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[cleanup & objects.h splitting] Move StringHasher

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BUG=v8:6325,v8:5402

Change-Id: If0c975fe377c0178c488fc1bedd02f9c8289ebbc
Reviewed-on: https://chromium-review.googlesource.com/490086
Reviewed-by: Michael Starzinger <mstarzinger@chromium.org>
Commit-Queue: Marja Hölttä <marja@chromium.org>
Cr-Commit-Position: refs/heads/master@{#44979}
This commit is contained in:
Marja Hölttä 2017-04-28 14:13:10 +02:00 committed by Commit Bot
parent f05c09dd2e
commit 95a7cfe0ea
11 changed files with 247 additions and 218 deletions
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2
BUILD.gn
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@ -1890,6 +1890,8 @@ v8_source_set("v8_base") {
"src/string-builder.h",
"src/string-case.cc",
"src/string-case.h",
"src/string-hasher-inl.h",
"src/string-hasher.h",
"src/string-search.h",
"src/string-stream.cc",
"src/string-stream.h",

1
src/ast/ast-value-factory.cc
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@ -31,6 +31,7 @@
#include "src/char-predicates-inl.h"
#include "src/objects-inl.h"
#include "src/objects.h"
#include "src/string-hasher.h"
#include "src/utils.h"
namespace v8 {

1
src/factory.h
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@ -12,6 +12,7 @@
#include "src/objects/descriptor-array.h"
#include "src/objects/dictionary.h"
#include "src/objects/scope-info.h"
#include "src/string-hasher.h"
namespace v8 {
namespace internal {

1
src/heap/heap-inl.h
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@ -23,6 +23,7 @@
#include "src/msan.h"
#include "src/objects-inl.h"
#include "src/objects/scope-info.h"
#include "src/string-hasher.h"
namespace v8 {
namespace internal {

1
src/json-parser.cc
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@ -13,6 +13,7 @@
#include "src/objects-inl.h"
#include "src/parsing/token.h"
#include "src/property-descriptor.h"
#include "src/string-hasher.h"
#include "src/transitions.h"
#include "src/unicode-cache.h"

147
src/objects-inl.h
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@ -37,6 +37,7 @@
#include "src/objects/scope-info.h"
#include "src/property.h"
#include "src/prototype.h"
#include "src/string-hasher-inl.h"
#include "src/transitions-inl.h"
#include "src/v8memory.h"
@ -7281,152 +7282,6 @@ bool Name::IsPrivate() {
return this->IsSymbol() && Symbol::cast(this)->is_private();
}
StringHasher::StringHasher(int length, uint32_t seed)
: length_(length),
raw_running_hash_(seed),
array_index_(0),
is_array_index_(0 < length_ && length_ <= String::kMaxArrayIndexSize),
is_first_char_(true) {
DCHECK(FLAG_randomize_hashes || raw_running_hash_ == 0);
}
bool StringHasher::has_trivial_hash() {
return length_ > String::kMaxHashCalcLength;
}
uint32_t StringHasher::AddCharacterCore(uint32_t running_hash, uint16_t c) {
running_hash += c;
running_hash += (running_hash << 10);
running_hash ^= (running_hash >> 6);
return running_hash;
}
uint32_t StringHasher::GetHashCore(uint32_t running_hash) {
running_hash += (running_hash << 3);
running_hash ^= (running_hash >> 11);
running_hash += (running_hash << 15);
if ((running_hash & String::kHashBitMask) == 0) {
return kZeroHash;
}
return running_hash;
}
uint32_t StringHasher::ComputeRunningHash(uint32_t running_hash,
const uc16* chars, int length) {
DCHECK_NOT_NULL(chars);
DCHECK(length >= 0);
for (int i = 0; i < length; ++i) {
running_hash = AddCharacterCore(running_hash, *chars++);
}
return running_hash;
}
uint32_t StringHasher::ComputeRunningHashOneByte(uint32_t running_hash,
const char* chars,
int length) {
DCHECK_NOT_NULL(chars);
DCHECK(length >= 0);
for (int i = 0; i < length; ++i) {
uint16_t c = static_cast<uint16_t>(*chars++);
running_hash = AddCharacterCore(running_hash, c);
}
return running_hash;
}
void StringHasher::AddCharacter(uint16_t c) {
// Use the Jenkins one-at-a-time hash function to update the hash
// for the given character.
raw_running_hash_ = AddCharacterCore(raw_running_hash_, c);
}
bool StringHasher::UpdateIndex(uint16_t c) {
DCHECK(is_array_index_);
if (c < '0' || c > '9') {
is_array_index_ = false;
return false;
}
int d = c - '0';
if (is_first_char_) {
is_first_char_ = false;
if (c == '0' && length_ > 1) {
is_array_index_ = false;
return false;
}
}
if (array_index_ > 429496729U - ((d + 3) >> 3)) {
is_array_index_ = false;
return false;
}
array_index_ = array_index_ * 10 + d;
return true;
}
template<typename Char>
inline void StringHasher::AddCharacters(const Char* chars, int length) {
DCHECK(sizeof(Char) == 1 || sizeof(Char) == 2);
int i = 0;
if (is_array_index_) {
for (; i < length; i++) {
AddCharacter(chars[i]);
if (!UpdateIndex(chars[i])) {
i++;
break;
}
}
}
for (; i < length; i++) {
DCHECK(!is_array_index_);
AddCharacter(chars[i]);
}
}
template <typename schar>
uint32_t StringHasher::HashSequentialString(const schar* chars,
int length,
uint32_t seed) {
StringHasher hasher(length, seed);
if (!hasher.has_trivial_hash()) hasher.AddCharacters(chars, length);
return hasher.GetHashField();
}
IteratingStringHasher::IteratingStringHasher(int len, uint32_t seed)
: StringHasher(len, seed) {}
uint32_t IteratingStringHasher::Hash(String* string, uint32_t seed) {
IteratingStringHasher hasher(string->length(), seed);
// Nothing to do.
if (hasher.has_trivial_hash()) return hasher.GetHashField();
ConsString* cons_string = String::VisitFlat(&hasher, string);
if (cons_string == nullptr) return hasher.GetHashField();
hasher.VisitConsString(cons_string);
return hasher.GetHashField();
}
void IteratingStringHasher::VisitOneByteString(const uint8_t* chars,
int length) {
AddCharacters(chars, length);
}
void IteratingStringHasher::VisitTwoByteString(const uint16_t* chars,
int length) {
AddCharacters(chars, length);
}
bool Name::AsArrayIndex(uint32_t* index) {
return IsString() && String::cast(this)->AsArrayIndex(index);
}

72
src/objects.h
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@ -7776,78 +7776,6 @@ class AliasedArgumentsEntry: public Struct {
enum AllowNullsFlag {ALLOW_NULLS, DISALLOW_NULLS};
enum RobustnessFlag {ROBUST_STRING_TRAVERSAL, FAST_STRING_TRAVERSAL};
class V8_EXPORT_PRIVATE StringHasher {
public:
explicit inline StringHasher(int length, uint32_t seed);
template <typename schar>
static inline uint32_t HashSequentialString(const schar* chars,
int length,
uint32_t seed);
// Reads all the data, even for long strings and computes the utf16 length.
static uint32_t ComputeUtf8Hash(Vector<const char> chars,
uint32_t seed,
int* utf16_length_out);
// Calculated hash value for a string consisting of 1 to
// String::kMaxArrayIndexSize digits with no leading zeros (except "0").
// value is represented decimal value.
static uint32_t MakeArrayIndexHash(uint32_t value, int length);
// No string is allowed to have a hash of zero. That value is reserved
// for internal properties. If the hash calculation yields zero then we
// use 27 instead.
static const int kZeroHash = 27;
// Reusable parts of the hashing algorithm.
INLINE(static uint32_t AddCharacterCore(uint32_t running_hash, uint16_t c));
INLINE(static uint32_t GetHashCore(uint32_t running_hash));
INLINE(static uint32_t ComputeRunningHash(uint32_t running_hash,
const uc16* chars, int length));
INLINE(static uint32_t ComputeRunningHashOneByte(uint32_t running_hash,
const char* chars,
int length));
protected:
// Returns the value to store in the hash field of a string with
// the given length and contents.
uint32_t GetHashField();
// Returns true if the hash of this string can be computed without
// looking at the contents.
inline bool has_trivial_hash();
// Adds a block of characters to the hash.
template<typename Char>
inline void AddCharacters(const Char* chars, int len);
private:
// Add a character to the hash.
inline void AddCharacter(uint16_t c);
// Update index. Returns true if string is still an index.
inline bool UpdateIndex(uint16_t c);
int length_;
uint32_t raw_running_hash_;
uint32_t array_index_;
bool is_array_index_;
bool is_first_char_;
DISALLOW_COPY_AND_ASSIGN(StringHasher);
};
class IteratingStringHasher : public StringHasher {
public:
static inline uint32_t Hash(String* string, uint32_t seed);
inline void VisitOneByteString(const uint8_t* chars, int length);
inline void VisitTwoByteString(const uint16_t* chars, int length);
private:
inline IteratingStringHasher(int len, uint32_t seed);
void VisitConsString(ConsString* cons_string);
DISALLOW_COPY_AND_ASSIGN(IteratingStringHasher);
};
// The characteristics of a string are stored in its map. Retrieving these
// few bits of information is moderately expensive, involving two memory
// loads where the second is dependent on the first. To improve efficiency

1
src/profiler/heap-snapshot-generator.h
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@ -12,6 +12,7 @@
#include "src/base/platform/time.h"
#include "src/objects.h"
#include "src/profiler/strings-storage.h"
#include "src/string-hasher.h"
#include "src/visitors.h"
namespace v8 {

147
src/string-hasher-inl.h Normal file
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@ -0,0 +1,147 @@
// Copyright 2017 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.
#ifndef V8_STRING_HASHER_INL_H_
#define V8_STRING_HASHER_INL_H_
#include "src/objects.h"
#include "src/string-hasher.h"
namespace v8 {
namespace internal {
StringHasher::StringHasher(int length, uint32_t seed)
: length_(length),
raw_running_hash_(seed),
array_index_(0),
is_array_index_(0 < length_ && length_ <= String::kMaxArrayIndexSize),
is_first_char_(true) {
DCHECK(FLAG_randomize_hashes || raw_running_hash_ == 0);
}
bool StringHasher::has_trivial_hash() {
return length_ > String::kMaxHashCalcLength;
}
uint32_t StringHasher::AddCharacterCore(uint32_t running_hash, uint16_t c) {
running_hash += c;
running_hash += (running_hash << 10);
running_hash ^= (running_hash >> 6);
return running_hash;
}
uint32_t StringHasher::GetHashCore(uint32_t running_hash) {
running_hash += (running_hash << 3);
running_hash ^= (running_hash >> 11);
running_hash += (running_hash << 15);
if ((running_hash & String::kHashBitMask) == 0) {
return kZeroHash;
}
return running_hash;
}
uint32_t StringHasher::ComputeRunningHash(uint32_t running_hash,
const uc16* chars, int length) {
DCHECK_NOT_NULL(chars);
DCHECK(length >= 0);
for (int i = 0; i < length; ++i) {
running_hash = AddCharacterCore(running_hash, *chars++);
}
return running_hash;
}
uint32_t StringHasher::ComputeRunningHashOneByte(uint32_t running_hash,
const char* chars,
int length) {
DCHECK_NOT_NULL(chars);
DCHECK(length >= 0);
for (int i = 0; i < length; ++i) {
uint16_t c = static_cast<uint16_t>(*chars++);
running_hash = AddCharacterCore(running_hash, c);
}
return running_hash;
}
void StringHasher::AddCharacter(uint16_t c) {
// Use the Jenkins one-at-a-time hash function to update the hash
// for the given character.
raw_running_hash_ = AddCharacterCore(raw_running_hash_, c);
}
bool StringHasher::UpdateIndex(uint16_t c) {
DCHECK(is_array_index_);
if (c < '0' || c > '9') {
is_array_index_ = false;
return false;
}
int d = c - '0';
if (is_first_char_) {
is_first_char_ = false;
if (c == '0' && length_ > 1) {
is_array_index_ = false;
return false;
}
}
if (array_index_ > 429496729U - ((d + 3) >> 3)) {
is_array_index_ = false;
return false;
}
array_index_ = array_index_ * 10 + d;
return true;
}
template <typename Char>
inline void StringHasher::AddCharacters(const Char* chars, int length) {
DCHECK(sizeof(Char) == 1 || sizeof(Char) == 2);
int i = 0;
if (is_array_index_) {
for (; i < length; i++) {
AddCharacter(chars[i]);
if (!UpdateIndex(chars[i])) {
i++;
break;
}
}
}
for (; i < length; i++) {
DCHECK(!is_array_index_);
AddCharacter(chars[i]);
}
}
template <typename schar>
uint32_t StringHasher::HashSequentialString(const schar* chars, int length,
uint32_t seed) {
StringHasher hasher(length, seed);
if (!hasher.has_trivial_hash()) hasher.AddCharacters(chars, length);
return hasher.GetHashField();
}
IteratingStringHasher::IteratingStringHasher(int len, uint32_t seed)
: StringHasher(len, seed) {}
uint32_t IteratingStringHasher::Hash(String* string, uint32_t seed) {
IteratingStringHasher hasher(string->length(), seed);
// Nothing to do.
if (hasher.has_trivial_hash()) return hasher.GetHashField();
ConsString* cons_string = String::VisitFlat(&hasher, string);
if (cons_string == nullptr) return hasher.GetHashField();
hasher.VisitConsString(cons_string);
return hasher.GetHashField();
}
void IteratingStringHasher::VisitOneByteString(const uint8_t* chars,
int length) {
AddCharacters(chars, length);
}
void IteratingStringHasher::VisitTwoByteString(const uint16_t* chars,
int length) {
AddCharacters(chars, length);
}
} // namespace internal
} // namespace v8
#endif // V8_STRING_HASHER_INL_H_

90
src/string-hasher.h Normal file
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@ -0,0 +1,90 @@
// Copyright 2017 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.
#ifndef V8_STRING_HASHER_H_
#define V8_STRING_HASHER_H_
#include "src/globals.h"
namespace v8 {
namespace internal {
class ConsString;
class String;
template <typename T>
class Vector;
class V8_EXPORT_PRIVATE StringHasher {
public:
explicit inline StringHasher(int length, uint32_t seed);
template <typename schar>
static inline uint32_t HashSequentialString(const schar* chars, int length,
uint32_t seed);
// Reads all the data, even for long strings and computes the utf16 length.
static uint32_t ComputeUtf8Hash(Vector<const char> chars, uint32_t seed,
int* utf16_length_out);
// Calculated hash value for a string consisting of 1 to
// String::kMaxArrayIndexSize digits with no leading zeros (except "0").
// value is represented decimal value.
static uint32_t MakeArrayIndexHash(uint32_t value, int length);
// No string is allowed to have a hash of zero. That value is reserved
// for internal properties. If the hash calculation yields zero then we
// use 27 instead.
static const int kZeroHash = 27;
// Reusable parts of the hashing algorithm.
INLINE(static uint32_t AddCharacterCore(uint32_t running_hash, uint16_t c));
INLINE(static uint32_t GetHashCore(uint32_t running_hash));
INLINE(static uint32_t ComputeRunningHash(uint32_t running_hash,
const uc16* chars, int length));
INLINE(static uint32_t ComputeRunningHashOneByte(uint32_t running_hash,
const char* chars,
int length));
protected:
// Returns the value to store in the hash field of a string with
// the given length and contents.
uint32_t GetHashField();
// Returns true if the hash of this string can be computed without
// looking at the contents.
inline bool has_trivial_hash();
// Adds a block of characters to the hash.
template <typename Char>
inline void AddCharacters(const Char* chars, int len);
private:
// Add a character to the hash.
inline void AddCharacter(uint16_t c);
// Update index. Returns true if string is still an index.
inline bool UpdateIndex(uint16_t c);
int length_;
uint32_t raw_running_hash_;
uint32_t array_index_;
bool is_array_index_;
bool is_first_char_;
DISALLOW_COPY_AND_ASSIGN(StringHasher);
};
class IteratingStringHasher : public StringHasher {
public:
static inline uint32_t Hash(String* string, uint32_t seed);
inline void VisitOneByteString(const uint8_t* chars, int length);
inline void VisitTwoByteString(const uint16_t* chars, int length);
private:
inline IteratingStringHasher(int len, uint32_t seed);
void VisitConsString(ConsString* cons_string);
DISALLOW_COPY_AND_ASSIGN(IteratingStringHasher);
};
} // namespace internal
} // namespace v8
#endif // V8_STRING_HASHER_H_

2
src/v8.gyp
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@ -1300,6 +1300,8 @@
'string-builder.h',
'string-case.cc',
'string-case.h',
'string-hasher-inl.h',
'string-hasher.h',
'string-search.h',
'string-stream.cc',
'string-stream.h',