Merge pull request #1 from ipfs/feat/unixfs-format

feat/unixfs format

Author: daviddias

package.json

@@ -4,7 +4,7 @@
   "description": "JavaScript implementation of IPFS' unixfs (a Unix FileSystem representation on top of a MerkleDAG)",
   "main": "src/index.js",
   "scripts": {
-    "test": "mocha tests/*-test.js"
+    "test": "mocha tests/test-*.js"
   },
   "repository": {
     "type": "git",
@@ -24,5 +24,8 @@
     "mocha": "^2.4.5",
     "pre-commit": "^1.1.2",
     "standard": "^6.0.4"
+  },
+  "dependencies": {
+    "protocol-buffers": "^3.1.5"
   }
 }

src/index.js

@@ -0,0 +1 @@
+exports.format = require('./unixfs-format.js')

src/unixfs-format.js

@@ -0,0 +1,86 @@
+const fs = require('fs')
+const path = require('path')
+const protobuf = require('protocol-buffers')
+const schema = fs.readFileSync(path.resolve(__dirname, 'unixfs.proto'))
+const pb = protobuf(schema)
+const unixfsData = pb.Data // encode/decode
+// const unixfsMetadata = pb.MetaData // encode/decode
+
+const types = [
+  'raw',
+  'directory',
+  'file',
+  'metadata',
+  'symlink'
+]
+
+exports = module.exports = Data
+
+function Data (type, data) {
+  if (!(this instanceof Data)) {
+    return new Data(type, data)
+  }
+  if (types.indexOf(type) === -1) {
+    throw new Error('Type: ' + type + ' is not valid')
+  }
+
+  this.type = type
+  this.data = data
+  this.blockSizes = []
+
+  this.addBlockSize = (size) => {
+    this.blockSizes.push(size)
+  }
+
+  this.removeBlockSize = (index) => {
+    this.blockSizes.splice(index, 1)
+  }
+
+  // data.length + blockSizes
+  this.fileSize = () => {
+    var sum = 0
+    this.blockSizes.forEach((size) => {
+      sum += size
+    })
+    if (data) {
+      sum += data.length
+    }
+    return sum
+  }
+
+  // encode to protobuf
+  this.marshal = () => {
+    var type
+
+    switch (this.type) {
+      case 'raw': type = unixfsData.DataType.Raw; break
+      case 'directory': type = unixfsData.DataType.Directory; break
+      case 'file': type = unixfsData.DataType.File; break
+      case 'metadata': type = unixfsData.DataType.Metadata; break
+      case 'symlink': type = unixfsData.DataType.Symlink; break
+    }
+    var fileSize = this.fileSize()
+
+    if (fileSize === 0) {
+      fileSize = undefined
+    }
+
+    return unixfsData.encode({
+      Type: type,
+      Data: this.data,
+      filesize: fileSize,
+      blocksizes: this.blockSizes.length > 0 ? this.blockSizes : undefined
+    })
+  }
+}
+
+// decode from protobuf https://github.com/ipfs/go-ipfs/blob/master/unixfs/format.go#L24
+exports.unmarshal = (marsheled) => {
+  const decoded = unixfsData.decode(marsheled)
+  if (!decoded.Data) {
+    decoded.Data = undefined
+  }
+  const obj = new Data(types[decoded.Type], decoded.Data)
+  obj.blockSizes = decoded.blocksizes
+  return obj
+}

src/unixfs.proto

@@ -0,0 +1,18 @@
+message Data {
+	enum DataType {
+		Raw = 0;
+		Directory = 1;
+		File = 2;
+		Metadata = 3;
+		Symlink = 4;
+	}
+
+	required DataType Type = 1;
+	optional bytes Data = 2;
+	optional uint64 filesize = 3;
+	repeated uint64 blocksizes = 4;
+}
+
+message Metadata {
+	required string MimeType = 1;
+}

tests/test-data/directory.unixfs

@@ -0,0 +1 @@
+

tests/test-data/directory/file.txt

@@ -0,0 +1 @@
+Hello UnixFS

tests/test-data/file.txt

@@ -0,0 +1 @@
+Hello UnixFS

tests/test-data/file.txt.unixfs

@@ -0,0 +1,2 @@
+Hello UnixFS
+

tests/test-data/raw.unixfs

@@ -0,0 +1,2 @@
+Hello UnixFS
+

tests/test-data/symlink.txt

@@ -0,0 +1 @@
+file.txt