Remove `fastfs.readWhile`

Reviewed By: davidaurelio

Differential Revision: D4021265

fbshipit-source-id: 578ad54ea5a81e5b091cecafcb2fe6d08746e7f6

packager/react-packager/src/node-haste/Module.js

@@ -10,10 +10,10 @@
 
 const crypto = require('crypto');
 const docblock = require('./DependencyGraph/docblock');
+const extractRequires = require('./lib/extractRequires');
 const isAbsolutePath = require('absolute-path');
 const jsonStableStringify = require('json-stable-stringify');
 const path = require('./fastpath');
-const extractRequires = require('./lib/extractRequires');
 
 class Module {
 
@@ -115,12 +115,16 @@ class Module {
     return {id, moduleDocBlock};
   }
 
-  _readDocBlock(contentPromise) {
+  _read() {
+    if (!this._readPromise) {
+      this._readPromise = this._fastfs.readFile(this.path);
+    }
+    return this._readPromise;
+  }
+
+  _readDocBlock() {
     if (!this._docBlock) {
-      if (!contentPromise) {
-        contentPromise = this._fastfs.readWhile(this.path, whileInDocBlock);
-      }
-      this._docBlock = contentPromise
+      this._docBlock = this._read()
         .then(docBlock => this._parseDocBlock(docBlock));
     }
     return this._docBlock;
@@ -131,10 +135,9 @@ class Module {
       this.path,
       cacheKey('moduleData', transformOptions),
       () => {
-        const fileContentPromise = this._fastfs.readFile(this.path);
         return Promise.all([
-          fileContentPromise,
-          this._readDocBlock(fileContentPromise),
+          this._read(),
+          this._readDocBlock(),
         ]).then(([source, {id, moduleDocBlock}]) => {
           // Ignore requires in JSON files or generated code. An example of this
           // is prebuilt files like the SourceMap library.
@@ -194,21 +197,6 @@ class Module {
   }
 }
 
-function whileInDocBlock(chunk, i, result) {
-  // consume leading whitespace
-  if (!/\S/.test(result)) {
-    return true;
-  }
-
-  // check for start of doc block
-  if (!/^\s*\/(\*{2}|\*?$)/.test(result)) {
-    return false;
-  }
-
-  // check for end of doc block
-  return !/\*\//.test(result);
-}
-
 // use weak map to speed up hash creation of known objects
 const knownHashes = new WeakMap();
 function stableObjectHash(object) {

packager/react-packager/src/node-haste/__tests__/fastfs-integrated-test.js

@@ -1,91 +0,0 @@
-/**
- * Copyright (c) 2015-present, Facebook, Inc.
- * All rights reserved.
- *
- * This source code is licensed under the BSD-style license found in the
- * LICENSE file in the root directory of this source tree. An additional grant
- * of patent rights can be found in the PATENTS file in the same directory.
- */
-'use strict';
-
-jest.autoMockOff()
-  .dontMock('graceful-fs');
-
-const Fastfs = require('../fastfs');
-
-const {EventEmitter} = require('events');
-const fs = require('fs');
-const path = require('path');
-
-const fileName = path.resolve(__dirname, 'fastfs-data');
-const contents = fs.readFileSync(fileName, 'utf-8');
-
-describe('fastfs:', function() {
-  let fastfs;
-  const roots = [__dirname];
-  const watcher = new EventEmitter();
-
-  beforeEach(function() {
-    fastfs = new Fastfs(
-      'arbitrary',
-      roots,
-      watcher,
-      [`${__dirname}/fastfs-data`],
-      {}
-    );
-  });
-
-  describe('partial reading', () => {
-    // these are integrated tests that read real files from disk
-
-    pit('reads a file while a predicate returns true', function() {
-      return fastfs.readWhile(fileName, () => true).then(readContent =>
-        expect(readContent).toEqual(contents)
-      );
-    });
-
-    pit('invokes the predicate with the new chunk, the invocation index, and the result collected so far', () => {
-      const predicate = jest.genMockFn().mockReturnValue(true);
-      return fastfs.readWhile(fileName, predicate).then(() => {
-        let aggregated = '';
-        const {calls} = predicate.mock;
-        expect(calls).not.toEqual([]);
-
-        calls.forEach((call, i) => {
-          const [chunk] = call;
-          aggregated += chunk;
-          expect(chunk).not.toBe('');
-          expect(call).toEqual([chunk, i, aggregated]);
-        });
-
-        expect(aggregated).toEqual(contents);
-      });
-    });
-
-    pit('stops reading when the predicate returns false', () => {
-      const predicate = jest.genMockFn().mockImpl((_, i) => i !== 0);
-      return fastfs.readWhile(fileName, predicate).then((readContent) => {
-        const {calls} = predicate.mock;
-        expect(calls.length).toBe(1);
-        expect(readContent).toBe(calls[0][2]);
-      });
-    });
-
-    pit('after reading the whole file with `readWhile`, `read()` still works', () => {
-      // this test allows to reuse the results of `readWhile` for `readFile`
-      return fastfs.readWhile(fileName, () => true).then(() => {
-        fastfs.readFile(fileName).then(readContent =>
-          expect(readContent).toEqual(contents)
-        );
-      });
-    });
-
-    pit('after reading parts of the file with `readWhile`, `read()` still works', () => {
-      return fastfs.readWhile(fileName, () => false).then(() => {
-        fastfs.readFile(fileName).then(readContent =>
-          expect(readContent).toEqual(contents)
-        );
-      });
-    });
-  });
-});

packager/react-packager/src/node-haste/fastfs.js

@@ -9,11 +9,11 @@
 'use strict';
 
 const denodeify = require('denodeify');
-const {EventEmitter} = require('events');
-
 const fs = require('fs');
 const path = require('./fastpath');
 
+const {EventEmitter} = require('events');
+
 const readFile = denodeify(fs.readFile);
 const stat = denodeify(fs.stat);
 
@@ -101,14 +101,6 @@ class Fastfs extends EventEmitter {
     return file.read();
   }
 
-  readWhile(filePath, predicate) {
-    const file = this._getFile(filePath);
-    if (!file) {
-      throw new Error(`Unable to find file with path: ${filePath}`);
-    }
-    return file.readWhile(predicate);
-  }
-
   closest(filePath, name) {
     for (let file = this._getFile(filePath).parent;
          file;
@@ -235,15 +227,6 @@ class File {
     return this._read;
   }
 
-  readWhile(predicate) {
-    return readWhile(this.path, predicate).then(({result, completed}) => {
-      if (completed && !this._read) {
-        this._read = Promise.resolve(result);
-      }
-      return result;
-    });
-  }
-
   stat() {
     if (!this._stat) {
       this._stat = stat(this.path);
@@ -303,58 +286,6 @@ class File {
   }
 }
 
-function readWhile(filePath, predicate) {
-  return new Promise((resolve, reject) => {
-    fs.open(filePath, 'r', (openError, fd) => {
-      if (openError) {
-        reject(openError);
-        return;
-      }
-
-      read(
-        fd,
-        /*global Buffer: true*/
-        new Buffer(512),
-        makeReadCallback(fd, predicate, (readError, result, completed) => {
-          if (readError) {
-            reject(readError);
-          } else {
-            resolve({result, completed});
-          }
-        })
-      );
-    });
-  });
-}
-
-function read(fd, buffer, callback) {
-  fs.read(fd, buffer, 0, buffer.length, -1, callback);
-}
-
-function close(fd, error, result, complete, callback) {
-  fs.close(fd, closeError => callback(error || closeError, result, complete));
-}
-
-function makeReadCallback(fd, predicate, callback) {
-  let result = '';
-  let index = 0;
-  return function readCallback(error, bytesRead, buffer) {
-    if (error) {
-      close(fd, error, undefined, false, callback);
-      return;
-    }
-
-    const completed = bytesRead === 0;
-    const chunk = completed ? '' : buffer.toString('utf8', 0, bytesRead);
-    result += chunk;
-    if (completed || !predicate(chunk, index++, result)) {
-      close(fd, null, result, completed, callback);
-    } else {
-      read(fd, buffer, readCallback);
-    }
-  };
-}
-
 function isDescendant(root, child) {
   return root === child || child.startsWith(root + path.sep);
 }