chore: use same hash for empty node as go

package.json

@@ -59,8 +59,8 @@
     "bs58": "^4.0.1",
     "cids": "~0.5.3",
     "deep-extend": "~0.6.0",
-    "ipfs-unixfs": "~0.1.14",
-    "ipld": "^0.17.2",
+    "ipfs-unixfs": "~0.1.15",
+    "ipld": "~0.17.2",
     "ipld-dag-pb": "~0.14.4",
     "left-pad": "^1.3.0",
     "lodash": "^4.17.10",

src/exporter/file.js

@@ -30,7 +30,7 @@ module.exports = (node, name, path, pathRest, resolve, size, dag, parent, depth,
   }
 
   if (length === 0) {
-    return pull.empty()
+    return pull.once(Buffer.alloc(0))
   }
 
   if (!offset) {
@@ -56,36 +56,37 @@ module.exports = (node, name, path, pathRest, resolve, size, dag, parent, depth,
 
 function streamBytes (dag, node, fileSize, offset, length) {
   if (offset === fileSize || length === 0) {
-    return pull.empty()
+    return pull.once(Buffer.alloc(0))
   }
 
   const end = offset + length
-  let streamPosition = 0
 
   function getData ({ node, start }) {
-    if (!node || !node.data) {
-      return
-    }
-
     try {
       const file = UnixFS.unmarshal(node.data)
 
       if (!file.data) {
-        return
+        return Buffer.alloc(0)
       }
 
-      const block = extractDataFromBlock(file.data, start, offset, end)
-
-      streamPosition += block.length
-
-      return block
+      return extractDataFromBlock(file.data, start, offset, end)
     } catch (error) {
       throw new Error(`Failed to unmarshal node - ${error.message}`)
     }
   }
 
+  // as we step through the children, keep track of where we are in the stream
+  // so we can filter out nodes we're not interested in
+  let streamPosition = 0
+
   function visitor ({ node }) {
     const file = UnixFS.unmarshal(node.data)
+    const nodeHasData = Boolean(file.data && file.data.length)
+
+    // handle case where data is present on leaf nodes and internal nodes
+    if (nodeHasData && node.links.length) {
+      streamPosition += file.data.length
+    }
 
     // work out which child nodes contain the requested data
     const filteredLinks = node.links
@@ -100,7 +101,7 @@ function streamBytes (dag, node, fileSize, offset, length) {
 
         return child
       })
-      .filter((child, index) => {
+      .filter((child) => {
         return (offset >= child.start && offset < child.end) || // child has offset byte
           (end > child.start && end <= child.end) || // child has end byte
           (offset < child.start && end > child.end) // child is between offset and end bytes
@@ -138,6 +139,12 @@ function streamBytes (dag, node, fileSize, offset, length) {
 function extractDataFromBlock (block, streamPosition, begin, end) {
   const blockLength = block.length
 
+  if (begin >= streamPosition + blockLength) {
+    // If begin is after the start of the block, return an empty block
+    // This can happen when internal nodes contain data
+    return Buffer.alloc(0)
+  }
+
   if (end - streamPosition < blockLength) {
     // If the end byte is in the current block, truncate the block to the end byte
     block = block.slice(0, end - streamPosition)

test/exporter.js

@@ -14,6 +14,17 @@ const CID = require('cids')
 const loadFixture = require('aegir/fixtures')
 const doUntil = require('async/doUntil')
 const waterfall = require('async/waterfall')
+const parallel = require('async/parallel')
+const series = require('async/series')
+const fs = require('fs')
+const path = require('path')
+const push = require('pull-pushable')
+const toPull = require('stream-to-pull-stream')
+const toStream = require('pull-stream-to-stream')
+const {
+  DAGNode,
+  DAGLink
+} = require('ipld-dag-pb')
 
 const unixFSEngine = require('./../src')
 const exporter = unixFSEngine.exporter
@@ -64,6 +75,52 @@ module.exports = (repo) => {
       })
     }
 
+    function addTestDirectory ({directory, strategy = 'balanced', maxChunkSize}, callback) {
+      const input = push()
+      const dirName = path.basename(directory)
+
+      pull(
+        input,
+        pull.map((file) => {
+          return {
+            path: path.join(dirName, path.basename(file)),
+            content: toPull.source(fs.createReadStream(file))
+          }
+        }),
+        importer(ipld, {
+          strategy,
+          maxChunkSize
+        }),
+        pull.collect(callback)
+      )
+
+      const listFiles = (directory, depth, stream, cb) => {
+        waterfall([
+          (done) => fs.stat(directory, done),
+          (stats, done) => {
+            if (stats.isDirectory()) {
+              return waterfall([
+                (done) => fs.readdir(directory, done),
+                (children, done) => {
+                  series(
+                    children.map(child => (next) => listFiles(path.join(directory, child), depth + 1, stream, next)),
+                    done
+                  )
+                }
+              ], done)
+            }
+
+            stream.push(directory)
+            done()
+          }
+        ], cb)
+      }
+
+      listFiles(directory, 0, input, () => {
+        input.end()
+      })
+    }
+
     function checkBytesThatSpanBlocks (strategy, cb) {
       const bytesInABlock = 262144
       const bytes = Buffer.alloc(bytesInABlock + 100, 0)
@@ -517,6 +574,55 @@ module.exports = (repo) => {
       checkBytesThatSpanBlocks('trickle', done)
     })
 
+    it('exports a directory containing an empty file whose content gets turned into a ReadableStream', function (done) {
+      // replicates the behaviour of ipfs.files.get
+      waterfall([
+        (cb) => addTestDirectory({
+          directory: path.join(__dirname, 'fixtures', 'dir-with-empty-files')
+        }, cb),
+        (result, cb) => {
+          const dir = result.pop()
+
+          pull(
+            exporter(dir.multihash, ipld),
+            pull.map((file) => {
+              if (file.content) {
+                file.content = toStream.source(file.content)
+                file.content.pause()
+              }
+
+              return file
+            }),
+            pull.collect((error, files) => {
+              if (error) {
+                return cb(error)
+              }
+
+              series(
+                files
+                  .filter(file => Boolean(file.content))
+                  .map(file => {
+                    return (done) => {
+                      if (file.content) {
+                        file.content
+                          .pipe(toStream.sink(pull.collect((error, bufs) => {
+                            expect(error).to.not.exist()
+                            expect(bufs.length).to.equal(1)
+                            expect(bufs[0].length).to.equal(0)
+
+                            done()
+                          })))
+                      }
+                    }
+                  }),
+                cb
+              )
+            })
+          )
+        }
+      ], done)
+    })
+
     // TODO: This needs for the stores to have timeouts,
     // otherwise it is impossible to predict if a file doesn't
     // really exist
@@ -532,6 +638,100 @@ module.exports = (repo) => {
         })
       )
     })
+
+    it('exports file with data on internal and leaf nodes', function (done) {
+      waterfall([
+        (cb) => createAndPersistNode(ipld, 'raw', [0x04, 0x05, 0x06, 0x07], [], cb),
+        (leaf, cb) => createAndPersistNode(ipld, 'file', [0x00, 0x01, 0x02, 0x03], [
+          leaf
+        ], cb),
+        (file, cb) => {
+          pull(
+            exporter(file.multihash, ipld),
+            pull.asyncMap((file, cb) => readFile(file, cb)),
+            pull.through(buffer => {
+              expect(buffer).to.deep.equal(Buffer.from([0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07]))
+            }),
+            pull.collect(cb)
+          )
+        }
+      ], done)
+    })
+
+    it('exports file with data on some internal and leaf nodes', function (done) {
+      // create a file node with three children:
+      // where:
+      //   i = internal node without data
+      //   d = internal node with data
+      //   l = leaf node with data
+      //             i
+      //          /  |  \
+      //         l   d   i
+      //             |     \
+      //             l      l
+      waterfall([
+        (cb) => {
+          // create leaves
+          parallel([
+            (next) => createAndPersistNode(ipld, 'raw', [0x00, 0x01, 0x02, 0x03], [], next),
+            (next) => createAndPersistNode(ipld, 'raw', [0x08, 0x09, 0x10, 0x11], [], next),
+            (next) => createAndPersistNode(ipld, 'raw', [0x12, 0x13, 0x14, 0x15], [], next)
+          ], cb)
+        },
+        (leaves, cb) => {
+          parallel([
+            (next) => createAndPersistNode(ipld, 'raw', [0x04, 0x05, 0x06, 0x07], [leaves[1]], next),
+            (next) => createAndPersistNode(ipld, 'raw', null, [leaves[2]], next)
+          ], (error, internalNodes) => {
+            if (error) {
+              return cb(error)
+            }
+
+            createAndPersistNode(ipld, 'file', null, [
+              leaves[0],
+              internalNodes[0],
+              internalNodes[1]
+            ], cb)
+          })
+        },
+        (file, cb) => {
+          pull(
+            exporter(file.multihash, ipld),
+            pull.asyncMap((file, cb) => readFile(file, cb)),
+            pull.through(buffer => {
+              expect(buffer).to.deep.equal(
+                Buffer.from([
+                  0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
+                  0x08, 0x09, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15
+                ])
+              )
+            }),
+            pull.collect(cb)
+          )
+        }
+      ], done)
+    })
+
+    it('exports file with data on internal and leaf nodes with an offset that only fetches data from leaf nodes', function (done) {
+      waterfall([
+        (cb) => createAndPersistNode(ipld, 'raw', [0x04, 0x05, 0x06, 0x07], [], cb),
+        (leaf, cb) => createAndPersistNode(ipld, 'file', [0x00, 0x01, 0x02, 0x03], [
+          leaf
+        ], cb),
+        (file, cb) => {
+          pull(
+            exporter(file.multihash, ipld, {
+              offset: 4
+            }),
+            pull.asyncMap((file, cb) => readFile(file, cb)),
+            pull.through(buffer => {
+              expect(buffer).to.deep.equal(Buffer.from([0x04, 0x05, 0x06, 0x07]))
+            }),
+            pull.collect(cb)
+          )
+        }
+      ], done)
+    })
   })
 }
 
@@ -567,3 +767,26 @@ function readFile (file, done) {
     })
   )
 }
+
+function createAndPersistNode (ipld, type, data, children, callback) {
+  const file = new UnixFS(type, data ? Buffer.from(data) : undefined)
+  const links = []
+
+  children.forEach(child => {
+    const leaf = UnixFS.unmarshal(child.data)
+
+    file.addBlockSize(leaf.fileSize())
+
+    links.push(new DAGLink('', child.size, child.multihash))
+  })
+
+  DAGNode.create(file.marshal(), links, (error, node) => {
+    if (error) {
+      return callback(error)
+    }
+
+    ipld.put(node, {
+      cid: new CID(node.multihash)
+    }, (error) => callback(error, node))
+  })
+}

test/importer.js

@@ -7,7 +7,7 @@ const extend = require('deep-extend')
 const chai = require('chai')
 chai.use(require('dirty-chai'))
 const expect = chai.expect
-const sinon = require('sinon')
+const spy = require('sinon/lib/sinon/spy')
 const BlockService = require('ipfs-block-service')
 const pull = require('pull-stream')
 const mh = require('multihashes')
@@ -214,7 +214,7 @@ module.exports = (repo) => {
             expect(err).to.not.exist()
             expect(nodes.length).to.be.eql(1)
             // always yield empty node
-            expect(mh.toB58String(nodes[0].multihash)).to.be.eql('QmfJMCvenrj4SKKRc48DYPxwVdS44qCUCqqtbqhJuSTWXP')
+            expect(mh.toB58String(nodes[0].multihash)).to.be.eql('QmbFMke1KXqnYyBBWxB74N4c5SBnJMVAiMNRcGu6x1AwQH')
             done()
           }))
       })
@@ -456,7 +456,7 @@ module.exports = (repo) => {
       })
 
       it('will call an optional progress function', (done) => {
-        options.progress = sinon.spy()
+        options.progress = spy()
 
         pull(
           pull.values([{

test/node.js

@@ -10,8 +10,8 @@ const mkdirp = require('mkdirp')
 const series = require('async/series')
 
 describe('IPFS UnixFS Engine', () => {
-  const repoExample = path.join(process.cwd(), '/test/test-repo')
-  const repoTests = path.join(os.tmpdir(), '/unixfs-tests-' + Date.now())
+  const repoExample = path.join(process.cwd(), 'test', 'test-repo')
+  const repoTests = path.join(os.tmpdir(), 'unixfs-tests-' + Date.now())
 
   const repo = new IPFSRepo(repoTests)
 

test/with-dag-api.js

@@ -225,7 +225,7 @@ describe('with dag-api', function () {
             expect(err).to.not.exist()
             expect(nodes.length).to.be.eql(1)
             // always yield empty node
-            expect(mh.toB58String(nodes[0].multihash)).to.be.eql('QmfJMCvenrj4SKKRc48DYPxwVdS44qCUCqqtbqhJuSTWXP')
+            expect(mh.toB58String(nodes[0].multihash)).to.be.eql('QmbFMke1KXqnYyBBWxB74N4c5SBnJMVAiMNRcGu6x1AwQH')
             done()
           }))
       })