Swarm-Hash

lib/swarm-hash.js

@@ -0,0 +1,31 @@
+// Thanks https://github.com/axic/swarmhash
+
+var keccak = require("eth-lib/lib/hash").keccak256;
+var Bytes = require("eth-lib/lib/bytes");
+
+var swarmHashBlock = function swarmHashBlock(length, data) {
+  return keccak(Bytes.flatten([Bytes.reverse(Bytes.pad(6, Bytes.fromNumber(length))), "0x0000", data]));
+};
+
+var swarmHash = function swarmHash(data) {
+  var length = Bytes.length(data);
+
+  if (length <= 4096) {
+    return swarmHashBlock(length, data);
+  }
+
+  var maxSize = 4096;
+  while (maxSize * (4096 / 32) < length) {
+    maxSize *= 4096 / 32;
+  }
+
+  var innerNodes = [];
+  for (var i = 0; i < length; i += maxSize) {
+    var size = maxSize < length - i ? maxSize : length - i;
+    innerNodes.push(swarmHash(Bytes.slice(data, i, i + size)));
+  }
+
+  return swarmHashBlock(length, Bytes.flatten(innerNodes));
+};
+
+module.exports = swarmHash;

lib/swarm.js

@@ -1,4 +1,5 @@
 var mimetype = require('mime-types');
+var hash = require("./swarm-hash.js");
 var pick = require("./pick.js");
 var request = require("xhr-request-promise");
 var downloadUrl = "http://ethereum-mist.s3.amazonaws.com/swarm/";
@@ -583,6 +584,7 @@ module.exports = function (_ref) {
     uploadDirectory: uploadDirectory,
     uploadDirectoryFromDisk: uploadDirectoryFromDisk,
     uploadToManifest: uploadToManifest,
-    pick: pick
+    pick: pick,
+    hash: hash
   };
 };

package.json

@@ -18,8 +18,10 @@
     "url": "https://github.com/maiavictor/swarm-js"
   },
   "dependencies": {
+    "bluebird": "^3.5.0",
     "buffer": "^5.0.5",
     "decompress": "^4.0.0",
+    "eth-lib": "^0.1.25",
     "fs-extra": "^2.1.2",
     "fs-promise": "^2.0.0",
     "got": "^7.1.0",

src/swarm-hash.js

@@ -0,0 +1,33 @@
+// Thanks https://github.com/axic/swarmhash
+
+const keccak = require("eth-lib/lib/hash").keccak256;
+const Bytes = require("eth-lib/lib/bytes");
+
+const swarmHashBlock = (length, data) =>
+  keccak(Bytes.flatten([
+    Bytes.reverse(Bytes.pad(6, Bytes.fromNumber(length))),
+    "0x0000",
+    data]));
+
+const swarmHash = (data) => {
+  const length = Bytes.length(data);
+
+  if (length <= 4096) {
+    return swarmHashBlock(length, data);
+  }
+
+  let maxSize = 4096;
+  while ((maxSize * (4096 / 32)) < length) {
+    maxSize *= (4096 / 32);
+  }
+
+  let innerNodes = [];
+  for (let i = 0; i < length; i += maxSize) {
+    const size = (maxSize < (length - i)) ? maxSize : (length - i);
+    innerNodes.push(swarmHash(Bytes.slice(data, i, i + size)));
+  }
+
+  return swarmHashBlock(length, Bytes.flatten(innerNodes));
+};
+
+module.exports = swarmHash;

src/swarm.js

@@ -1,4 +1,5 @@
 const mimetype = require('mime-types');
+const hash = require("./swarm-hash.js");
 const pick = require("./pick.js");
 const request = require("xhr-request-promise");
 const downloadUrl = "http://ethereum-mist.s3.amazonaws.com/swarm/";
@@ -438,7 +439,8 @@ module.exports = ({fsp, files, os, path, child_process}) => {
     uploadDirectory,
     uploadDirectoryFromDisk,
     uploadToManifest,
-    pick
+    pick,
+    hash
   };
 
 };