From 4368b140035b79bf7930ef2095f008839ca131ed Mon Sep 17 00:00:00 2001
From: aadi <aadi@stripe.com>
Date: Tue, 3 Sep 2024 19:52:02 +0000
Subject: [PATCH] Add murmur3 to hash module

---
 build/go_dependencies.bzl        |  6 ++++++
 go.mod                           |  1 +
 go.sum                           |  2 ++
 go/hashmodule/BUILD              |  1 +
 go/hashmodule/hashmodule.go      | 35 ++++++++++++++++++++++++--------
 go/hashmodule/hashmodule_test.go |  5 +++++
 6 files changed, 42 insertions(+), 8 deletions(-)

diff --git a/build/go_dependencies.bzl b/build/go_dependencies.bzl
index a913171..65f4e53 100644
--- a/build/go_dependencies.bzl
+++ b/build/go_dependencies.bzl
@@ -25,6 +25,12 @@ def go_dependencies():
         sum = "h1:AV2c/EiW3KqPNT9ZKl07ehoAGi4C5/01Cfbblndcapg=",
         version = "v1.0.0",
     )
+    go_repository(
+        name = "com_github_spaolacci_murmur3",
+        importpath = "github.com/spaolacci/murmur3",
+        sum = "h1:7c1g84S4BPRrfL5Xrdp6fOJ206sU9y293DDHaoy0bLI=",
+        version = "v1.1.0",
+    )
     go_repository(
         name = "in_gopkg_check_v1",
         importpath = "gopkg.in/check.v1",
diff --git a/go.mod b/go.mod
index 42b2809..b6e5807 100644
--- a/go.mod
+++ b/go.mod
@@ -3,6 +3,7 @@ module github.com/stripe/skycfg
 go 1.16
 
 require (
+	github.com/spaolacci/murmur3 v1.1.0 // indirect
 	go.starlark.net v0.0.0-20201204201740-42d4f566359b
 	google.golang.org/protobuf v1.25.0
 	gopkg.in/yaml.v2 v2.2.1
diff --git a/go.sum b/go.sum
index de905d7..d941099 100644
--- a/go.sum
+++ b/go.sum
@@ -24,6 +24,8 @@ github.com/google/go-cmp v0.4.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/
 github.com/google/go-cmp v0.5.0 h1:/QaMHBdZ26BB3SSst0Iwl10Epc+xhTquomWX0oZEB6w=
 github.com/google/go-cmp v0.5.0/go.mod h1:v8dTdLbMG2kIc/vJvl+f65V22dbkXbowE6jgT/gNBxE=
 github.com/prometheus/client_model v0.0.0-20190812154241-14fe0d1b01d4/go.mod h1:xMI15A0UPsDsEKsMN9yxemIoYk6Tm2C1GtYGdfGttqA=
+github.com/spaolacci/murmur3 v1.1.0 h1:7c1g84S4BPRrfL5Xrdp6fOJ206sU9y293DDHaoy0bLI=
+github.com/spaolacci/murmur3 v1.1.0/go.mod h1:JwIasOWyU6f++ZhiEuf87xNszmSA2myDM2Kzu9HwQUA=
 go.starlark.net v0.0.0-20201204201740-42d4f566359b h1:yHUzJ1WfcdR1oOafytJ6K1/ntYwnEIXICNVzHb+FzbA=
 go.starlark.net v0.0.0-20201204201740-42d4f566359b/go.mod h1:5YFcFnRptTN+41758c2bMPiqpGg4zBfYji1IQz8wNFk=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
diff --git a/go/hashmodule/BUILD b/go/hashmodule/BUILD
index a9d22f3..a5ceb9b 100644
--- a/go/hashmodule/BUILD
+++ b/go/hashmodule/BUILD
@@ -6,6 +6,7 @@ go_library(
     importpath = "github.com/stripe/skycfg/go/hashmodule",
     visibility = ["//visibility:public"],
     deps = [
+        "@com_github_spaolacci_murmur3//:go_default_library",
         "@net_starlark_go//starlark",
         "@net_starlark_go//starlarkstruct",
     ],
diff --git a/go/hashmodule/hashmodule.go b/go/hashmodule/hashmodule.go
index 98ec404..db4c379 100644
--- a/go/hashmodule/hashmodule.go
+++ b/go/hashmodule/hashmodule.go
@@ -24,26 +24,32 @@ import (
 	"fmt"
 	"hash"
 
+	"github.com/spaolacci/murmur3"
+
 	"go.starlark.net/starlark"
 	"go.starlark.net/starlarkstruct"
 )
 
 // NewModule returns a Starlark module of common hash functions.
 //
-//  hash = module(
-//    md5,
-//    sha1,
-//    sha256,
-//  )
+// hash = module(
+//
+//	  md5,
+//		sha1,
+//		sha256,
+//		murmur3,
+//
+// )
 //
 // See `docs/modules.asciidoc` for details on the API of each function.
 func NewModule() *starlarkstruct.Module {
 	return &starlarkstruct.Module{
 		Name: "hash",
 		Members: starlark.StringDict{
-			"md5":    starlark.NewBuiltin("hash.md5", fnHash(md5.New)),
-			"sha1":   starlark.NewBuiltin("hash.sha1", fnHash(sha1.New)),
-			"sha256": starlark.NewBuiltin("hash.sha256", fnHash(sha256.New)),
+			"md5":     starlark.NewBuiltin("hash.md5", fnHash(md5.New)),
+			"sha1":    starlark.NewBuiltin("hash.sha1", fnHash(sha1.New)),
+			"sha256":  starlark.NewBuiltin("hash.sha256", fnHash(sha256.New)),
+			"murmur3": starlark.NewBuiltin("hash.murmur3", fnHash64(murmur3.New64)),
 		},
 	}
 }
@@ -60,3 +66,16 @@ func fnHash(hash func() hash.Hash) func(*starlark.Thread, *starlark.Builtin, sta
 		return starlark.String(fmt.Sprintf("%x", h.Sum(nil))), nil
 	}
 }
+
+func fnHash64(hash func() hash.Hash64) func(*starlark.Thread, *starlark.Builtin, starlark.Tuple, []starlark.Tuple) (starlark.Value, error) {
+	return func(t *starlark.Thread, fn *starlark.Builtin, args starlark.Tuple, kwargs []starlark.Tuple) (starlark.Value, error) {
+		var s starlark.String
+		if err := starlark.UnpackPositionalArgs(fn.Name(), args, kwargs, 1, &s); err != nil {
+			return nil, err
+		}
+
+		h := hash()
+		h.Write([]byte(string(s)))
+		return starlark.String(fmt.Sprintf("%x", h.Sum(nil))), nil
+	}
+}
diff --git a/go/hashmodule/hashmodule_test.go b/go/hashmodule/hashmodule_test.go
index 3c9d14d..50bf7be 100644
--- a/go/hashmodule/hashmodule_test.go
+++ b/go/hashmodule/hashmodule_test.go
@@ -51,6 +51,11 @@ func TestHashes(t *testing.T) {
 			hashFunc:  "sha256",
 			expOutput: "a9c78816353b119a0ba2a1281675b147fd47abee11a8d41d5abb739dce8273b7",
 		},
+		hashTestCase{
+			input:     "test murmur3 string",
+			hashFunc:  "murmur3",
+			expOutput: "91dd87efc613eb2c",
+		},
 	}
 
 	for _, testCase := range testCases {