Move string-related runtime functions into separate files.

src/uri.h

-// Copyright 2013 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_URI_H_
-#define V8_URI_H_
-
-#include "src/v8.h"
-
-#include "src/conversions.h"
-#include "src/string-search.h"
-#include "src/utils.h"
-
-namespace v8 {
-namespace internal {
-
-
-template <typename Char>
-static INLINE(Vector<const Char> GetCharVector(Handle<String> string));
-
-
-template <>
-Vector<const uint8_t> GetCharVector(Handle<String> string) {
-  String::FlatContent flat = string->GetFlatContent();
-  DCHECK(flat.IsOneByte());
-  return flat.ToOneByteVector();
-}
-
-
-template <>
-Vector<const uc16> GetCharVector(Handle<String> string) {
-  String::FlatContent flat = string->GetFlatContent();
-  DCHECK(flat.IsTwoByte());
-  return flat.ToUC16Vector();
-}
-
-
-class URIUnescape : public AllStatic {
- public:
-  template<typename Char>
-  MUST_USE_RESULT static MaybeHandle<String> Unescape(Isolate* isolate,
-                                                      Handle<String> source);
-
- private:
-  static const signed char kHexValue['g'];
-
-  template<typename Char>
-  MUST_USE_RESULT static MaybeHandle<String> UnescapeSlow(
-      Isolate* isolate, Handle<String> string, int start_index);
-
-  static INLINE(int TwoDigitHex(uint16_t character1, uint16_t character2));
-
-  template <typename Char>
-  static INLINE(int UnescapeChar(Vector<const Char> vector,
-                                 int i,
-                                 int length,
-                                 int* step));
-};
-
-
-const signed char URIUnescape::kHexValue[] = {
-    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-    -0,  1,  2,  3,  4,  5,  6,  7,  8,  9, -1, -1, -1, -1, -1, -1,
-    -1, 10, 11, 12, 13, 14, 15, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-    -1, 10, 11, 12, 13, 14, 15 };
-
-
-template<typename Char>
-MaybeHandle<String> URIUnescape::Unescape(Isolate* isolate,
-                                          Handle<String> source) {
-  int index;
-  { DisallowHeapAllocation no_allocation;
-    StringSearch<uint8_t, Char> search(isolate, STATIC_CHAR_VECTOR("%"));
-    index = search.Search(GetCharVector<Char>(source), 0);
-    if (index < 0) return source;
-  }
-  return UnescapeSlow<Char>(isolate, source, index);
-}
-
-
-template <typename Char>
-MaybeHandle<String> URIUnescape::UnescapeSlow(
-    Isolate* isolate, Handle<String> string, int start_index) {
-  bool one_byte = true;
-  int length = string->length();
-
-  int unescaped_length = 0;
-  { DisallowHeapAllocation no_allocation;
-    Vector<const Char> vector = GetCharVector<Char>(string);
-    for (int i = start_index; i < length; unescaped_length++) {
-      int step;
-      if (UnescapeChar(vector, i, length, &step) >
-              String::kMaxOneByteCharCode) {
-        one_byte = false;
-      }
-      i += step;
-    }
-  }
-
-  DCHECK(start_index < length);
-  Handle<String> first_part =
-      isolate->factory()->NewProperSubString(string, 0, start_index);
-
-  int dest_position = 0;
-  Handle<String> second_part;
-  DCHECK(unescaped_length <= String::kMaxLength);
-  if (one_byte) {
-    Handle<SeqOneByteString> dest = isolate->factory()->NewRawOneByteString(
-        unescaped_length).ToHandleChecked();
-    DisallowHeapAllocation no_allocation;
-    Vector<const Char> vector = GetCharVector<Char>(string);
-    for (int i = start_index; i < length; dest_position++) {
-      int step;
-      dest->SeqOneByteStringSet(dest_position,
-                                UnescapeChar(vector, i, length, &step));
-      i += step;
-    }
-    second_part = dest;
-  } else {
-    Handle<SeqTwoByteString> dest = isolate->factory()->NewRawTwoByteString(
-        unescaped_length).ToHandleChecked();
-    DisallowHeapAllocation no_allocation;
-    Vector<const Char> vector = GetCharVector<Char>(string);
-    for (int i = start_index; i < length; dest_position++) {
-      int step;
-      dest->SeqTwoByteStringSet(dest_position,
-                                UnescapeChar(vector, i, length, &step));
-      i += step;
-    }
-    second_part = dest;
-  }
-  return isolate->factory()->NewConsString(first_part, second_part);
-}
-
-
-int URIUnescape::TwoDigitHex(uint16_t character1, uint16_t character2) {
-  if (character1 > 'f') return -1;
-  int hi = kHexValue[character1];
-  if (hi == -1) return -1;
-  if (character2 > 'f') return -1;
-  int lo = kHexValue[character2];
-  if (lo == -1) return -1;
-  return (hi << 4) + lo;
-}
-
-
-template <typename Char>
-int URIUnescape::UnescapeChar(Vector<const Char> vector,
-                              int i,
-                              int length,
-                              int* step) {
-  uint16_t character = vector[i];
-  int32_t hi = 0;
-  int32_t lo = 0;
-  if (character == '%' &&
-      i <= length - 6 &&
-      vector[i + 1] == 'u' &&
-      (hi = TwoDigitHex(vector[i + 2],
-                        vector[i + 3])) != -1 &&
-      (lo = TwoDigitHex(vector[i + 4],
-                        vector[i + 5])) != -1) {
-    *step = 6;
-    return (hi << 8) + lo;
-  } else if (character == '%' &&
-      i <= length - 3 &&
-      (lo = TwoDigitHex(vector[i + 1],
-                        vector[i + 2])) != -1) {
-    *step = 3;
-    return lo;
-  } else {
-    *step = 1;
-    return character;
-  }
-}
-
-
-class URIEscape : public AllStatic {
- public:
-  template<typename Char>
-  MUST_USE_RESULT static MaybeHandle<String> Escape(Isolate* isolate,
-                                                    Handle<String> string);
-
- private:
-  static const char kHexChars[17];
-  static const char kNotEscaped[256];
-
-  static bool IsNotEscaped(uint16_t c) { return kNotEscaped[c] != 0; }
-};
-
-
-const char URIEscape::kHexChars[] = "0123456789ABCDEF";
-
-
-// kNotEscaped is generated by the following:
-//
-// #!/bin/perl
-// for (my $i = 0; $i < 256; $i++) {
-//   print "\n" if $i % 16 == 0;
-//   my $c = chr($i);
-//   my $escaped = 1;
-//   $escaped = 0 if $c =~ m#[A-Za-z0-9@*_+./-]#;
-//   print $escaped ? "0, " : "1, ";
-// }
-
-const char URIEscape::kNotEscaped[] = {
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0, 1, 1, 1,
-    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0,
-    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 1,
-    0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
-    1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0,
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
-    0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };
-
-
-template<typename Char>
-MaybeHandle<String> URIEscape::Escape(Isolate* isolate, Handle<String> string) {
-  DCHECK(string->IsFlat());
-  int escaped_length = 0;
-  int length = string->length();
-
-  { DisallowHeapAllocation no_allocation;
-    Vector<const Char> vector = GetCharVector<Char>(string);
-    for (int i = 0; i < length; i++) {
-      uint16_t c = vector[i];
-      if (c >= 256) {
-        escaped_length += 6;
-      } else if (IsNotEscaped(c)) {
-        escaped_length++;
-      } else {
-        escaped_length += 3;
-      }
-
-      // We don't allow strings that are longer than a maximal length.
-      DCHECK(String::kMaxLength < 0x7fffffff - 6);  // Cannot overflow.
-      if (escaped_length > String::kMaxLength) break;  // Provoke exception.
-    }
-  }
-
-  // No length change implies no change.  Return original string if no change.
-  if (escaped_length == length) return string;
-
-  Handle<SeqOneByteString> dest;
-  ASSIGN_RETURN_ON_EXCEPTION(
-      isolate, dest,
-      isolate->factory()->NewRawOneByteString(escaped_length),
-      String);
-  int dest_position = 0;
-
-  { DisallowHeapAllocation no_allocation;
-    Vector<const Char> vector = GetCharVector<Char>(string);
-    for (int i = 0; i < length; i++) {
-      uint16_t c = vector[i];
-      if (c >= 256) {
-        dest->SeqOneByteStringSet(dest_position, '%');
-        dest->SeqOneByteStringSet(dest_position+1, 'u');
-        dest->SeqOneByteStringSet(dest_position+2, kHexChars[c >> 12]);
-        dest->SeqOneByteStringSet(dest_position+3, kHexChars[(c >> 8) & 0xf]);
-        dest->SeqOneByteStringSet(dest_position+4, kHexChars[(c >> 4) & 0xf]);
-        dest->SeqOneByteStringSet(dest_position+5, kHexChars[c & 0xf]);
-        dest_position += 6;
-      } else if (IsNotEscaped(c)) {
-        dest->SeqOneByteStringSet(dest_position, c);
-        dest_position++;
-      } else {
-        dest->SeqOneByteStringSet(dest_position, '%');
-        dest->SeqOneByteStringSet(dest_position+1, kHexChars[c >> 4]);
-        dest->SeqOneByteStringSet(dest_position+2, kHexChars[c & 0xf]);
-        dest_position += 3;
-      }
-    }
-  }
-
-  return dest;
-}
-
-} }  // namespace v8::internal
-
-#endif  // V8_URI_H_