From dc9f5bd0cedbec322691f76fddc4c93a7cb24fa0 Mon Sep 17 00:00:00 2001
From: Eng Zer Jun <engzerjun@gmail.com>
Date: Fri, 15 Nov 2024 01:21:01 +0800
Subject: [PATCH] Remove unmaintained
 `github.com/golang-collections/collections` dependency

The `github.com/golang-collections/collections` module has not been
updated in since July 2013. As we are only using its stack package, we
can adapt the required code directly and remove this dependency.

Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>
---
 felix/idalloc/index_allocator.go | 43 +++++++++++++++++++++++++++-----
 go.mod                           |  1 -
 go.sum                           |  2 --
 3 files changed, 37 insertions(+), 9 deletions(-)

diff --git a/felix/idalloc/index_allocator.go b/felix/idalloc/index_allocator.go
index 56e494226cf..d5ecb14b9cf 100644
--- a/felix/idalloc/index_allocator.go
+++ b/felix/idalloc/index_allocator.go
@@ -18,8 +18,6 @@ import (
 	"errors"
 	"sort"
 
-	"github.com/golang-collections/collections/stack"
-
 	"github.com/projectcalico/calico/libcalico-go/lib/set"
 )
 
@@ -45,7 +43,7 @@ func (i ByMaxIndex) Less(a, b int) bool { return i[a].Max < i[b].Max }
 func (i ByMaxIndex) Swap(a, b int) { i[a], i[b] = i[b], i[a] }
 
 type IndexAllocator struct {
-	indexStack *stack.Stack
+	indexStack *stack
 	exclusions []IndexRange
 }
 
@@ -58,7 +56,7 @@ func NewIndexAllocator(indexRanges []IndexRange, exclusions []IndexRange) *Index
 	}
 
 	r := &IndexAllocator{
-		indexStack: stack.New(),
+		indexStack: &stack{},
 		exclusions: exclusions,
 	}
 
@@ -91,10 +89,10 @@ func NewIndexAllocator(indexRanges []IndexRange, exclusions []IndexRange) *Index
 }
 
 func (r *IndexAllocator) GrabIndex() (int, error) {
-	if r.indexStack.Len() == 0 {
+	if r.indexStack.IsEmpty() {
 		return 0, errors.New("no more indices available")
 	}
-	return r.indexStack.Pop().(int), nil
+	return r.indexStack.Pop(), nil
 }
 
 func (r *IndexAllocator) ReleaseIndex(index int) {
@@ -113,3 +111,36 @@ func (r *IndexAllocator) GrabBlock(len int) (set.Set[int], error) {
 	}
 	return indices, nil
 }
+
+type (
+	// stack is an implementation of the stack data structure.
+	// Adapted from https://github.com/golang-collections/collections/blob/604e922904d35e97f98a774db7881f049cd8d970/stack/stack.go.
+	stack struct {
+		top *node
+	}
+	node struct {
+		value int
+		prev  *node
+	}
+)
+
+// IsEmpty returns true if the stack is empty.
+func (s *stack) IsEmpty() bool {
+	return s.top == nil
+}
+
+// Pop the top item of the stack and return it
+func (s *stack) Pop() int {
+	if s.IsEmpty() {
+		return 0
+	}
+
+	n := s.top
+	s.top = n.prev
+	return n.value
+}
+
+// Push a value onto the top of the stack
+func (s *stack) Push(value int) {
+	s.top = &node{value, s.top}
+}
diff --git a/go.mod b/go.mod
index 02d22f61d41..d71fc844c6f 100644
--- a/go.mod
+++ b/go.mod
@@ -28,7 +28,6 @@ require (
 	github.com/gofrs/flock v0.8.1
 	github.com/gogo/googleapis v1.4.1
 	github.com/gogo/protobuf v1.3.2
-	github.com/golang-collections/collections v0.0.0-20130729185459-604e922904d3
 	github.com/golang/protobuf v1.5.4
 	github.com/golang/snappy v0.0.4
 	github.com/google/btree v1.1.2
diff --git a/go.sum b/go.sum
index 499cea42d59..0eaebd1476e 100644
--- a/go.sum
+++ b/go.sum
@@ -286,8 +286,6 @@ github.com/gogo/googleapis v1.4.1 h1:1Yx4Myt7BxzvUr5ldGSbwYiZG6t9wGBZ+8/fX3Wvtq0
 github.com/gogo/googleapis v1.4.1/go.mod h1:2lpHqI5OcWCtVElxXnPt+s8oJvMpySlOyM6xDCrzib4=
 github.com/gogo/protobuf v1.3.2 h1:Ov1cvc58UF3b5XjBnZv7+opcTcQFZebYjWzi34vdm4Q=
 github.com/gogo/protobuf v1.3.2/go.mod h1:P1XiOD3dCwIKUDQYPy72D8LYyHL2YPYrpS2s69NZV8Q=
-github.com/golang-collections/collections v0.0.0-20130729185459-604e922904d3 h1:zN2lZNZRflqFyxVaTIU61KNKQ9C0055u9CAfpmqUvo4=
-github.com/golang-collections/collections v0.0.0-20130729185459-604e922904d3/go.mod h1:nPpo7qLxd6XL3hWJG/O60sR8ZKfMCiIoNap5GvD12KU=
 github.com/golang-jwt/jwt/v4 v4.5.0 h1:7cYmW1XlMY7h7ii7UhUyChSgS5wUJEnm9uZVTGqOWzg=
 github.com/golang-jwt/jwt/v4 v4.5.0/go.mod h1:m21LjoU+eqJr34lmDMbreY2eSTRJ1cv77w39/MY0Ch0=
 github.com/golang/glog v0.0.0-20160126235308-23def4e6c14b/go.mod h1:SBH7ygxi8pfUlaOkMMuAQtPIUF8ecWP5IEl/CR7VP2Q=