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authorNick Khyl <nickk@tailscale.com>2024-12-05 13:16:48 -0600
committerNick Khyl <nickk@tailscale.com>2024-12-05 13:16:48 -0600
commit0267fe83b200f1702a2fa0a395442c02a053fadb (patch)
tree63654c55225eeb834de59a5a0bc8d19033c6145b /util/deephash/pointer.go
parent87546a5edf6b6503a87eeb2d666baba57398a066 (diff)
downloadtailscale-1.78.0.tar.xz
tailscale-1.78.0.zip
VERSION.txt: this is v1.78.0v1.78.0
Signed-off-by: Nick Khyl <nickk@tailscale.com>
Diffstat (limited to 'util/deephash/pointer.go')
-rw-r--r--util/deephash/pointer.go228
1 files changed, 114 insertions, 114 deletions
diff --git a/util/deephash/pointer.go b/util/deephash/pointer.go
index aafae47a2..71b11d7ff 100644
--- a/util/deephash/pointer.go
+++ b/util/deephash/pointer.go
@@ -1,114 +1,114 @@
-// Copyright (c) Tailscale Inc & AUTHORS
-// SPDX-License-Identifier: BSD-3-Clause
-
-package deephash
-
-import (
- "net/netip"
- "reflect"
- "time"
- "unsafe"
-)
-
-// unsafePointer is an untyped pointer.
-// It is the caller's responsibility to call operations on the correct type.
-//
-// This pointer only ever points to a small set of kinds or types:
-// time.Time, netip.Addr, string, array, slice, struct, map, pointer, interface,
-// or a pointer to memory that is directly hashable.
-//
-// Arrays are represented as pointers to the first element.
-// Structs are represented as pointers to the first field.
-// Slices are represented as pointers to a slice header.
-// Pointers are represented as pointers to a pointer.
-//
-// We do not support direct operations on maps and interfaces, and instead
-// rely on pointer.asValue to convert the pointer back to a reflect.Value.
-// Conversion of an unsafe.Pointer to reflect.Value guarantees that the
-// read-only flag in the reflect.Value is unpopulated, avoiding panics that may
-// otherwise have occurred since the value was obtained from an unexported field.
-type unsafePointer struct{ p unsafe.Pointer }
-
-func unsafePointerOf(v reflect.Value) unsafePointer {
- return unsafePointer{v.UnsafePointer()}
-}
-func (p unsafePointer) isNil() bool {
- return p.p == nil
-}
-
-// pointerElem dereferences a pointer.
-// p must point to a pointer.
-func (p unsafePointer) pointerElem() unsafePointer {
- return unsafePointer{*(*unsafe.Pointer)(p.p)}
-}
-
-// sliceLen returns the slice length.
-// p must point to a slice.
-func (p unsafePointer) sliceLen() int {
- return (*reflect.SliceHeader)(p.p).Len
-}
-
-// sliceArray returns a pointer to the underlying slice array.
-// p must point to a slice.
-func (p unsafePointer) sliceArray() unsafePointer {
- return unsafePointer{unsafe.Pointer((*reflect.SliceHeader)(p.p).Data)}
-}
-
-// arrayIndex returns a pointer to an element in the array.
-// p must point to an array.
-func (p unsafePointer) arrayIndex(index int, size uintptr) unsafePointer {
- return unsafePointer{unsafe.Add(p.p, uintptr(index)*size)}
-}
-
-// structField returns a pointer to a field in a struct.
-// p must pointer to a struct.
-func (p unsafePointer) structField(index int, offset, size uintptr) unsafePointer {
- return unsafePointer{unsafe.Add(p.p, offset)}
-}
-
-// asString casts p as a *string.
-func (p unsafePointer) asString() *string {
- return (*string)(p.p)
-}
-
-// asTime casts p as a *time.Time.
-func (p unsafePointer) asTime() *time.Time {
- return (*time.Time)(p.p)
-}
-
-// asAddr casts p as a *netip.Addr.
-func (p unsafePointer) asAddr() *netip.Addr {
- return (*netip.Addr)(p.p)
-}
-
-// asValue casts p as a reflect.Value containing a pointer to value of t.
-func (p unsafePointer) asValue(typ reflect.Type) reflect.Value {
- return reflect.NewAt(typ, p.p)
-}
-
-// asMemory returns the memory pointer at by p for a specified size.
-func (p unsafePointer) asMemory(size uintptr) []byte {
- return unsafe.Slice((*byte)(p.p), size)
-}
-
-// visitStack is a stack of pointers visited.
-// Pointers are pushed onto the stack when visited, and popped when leaving.
-// The integer value is the depth at which the pointer was visited.
-// The length of this stack should be zero after every hashing operation.
-type visitStack map[unsafe.Pointer]int
-
-func (v visitStack) seen(p unsafe.Pointer) (int, bool) {
- idx, ok := v[p]
- return idx, ok
-}
-
-func (v *visitStack) push(p unsafe.Pointer) {
- if *v == nil {
- *v = make(map[unsafe.Pointer]int)
- }
- (*v)[p] = len(*v)
-}
-
-func (v visitStack) pop(p unsafe.Pointer) {
- delete(v, p)
-}
+// Copyright (c) Tailscale Inc & AUTHORS
+// SPDX-License-Identifier: BSD-3-Clause
+
+package deephash
+
+import (
+ "net/netip"
+ "reflect"
+ "time"
+ "unsafe"
+)
+
+// unsafePointer is an untyped pointer.
+// It is the caller's responsibility to call operations on the correct type.
+//
+// This pointer only ever points to a small set of kinds or types:
+// time.Time, netip.Addr, string, array, slice, struct, map, pointer, interface,
+// or a pointer to memory that is directly hashable.
+//
+// Arrays are represented as pointers to the first element.
+// Structs are represented as pointers to the first field.
+// Slices are represented as pointers to a slice header.
+// Pointers are represented as pointers to a pointer.
+//
+// We do not support direct operations on maps and interfaces, and instead
+// rely on pointer.asValue to convert the pointer back to a reflect.Value.
+// Conversion of an unsafe.Pointer to reflect.Value guarantees that the
+// read-only flag in the reflect.Value is unpopulated, avoiding panics that may
+// otherwise have occurred since the value was obtained from an unexported field.
+type unsafePointer struct{ p unsafe.Pointer }
+
+func unsafePointerOf(v reflect.Value) unsafePointer {
+ return unsafePointer{v.UnsafePointer()}
+}
+func (p unsafePointer) isNil() bool {
+ return p.p == nil
+}
+
+// pointerElem dereferences a pointer.
+// p must point to a pointer.
+func (p unsafePointer) pointerElem() unsafePointer {
+ return unsafePointer{*(*unsafe.Pointer)(p.p)}
+}
+
+// sliceLen returns the slice length.
+// p must point to a slice.
+func (p unsafePointer) sliceLen() int {
+ return (*reflect.SliceHeader)(p.p).Len
+}
+
+// sliceArray returns a pointer to the underlying slice array.
+// p must point to a slice.
+func (p unsafePointer) sliceArray() unsafePointer {
+ return unsafePointer{unsafe.Pointer((*reflect.SliceHeader)(p.p).Data)}
+}
+
+// arrayIndex returns a pointer to an element in the array.
+// p must point to an array.
+func (p unsafePointer) arrayIndex(index int, size uintptr) unsafePointer {
+ return unsafePointer{unsafe.Add(p.p, uintptr(index)*size)}
+}
+
+// structField returns a pointer to a field in a struct.
+// p must pointer to a struct.
+func (p unsafePointer) structField(index int, offset, size uintptr) unsafePointer {
+ return unsafePointer{unsafe.Add(p.p, offset)}
+}
+
+// asString casts p as a *string.
+func (p unsafePointer) asString() *string {
+ return (*string)(p.p)
+}
+
+// asTime casts p as a *time.Time.
+func (p unsafePointer) asTime() *time.Time {
+ return (*time.Time)(p.p)
+}
+
+// asAddr casts p as a *netip.Addr.
+func (p unsafePointer) asAddr() *netip.Addr {
+ return (*netip.Addr)(p.p)
+}
+
+// asValue casts p as a reflect.Value containing a pointer to value of t.
+func (p unsafePointer) asValue(typ reflect.Type) reflect.Value {
+ return reflect.NewAt(typ, p.p)
+}
+
+// asMemory returns the memory pointer at by p for a specified size.
+func (p unsafePointer) asMemory(size uintptr) []byte {
+ return unsafe.Slice((*byte)(p.p), size)
+}
+
+// visitStack is a stack of pointers visited.
+// Pointers are pushed onto the stack when visited, and popped when leaving.
+// The integer value is the depth at which the pointer was visited.
+// The length of this stack should be zero after every hashing operation.
+type visitStack map[unsafe.Pointer]int
+
+func (v visitStack) seen(p unsafe.Pointer) (int, bool) {
+ idx, ok := v[p]
+ return idx, ok
+}
+
+func (v *visitStack) push(p unsafe.Pointer) {
+ if *v == nil {
+ *v = make(map[unsafe.Pointer]int)
+ }
+ (*v)[p] = len(*v)
+}
+
+func (v visitStack) pop(p unsafe.Pointer) {
+ delete(v, p)
+}