  } catch (err) {
+    console.log(err);
+  } finally {
+    await snap.release();
+  }
+
   await conn.disconnect();
 });
 

src/index.js

@@ -12,10 +12,13 @@ export const connect = async (host_or_ip, port, password) => {
 export const create_api = conn => {
   return {
     directory : {
+      create: async remote_path => ops.create_directory(conn, remote_path),
       list: async (remote_path, page_reader_cb) =>
         ops.list_directory(conn, remote_path, page_reader_cb),
-      create : async remote_path => ops.create_directory(conn, remote_path),
       remove: async remote_path => ops.remove_directory(conn, remote_path),
+      snapshot: async remote_path => {
+        return ops.snapshot_directory(conn, remote_path);
+      },
     },
     file : {
       create_or_open : async remote_path => new file(

src/ops/index.js

@@ -4,6 +4,69 @@ import {Uint64BE} from 'int64-buffer';
 import file from '../io/file';
 import packet from '../networking/packet';
 
+const _snapshot_directory = async (conn, remote_path) => {
+  try {
+    const request = new packet();
+    request.encode_utf8(remote_path);
+
+    const response =
+      await conn.send('::RemoteJSONCreateDirectorySnapshot', request);
+    response.decode_ui32(); // Service flags
+
+    const result = response.decode_i32();
+    if (result === 0) {
+      const data = JSON.parse(response.decode_utf8());
+
+      let released = false;
+      const release = async () => {
+        if (!released) {
+          released = true;
+          const request = new packet();
+          request.encode_ui64(data.handle);
+          await conn.send('::RemoteJSONReleaseDirectorySnapshot', request);
+        }
+      };
+
+      try {
+        const get_page = async page => {
+          try {
+            const request = new packet();
+            request.encode_utf8(remote_path);
+            request.encode_ui64(data.handle);
+            request.encode_ui32(page);
+
+            const response =
+              await conn.send('::RemoteJSONReadDirectorySnapshot', request);
+            response.decode_ui32(); // Service flags
+
+            const result = response.decode_i32();
+            if (result === 0 || result === -120) {
+              const data = JSON.parse(response.decode_utf8());
+              return data.directory_list;
+            }
+          } catch (err) {
+            await release();
+            return Promise.reject(new Error(`'get_page' failed: ${err}`));
+          }
+          return [];
+        };
+
+        return {
+          get_page,
+          page_count: data.page_count,
+          release,
+          remote_path,
+        };
+      } catch (err) {
+        await release();
+        return Promise.reject(new Error(`'snapshot_directory' failed: ${err}`));
+      }
+    }
+  } catch (err) {
+    return Promise.reject(new Error(`'snapshot_directory' failed: ${err}`));
+  }
+};
+
 export const close_file =
   async (conn, remote_path, handle, optional_thread_id) => {
     try {
@@ -209,50 +272,13 @@ export const get_file_attributes =
   };
 
 export const list_directory = async (conn, remote_path, page_reader_cb) => {
+  const dir_snapshot = await _snapshot_directory(conn, remote_path);
   try {
-    const request = new packet();
+    await page_reader_cb(dir_snapshot.remote_path, dir_snapshot.page_count, dir_snapshot.get_page);
-    request.encode_utf8(remote_path);
+    await dir_snapshot.release();
-
-    const response =
-        await conn.send('::RemoteJSONCreateDirectorySnapshot', request);
-    response.decode_ui32(); // Service flags
-
-    const result = response.decode_i32();
-    if (result === 0) {
-      const data = JSON.parse(response.decode_utf8());
-      const cleanup = async () => {
-        const request = new packet();
-        request.encode_ui64(data.handle);
-        await conn.send('::RemoteJSONReleaseDirectorySnapshot', request);
-      };
-      try {
-        const get_page = async page => {
-          const request = new packet();
-          request.encode_utf8(remote_path);
-          request.encode_ui64(data.handle);
-          request.encode_ui32(page);
-
-          const response =
-              await conn.send('::RemoteJSONReadDirectorySnapshot', request);
-          response.decode_ui32(); // Service flags
-
-          const result = response.decode_i32();
-          if (result === 0 || result === -120) {
-            const data = JSON.parse(response.decode_utf8());
-            return data.directory_list;
-          }
-          return [];
-        };
-
-        await page_reader_cb(remote_path, data.page_count, get_page);
-        await cleanup();
   } catch (err) {
-        await cleanup();
+    await dir_snapshot.release();
-        return Promise.reject(new Error(`'list_directory' failed: ${err}`));
+    return Promise.reject(`'list_directory' failed: ${err}`);
-      }
-    }
-  } catch (err) {
-    return Promise.reject(new Error(`'list_directory' failed: ${err}`));
   }
 };
 
@@ -313,6 +339,8 @@ export const remove_directory = async (conn, remote_path) => {
   }
 };
 
+export const snapshot_directory = _snapshot_directory;
+
 export const truncate_file =
   async (conn, handle, remote_path, length, optional_thread_id) => {
     try {
@@ -387,7 +415,7 @@ export const upload_file =
                 new file(conn, await open_file(conn, remote_path), remote_path);
               await cleanup(f);
               return Promise.reject(
-                new Error("'upload_file' failed: file exists"));
+                new Error('\'upload_file\' failed: file exists'));
             } catch (err) {
               await create_dest();
             }