Handlify escape and unescape.

src/uri.h

Index: src/uri.h
diff --git a/src/uri.h b/src/uri.h
new file mode 100644
index 0000000000000000000000000000000000000000..c7a6301f1210ac231f84dd7af6406285ace52c8b
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+++ b/src/uri.h
@@ -0,0 +1,309 @@
+// Copyright 2013 the V8 project authors. All rights reserved.
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+//       notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+//       copyright notice, this list of conditions and the following
+//       disclaimer in the documentation and/or other materials provided
+//       with the distribution.
+//     * Neither the name of Google Inc. nor the names of its
+//       contributors may be used to endorse or promote products derived
+//       from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#ifndef V8_URI_H_
+#define V8_URI_H_
+
+#include "v8.h"
+
+#include "string-search.h"
+#include "v8utils.h"
+#include "v8conversions.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();
+  ASSERT(flat.IsAscii());
+  return flat.ToOneByteVector();
+}
+
+
+template <>
+Vector<const uc16> GetCharVector(Handle<String> string) {
+  String::FlatContent flat = string->GetFlatContent();
+  ASSERT(flat.IsTwoByte());
+  return flat.ToUC16Vector();
+}
+
+
+class URIUnescape : public AllStatic {
+ public:
+  template<typename Char>
+  static Handle<String> Unescape(Isolate* isolate, Handle<String> source);
+
+ private:
+  static const signed char kHexValue['g'];
+
+  template<typename Char>
+  static Handle<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>
+Handle<String> URIUnescape::Unescape(Isolate* isolate, Handle<String> source) {
+  int index;
+  { AssertNoAllocation no_allocation;
+    StringSearch<uint8_t, Char> search(isolate, STATIC_ASCII_VECTOR("%"));
+    index = search.Search(GetCharVector<Char>(source), 0);
+    if (index < 0) return source;
+  }
+  return UnescapeSlow<Char>(isolate, source, index);
+}
+
+
+template <typename Char>
+Handle<String> URIUnescape::UnescapeSlow(
+    Isolate* isolate, Handle<String> string, int start_index) {
+  bool one_byte = true;
+  int length = string->length();
+
+  int unescaped_length = 0;
+  { AssertNoAllocation 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;
+    }
+  }
+
+  ASSERT(start_index < length);
+  Handle<String> first_part =
+      isolate->factory()->NewProperSubString(string, 0, start_index);
+
+  int dest_position = 0;
+  Handle<String> second_part;
+  if (one_byte) {
+    Handle<SeqOneByteString> dest =
+        isolate->factory()->NewRawOneByteString(unescaped_length);
+    AssertNoAllocation 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);
+    AssertNoAllocation 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>
+  static Handle<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>
+Handle<String> URIEscape::Escape(Isolate* isolate, Handle<String> string) {
+  ASSERT(string->IsFlat());
+  int escaped_length = 0;
+  int length = string->length();
+
+  { AssertNoAllocation 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.
+      ASSERT(String::kMaxLength < 0x7fffffff - 6);  // Cannot overflow.
+      if (escaped_length > String::kMaxLength) {
+        isolate->context()->mark_out_of_memory();
+        return Handle<String>::null();
+      }
+    }
+  }
+
+  // No length change implies no change.  Return original string if no change.
+  if (escaped_length == length) return string;
+
+  Handle<SeqOneByteString> dest =
+      isolate->factory()->NewRawOneByteString(escaped_length);
+  int dest_position = 0;
+
+  { AssertNoAllocation 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_