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Diffstat (limited to 'vendor/golang.org/x/tools/go/types/typeutil/map.go')
| -rw-r--r-- | vendor/golang.org/x/tools/go/types/typeutil/map.go | 313 |
1 files changed, 0 insertions, 313 deletions
diff --git a/vendor/golang.org/x/tools/go/types/typeutil/map.go b/vendor/golang.org/x/tools/go/types/typeutil/map.go deleted file mode 100644 index c7f7545..0000000 --- a/vendor/golang.org/x/tools/go/types/typeutil/map.go +++ /dev/null @@ -1,313 +0,0 @@ -// Copyright 2014 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 typeutil defines various utilities for types, such as Map, -// a mapping from types.Type to interface{} values. -package typeutil // import "golang.org/x/tools/go/types/typeutil" - -import ( - "bytes" - "fmt" - "go/types" - "reflect" -) - -// Map is a hash-table-based mapping from types (types.Type) to -// arbitrary interface{} values. The concrete types that implement -// the Type interface are pointers. Since they are not canonicalized, -// == cannot be used to check for equivalence, and thus we cannot -// simply use a Go map. -// -// Just as with map[K]V, a nil *Map is a valid empty map. -// -// Not thread-safe. -// -type Map struct { - hasher Hasher // shared by many Maps - table map[uint32][]entry // maps hash to bucket; entry.key==nil means unused - length int // number of map entries -} - -// entry is an entry (key/value association) in a hash bucket. -type entry struct { - key types.Type - value interface{} -} - -// SetHasher sets the hasher used by Map. -// -// All Hashers are functionally equivalent but contain internal state -// used to cache the results of hashing previously seen types. -// -// A single Hasher created by MakeHasher() may be shared among many -// Maps. This is recommended if the instances have many keys in -// common, as it will amortize the cost of hash computation. -// -// A Hasher may grow without bound as new types are seen. Even when a -// type is deleted from the map, the Hasher never shrinks, since other -// types in the map may reference the deleted type indirectly. -// -// Hashers are not thread-safe, and read-only operations such as -// Map.Lookup require updates to the hasher, so a full Mutex lock (not a -// read-lock) is require around all Map operations if a shared -// hasher is accessed from multiple threads. -// -// If SetHasher is not called, the Map will create a private hasher at -// the first call to Insert. -// -func (m *Map) SetHasher(hasher Hasher) { - m.hasher = hasher -} - -// Delete removes the entry with the given key, if any. -// It returns true if the entry was found. -// -func (m *Map) Delete(key types.Type) bool { - if m != nil && m.table != nil { - hash := m.hasher.Hash(key) - bucket := m.table[hash] - for i, e := range bucket { - if e.key != nil && types.Identical(key, e.key) { - // We can't compact the bucket as it - // would disturb iterators. - bucket[i] = entry{} - m.length-- - return true - } - } - } - return false -} - -// At returns the map entry for the given key. -// The result is nil if the entry is not present. -// -func (m *Map) At(key types.Type) interface{} { - if m != nil && m.table != nil { - for _, e := range m.table[m.hasher.Hash(key)] { - if e.key != nil && types.Identical(key, e.key) { - return e.value - } - } - } - return nil -} - -// Set sets the map entry for key to val, -// and returns the previous entry, if any. -func (m *Map) Set(key types.Type, value interface{}) (prev interface{}) { - if m.table != nil { - hash := m.hasher.Hash(key) - bucket := m.table[hash] - var hole *entry - for i, e := range bucket { - if e.key == nil { - hole = &bucket[i] - } else if types.Identical(key, e.key) { - prev = e.value - bucket[i].value = value - return - } - } - - if hole != nil { - *hole = entry{key, value} // overwrite deleted entry - } else { - m.table[hash] = append(bucket, entry{key, value}) - } - } else { - if m.hasher.memo == nil { - m.hasher = MakeHasher() - } - hash := m.hasher.Hash(key) - m.table = map[uint32][]entry{hash: {entry{key, value}}} - } - - m.length++ - return -} - -// Len returns the number of map entries. -func (m *Map) Len() int { - if m != nil { - return m.length - } - return 0 -} - -// Iterate calls function f on each entry in the map in unspecified order. -// -// If f should mutate the map, Iterate provides the same guarantees as -// Go maps: if f deletes a map entry that Iterate has not yet reached, -// f will not be invoked for it, but if f inserts a map entry that -// Iterate has not yet reached, whether or not f will be invoked for -// it is unspecified. -// -func (m *Map) Iterate(f func(key types.Type, value interface{})) { - if m != nil { - for _, bucket := range m.table { - for _, e := range bucket { - if e.key != nil { - f(e.key, e.value) - } - } - } - } -} - -// Keys returns a new slice containing the set of map keys. -// The order is unspecified. -func (m *Map) Keys() []types.Type { - keys := make([]types.Type, 0, m.Len()) - m.Iterate(func(key types.Type, _ interface{}) { - keys = append(keys, key) - }) - return keys -} - -func (m *Map) toString(values bool) string { - if m == nil { - return "{}" - } - var buf bytes.Buffer - fmt.Fprint(&buf, "{") - sep := "" - m.Iterate(func(key types.Type, value interface{}) { - fmt.Fprint(&buf, sep) - sep = ", " - fmt.Fprint(&buf, key) - if values { - fmt.Fprintf(&buf, ": %q", value) - } - }) - fmt.Fprint(&buf, "}") - return buf.String() -} - -// String returns a string representation of the map's entries. -// Values are printed using fmt.Sprintf("%v", v). -// Order is unspecified. -// -func (m *Map) String() string { - return m.toString(true) -} - -// KeysString returns a string representation of the map's key set. -// Order is unspecified. -// -func (m *Map) KeysString() string { - return m.toString(false) -} - -//////////////////////////////////////////////////////////////////////// -// Hasher - -// A Hasher maps each type to its hash value. -// For efficiency, a hasher uses memoization; thus its memory -// footprint grows monotonically over time. -// Hashers are not thread-safe. -// Hashers have reference semantics. -// Call MakeHasher to create a Hasher. -type Hasher struct { - memo map[types.Type]uint32 -} - -// MakeHasher returns a new Hasher instance. -func MakeHasher() Hasher { - return Hasher{make(map[types.Type]uint32)} -} - -// Hash computes a hash value for the given type t such that -// Identical(t, t') => Hash(t) == Hash(t'). -func (h Hasher) Hash(t types.Type) uint32 { - hash, ok := h.memo[t] - if !ok { - hash = h.hashFor(t) - h.memo[t] = hash - } - return hash -} - -// hashString computes the Fowler–Noll–Vo hash of s. -func hashString(s string) uint32 { - var h uint32 - for i := 0; i < len(s); i++ { - h ^= uint32(s[i]) - h *= 16777619 - } - return h -} - -// hashFor computes the hash of t. -func (h Hasher) hashFor(t types.Type) uint32 { - // See Identical for rationale. - switch t := t.(type) { - case *types.Basic: - return uint32(t.Kind()) - - case *types.Array: - return 9043 + 2*uint32(t.Len()) + 3*h.Hash(t.Elem()) - - case *types.Slice: - return 9049 + 2*h.Hash(t.Elem()) - - case *types.Struct: - var hash uint32 = 9059 - for i, n := 0, t.NumFields(); i < n; i++ { - f := t.Field(i) - if f.Anonymous() { - hash += 8861 - } - hash += hashString(t.Tag(i)) - hash += hashString(f.Name()) // (ignore f.Pkg) - hash += h.Hash(f.Type()) - } - return hash - - case *types.Pointer: - return 9067 + 2*h.Hash(t.Elem()) - - case *types.Signature: - var hash uint32 = 9091 - if t.Variadic() { - hash *= 8863 - } - return hash + 3*h.hashTuple(t.Params()) + 5*h.hashTuple(t.Results()) - - case *types.Interface: - var hash uint32 = 9103 - for i, n := 0, t.NumMethods(); i < n; i++ { - // See go/types.identicalMethods for rationale. - // Method order is not significant. - // Ignore m.Pkg(). - m := t.Method(i) - hash += 3*hashString(m.Name()) + 5*h.Hash(m.Type()) - } - return hash - - case *types.Map: - return 9109 + 2*h.Hash(t.Key()) + 3*h.Hash(t.Elem()) - - case *types.Chan: - return 9127 + 2*uint32(t.Dir()) + 3*h.Hash(t.Elem()) - - case *types.Named: - // Not safe with a copying GC; objects may move. - return uint32(reflect.ValueOf(t.Obj()).Pointer()) - - case *types.Tuple: - return h.hashTuple(t) - } - panic(t) -} - -func (h Hasher) hashTuple(tuple *types.Tuple) uint32 { - // See go/types.identicalTypes for rationale. - n := tuple.Len() - var hash uint32 = 9137 + 2*uint32(n) - for i := 0; i < n; i++ { - hash += 3 * h.Hash(tuple.At(i).Type()) - } - return hash -} |