| Index: src/core/SkTHash.h
|
| diff --git a/src/core/SkTHash.h b/src/core/SkTHash.h
|
| deleted file mode 100644
|
| index ffcdea5329f8e0286539a24839740ac707e6ddd8..0000000000000000000000000000000000000000
|
| --- a/src/core/SkTHash.h
|
| +++ /dev/null
|
| @@ -1,292 +0,0 @@
|
| -/*
|
| - * Copyright 2015 Google Inc.
|
| - *
|
| - * Use of this source code is governed by a BSD-style license that can be
|
| - * found in the LICENSE file.
|
| - */
|
| -
|
| -#ifndef SkTHash_DEFINED
|
| -#define SkTHash_DEFINED
|
| -
|
| -#include "SkChecksum.h"
|
| -#include "SkTypes.h"
|
| -#include "SkTemplates.h"
|
| -
|
| -// Before trying to use SkTHashTable, look below to see if SkTHashMap or SkTHashSet works for you.
|
| -// They're easier to use, usually perform the same, and have fewer sharp edges.
|
| -
|
| -// T and K are treated as ordinary copyable C++ types.
|
| -// Traits must have:
|
| -// - static K GetKey(T)
|
| -// - static uint32_t Hash(K)
|
| -// If the key is large and stored inside T, you may want to make K a const&.
|
| -// Similarly, if T is large you might want it to be a pointer.
|
| -template <typename T, typename K, typename Traits = T>
|
| -class SkTHashTable : SkNoncopyable {
|
| -public:
|
| - SkTHashTable() : fCount(0), fRemoved(0), fCapacity(0) {}
|
| -
|
| - // Clear the table.
|
| - void reset() {
|
| - this->~SkTHashTable();
|
| - SkNEW_PLACEMENT(this, SkTHashTable);
|
| - }
|
| -
|
| - // How many entries are in the table?
|
| - int count() const { return fCount; }
|
| -
|
| - // !!!!!!!!!!!!!!!!! CAUTION !!!!!!!!!!!!!!!!!
|
| - // set(), find() and foreach() all allow mutable access to table entries.
|
| - // If you change an entry so that it no longer has the same key, all hell
|
| - // will break loose. Do not do that!
|
| - //
|
| - // Please prefer to use SkTHashMap or SkTHashSet, which do not have this danger.
|
| -
|
| - // The pointers returned by set() and find() are valid only until the next call to set().
|
| - // The pointers you receive in foreach() are only valid for its duration.
|
| -
|
| - // Copy val into the hash table, returning a pointer to the copy now in the table.
|
| - // If there already is an entry in the table with the same key, we overwrite it.
|
| - T* set(const T& val) {
|
| - if (4 * (fCount+fRemoved) >= 3 * fCapacity) {
|
| - this->resize(fCapacity > 0 ? fCapacity * 2 : 4);
|
| - }
|
| - return this->uncheckedSet(val);
|
| - }
|
| -
|
| - // If there is an entry in the table with this key, return a pointer to it. If not, NULL.
|
| - T* find(const K& key) const {
|
| - uint32_t hash = Hash(key);
|
| - int index = hash & (fCapacity-1);
|
| - for (int n = 0; n < fCapacity; n++) {
|
| - Slot& s = fSlots[index];
|
| - if (s.empty()) {
|
| - return NULL;
|
| - }
|
| - if (!s.removed() && hash == s.hash && key == Traits::GetKey(s.val)) {
|
| - return &s.val;
|
| - }
|
| - index = this->next(index, n);
|
| - }
|
| - SkASSERT(fCapacity == 0);
|
| - return NULL;
|
| - }
|
| -
|
| - // Remove the value with this key from the hash table.
|
| - void remove(const K& key) {
|
| - SkASSERT(this->find(key));
|
| -
|
| - uint32_t hash = Hash(key);
|
| - int index = hash & (fCapacity-1);
|
| - for (int n = 0; n < fCapacity; n++) {
|
| - Slot& s = fSlots[index];
|
| - SkASSERT(!s.empty());
|
| - if (!s.removed() && hash == s.hash && key == Traits::GetKey(s.val)) {
|
| - fRemoved++;
|
| - fCount--;
|
| - s.markRemoved();
|
| - return;
|
| - }
|
| - index = this->next(index, n);
|
| - }
|
| - SkASSERT(fCapacity == 0);
|
| - }
|
| -
|
| - // Call fn on every entry in the table. You may mutate the entries, but be very careful.
|
| - template <typename Fn> // f(T*)
|
| - void foreach(Fn&& fn) {
|
| - for (int i = 0; i < fCapacity; i++) {
|
| - if (!fSlots[i].empty() && !fSlots[i].removed()) {
|
| - fn(&fSlots[i].val);
|
| - }
|
| - }
|
| - }
|
| -
|
| - // Call fn on every entry in the table. You may not mutate anything.
|
| - template <typename Fn> // f(T) or f(const T&)
|
| - void foreach(Fn&& fn) const {
|
| - for (int i = 0; i < fCapacity; i++) {
|
| - if (!fSlots[i].empty() && !fSlots[i].removed()) {
|
| - fn(fSlots[i].val);
|
| - }
|
| - }
|
| - }
|
| -
|
| -private:
|
| - T* uncheckedSet(const T& val) {
|
| - const K& key = Traits::GetKey(val);
|
| - uint32_t hash = Hash(key);
|
| - int index = hash & (fCapacity-1);
|
| - for (int n = 0; n < fCapacity; n++) {
|
| - Slot& s = fSlots[index];
|
| - if (s.empty() || s.removed()) {
|
| - // New entry.
|
| - if (s.removed()) {
|
| - fRemoved--;
|
| - }
|
| - s.val = val;
|
| - s.hash = hash;
|
| - fCount++;
|
| - return &s.val;
|
| - }
|
| - if (hash == s.hash && key == Traits::GetKey(s.val)) {
|
| - // Overwrite previous entry.
|
| - // Note: this triggers extra copies when adding the same value repeatedly.
|
| - s.val = val;
|
| - return &s.val;
|
| - }
|
| - index = this->next(index, n);
|
| - }
|
| - SkASSERT(false);
|
| - return NULL;
|
| - }
|
| -
|
| - void resize(int capacity) {
|
| - int oldCapacity = fCapacity;
|
| - SkDEBUGCODE(int oldCount = fCount);
|
| -
|
| - fCount = fRemoved = 0;
|
| - fCapacity = capacity;
|
| - SkAutoTArray<Slot> oldSlots(capacity);
|
| - oldSlots.swap(fSlots);
|
| -
|
| - for (int i = 0; i < oldCapacity; i++) {
|
| - const Slot& s = oldSlots[i];
|
| - if (!s.empty() && !s.removed()) {
|
| - this->uncheckedSet(s.val);
|
| - }
|
| - }
|
| - SkASSERT(fCount == oldCount);
|
| - }
|
| -
|
| - int next(int index, int n) const {
|
| - // A valid strategy explores all slots in [0, fCapacity) as n walks from 0 to fCapacity-1.
|
| - // Both of these strategies are valid:
|
| - //return (index + 0 + 1) & (fCapacity-1); // Linear probing.
|
| - return (index + n + 1) & (fCapacity-1); // Quadratic probing.
|
| - }
|
| -
|
| - static uint32_t Hash(const K& key) {
|
| - uint32_t hash = Traits::Hash(key);
|
| - return hash < 2 ? hash+2 : hash; // We reserve hash 0 and 1 to mark empty or removed slots.
|
| - }
|
| -
|
| - struct Slot {
|
| - Slot() : hash(0) {}
|
| - bool empty() const { return this->hash == 0; }
|
| - bool removed() const { return this->hash == 1; }
|
| -
|
| - void markRemoved() { this->hash = 1; }
|
| -
|
| - T val;
|
| - uint32_t hash;
|
| - };
|
| -
|
| - int fCount, fRemoved, fCapacity;
|
| - SkAutoTArray<Slot> fSlots;
|
| -};
|
| -
|
| -// Maps K->V. A more user-friendly wrapper around SkTHashTable, suitable for most use cases.
|
| -// K and V are treated as ordinary copyable C++ types, with no assumed relationship between the two.
|
| -template <typename K, typename V, uint32_t(*HashK)(const K&) = &SkGoodHash>
|
| -class SkTHashMap : SkNoncopyable {
|
| -public:
|
| - SkTHashMap() {}
|
| -
|
| - // Clear the map.
|
| - void reset() { fTable.reset(); }
|
| -
|
| - // How many key/value pairs are in the table?
|
| - int count() const { return fTable.count(); }
|
| -
|
| - // N.B. The pointers returned by set() and find() are valid only until the next call to set().
|
| -
|
| - // Set key to val in the table, replacing any previous value with the same key.
|
| - // We copy both key and val, and return a pointer to the value copy now in the table.
|
| - V* set(const K& key, const V& val) {
|
| - Pair in = { key, val };
|
| - Pair* out = fTable.set(in);
|
| - return &out->val;
|
| - }
|
| -
|
| - // If there is key/value entry in the table with this key, return a pointer to the value.
|
| - // If not, return NULL.
|
| - V* find(const K& key) const {
|
| - if (Pair* p = fTable.find(key)) {
|
| - return &p->val;
|
| - }
|
| - return NULL;
|
| - }
|
| -
|
| - // Remove the key/value entry in the table with this key.
|
| - void remove(const K& key) {
|
| - SkASSERT(this->find(key));
|
| - fTable.remove(key);
|
| - }
|
| -
|
| - // Call fn on every key/value pair in the table. You may mutate the value but not the key.
|
| - template <typename Fn> // f(K, V*) or f(const K&, V*)
|
| - void foreach(Fn&& fn) {
|
| - fTable.foreach([&fn](Pair* p){ fn(p->key, &p->val); });
|
| - }
|
| -
|
| - // Call fn on every key/value pair in the table. You may not mutate anything.
|
| - template <typename Fn> // f(K, V), f(const K&, V), f(K, const V&) or f(const K&, const V&).
|
| - void foreach(Fn&& fn) const {
|
| - fTable.foreach([&fn](const Pair& p){ fn(p.key, p.val); });
|
| - }
|
| -
|
| -private:
|
| - struct Pair {
|
| - K key;
|
| - V val;
|
| - static const K& GetKey(const Pair& p) { return p.key; }
|
| - static uint32_t Hash(const K& key) { return HashK(key); }
|
| - };
|
| -
|
| - SkTHashTable<Pair, K> fTable;
|
| -};
|
| -
|
| -// A set of T. T is treated as an ordiary copyable C++ type.
|
| -template <typename T, uint32_t(*HashT)(const T&) = &SkGoodHash>
|
| -class SkTHashSet : SkNoncopyable {
|
| -public:
|
| - SkTHashSet() {}
|
| -
|
| - // Clear the set.
|
| - void reset() { fTable.reset(); }
|
| -
|
| - // How many items are in the set?
|
| - int count() const { return fTable.count(); }
|
| -
|
| - // Copy an item into the set.
|
| - void add(const T& item) { fTable.set(item); }
|
| -
|
| - // Is this item in the set?
|
| - bool contains(const T& item) const { return SkToBool(this->find(item)); }
|
| -
|
| - // If an item equal to this is in the set, return a pointer to it, otherwise null.
|
| - // This pointer remains valid until the next call to add().
|
| - const T* find(const T& item) const { return fTable.find(item); }
|
| -
|
| - // Remove the item in the set equal to this.
|
| - void remove(const T& item) {
|
| - SkASSERT(this->contains(item));
|
| - fTable.remove(item);
|
| - }
|
| -
|
| - // Call fn on every item in the set. You may not mutate anything.
|
| - template <typename Fn> // f(T), f(const T&)
|
| - void foreach (Fn&& fn) const {
|
| - fTable.foreach(fn);
|
| - }
|
| -
|
| -private:
|
| - struct Traits {
|
| - static const T& GetKey(const T& item) { return item; }
|
| - static uint32_t Hash(const T& item) { return HashT(item); }
|
| - };
|
| - SkTHashTable<T, T, Traits> fTable;
|
| -};
|
| -
|
| -#endif//SkTHash_DEFINED
|
|
|