From 8590bd6de76c7bda0a8489f2ba64f0d25b6f6d4a Mon Sep 17 00:00:00 2001
From: Michael Hohn <hohn@github.com>
Date: Wed, 14 May 2025 10:38:17 -0700
Subject: [PATCH] tuple hashing functions across languages

---
 experimental/qldb-specification/readme.org    | 22 +++++++++++++++
 experimental/qldb-specification/tuple-hash.go | 28 +++++++++++++++++++
 experimental/qldb-specification/tuple-hash.js |  9 ++++++
 experimental/qldb-specification/tuple-hash.py | 12 ++++++++
 4 files changed, 71 insertions(+)
 create mode 100644 experimental/qldb-specification/readme.org
 create mode 100644 experimental/qldb-specification/tuple-hash.go
 create mode 100644 experimental/qldb-specification/tuple-hash.js
 create mode 100644 experimental/qldb-specification/tuple-hash.py

diff --git a/experimental/qldb-specification/readme.org b/experimental/qldb-specification/readme.org
new file mode 100644
index 0000000..5975400
--- /dev/null
+++ b/experimental/qldb-specification/readme.org
@@ -0,0 +1,22 @@
+* tuple hashing functions across languages
+  There are three parallel implementations of a hash for every entry of a tuple
+  list.  The functions produce identical results across 3 languages and can be
+  used across agent / server / client.
+
+  #+BEGIN_SRC sh 
+    hohn@ghm3 ~/work-gh/mrva/mrvacommander/experimental/qldb-specification
+    0:$ node tuple-hash.js
+    [
+      '91b80a9933218ff5bc62df8ff71f1252',
+      'b0934b29293e91aefaac73c99fc75e94'
+    ]
+
+    hohn@ghm3 ~/work-gh/mrva/mrvacommander/experimental/qldb-specification
+    0:$ python3 tuple-hash.py
+    ['91b80a9933218ff5bc62df8ff71f1252', 'b0934b29293e91aefaac73c99fc75e94']
+
+    hohn@ghm3 ~/work-gh/mrva/mrvacommander/experimental/qldb-specification
+    0:$ go run tuple-hash.go
+    [91b80a9933218ff5bc62df8ff71f1252 b0934b29293e91aefaac73c99fc75e94]
+  #+END_SRC
+
diff --git a/experimental/qldb-specification/tuple-hash.go b/experimental/qldb-specification/tuple-hash.go
new file mode 100644
index 0000000..1e0f745
--- /dev/null
+++ b/experimental/qldb-specification/tuple-hash.go
@@ -0,0 +1,28 @@
+package main
+
+import (
+	"crypto/md5"
+	"encoding/hex"
+	"encoding/json"
+	"fmt"
+)
+
+func main() {
+	atl_L := [][2]interface{}{
+		{1, "s1"},
+		{2, "str"},
+	}
+
+	var sl_hash []string
+
+	for _, item := range atl_L {
+		jsonBytes, err := json.Marshal(item)
+		if err != nil {
+			panic(err)
+		}
+		sum := md5.Sum(jsonBytes)
+		sl_hash = append(sl_hash, hex.EncodeToString(sum[:]))
+	}
+
+	fmt.Println(sl_hash)
+}
diff --git a/experimental/qldb-specification/tuple-hash.js b/experimental/qldb-specification/tuple-hash.js
new file mode 100644
index 0000000..c2c2b91
--- /dev/null
+++ b/experimental/qldb-specification/tuple-hash.js
@@ -0,0 +1,9 @@
+const crypto = require("crypto");
+
+const atl_L = [[1, "s1"], [2, "str"]];
+const sl_hash = atl_L.map(item => {
+    const json = JSON.stringify(item);
+    return crypto.createHash("md5").update(json).digest("hex");
+});
+
+console.log(sl_hash);
diff --git a/experimental/qldb-specification/tuple-hash.py b/experimental/qldb-specification/tuple-hash.py
new file mode 100644
index 0000000..c8a5782
--- /dev/null
+++ b/experimental/qldb-specification/tuple-hash.py
@@ -0,0 +1,12 @@
+import hashlib
+import json
+
+atl_L = [(1, "s1"), (2, "str")]
+sl_hash = []
+
+for item in atl_L:
+    encoded = json.dumps(item, separators=(',', ':')).encode("utf-8")
+    md5sum = hashlib.md5(encoded).hexdigest()
+    sl_hash.append(md5sum)
+
+print(sl_hash)