Move hashmap into base/.

src/base/hashmap.cc

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// This file is ported from src/hashmap.h
-
-#ifndef V8_LIBSAMPLER_HASHMAP_H_
-#define V8_LIBSAMPLER_HASHMAP_H_
-
-#include "src/base/bits.h"
-#include "src/base/logging.h"
-#include "src/libsampler/utils.h"
+#include "src/base/hashmap.h"
 
 namespace v8 {
-namespace sampler {
-
-class HashMapImpl {
- public:
-  typedef bool (*MatchFun) (void* key1, void* key2);
-
-  // The default capacity.
-  static const uint32_t kDefaultHashMapCapacity = 8;
-
-  // initial_capacity is the size of the initial hash map;
-  // it must be a power of 2 (and thus must not be 0).
-  HashMapImpl(MatchFun match,
-              uint32_t capacity = kDefaultHashMapCapacity);
-
-  ~HashMapImpl();
-
-  // HashMap entries are (key, value, hash) triplets.
-  // Some clients may not need to use the value slot
-  // (e.g. implementers of sets, where the key is the value).
-  struct Entry {
-    void* key;
-    void* value;
-    uint32_t hash;  // The full hash value for key
-    int order;  // If you never remove entries this is the insertion order.
-  };
-
-  // If an entry with matching key is found, returns that entry.
-  // Otherwise, NULL is returned.
-  Entry* Lookup(void* key, uint32_t hash) const;
-
-  // If an entry with matching key is found, returns that entry.
-  // If no matching entry is found, a new entry is inserted with
-  // corresponding key, key hash, and NULL value.
-  Entry* LookupOrInsert(void* key, uint32_t hash);
-
-  // Removes the entry with matching key.
-  // It returns the value of the deleted entry
-  // or null if there is no value for such key.
-  void* Remove(void* key, uint32_t hash);
-
-  // Empties the hash map (occupancy() == 0).
-  void Clear();
-
-  // The number of (non-empty) entries in the table.
-  uint32_t occupancy() const { return occupancy_; }
-
-  // The capacity of the table. The implementation
-  // makes sure that occupancy is at most 80% of
-  // the table capacity.
-  uint32_t capacity() const { return capacity_; }
-
-  // Iteration
-  //
-  // for (Entry* p = map.Start(); p != NULL; p = map.Next(p)) {
-  //   ...
-  // }
-  //
-  // If entries are inserted during iteration, the effect of
-  // calling Next() is undefined.
-  Entry* Start() const;
-  Entry* Next(Entry* p) const;
-
-  // Some match functions defined for convenience.
-  static bool PointersMatch(void* key1, void* key2) {
-    return key1 == key2;
-  }
-
- private:
-  MatchFun match_;
-  Entry* map_;
-  uint32_t capacity_;
-  uint32_t occupancy_;
-
-  Entry* map_end() const { return map_ + capacity_; }
-  Entry* Probe(void* key, uint32_t hash) const;
-  void Initialize(uint32_t capacity);
-  void Resize();
-};
-
-typedef HashMapImpl HashMap;
-
-HashMapImpl::HashMapImpl(MatchFun match, uint32_t initial_capacity) {
-  match_ = match;
-  Initialize(initial_capacity);
-}
-
-
-HashMapImpl::~HashMapImpl() {
-  Malloced::Delete(map_);
-}
-
+namespace base {
 
 HashMapImpl::Entry* HashMapImpl::Lookup(void* key, uint32_t hash) const {
   Entry* p = Probe(key, hash);
   return p->key != NULL ? p : NULL;
 }
 
-
-HashMapImpl::Entry* HashMapImpl::LookupOrInsert(void* key, uint32_t hash) {
-  // Find a matching entry.
-  Entry* p = Probe(key, hash);
-  if (p->key != NULL) {
-    return p;
-  }
-
-  // No entry found; insert one.
-  p->key = key;
-  p->value = NULL;
-  p->hash = hash;
-  p->order = occupancy_;
-  occupancy_++;
-
-  // Grow the map if we reached >= 80% occupancy.
-  if (occupancy_ + occupancy_ / 4 >= capacity_) {
-    Resize();
-    p = Probe(key, hash);
-  }
-
-  return p;
-}
-
-
 void* HashMapImpl::Remove(void* key, uint32_t hash) {
   // Lookup the entry for the key to remove.
   Entry* p = Probe(key, hash);
   if (p->key == NULL) {
     // Key not found nothing to remove.
     return NULL;
   }
 
   void* value = p->value;
   // To remove an entry we need to ensure that it does not create an empty
@@ skipping 27 matching lines @@
     if (q->key == NULL) {
       break;
     }
 
     // Find the initial position for the entry at position q.
     Entry* r = map_ + (q->hash & (capacity_ - 1));
 
     // If the entry at position q has its initial position outside the range
     // between p and q it can be moved forward to position p and will still be
     // found. There is now a new candidate entry for clearing.
-    if ((q > p && (r <= p || r > q)) ||
-        (q < p && (r <= p && r > q))) {
+    if ((q > p && (r <= p || r > q)) || (q < p && (r <= p && r > q))) {
       *p = *q;
       p = q;
     }
   }
 
   // Clear the entry which is allowed to en emptied.
   p->key = NULL;
   occupancy_--;
   return value;
 }
 
-
 void HashMapImpl::Clear() {
   // Mark all entries as empty.
   const Entry* end = map_end();
   for (Entry* p = map_; p < end; p++) {
     p->key = NULL;
   }
   occupancy_ = 0;
 }
 
-
-HashMapImpl::Entry* HashMapImpl::Start() const {
-  return Next(map_ - 1);
-}
-
+HashMapImpl::Entry* HashMapImpl::Start() const { return Next(map_ - 1); }
 
 HashMapImpl::Entry* HashMapImpl::Next(Entry* p) const {
   const Entry* end = map_end();
   DCHECK(map_ - 1 <= p && p < end);
   for (p++; p < end; p++) {
     if (p->key != NULL) {
       return p;
     }
   }
   return NULL;
 }
 
-
 HashMapImpl::Entry* HashMapImpl::Probe(void* key, uint32_t hash) const {
   DCHECK(key != NULL);
 
   DCHECK(base::bits::IsPowerOfTwo32(capacity_));
   Entry* p = map_ + (hash & (capacity_ - 1));
   const Entry* end = map_end();
   DCHECK(map_ <= p && p < end);
 
   DCHECK(occupancy_ < capacity_);  // Guarantees loop termination.
   while (p->key != NULL && (hash != p->hash || !match_(key, p->key))) {
     p++;
     if (p >= end) {
       p = map_;
     }
   }
 
   return p;
 }
 
+HashMapImpl::Entry* HashMapImpl::LookupOrInsert(void* key, uint32_t hash) {

[Yang, 2016/05/30 09:19:04]

This is still very similar to
TemplateHashMapImpl<AllocationPolicy>::LookupOrInsert aside from the
AllocationPolicy.

Can we define a default allocation policy in src/base that uses malloc and free,
to get rid of the mostly duplicate code in
TemplateHashMapImpl<AllocationPolicy>::LookupOrInsert?

+  // Find a matching entry.
+  Entry* p = Probe(key, hash);
+  if (p->key != NULL) {
+    return p;
+  }
 
-void HashMapImpl::Initialize(uint32_t capacity) {
-  DCHECK(base::bits::IsPowerOfTwo32(capacity));
-  map_ = reinterpret_cast<Entry*>(Malloced::New(capacity * sizeof(Entry)));
-  CHECK(map_ != NULL);
-  capacity_ = capacity;
-  Clear();
+  // No entry found; insert one.
+  p->key = key;
+  p->value = NULL;
+  p->hash = hash;
+  p->order = occupancy_;
+  occupancy_++;
+
+  // Grow the map if we reached >= 80% occupancy.
+  if (occupancy_ + occupancy_ / 4 >= capacity_) {
+    Resize();
+    p = Probe(key, hash);
+  }
+
+  return p;
 }
 
+HashMap::HashMap(MatchFun match, uint32_t initial_capacity) : HashMapImpl() {
+  match_ = match;
+  Initialize(initial_capacity);
+}
 
-void HashMapImpl::Resize() {
+HashMap::~HashMap() { free(map_); }
+
+void HashMap::Resize() {
   Entry* map = map_;
   uint32_t n = occupancy_;
 
   // Allocate larger map.
   Initialize(capacity_ * 2);
 
   // Rehash all current entries.
   for (Entry* p = map; n > 0; p++) {
     if (p->key != NULL) {
       Entry* entry = LookupOrInsert(p->key, p->hash);
       entry->value = p->value;
       entry->order = p->order;
       n--;
     }
   }
 
   // Delete old map.
-  Malloced::Delete(map);
+  free(map);
 }
 
-}  // namespace sampler
+void HashMap::Initialize(uint32_t capacity) {
+  DCHECK(base::bits::IsPowerOfTwo32(capacity));
+  map_ = reinterpret_cast<Entry*>(malloc(capacity * sizeof(Entry)));
+  if (map_ == NULL) {
+    FATAL("HashMapImpl::Initialize");
+    return;
+  }
+  capacity_ = capacity;
+  Clear();
+}
+
+}  // namespace base
 }  // namespace v8
-
-#endif  // V8_LIBSAMPLER_HASHMAP_H_