Separate DuplicateFinder from Scanner.

src/parsing/scanner.cc

 // Copyright 2011 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.
 
 // Features shared by parsing and pre-parsing scanners.
 
 #include "src/parsing/scanner.h"
 
 #include <stdint.h>
 
 #include <cmath>
 
 #include "src/ast/ast-value-factory.h"
 #include "src/char-predicates-inl.h"
 #include "src/conversions-inl.h"
 #include "src/list-inl.h"
+#include "src/parsing/duplicate-finder.h"  // for Scanner::FindSymbol
 #include "src/parsing/parser.h"
 
 namespace v8 {
 namespace internal {
 
 Handle<String> Scanner::LiteralBuffer::Internalize(Isolate* isolate) const {
   if (is_one_byte()) {
     return isolate->factory()->InternalizeOneByteString(one_byte_literal());
   }
   return isolate->factory()->InternalizeTwoByteString(two_byte_literal());
@@ skipping 1540 matching lines @@
 
 
 bool Scanner::ContainsDot() {
   DCHECK(is_literal_one_byte());
   Vector<const uint8_t> str = literal_one_byte_string();
   return std::find(str.begin(), str.end(), '.') != str.end();
 }
 
 
 int Scanner::FindSymbol(DuplicateFinder* finder, int value) {
+  // TODO(vogelheim): Move this logic into the calling class; this can be fully
+  //                  implemented using the public interface.
   if (is_literal_one_byte()) {
     return finder->AddOneByteSymbol(literal_one_byte_string(), value);
   }
   return finder->AddTwoByteSymbol(literal_two_byte_string(), value);
 }
 
 
 bool Scanner::SetBookmark() {
   if (c0_ != kNoBookmark && bookmark_c0_ == kNoBookmark &&
       next_next_.token == Token::UNINITIALIZED && source_->SetBookmark()) {
@@ skipping 39 matching lines @@
 void Scanner::CopyTokenDesc(TokenDesc* to, TokenDesc* from) {
   DCHECK_NOT_NULL(to);
   DCHECK_NOT_NULL(from);
   to->token = from->token;
   to->location = from->location;
   to->literal_chars->CopyFrom(from->literal_chars);
   to->raw_literal_chars->CopyFrom(from->raw_literal_chars);
 }
 
 
-int DuplicateFinder::AddOneByteSymbol(Vector<const uint8_t> key, int value) {
-  return AddSymbol(key, true, value);
-}
-
-
-int DuplicateFinder::AddTwoByteSymbol(Vector<const uint16_t> key, int value) {
-  return AddSymbol(Vector<const uint8_t>::cast(key), false, value);
-}
-
-
-int DuplicateFinder::AddSymbol(Vector<const uint8_t> key,
-                               bool is_one_byte,
-                               int value) {
-  uint32_t hash = Hash(key, is_one_byte);
-  byte* encoding = BackupKey(key, is_one_byte);
-  base::HashMap::Entry* entry = map_.LookupOrInsert(encoding, hash);
-  int old_value = static_cast<int>(reinterpret_cast<intptr_t>(entry->value));
-  entry->value =
-    reinterpret_cast<void*>(static_cast<intptr_t>(value | old_value));
-  return old_value;
-}
-
-
-int DuplicateFinder::AddNumber(Vector<const uint8_t> key, int value) {
-  DCHECK(key.length() > 0);
-  // Quick check for already being in canonical form.
-  if (IsNumberCanonical(key)) {
-    return AddOneByteSymbol(key, value);
-  }
-
-  int flags = ALLOW_HEX | ALLOW_OCTAL | ALLOW_IMPLICIT_OCTAL | ALLOW_BINARY;
-  double double_value = StringToDouble(
-      unicode_constants_, key, flags, 0.0);
-  int length;
-  const char* string;
-  if (!std::isfinite(double_value)) {
-    string = "Infinity";
-    length = 8;  // strlen("Infinity");
-  } else {
-    string = DoubleToCString(double_value,
-                             Vector<char>(number_buffer_, kBufferSize));
-    length = StrLength(string);
-  }
-  return AddSymbol(Vector<const byte>(reinterpret_cast<const byte*>(string),
-                                      length), true, value);
-}
-
-
-bool DuplicateFinder::IsNumberCanonical(Vector<const uint8_t> number) {
-  // Test for a safe approximation of number literals that are already
-  // in canonical form: max 15 digits, no leading zeroes, except an
-  // integer part that is a single zero, and no trailing zeros below
-  // the decimal point.
-  int pos = 0;
-  int length = number.length();
-  if (number.length() > 15) return false;
-  if (number[pos] == '0') {
-    pos++;
-  } else {
-    while (pos < length &&
-           static_cast<unsigned>(number[pos] - '0') <= ('9' - '0')) pos++;
-  }
-  if (length == pos) return true;
-  if (number[pos] != '.') return false;
-  pos++;
-  bool invalid_last_digit = true;
-  while (pos < length) {
-    uint8_t digit = number[pos] - '0';
-    if (digit > '9' - '0') return false;
-    invalid_last_digit = (digit == 0);
-    pos++;
-  }
-  return !invalid_last_digit;
-}
-
-
-uint32_t DuplicateFinder::Hash(Vector<const uint8_t> key, bool is_one_byte) {
-  // Primitive hash function, almost identical to the one used
-  // for strings (except that it's seeded by the length and representation).
-  int length = key.length();
-  uint32_t hash = (length << 1) | (is_one_byte ? 1 : 0);
-  for (int i = 0; i < length; i++) {
-    uint32_t c = key[i];
-    hash = (hash + c) * 1025;
-    hash ^= (hash >> 6);
-  }
-  return hash;
-}
-
-
-bool DuplicateFinder::Match(void* first, void* second) {
-  // Decode lengths.
-  // Length + representation is encoded as base 128, most significant heptet
-  // first, with a 8th bit being non-zero while there are more heptets.
-  // The value encodes the number of bytes following, and whether the original
-  // was Latin1.
-  byte* s1 = reinterpret_cast<byte*>(first);
-  byte* s2 = reinterpret_cast<byte*>(second);
-  uint32_t length_one_byte_field = 0;
-  byte c1;
-  do {
-    c1 = *s1;
-    if (c1 != *s2) return false;
-    length_one_byte_field = (length_one_byte_field << 7) | (c1 & 0x7f);
-    s1++;
-    s2++;
-  } while ((c1 & 0x80) != 0);
-  int length = static_cast<int>(length_one_byte_field >> 1);
-  return memcmp(s1, s2, length) == 0;
-}
-
-
-byte* DuplicateFinder::BackupKey(Vector<const uint8_t> bytes,
-                                 bool is_one_byte) {
-  uint32_t one_byte_length = (bytes.length() << 1) | (is_one_byte ? 1 : 0);
-  backing_store_.StartSequence();
-  // Emit one_byte_length as base-128 encoded number, with the 7th bit set
-  // on the byte of every heptet except the last, least significant, one.
-  if (one_byte_length >= (1 << 7)) {
-    if (one_byte_length >= (1 << 14)) {
-      if (one_byte_length >= (1 << 21)) {
-        if (one_byte_length >= (1 << 28)) {
-          backing_store_.Add(
-              static_cast<uint8_t>((one_byte_length >> 28) | 0x80));
-        }
-        backing_store_.Add(
-            static_cast<uint8_t>((one_byte_length >> 21) | 0x80u));
-      }
-      backing_store_.Add(
-          static_cast<uint8_t>((one_byte_length >> 14) | 0x80u));
-    }
-    backing_store_.Add(static_cast<uint8_t>((one_byte_length >> 7) | 0x80u));
-  }
-  backing_store_.Add(static_cast<uint8_t>(one_byte_length & 0x7f));
-
-  backing_store_.AddBlock(bytes);
-  return backing_store_.EndSequence().start();
-}
 
 }  // namespace internal
 }  // namespace v8