Add mongo content provider example.

package.json

@@ -12,7 +12,8 @@
     "build:watch": "npx tsc -w",
     "build:prod": "yarn clean && cross-env NODE_ENV=production tsc -p ./tsconfig.production.json",
     "push": "yarn test && yarn build:prod && yarn publish",
-    "run:examples:file": "node ./dist/examples/express-file-server/index.js"
+    "run:examples:file": "node ./dist/examples/express-file-server/index.js",
+    "run:examples:mongo": "node ./dist/examples/express-mongo-server/index.js"
   },
   "keywords": [
     "partial-content",
@@ -23,11 +24,13 @@
     "@types/chai": "^4.1.7",
     "@types/express": "^4.16.1",
     "@types/mocha": "^5.2.6",
+    "@types/mongodb": "^3.1.22",
     "@types/sinon": "^7.0.9",
     "chai": "^4.2.0",
     "cross-env": "^5.2.0",
     "express": "^4.16.4",
     "mocha": "^6.0.2",
+    "mongodb": "^3.1.13",
     "nyc": "^13.3.0",
     "rimraf": "^2.6.3",
     "sinon": "^7.2.7",

src/createPartialContentHandler.ts

@@ -54,6 +54,7 @@ export function createPartialContentHandler(contentProvider: ContentProvider, lo
     // Return 206 Partial Content status
     logger.debug("Returning partial content for range: ", JSON.stringify(range));
     res.status(206);
-    getStream(range).pipe(res);
+
+    return getStream(range).pipe(res);
   };
 }

src/examples/express-mongo-server/MongoFileDocument.ts

@@ -0,0 +1,6 @@
+export interface MongoFileDocument {
+  _id: string;
+  contentType: string;
+  filename: string;
+  size: number;
+}

src/examples/express-mongo-server/index.ts

@@ -0,0 +1,15 @@
+import express from "express";
+import { createPartialContentHandler } from "../../index";
+import { mongoContentProvider } from "./mongoContentProvider";
+import { logger } from "./logger";
+
+const handler = createPartialContentHandler(mongoContentProvider, logger);
+
+const app = express();
+const port = 8080;
+
+app.get("/files/:name", handler);
+
+app.listen(port, () => {
+  logger.debug("Server started!");
+});

src/examples/express-mongo-server/logger.ts

@@ -0,0 +1,9 @@
+export const logger = {
+  debug(message: string, extra?: any) {
+    if (extra) {
+      console.log(`[debug]: ${message}`, extra);
+    } else {
+      console.log(`[debug]: ${message}`);
+    }
+  }
+};

src/examples/express-mongo-server/mongoContentProvider.ts

@@ -0,0 +1,72 @@
+import { Request } from "express";
+import fs from "fs";
+import path from "path";
+import { MongoClient, Db, GridFSBucket } from "mongodb";
+import { Range, ContentDoesNotExistError, ContentProvider } from "../../index";
+import { getFileMeta } from "./utils";
+import { logger } from "./logger";
+import { MongoFileDocument } from "./MongoFileDocument";
+
+const connectionString = process.env["MongoUrl"];
+
+if (!connectionString) {
+  throw new Error("MongoUrl env var is not defined!");
+}
+
+const client = new MongoClient(connectionString, { useNewUrlParser: true });
+let db: Db;
+let bucket: GridFSBucket;
+client.connect(error => {
+  if (error) {
+    throw error;
+  }
+
+  db = client.db("test");
+
+  bucket = new GridFSBucket(db);
+  bucket.drop(error => {
+    if (error && error.message !== "ns not found") {
+      throw error;
+    }
+
+    console.info("Dropped bucket.");
+
+    const fileName = "readme.txt";
+
+    const readStream = fs.createReadStream(path.join(__dirname, "files", fileName));
+
+    readStream.on("close", () => {
+      console.log("readme.txt uploaded to gridfs.");
+    });
+
+    const writeStream = bucket.openUploadStream(fileName, { contentType: "text/plain" });
+
+    readStream.pipe(writeStream);
+  });
+});
+
+export const mongoContentProvider: ContentProvider = async (req: Request) => {
+  const fileName = req.params.name;
+  const file = await getFileMeta(fileName, db);
+  if (!file) {
+    throw new ContentDoesNotExistError(`File doesn't exist: ${fileName}`);
+  }
+  const totalSize = file.size;
+  const mimeType = file.contentType;
+  const getStream = (range?: Range) => {
+    if (!range) {
+      return bucket.openDownloadStreamByName(fileName);
+    }
+    const { start, end } = range;
+    logger.debug(`start: ${start}, end: ${end}`);
+    // Note: The `end` offset in Mongo stream isn't inclusive, need to append 1 to it to ensure it returns
+    // the right sized content. Otherwise the stream size will be one byte short of the expected value.
+    return bucket.openDownloadStreamByName(fileName, { start, end: end + 1, revision: -1 });
+  };
+  return {
+    fileName,
+    totalSize,
+    mimeType,
+    getStream
+  };
+};

src/examples/express-mongo-server/utils.ts

@@ -0,0 +1,17 @@
+import { Db } from "mongodb";
+import { MongoFileDocument } from "./MongoFileDocument";
+import { logger } from "./logger";
+
+export const getFileMeta = async (fileName: string, db: Db) => {
+  logger.debug(`Fetching file information for ${fileName}`);
+  const result = await db.collection("fs.files").findOne({ filename: fileName });
+  logger.debug(`File meta: `, result);
+  return result
+    ? {
+        _id: result._id,
+        contentType: result.contentType,
+        fileName,
+        size: result.length
+      }
+    : null;
+};

yarn.lock

@@ -127,6 +127,13 @@
     "@types/connect" "*"
     "@types/node" "*"
 
+"@types/bson@*":
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/@types/bson/-/bson-4.0.0.tgz#9073772679d749116eb1dfca56f8eaac6d59cc7a"
+  integrity sha512-pq/rqJwJWkbS10crsG5bgnrisL8pML79KlMKQMoQwLUjlPAkrUHMvHJ3oGwE7WHR61Lv/nadMwXVAD2b+fpD8Q==
+  dependencies:
+    "@types/node" "*"
+
 "@types/chai@^4.1.7":
   version "4.1.7"
   resolved "https://registry.yarnpkg.com/@types/chai/-/chai-4.1.7.tgz#1b8e33b61a8c09cbe1f85133071baa0dbf9fa71a"
@@ -166,6 +173,14 @@
   resolved "https://registry.yarnpkg.com/@types/mocha/-/mocha-5.2.6.tgz#b8622d50557dd155e9f2f634b7d68fd38de5e94b"
   integrity sha512-1axi39YdtBI7z957vdqXI4Ac25e7YihYQtJa+Clnxg1zTJEaIRbndt71O3sP4GAMgiAm0pY26/b9BrY4MR/PMw==
 
+"@types/mongodb@^3.1.22":
+  version "3.1.22"
+  resolved "https://registry.yarnpkg.com/@types/mongodb/-/mongodb-3.1.22.tgz#66f96c7acbf7135ce6295a8d6c26f1d97388a84b"
+  integrity sha512-hvNR0txBlJJAy1eZOeIDshW4dnQaC694COou4eHHaMdIcteCfoCQATD7sYNlXxNxfTc1iIbHUi7A8CAhQe08uA==
+  dependencies:
+    "@types/bson" "*"
+    "@types/node" "*"
+
 "@types/node@*":
   version "11.10.5"
   resolved "https://registry.yarnpkg.com/@types/node/-/node-11.10.5.tgz#fbaca34086bdc118011e1f05c47688d432f2d571"
@@ -358,6 +373,11 @@ browser-stdout@1.3.1:
   resolved "https://registry.yarnpkg.com/browser-stdout/-/browser-stdout-1.3.1.tgz#baa559ee14ced73452229bad7326467c61fabd60"
   integrity sha512-qhAVI1+Av2X7qelOfAIYwXONood6XlZE/fXaBSmW/T5SzLAmCgzi+eiWE7fUvbHaeNBQH13UftjpXxsfLkMpgw==
 
+bson@^1.1.0:
+  version "1.1.1"
+  resolved "https://registry.yarnpkg.com/bson/-/bson-1.1.1.tgz#4330f5e99104c4e751e7351859e2d408279f2f13"
+  integrity sha512-jCGVYLoYMHDkOsbwJZBCqwMHyH4c+wzgI9hG7Z6SZJRXWr+x58pdIbm2i9a/jFGCkRJqRUr8eoI7lDWa0hTkxg==
+
 bytes@3.0.0:
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/bytes/-/bytes-3.0.0.tgz#d32815404d689699f85a4ea4fa8755dd13a96048"
@@ -1491,6 +1511,11 @@ mem@^4.0.0:
     mimic-fn "^1.0.0"
     p-is-promise "^2.0.0"
 
+memory-pager@^1.0.2:
+  version "1.5.0"
+  resolved "https://registry.yarnpkg.com/memory-pager/-/memory-pager-1.5.0.tgz#d8751655d22d384682741c972f2c3d6dfa3e66b5"
+  integrity sha512-ZS4Bp4r/Zoeq6+NLJpP+0Zzm0pR8whtGPf1XExKLJBAczGMnSi3It14OiNCStjQjM6NU1okjQGSxgEZN8eBYKg==
+
 merge-descriptors@1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/merge-descriptors/-/merge-descriptors-1.0.1.tgz#b00aaa556dd8b44568150ec9d1b953f3f90cbb61"
@@ -1610,6 +1635,25 @@ mocha@^6.0.2:
     yargs-parser "11.1.1"
     yargs-unparser "1.5.0"
 
+mongodb-core@3.1.11:
+  version "3.1.11"
+  resolved "https://registry.yarnpkg.com/mongodb-core/-/mongodb-core-3.1.11.tgz#b253038dbb4d7329f3d1c2ee5400bb0c9221fde5"
+  integrity sha512-rD2US2s5qk/ckbiiGFHeu+yKYDXdJ1G87F6CG3YdaZpzdOm5zpoAZd/EKbPmFO6cQZ+XVXBXBJ660sSI0gc6qg==
+  dependencies:
+    bson "^1.1.0"
+    require_optional "^1.0.1"
+    safe-buffer "^5.1.2"
+  optionalDependencies:
+    saslprep "^1.0.0"
+
+mongodb@^3.1.13:
+  version "3.1.13"
+  resolved "https://registry.yarnpkg.com/mongodb/-/mongodb-3.1.13.tgz#f8cdcbb36ad7a08b570bd1271c8525753f75f9f4"
+  integrity sha512-sz2dhvBZQWf3LRNDhbd30KHVzdjZx9IKC0L+kSZ/gzYquCF5zPOgGqRz6sSCqYZtKP2ekB4nfLxhGtzGHnIKxA==
+  dependencies:
+    mongodb-core "3.1.11"
+    safe-buffer "^5.1.2"
+
 ms@2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/ms/-/ms-2.0.0.tgz#5608aeadfc00be6c2901df5f9861788de0d597c8"
@@ -2025,6 +2069,14 @@ require-main-filename@^1.0.1:
   resolved "https://registry.yarnpkg.com/require-main-filename/-/require-main-filename-1.0.1.tgz#97f717b69d48784f5f526a6c5aa8ffdda055a4d1"
   integrity sha1-l/cXtp1IeE9fUmpsWqj/3aBVpNE=
 
+require_optional@^1.0.1:
+  version "1.0.1"
+  resolved "https://registry.yarnpkg.com/require_optional/-/require_optional-1.0.1.tgz#4cf35a4247f64ca3df8c2ef208cc494b1ca8fc2e"
+  integrity sha512-qhM/y57enGWHAe3v/NcwML6a3/vfESLe/sGM2dII+gEO0BpKRUkWZow/tyloNqJyN6kXSl3RyyM8Ll5D/sJP8g==
+  dependencies:
+    resolve-from "^2.0.0"
+    semver "^5.1.0"
+
 resolve-dir@^1.0.0, resolve-dir@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/resolve-dir/-/resolve-dir-1.0.1.tgz#79a40644c362be82f26effe739c9bb5382046f43"
@@ -2033,6 +2085,11 @@ resolve-dir@^1.0.0, resolve-dir@^1.0.1:
     expand-tilde "^2.0.0"
     global-modules "^1.0.0"
 
+resolve-from@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/resolve-from/-/resolve-from-2.0.0.tgz#9480ab20e94ffa1d9e80a804c7ea147611966b57"
+  integrity sha1-lICrIOlP+h2egKgEx+oUdhGWa1c=
+
 resolve-from@^4.0.0:
   version "4.0.0"
   resolved "https://registry.yarnpkg.com/resolve-from/-/resolve-from-4.0.0.tgz#4abcd852ad32dd7baabfe9b40e00a36db5f392e6"
@@ -2062,7 +2119,7 @@ rimraf@^2.6.2, rimraf@^2.6.3:
   dependencies:
     glob "^7.1.3"
 
-safe-buffer@5.1.2, safe-buffer@~5.1.1:
+safe-buffer@5.1.2, safe-buffer@^5.1.2, safe-buffer@~5.1.1:
   version "5.1.2"
   resolved "https://registry.yarnpkg.com/safe-buffer/-/safe-buffer-5.1.2.tgz#991ec69d296e0313747d59bdfd2b745c35f8828d"
   integrity sha512-Gd2UZBJDkXlY7GbJxfsE8/nvKkUEU1G38c1siN6QP6a9PT9MmHB8GnpscSmMJSoF8LOIrt8ud/wPtojys4G6+g==
@@ -2079,7 +2136,14 @@ safe-regex@^1.1.0:
   resolved "https://registry.yarnpkg.com/safer-buffer/-/safer-buffer-2.1.2.tgz#44fa161b0187b9549dd84bb91802f9bd8385cd6a"
   integrity sha512-YZo3K82SD7Riyi0E1EQPojLz7kpepnSQI9IyPbHHg1XXXevb5dJI7tpyN2ADxGcQbHG7vcyRHk0cbwqcQriUtg==
 
-"semver@2 || 3 || 4 || 5", semver@^5.5.0, semver@^5.6.0:
+saslprep@^1.0.0:
+  version "1.0.2"
+  resolved "https://registry.yarnpkg.com/saslprep/-/saslprep-1.0.2.tgz#da5ab936e6ea0bbae911ffec77534be370c9f52d"
+  integrity sha512-4cDsYuAjXssUSjxHKRe4DTZC0agDwsCqcMqtJAQPzC74nJ7LfAJflAtC1Zed5hMzEQKj82d3tuzqdGNRsLJ4Gw==
+  dependencies:
+    sparse-bitfield "^3.0.3"
+
+"semver@2 || 3 || 4 || 5", semver@^5.1.0, semver@^5.5.0, semver@^5.6.0:
   version "5.6.0"
   resolved "https://registry.yarnpkg.com/semver/-/semver-5.6.0.tgz#7e74256fbaa49c75aa7c7a205cc22799cac80004"
   integrity sha512-RS9R6R35NYgQn++fkDWaOmqGoj4Ek9gGs+DPxNUZKuwE183xjJroKvyo1IzVFeXvUrvmALy6FWD5xrdJT25gMg==
@@ -2229,6 +2293,13 @@ source-map@^0.6.1, source-map@~0.6.1:
   resolved "https://registry.yarnpkg.com/source-map/-/source-map-0.6.1.tgz#74722af32e9614e9c287a8d0bbde48b5e2f1a263"
   integrity sha512-UjgapumWlbMhkBgzT7Ykc5YXUT46F0iKu8SGXq0bcwP5dz/h0Plj6enJqjz1Zbq2l5WaqYnrVbwWOWMyF3F47g==
 
+sparse-bitfield@^3.0.3:
+  version "3.0.3"
+  resolved "https://registry.yarnpkg.com/sparse-bitfield/-/sparse-bitfield-3.0.3.tgz#ff4ae6e68656056ba4b3e792ab3334d38273ca11"
+  integrity sha1-/0rm5oZWBWuks+eSqzM004JzyhE=
+  dependencies:
+    memory-pager "^1.0.2"
+
 spawn-wrap@^1.4.2:
   version "1.4.2"
   resolved "https://registry.yarnpkg.com/spawn-wrap/-/spawn-wrap-1.4.2.tgz#cff58e73a8224617b6561abdc32586ea0c82248c"