From 548090e67f66acf84385c4152ca464e52d3e3319 Mon Sep 17 00:00:00 2001 From: Thomas Voss Date: Fri, 13 Sep 2024 13:01:48 +0200 Subject: Migrate away from templ and towards html/template --- .../x/tools/internal/event/label/label.go | 215 +++++++++++++++++++++ 1 file changed, 215 insertions(+) create mode 100644 vendor/golang.org/x/tools/internal/event/label/label.go (limited to 'vendor/golang.org/x/tools/internal/event/label') diff --git a/vendor/golang.org/x/tools/internal/event/label/label.go b/vendor/golang.org/x/tools/internal/event/label/label.go new file mode 100644 index 0000000..0f526e1 --- /dev/null +++ b/vendor/golang.org/x/tools/internal/event/label/label.go @@ -0,0 +1,215 @@ +// Copyright 2019 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +package label + +import ( + "fmt" + "io" + "reflect" + "unsafe" +) + +// Key is used as the identity of a Label. +// Keys are intended to be compared by pointer only, the name should be unique +// for communicating with external systems, but it is not required or enforced. +type Key interface { + // Name returns the key name. + Name() string + // Description returns a string that can be used to describe the value. + Description() string + + // Format is used in formatting to append the value of the label to the + // supplied buffer. + // The formatter may use the supplied buf as a scratch area to avoid + // allocations. + Format(w io.Writer, buf []byte, l Label) +} + +// Label holds a key and value pair. +// It is normally used when passing around lists of labels. +type Label struct { + key Key + packed uint64 + untyped interface{} +} + +// Map is the interface to a collection of Labels indexed by key. +type Map interface { + // Find returns the label that matches the supplied key. + Find(key Key) Label +} + +// List is the interface to something that provides an iterable +// list of labels. +// Iteration should start from 0 and continue until Valid returns false. +type List interface { + // Valid returns true if the index is within range for the list. + // It does not imply the label at that index will itself be valid. + Valid(index int) bool + // Label returns the label at the given index. + Label(index int) Label +} + +// list implements LabelList for a list of Labels. +type list struct { + labels []Label +} + +// filter wraps a LabelList filtering out specific labels. +type filter struct { + keys []Key + underlying List +} + +// listMap implements LabelMap for a simple list of labels. +type listMap struct { + labels []Label +} + +// mapChain implements LabelMap for a list of underlying LabelMap. +type mapChain struct { + maps []Map +} + +// OfValue creates a new label from the key and value. +// This method is for implementing new key types, label creation should +// normally be done with the Of method of the key. +func OfValue(k Key, value interface{}) Label { return Label{key: k, untyped: value} } + +// UnpackValue assumes the label was built using LabelOfValue and returns the value +// that was passed to that constructor. +// This method is for implementing new key types, for type safety normal +// access should be done with the From method of the key. +func (t Label) UnpackValue() interface{} { return t.untyped } + +// Of64 creates a new label from a key and a uint64. This is often +// used for non uint64 values that can be packed into a uint64. +// This method is for implementing new key types, label creation should +// normally be done with the Of method of the key. +func Of64(k Key, v uint64) Label { return Label{key: k, packed: v} } + +// Unpack64 assumes the label was built using LabelOf64 and returns the value that +// was passed to that constructor. +// This method is for implementing new key types, for type safety normal +// access should be done with the From method of the key. +func (t Label) Unpack64() uint64 { return t.packed } + +type stringptr unsafe.Pointer + +// OfString creates a new label from a key and a string. +// This method is for implementing new key types, label creation should +// normally be done with the Of method of the key. +func OfString(k Key, v string) Label { + hdr := (*reflect.StringHeader)(unsafe.Pointer(&v)) + return Label{ + key: k, + packed: uint64(hdr.Len), + untyped: stringptr(hdr.Data), + } +} + +// UnpackString assumes the label was built using LabelOfString and returns the +// value that was passed to that constructor. +// This method is for implementing new key types, for type safety normal +// access should be done with the From method of the key. +func (t Label) UnpackString() string { + var v string + hdr := (*reflect.StringHeader)(unsafe.Pointer(&v)) + hdr.Data = uintptr(t.untyped.(stringptr)) + hdr.Len = int(t.packed) + return v +} + +// Valid returns true if the Label is a valid one (it has a key). +func (t Label) Valid() bool { return t.key != nil } + +// Key returns the key of this Label. +func (t Label) Key() Key { return t.key } + +// Format is used for debug printing of labels. +func (t Label) Format(f fmt.State, r rune) { + if !t.Valid() { + io.WriteString(f, `nil`) + return + } + io.WriteString(f, t.Key().Name()) + io.WriteString(f, "=") + var buf [128]byte + t.Key().Format(f, buf[:0], t) +} + +func (l *list) Valid(index int) bool { + return index >= 0 && index < len(l.labels) +} + +func (l *list) Label(index int) Label { + return l.labels[index] +} + +func (f *filter) Valid(index int) bool { + return f.underlying.Valid(index) +} + +func (f *filter) Label(index int) Label { + l := f.underlying.Label(index) + for _, f := range f.keys { + if l.Key() == f { + return Label{} + } + } + return l +} + +func (lm listMap) Find(key Key) Label { + for _, l := range lm.labels { + if l.Key() == key { + return l + } + } + return Label{} +} + +func (c mapChain) Find(key Key) Label { + for _, src := range c.maps { + l := src.Find(key) + if l.Valid() { + return l + } + } + return Label{} +} + +var emptyList = &list{} + +func NewList(labels ...Label) List { + if len(labels) == 0 { + return emptyList + } + return &list{labels: labels} +} + +func Filter(l List, keys ...Key) List { + if len(keys) == 0 { + return l + } + return &filter{keys: keys, underlying: l} +} + +func NewMap(labels ...Label) Map { + return listMap{labels: labels} +} + +func MergeMaps(srcs ...Map) Map { + var nonNil []Map + for _, src := range srcs { + if src != nil { + nonNil = append(nonNil, src) + } + } + if len(nonNil) == 1 { + return nonNil[0] + } + return mapChain{maps: nonNil} +} -- cgit v1.2.3