Save datasets to cache.

And ensure datasets reference propelml.org URLs, not filesystem paths.

Fixes #375

src/cache.ts

@@ -0,0 +1,108 @@
+/*!
+   Copyright 2018 Propel http://propel.site/.  All rights reserved.
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+ */
+
+// When people load datasets in Propel, they need to be downloaded from HTTP.
+// To avoid making people download the same dataset every time they start
+// a training program, we provide a local cache of these datasets.
+// The $HOME/.propel/cache directory is where these files will be stored.
+
+import * as path from "path";
+import * as rimraf from "rimraf";
+import { assert, fetchArrayBuffer, IS_WEB, nodeRequire, URL } from "./util";
+import { mkdirp, propelDir } from "./util_node";
+
+export interface Cache {
+  clearAll(): Promise<void>;
+  get(url: string): Promise<null | ArrayBuffer>;
+  set(url: string, ab: ArrayBuffer): Promise<void>;
+}
+
+let cacheImpl: Cache;
+
+// TODO move this function to src/fetch.ts
+export async function fetchWithCache(url: string): Promise<ArrayBuffer> {
+  let ab = await cacheImpl.get(url);
+  if (ab != null) {
+    return ab;
+  }
+  ab = await fetchArrayBuffer(url);
+  cacheImpl.set(url, ab);
+  return ab;
+}
+
+export function clearAll(): Promise<void> {
+  return cacheImpl.clearAll();
+}
+
+function cacheBase(): string {
+  return path.resolve(propelDir(), "cache");
+}
+
+// Maps a URL to a cache filename. Example:
+// "http://propelml.org/data/mnist/train-images-idx3-ubyte.bin"
+// "$HOME/.propel/cache/propelml.org/data/mnist/train-images-idx3-ubyte.bin"
+export function url2Filename(url: string): string {
+  if (IS_WEB) return "";
+  const u = new URL(url);
+  if (!(u.protocol === "http:" || u.protocol === "https:")) {
+    throw Error(`Unsupported protocol '${u.protocol}'`);
+  }
+  if (u.pathname.indexOf("..") >= 0) {
+    throw Error("Cache name cannot include '..'");
+  }
+  const cacheFn = path.resolve(path.join(cacheBase(), u.host, u.pathname));
+  assert(cacheFn.startsWith(cacheBase()));
+  return cacheFn;
+}
+
+if (IS_WEB) {
+  // On web do nothing. No caching.
+  // Maybe use local storage?
+  cacheImpl = {
+    async clearAll(): Promise<void> { },
+    async get(url: string): Promise<null | ArrayBuffer> {
+      return null;
+    },
+    async set(url: string, ab: ArrayBuffer): Promise<void> { },
+  };
+} else {
+  // Node caching uses the disk.
+  const fs = nodeRequire("fs");
+
+  cacheImpl = {
+    async clearAll(): Promise<void> {
+      rimraf.sync(cacheBase());
+      console.log("Delete cache dir", cacheBase());
+    },
+
+    async get(url: string): Promise<null | ArrayBuffer> {
+      const cacheFn = url2Filename(url);
+      if (fs.existsSync(cacheFn)) {
+        const b = fs.readFileSync(cacheFn, null);
+        return b.buffer.slice(b.byteOffset,
+            b.byteOffset + b.byteLength) as ArrayBuffer;
+      } else {
+        return null;
+      }
+    },
+
+    async set(url: string, ab: ArrayBuffer): Promise<void> {
+      const cacheFn = url2Filename(url);
+      const cacheDir = path.dirname(cacheFn);
+      mkdirp(cacheDir);
+      fs.writeFileSync(cacheFn, Buffer.from(ab));
+    },
+  };
+}

src/cache_test.ts

@@ -0,0 +1,63 @@
+/*!
+   Copyright 2018 Propel http://propel.site/.  All rights reserved.
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+ */
+
+// Node-only test. Browsers have caching built-in.
+
+import * as fs from "fs";
+import { test } from "../tools/tester";
+import * as cache from "./cache";
+import { assert, IS_NODE, nodeRequire } from "./util";
+
+// Helper function to start a local web server.
+// TODO should be moved to tools/tester eventually.
+async function localServer(cb: (url: string) => Promise<void>): Promise<void> {
+  if (!IS_NODE) {
+    // We don't need a local server, since we're being hosted from one already.
+    await cb(`http://${document.location.host}/`);
+  } else {
+    const { createServer } = nodeRequire("http-server");
+    const server = createServer({ cors: true, root: "./build/dev_website" });
+    server.listen();
+    const port = server.server.address().port;
+    const url = `http://127.0.0.1:${port}/`;
+    try {
+      await cb(url);
+    } finally {
+      server.close();
+    }
+  }
+}
+
+if (IS_NODE) {
+  test(async function cache_url2Filename() {
+    const home = process.env.HOME;
+    const actual = cache.url2Filename(
+      "http://propelml.org/data/mnist/train-images-idx3-ubyte.bin");
+    assert(actual === home +
+      "/.propel/cache/propelml.org/data/mnist/train-images-idx3-ubyte.bin");
+  });
+}
+
+test(async function cache_fetchWithCache() {
+  cache.clearAll();
+  await localServer(async function(url: string) {
+    const ab = await cache.fetchWithCache(
+      url + "/data/mnist/train-images-idx3-ubyte.bin");
+    assert(ab.byteLength === 47040016);
+    if (IS_NODE) {
+      assert(fs.existsSync(cache.url2Filename(url)));
+    }
+  });
+});

src/dataset.ts

@@ -15,11 +15,13 @@
 
 // This module is inspired by TensorFlow's tf.data.Dataset.
 // https://www.tensorflow.org/api_docs/python/tf/data/Dataset
+import { TextDecoder } from "text-encoding";
 import { isUndefined } from "util";
 import { stack, tensor, Tensor } from "./api";
+import * as cache from "./cache";
 import * as mnist from "./mnist";
 import { NamedTensors } from "./tensor";
-import { assert, delay, fetchStr } from "./util";
+import { assert, delay } from "./util";
 
 export function datasetFromSlices(tensors: NamedTensors): Dataset {
   return new SliceDataset(tensors);
@@ -271,7 +273,10 @@ class ShuffleDataset extends Dataset {
 
 async function loadData(fn: string):
     Promise<{ features: Tensor, labels: Tensor }> {
-  const csv = await fetchStr(fn);
+  const ab = await cache.fetchWithCache(fn);
+  const dec = new TextDecoder("ascii");
+  const csv = dec.decode(new Uint8Array(ab));
+
   const lines = csv.trim().split("\n").map(line => line.split(","));
   const header = lines.shift();
   const nSamples = Number(header.shift());
@@ -302,17 +307,17 @@ async function loadData(fn: string):
  */
 export async function loadIris():
     Promise<{ features: Tensor, labels: Tensor }> {
-  return loadData("deps/data/iris.csv");
+  return loadData("http://propelml.org/data/iris.csv");
 }
 
 export async function loadBreastCancer():
     Promise<{ features: Tensor, labels: Tensor }> {
-  return loadData("deps/data/breast_cancer.csv");
+  return loadData("http://propelml.org/data/breast_cancer.csv");
 }
 
 export async function loadWine():
     Promise<{ features: Tensor, labels: Tensor }> {
-  return loadData("deps/data/wine_data.csv");
+  return loadData("http://propelml.org/data/wine_data.csv");
 }
 
 // TODO

src/disk_experiment.ts

@@ -24,17 +24,7 @@ import { Experiment, ExperimentOpts, print }  from "./experiment";
 import * as npy from "./npy";
 import { Params, params as createParams } from "./params";
 import { assert } from "./util";
-
-/** Returns "$HOME/.propel/" or PROPEL_DIR env var. */
-function propelDir(): string {
-  if (process.env.PROPEL_DIR) {
-    return process.env.PROPEL_DIR;
-  } else {
-    const homeDir = process.platform === "win32" ? process.env.USERPROFILE
-                                                 : process.env.HOME;
-    return path.join(homeDir, ".propel/");
-  }
-}
+import { isDir, propelDir } from "./util_node";
 
 export class DiskExperiment extends Experiment {
   constructor(readonly name: string, opts?: ExperimentOpts) {
@@ -126,15 +116,6 @@ export class DiskExperiment extends Experiment {
   }
 }
 
-export function isDir(p: string): boolean {
-  try {
-    return fs.statSync(p).isDirectory();
-  } catch (e) {
-    if (e.code === "ENOENT") return false;
-    throw e;
-  }
-}
-
 function filePatternSearch(p: string, pattern: RegExp): string[] {
   if (isDir(p)) {
     let results = [];

src/disk_experiment_test.ts

@@ -17,8 +17,9 @@ import * as os from "os";
 import * as path from "path";
 import * as rimraf from "rimraf";
 import { test } from "../tools/tester";
-import { DiskExperiment, isDir } from "./disk_experiment";
+import { DiskExperiment } from "./disk_experiment";
 import { assert, assertAllEqual } from "./tensor_util";
+import { isDir } from "./util_node";
 
 function setup() {
   process.env.PROPEL_DIR = path.join(os.tmpdir(), "propel_test");

src/experiment.ts

@@ -46,6 +46,9 @@ const defaultOpts: ExperimentOpts = {
 export async function experiment(name: string,
                                  opts?: ExperimentOpts): Promise<Experiment> {
   let exp: Experiment;
+  if (name === "cache") {
+    throw Error("Invalid experiment name.");
+  }
   if (IS_NODE) {
     const { DiskExperiment } = require("./disk_experiment");
     exp = new DiskExperiment(name, opts);

src/mnist.ts

@@ -13,18 +13,19 @@
    limitations under the License.
  */
 import { tensor, Tensor } from "./api";
-import { assert, fetchArrayBuffer } from "./util";
+import * as cache from "./cache";
+import { assert } from "./util";
 
 export function filenames(split: string): [string, string] {
   if (split === "train") {
     return [
-      "deps/data/mnist/train-labels-idx1-ubyte.bin",
-      "deps/data/mnist/train-images-idx3-ubyte.bin",
+      "http://propelml.org/data/mnist/train-labels-idx1-ubyte.bin",
+      "http://propelml.org/data/mnist/train-images-idx3-ubyte.bin",
     ];
   } else if (split === "test") {
     return [
-      "deps/data/mnist/t10k-labels-idx1-ubyte.bin",
-      "deps/data/mnist/t10k-images-idx3-ubyte.bin",
+      "http://propelml.org/data/mnist/t10k-labels-idx1-ubyte.bin",
+      "http://propelml.org/data/mnist/t10k-images-idx3-ubyte.bin",
     ];
   } else {
     throw new Error(`Bad split: ${split}`);
@@ -48,7 +49,7 @@ export async function loadSplit(split: string):
 }
 
 async function loadFile2(href: string) {
-  const ab = await fetchArrayBuffer(href);
+  const ab = await cache.fetchWithCache(href);
   const i32 = new Int32Array(ab);
   const ui8 = new Uint8Array(ab);
 

src/util_node.ts

@@ -0,0 +1,48 @@
+/*!
+   Copyright 2018 Propel http://propel.site/.  All rights reserved.
+   Licensed under the Apache License, Version 2.0 (the "License");
+   you may not use this file except in compliance with the License.
+   You may obtain a copy of the License at
+
+   http://www.apache.org/licenses/LICENSE-2.0
+
+   Unless required by applicable law or agreed to in writing, software
+   distributed under the License is distributed on an "AS IS" BASIS,
+   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+   See the License for the specific language governing permissions and
+   limitations under the License.
+ */
+
+import * as fs from "fs";
+import * as path from "path";
+import { assert } from "./util";
+
+export function isDir(p: string): boolean {
+  try {
+    return fs.statSync(p).isDirectory();
+  } catch (e) {
+    if (e.code === "ENOENT") return false;
+    throw e;
+  }
+}
+
+/** Returns "$HOME/.propel/" or PROPEL_DIR env var. */
+export function propelDir(): string {
+  if (process.env.PROPEL_DIR) {
+    return process.env.PROPEL_DIR;
+  } else {
+    const homeDir = process.platform === "win32" ? process.env.USERPROFILE
+                                                 : process.env.HOME;
+    return path.join(homeDir, ".propel/");
+  }
+}
+
+/** Recursive mkdir. */
+export function mkdirp(dirname: string): void {
+  if (!isDir(dirname)) {
+    const parentDir = path.dirname(dirname);
+    assert(parentDir !== dirname && parentDir.length > 1);
+    mkdirp(parentDir);
+    fs.mkdirSync(dirname);
+  }
+}

tools/test_isomorphic.ts

@@ -1,5 +1,6 @@
 import "../src/api_test";
 import "../src/backend_test";
+import "../src/cache_test";
 import "../src/conv_test";
 import "../src/dataset_test";
 import "../src/example_test";