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author | Matthew Heon <matthew.heon@gmail.com> | 2017-11-01 11:24:59 -0400 |
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committer | Matthew Heon <matthew.heon@gmail.com> | 2017-11-01 11:24:59 -0400 |
commit | a031b83a09a8628435317a03f199cdc18b78262f (patch) | |
tree | bc017a96769ce6de33745b8b0b1304ccf38e9df0 /vendor/github.com/ghodss/yaml/fields.go | |
parent | 2b74391cd5281f6fdf391ff8ad50fd1490f6bf89 (diff) | |
download | podman-a031b83a09a8628435317a03f199cdc18b78262f.tar.gz podman-a031b83a09a8628435317a03f199cdc18b78262f.tar.bz2 podman-a031b83a09a8628435317a03f199cdc18b78262f.zip |
Initial checkin from CRI-O repo
Signed-off-by: Matthew Heon <matthew.heon@gmail.com>
Diffstat (limited to 'vendor/github.com/ghodss/yaml/fields.go')
-rw-r--r-- | vendor/github.com/ghodss/yaml/fields.go | 501 |
1 files changed, 501 insertions, 0 deletions
diff --git a/vendor/github.com/ghodss/yaml/fields.go b/vendor/github.com/ghodss/yaml/fields.go new file mode 100644 index 000000000..586007402 --- /dev/null +++ b/vendor/github.com/ghodss/yaml/fields.go @@ -0,0 +1,501 @@ +// Copyright 2013 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 yaml + +import ( + "bytes" + "encoding" + "encoding/json" + "reflect" + "sort" + "strings" + "sync" + "unicode" + "unicode/utf8" +) + +// indirect walks down v allocating pointers as needed, +// until it gets to a non-pointer. +// if it encounters an Unmarshaler, indirect stops and returns that. +// if decodingNull is true, indirect stops at the last pointer so it can be set to nil. +func indirect(v reflect.Value, decodingNull bool) (json.Unmarshaler, encoding.TextUnmarshaler, reflect.Value) { + // If v is a named type and is addressable, + // start with its address, so that if the type has pointer methods, + // we find them. + if v.Kind() != reflect.Ptr && v.Type().Name() != "" && v.CanAddr() { + v = v.Addr() + } + for { + // Load value from interface, but only if the result will be + // usefully addressable. + if v.Kind() == reflect.Interface && !v.IsNil() { + e := v.Elem() + if e.Kind() == reflect.Ptr && !e.IsNil() && (!decodingNull || e.Elem().Kind() == reflect.Ptr) { + v = e + continue + } + } + + if v.Kind() != reflect.Ptr { + break + } + + if v.Elem().Kind() != reflect.Ptr && decodingNull && v.CanSet() { + break + } + if v.IsNil() { + if v.CanSet() { + v.Set(reflect.New(v.Type().Elem())) + } else { + v = reflect.New(v.Type().Elem()) + } + } + if v.Type().NumMethod() > 0 { + if u, ok := v.Interface().(json.Unmarshaler); ok { + return u, nil, reflect.Value{} + } + if u, ok := v.Interface().(encoding.TextUnmarshaler); ok { + return nil, u, reflect.Value{} + } + } + v = v.Elem() + } + return nil, nil, v +} + +// A field represents a single field found in a struct. +type field struct { + name string + nameBytes []byte // []byte(name) + equalFold func(s, t []byte) bool // bytes.EqualFold or equivalent + + tag bool + index []int + typ reflect.Type + omitEmpty bool + quoted bool +} + +func fillField(f field) field { + f.nameBytes = []byte(f.name) + f.equalFold = foldFunc(f.nameBytes) + return f +} + +// byName sorts field by name, breaking ties with depth, +// then breaking ties with "name came from json tag", then +// breaking ties with index sequence. +type byName []field + +func (x byName) Len() int { return len(x) } + +func (x byName) Swap(i, j int) { x[i], x[j] = x[j], x[i] } + +func (x byName) Less(i, j int) bool { + if x[i].name != x[j].name { + return x[i].name < x[j].name + } + if len(x[i].index) != len(x[j].index) { + return len(x[i].index) < len(x[j].index) + } + if x[i].tag != x[j].tag { + return x[i].tag + } + return byIndex(x).Less(i, j) +} + +// byIndex sorts field by index sequence. +type byIndex []field + +func (x byIndex) Len() int { return len(x) } + +func (x byIndex) Swap(i, j int) { x[i], x[j] = x[j], x[i] } + +func (x byIndex) Less(i, j int) bool { + for k, xik := range x[i].index { + if k >= len(x[j].index) { + return false + } + if xik != x[j].index[k] { + return xik < x[j].index[k] + } + } + return len(x[i].index) < len(x[j].index) +} + +// typeFields returns a list of fields that JSON should recognize for the given type. +// The algorithm is breadth-first search over the set of structs to include - the top struct +// and then any reachable anonymous structs. +func typeFields(t reflect.Type) []field { + // Anonymous fields to explore at the current level and the next. + current := []field{} + next := []field{{typ: t}} + + // Count of queued names for current level and the next. + count := map[reflect.Type]int{} + nextCount := map[reflect.Type]int{} + + // Types already visited at an earlier level. + visited := map[reflect.Type]bool{} + + // Fields found. + var fields []field + + for len(next) > 0 { + current, next = next, current[:0] + count, nextCount = nextCount, map[reflect.Type]int{} + + for _, f := range current { + if visited[f.typ] { + continue + } + visited[f.typ] = true + + // Scan f.typ for fields to include. + for i := 0; i < f.typ.NumField(); i++ { + sf := f.typ.Field(i) + if sf.PkgPath != "" { // unexported + continue + } + tag := sf.Tag.Get("json") + if tag == "-" { + continue + } + name, opts := parseTag(tag) + if !isValidTag(name) { + name = "" + } + index := make([]int, len(f.index)+1) + copy(index, f.index) + index[len(f.index)] = i + + ft := sf.Type + if ft.Name() == "" && ft.Kind() == reflect.Ptr { + // Follow pointer. + ft = ft.Elem() + } + + // Record found field and index sequence. + if name != "" || !sf.Anonymous || ft.Kind() != reflect.Struct { + tagged := name != "" + if name == "" { + name = sf.Name + } + fields = append(fields, fillField(field{ + name: name, + tag: tagged, + index: index, + typ: ft, + omitEmpty: opts.Contains("omitempty"), + quoted: opts.Contains("string"), + })) + if count[f.typ] > 1 { + // If there were multiple instances, add a second, + // so that the annihilation code will see a duplicate. + // It only cares about the distinction between 1 or 2, + // so don't bother generating any more copies. + fields = append(fields, fields[len(fields)-1]) + } + continue + } + + // Record new anonymous struct to explore in next round. + nextCount[ft]++ + if nextCount[ft] == 1 { + next = append(next, fillField(field{name: ft.Name(), index: index, typ: ft})) + } + } + } + } + + sort.Sort(byName(fields)) + + // Delete all fields that are hidden by the Go rules for embedded fields, + // except that fields with JSON tags are promoted. + + // The fields are sorted in primary order of name, secondary order + // of field index length. Loop over names; for each name, delete + // hidden fields by choosing the one dominant field that survives. + out := fields[:0] + for advance, i := 0, 0; i < len(fields); i += advance { + // One iteration per name. + // Find the sequence of fields with the name of this first field. + fi := fields[i] + name := fi.name + for advance = 1; i+advance < len(fields); advance++ { + fj := fields[i+advance] + if fj.name != name { + break + } + } + if advance == 1 { // Only one field with this name + out = append(out, fi) + continue + } + dominant, ok := dominantField(fields[i : i+advance]) + if ok { + out = append(out, dominant) + } + } + + fields = out + sort.Sort(byIndex(fields)) + + return fields +} + +// dominantField looks through the fields, all of which are known to +// have the same name, to find the single field that dominates the +// others using Go's embedding rules, modified by the presence of +// JSON tags. If there are multiple top-level fields, the boolean +// will be false: This condition is an error in Go and we skip all +// the fields. +func dominantField(fields []field) (field, bool) { + // The fields are sorted in increasing index-length order. The winner + // must therefore be one with the shortest index length. Drop all + // longer entries, which is easy: just truncate the slice. + length := len(fields[0].index) + tagged := -1 // Index of first tagged field. + for i, f := range fields { + if len(f.index) > length { + fields = fields[:i] + break + } + if f.tag { + if tagged >= 0 { + // Multiple tagged fields at the same level: conflict. + // Return no field. + return field{}, false + } + tagged = i + } + } + if tagged >= 0 { + return fields[tagged], true + } + // All remaining fields have the same length. If there's more than one, + // we have a conflict (two fields named "X" at the same level) and we + // return no field. + if len(fields) > 1 { + return field{}, false + } + return fields[0], true +} + +var fieldCache struct { + sync.RWMutex + m map[reflect.Type][]field +} + +// cachedTypeFields is like typeFields but uses a cache to avoid repeated work. +func cachedTypeFields(t reflect.Type) []field { + fieldCache.RLock() + f := fieldCache.m[t] + fieldCache.RUnlock() + if f != nil { + return f + } + + // Compute fields without lock. + // Might duplicate effort but won't hold other computations back. + f = typeFields(t) + if f == nil { + f = []field{} + } + + fieldCache.Lock() + if fieldCache.m == nil { + fieldCache.m = map[reflect.Type][]field{} + } + fieldCache.m[t] = f + fieldCache.Unlock() + return f +} + +func isValidTag(s string) bool { + if s == "" { + return false + } + for _, c := range s { + switch { + case strings.ContainsRune("!#$%&()*+-./:<=>?@[]^_{|}~ ", c): + // Backslash and quote chars are reserved, but + // otherwise any punctuation chars are allowed + // in a tag name. + default: + if !unicode.IsLetter(c) && !unicode.IsDigit(c) { + return false + } + } + } + return true +} + +const ( + caseMask = ^byte(0x20) // Mask to ignore case in ASCII. + kelvin = '\u212a' + smallLongEss = '\u017f' +) + +// foldFunc returns one of four different case folding equivalence +// functions, from most general (and slow) to fastest: +// +// 1) bytes.EqualFold, if the key s contains any non-ASCII UTF-8 +// 2) equalFoldRight, if s contains special folding ASCII ('k', 'K', 's', 'S') +// 3) asciiEqualFold, no special, but includes non-letters (including _) +// 4) simpleLetterEqualFold, no specials, no non-letters. +// +// The letters S and K are special because they map to 3 runes, not just 2: +// * S maps to s and to U+017F 'ſ' Latin small letter long s +// * k maps to K and to U+212A 'K' Kelvin sign +// See http://play.golang.org/p/tTxjOc0OGo +// +// The returned function is specialized for matching against s and +// should only be given s. It's not curried for performance reasons. +func foldFunc(s []byte) func(s, t []byte) bool { + nonLetter := false + special := false // special letter + for _, b := range s { + if b >= utf8.RuneSelf { + return bytes.EqualFold + } + upper := b & caseMask + if upper < 'A' || upper > 'Z' { + nonLetter = true + } else if upper == 'K' || upper == 'S' { + // See above for why these letters are special. + special = true + } + } + if special { + return equalFoldRight + } + if nonLetter { + return asciiEqualFold + } + return simpleLetterEqualFold +} + +// equalFoldRight is a specialization of bytes.EqualFold when s is +// known to be all ASCII (including punctuation), but contains an 's', +// 'S', 'k', or 'K', requiring a Unicode fold on the bytes in t. +// See comments on foldFunc. +func equalFoldRight(s, t []byte) bool { + for _, sb := range s { + if len(t) == 0 { + return false + } + tb := t[0] + if tb < utf8.RuneSelf { + if sb != tb { + sbUpper := sb & caseMask + if 'A' <= sbUpper && sbUpper <= 'Z' { + if sbUpper != tb&caseMask { + return false + } + } else { + return false + } + } + t = t[1:] + continue + } + // sb is ASCII and t is not. t must be either kelvin + // sign or long s; sb must be s, S, k, or K. + tr, size := utf8.DecodeRune(t) + switch sb { + case 's', 'S': + if tr != smallLongEss { + return false + } + case 'k', 'K': + if tr != kelvin { + return false + } + default: + return false + } + t = t[size:] + + } + if len(t) > 0 { + return false + } + return true +} + +// asciiEqualFold is a specialization of bytes.EqualFold for use when +// s is all ASCII (but may contain non-letters) and contains no +// special-folding letters. +// See comments on foldFunc. +func asciiEqualFold(s, t []byte) bool { + if len(s) != len(t) { + return false + } + for i, sb := range s { + tb := t[i] + if sb == tb { + continue + } + if ('a' <= sb && sb <= 'z') || ('A' <= sb && sb <= 'Z') { + if sb&caseMask != tb&caseMask { + return false + } + } else { + return false + } + } + return true +} + +// simpleLetterEqualFold is a specialization of bytes.EqualFold for +// use when s is all ASCII letters (no underscores, etc) and also +// doesn't contain 'k', 'K', 's', or 'S'. +// See comments on foldFunc. +func simpleLetterEqualFold(s, t []byte) bool { + if len(s) != len(t) { + return false + } + for i, b := range s { + if b&caseMask != t[i]&caseMask { + return false + } + } + return true +} + +// tagOptions is the string following a comma in a struct field's "json" +// tag, or the empty string. It does not include the leading comma. +type tagOptions string + +// parseTag splits a struct field's json tag into its name and +// comma-separated options. +func parseTag(tag string) (string, tagOptions) { + if idx := strings.Index(tag, ","); idx != -1 { + return tag[:idx], tagOptions(tag[idx+1:]) + } + return tag, tagOptions("") +} + +// Contains reports whether a comma-separated list of options +// contains a particular substr flag. substr must be surrounded by a +// string boundary or commas. +func (o tagOptions) Contains(optionName string) bool { + if len(o) == 0 { + return false + } + s := string(o) + for s != "" { + var next string + i := strings.Index(s, ",") + if i >= 0 { + s, next = s[:i], s[i+1:] + } + if s == optionName { + return true + } + s = next + } + return false +} |