From ca19be4390a58aaddea96160b5db873dcf6a0c6c Mon Sep 17 00:00:00 2001
From: Matthias Kretschmann <m@kretschmann.io>
Date: Thu, 24 Sep 2020 16:34:42 +0200
Subject: [PATCH] test node-xz

---
 package-lock.json                    | 32 ++++++++++++++++------------
 package.json                         |  5 ++---
 src/metadatastore/OnChainMetaData.ts | 10 +++++----
 3 files changed, 26 insertions(+), 21 deletions(-)

diff --git a/package-lock.json b/package-lock.json
index db59350f..03af6841 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1458,12 +1458,6 @@
         "@types/node": "*"
       }
     },
-    "@types/lz-string": {
-      "version": "1.3.34",
-      "resolved": "https://registry.npmjs.org/@types/lz-string/-/lz-string-1.3.34.tgz",
-      "integrity": "sha512-j6G1e8DULJx3ONf6NdR5JiR2ZY3K3PaaqiEuKYkLQO0Czfi1AzrtjfnfCROyWGeDd5IVMKCwsgSmMip9OWijow==",
-      "dev": true
-    },
     "@types/mocha": {
       "version": "8.0.3",
       "resolved": "https://registry.npmjs.org/@types/mocha/-/mocha-8.0.3.tgz",
@@ -6643,11 +6637,6 @@
       "integrity": "sha512-zTU3DaZaF3Rt9rhN3uBMGQD3dD2/vFQqnvZCDv4dl5iOzq2IZQqTxu90r4E5J+nP70J3ilqVCrbho2eWaeW8Ow==",
       "dev": true
     },
-    "lz-string": {
-      "version": "1.4.4",
-      "resolved": "https://registry.npmjs.org/lz-string/-/lz-string-1.4.4.tgz",
-      "integrity": "sha1-wNjq82BZ9wV5bh40SBHPTEmNOiY="
-    },
     "macos-release": {
       "version": "2.4.1",
       "resolved": "https://registry.npmjs.org/macos-release/-/macos-release-2.4.1.tgz",
@@ -10341,9 +10330,9 @@
       },
       "dependencies": {
         "@types/node": {
-          "version": "12.12.59",
-          "resolved": "https://registry.npmjs.org/@types/node/-/node-12.12.59.tgz",
-          "integrity": "sha512-D2MISWfv2j17aFBAkMD3lQ97vYpXCkAJMJf0mx2eKHNkzXA6Vo9w7A7BWi9fH8sOH1zeFb7fIhOo22z0TtrSag=="
+          "version": "12.12.62",
+          "resolved": "https://registry.npmjs.org/@types/node/-/node-12.12.62.tgz",
+          "integrity": "sha512-qAfo81CsD7yQIM9mVyh6B/U47li5g7cfpVQEDMfQeF8pSZVwzbhwU3crc0qG4DmpsebpJPR49AKOExQyJ05Cpg=="
         }
       }
     },
@@ -11884,6 +11873,21 @@
       "resolved": "https://registry.npmjs.org/xtend/-/xtend-4.0.2.tgz",
       "integrity": "sha512-LKYU1iAXJXUgAXn9URjiu+MWhyUXHsvfp7mcuYm9dSUKK0/CjtrUwFAxD82/mCWbtLsGjFIad0wIsod4zrTAEQ=="
     },
+    "xz": {
+      "version": "2.0.2",
+      "resolved": "https://registry.npmjs.org/xz/-/xz-2.0.2.tgz",
+      "integrity": "sha512-K0rWxVLh2yRuvM0alMiwzxkkygUZcrJ8pNZ0JT0yTGoZ0FyqwHnY6Mbt7BcATP9abMVeCpiEqmear2ixHZSaLQ==",
+      "requires": {
+        "node-addon-api": "^1.6.1"
+      },
+      "dependencies": {
+        "node-addon-api": {
+          "version": "1.7.2",
+          "resolved": "https://registry.npmjs.org/node-addon-api/-/node-addon-api-1.7.2.tgz",
+          "integrity": "sha512-ibPK3iA+vaY1eEjESkQkM0BbCqFOaZMiXRTtdB0u7b4djtY6JnsjvPdUHVMg6xQt3B8fpTTWHI9A+ADjM9frzg=="
+        }
+      }
+    },
     "y18n": {
       "version": "4.0.0",
       "resolved": "https://registry.npmjs.org/y18n/-/y18n-4.0.0.tgz",
diff --git a/package.json b/package.json
index c5e8878c..97b2c8f7 100644
--- a/package.json
+++ b/package.json
@@ -45,19 +45,18 @@
     "@oceanprotocol/contracts": "^0.4.4",
     "decimal.js": "^10.2.0",
     "fs": "0.0.1-security",
-    "lz-string": "^1.4.4",
     "node-fetch": "^2.6.1",
     "save-file": "^2.3.1",
     "uuid": "^8.3.0",
     "web3": "^1.3.0",
-    "web3-eth-contract": "^1.3.0"
+    "web3-eth-contract": "^1.3.0",
+    "xz": "^2.0.2"
   },
   "devDependencies": {
     "@release-it/bumper": "^2.0.0",
     "@truffle/hdwallet-provider": "^1.0.37",
     "@types/chai": "^4.2.11",
     "@types/chai-spies": "^1.0.1",
-    "@types/lz-string": "^1.3.34",
     "@types/mocha": "^8.0.3",
     "@types/node": "^14.6.4",
     "@types/node-fetch": "^2.5.5",
diff --git a/src/metadatastore/OnChainMetaData.ts b/src/metadatastore/OnChainMetaData.ts
index 57817cb8..6011dedf 100644
--- a/src/metadatastore/OnChainMetaData.ts
+++ b/src/metadatastore/OnChainMetaData.ts
@@ -5,7 +5,7 @@ import { AbiItem } from 'web3-utils/types'
 import Web3 from 'web3'
 import defaultDDOContractABI from '@oceanprotocol/contracts/artifacts/Metadata.json'
 import { didZeroX } from '../utils'
-import lz from 'lz-string'
+import { Compressor } from 'xz'
 
 /**
  * Provides an interface with Metadata Store.
@@ -35,12 +35,14 @@ export class OnChainMetadataStore {
   }
 
   /**
-   * Compress DDO using lz-string
+   * Compress DDO using xz/lzma2
    */
   public async compressDDO(ddo: DDO): Promise<string> {
     const data = DDO.serialize(ddo)
-    const compressed = lz.compress(data)
-    return this.getHex(compressed)
+    const buffer = Buffer.from(data)
+    const compression = new Compressor({ preset: 9 })
+    const compressed = await compression.updatePromise(buffer)
+    return this.getHex(compressed.toString())
   }
 
   /**