Move googleurl into the Chrome repo.

url/url_canon_icu.cc

+// Copyright 2011, Google Inc.
+// 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.
+
+// ICU integration functions.
+
+#include <stdlib.h>
+#include <string.h>
+#include <unicode/ucnv.h>
+#include <unicode/ucnv_cb.h>
+#include <unicode/uidna.h>
+
+#include "googleurl/src/url_canon_icu.h"
+#include "googleurl/src/url_canon_internal.h"  // for _itoa_s
+
+#include "base/logging.h"
+
+namespace url_canon {
+
+namespace {
+
+// Called when converting a character that can not be represented, this will
+// append an escaped version of the numerical character reference for that code
+// point. It is of the form "&#1234;" and we will escape the non-digits to
+// "%26%231234%3B". Why? This is what Netscape did back in the olden days.
+void appendURLEscapedChar(const void* context,
+                          UConverterFromUnicodeArgs* from_args,
+                          const UChar* code_units,
+                          int32_t length,
+                          UChar32 code_point,
+                          UConverterCallbackReason reason,
+                          UErrorCode* err) {
+  if (reason == UCNV_UNASSIGNED) {
+    *err = U_ZERO_ERROR;
+
+    const static int prefix_len = 6;
+    const static char prefix[prefix_len + 1] = "%26%23";  // "&#" percent-escaped
+    ucnv_cbFromUWriteBytes(from_args, prefix, prefix_len, 0, err);
+
+    DCHECK(code_point < 0x110000);
+    char number[8];  // Max Unicode code point is 7 digits.
+    _itoa_s(code_point, number, 10);
+    int number_len = static_cast<int>(strlen(number));
+    ucnv_cbFromUWriteBytes(from_args, number, number_len, 0, err);
+
+    const static int postfix_len = 3;
+    const static char postfix[postfix_len + 1] = "%3B";   // ";" percent-escaped
+    ucnv_cbFromUWriteBytes(from_args, postfix, postfix_len, 0, err);
+  }
+}
+
+// A class for scoping the installation of the invalid character callback.
+class AppendHandlerInstaller {
+ public:
+  // The owner of this object must ensure that the converter is alive for the
+  // duration of this object's lifetime.
+  AppendHandlerInstaller(UConverter* converter) : converter_(converter) {
+    UErrorCode err = U_ZERO_ERROR;
+    ucnv_setFromUCallBack(converter_, appendURLEscapedChar, 0,
+                          &old_callback_, &old_context_, &err);
+  }
+
+  ~AppendHandlerInstaller() {
+    UErrorCode err = U_ZERO_ERROR;
+    ucnv_setFromUCallBack(converter_, old_callback_, old_context_, 0, 0, &err);
+  }
+
+ private:
+  UConverter* converter_;
+
+  UConverterFromUCallback old_callback_;
+  const void* old_context_;
+};
+
+}  // namespace
+
+ICUCharsetConverter::ICUCharsetConverter(UConverter* converter)
+    : converter_(converter) {
+}
+
+ICUCharsetConverter::~ICUCharsetConverter() {
+}
+
+void ICUCharsetConverter::ConvertFromUTF16(const char16* input,
+                                           int input_len,
+                                           CanonOutput* output) {
+  // Install our error handler. It will be called for character that can not
+  // be represented in the destination character set.
+  AppendHandlerInstaller handler(converter_);
+
+  int begin_offset = output->length();
+  int dest_capacity = output->capacity() - begin_offset;
+  output->set_length(output->length());
+
+  do {
+    UErrorCode err = U_ZERO_ERROR;
+    char* dest = &output->data()[begin_offset];
+    int required_capacity = ucnv_fromUChars(converter_, dest, dest_capacity,
+                                            input, input_len, &err);
+    if (err != U_BUFFER_OVERFLOW_ERROR) {
+      output->set_length(begin_offset + required_capacity);
+      return;
+    }
+
+    // Output didn't fit, expand
+    dest_capacity = required_capacity;
+    output->Resize(begin_offset + dest_capacity);
+  } while (true);
+}
+
+// Converts the Unicode input representing a hostname to ASCII using IDN rules.
+// The output must be ASCII, but is represented as wide characters.
+//
+// On success, the output will be filled with the ASCII host name and it will
+// return true. Unlike most other canonicalization functions, this assumes that
+// the output is empty. The beginning of the host will be at offset 0, and
+// the length of the output will be set to the length of the new host name.
+//
+// On error, this will return false. The output in this case is undefined.
+bool IDNToASCII(const char16* src, int src_len, CanonOutputW* output) {
+  DCHECK(output->length() == 0);  // Output buffer is assumed empty.
+  while (true) {
+    // Use ALLOW_UNASSIGNED to be more tolerant of hostnames that violate
+    // the spec (which do exist). This does not present any risk and is a
+    // little more future proof.
+    UErrorCode err = U_ZERO_ERROR;
+    int num_converted = uidna_IDNToASCII(src, src_len, output->data(),
+                                         output->capacity(),
+                                         UIDNA_ALLOW_UNASSIGNED, NULL, &err);
+    if (err == U_ZERO_ERROR) {
+      output->set_length(num_converted);
+      return true;
+    }
+    if (err != U_BUFFER_OVERFLOW_ERROR)
+      return false;  // Unknown error, give up.
+
+    // Not enough room in our buffer, expand.
+    output->Resize(output->capacity() * 2);
+  }
+}
+
+bool ReadUTFChar(const char* str, int* begin, int length,
+                 unsigned* code_point_out) {
+  int code_point;  // Avoids warning when U8_NEXT writes -1 to it.
+  U8_NEXT(str, *begin, length, code_point);
+  *code_point_out = static_cast<unsigned>(code_point);
+
+  // The ICU macro above moves to the next char, we want to point to the last
+  // char consumed.
+  (*begin)--;
+
+  // Validate the decoded value.
+  if (U_IS_UNICODE_CHAR(code_point))
+    return true;
+  *code_point_out = kUnicodeReplacementCharacter;
+  return false;
+}
+
+bool ReadUTFChar(const char16* str, int* begin, int length,
+                 unsigned* code_point) {
+  if (U16_IS_SURROGATE(str[*begin])) {
+    if (!U16_IS_SURROGATE_LEAD(str[*begin]) || *begin + 1 >= length ||
+        !U16_IS_TRAIL(str[*begin + 1])) {
+      // Invalid surrogate pair.
+      *code_point = kUnicodeReplacementCharacter;
+      return false;
+    } else {
+      // Valid surrogate pair.
+      *code_point = U16_GET_SUPPLEMENTARY(str[*begin], str[*begin + 1]);
+      (*begin)++;
+    }
+  } else {
+    // Not a surrogate, just one 16-bit word.
+    *code_point = str[*begin];
+  }
+
+  if (U_IS_UNICODE_CHAR(*code_point))
+    return true;
+
+  // Invalid code point.
+  *code_point = kUnicodeReplacementCharacter;
+  return false;
+}
+
+}  // namespace url_canon